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The Audio Science Review Forum

Printed From: Graham Slee at Hifi System Components
Category: Headphone Audio
Forum Name: Graham Slee Headphone Amps
Forum Description: Questions, answers and product information zone for Graham Slee Headphone Amplifiers
URL: https://www.hifisystemcomponents.com/forum/forum_posts.asp?TID=4993
Printed Date: 22 Sep 2020 at 11:44am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com


Topic: The Audio Science Review Forum
Posted By: southall-1998
Subject: The Audio Science Review Forum
Date Posted: 04 Jul 2020 at 8:49pm
Do some of you chaps, browse on the ASR forum? 

Today I placed up a thread, asking if anyone has heard a Graham Slee Headphone Amp.

So far this is the response...

https://www.audiosciencereview.com/forum/index.php?threads/graham-slee-headphone-amps.14525/#post-447722 - https://www.audiosciencereview.com/forum/index.php?threads/graham-slee-headphone-amps.14525/#post-447722




-------------
Shane Lonergan.



Replies:
Posted By: Ash
Date Posted: 04 Jul 2020 at 10:50pm
One of the certainties of life - some people will always think they know best, even when they don't. Those who are anti-Slee and put down his products must prefer specs to real results. It was a similar story with the AKG K1000 earspeakers. A forward-thinking product that was mocked and ridiculed over the years when it actually takes a massive dump on the majority of the competition. People let their own arrogance betray them.

As a youtube audiophile says on his videos, the only person that needs to like the sound of your hifi is you.


Posted By: capetownwatches
Date Posted: 04 Jul 2020 at 11:34pm
I felt the need to respond...

-------------
Solo UL=Kingrex HQ1=NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero
LCD2F=HD600=SR207=DT990 600Ω=TH-X00=K612Pro=K240S=K171Mkll=M4U2=Y50
RCF Ayra 5=Mogami/Sommer->Neutrik/Amphenol


Posted By: BAK
Date Posted: 05 Jul 2020 at 3:25am
Originally posted by southall-1998 southall-1998 wrote:

Do some of you chaps, browse on the ASR forum? 

Today I placed up a thread, asking if anyone has heard a Graham Slee Headphone Amp.

So far this is the response...

https://www.audiosciencereview.com/forum/index.php?threads/graham-slee-headphone-amps.14525/#post-447722 - https://www.audiosciencereview.com/forum/index.php?threads/graham-slee-headphone-amps.14525/#post-447722


That is not a responsible response... the person did not even listen to the unit.
They only read the "not-inflated" specifications.

Every Graham Slee product is tested on an Audio Precision analyzer to meet or exceed the design specifications stated for that product.


-------------
Bruce
AT-14SA, Pickering XV-15/625, Technics SL-1600MK2, Reflex M, Lautus, Technics SH-8066, Dynaco ST120a, Eminence Beta 8A in custom cabs;; Using Majestic DAC
Enjoy Life Your Way!


Posted By: capetownwatches
Date Posted: 05 Jul 2020 at 4:29am
As can be gleaned from the forum name, ASR reduces everything to specifications and measurements. 
It seems the general consensus is that if a gear doesn't measure "well" it cannot sound "good". 

Very often this conclusion is derived without proper listening tests, and this is where things tend to go pear-shaped over there.




-------------
Solo UL=Kingrex HQ1=NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero
LCD2F=HD600=SR207=DT990 600Ω=TH-X00=K612Pro=K240S=K171Mkll=M4U2=Y50
RCF Ayra 5=Mogami/Sommer->Neutrik/Amphenol


Posted By: Ash
Date Posted: 05 Jul 2020 at 8:21am
"Teachers open the door; you enter by yourself."


Posted By: capetownwatches
Date Posted: 05 Jul 2020 at 3:09pm
I wonder why John Yang (Mr Topping) has such a bee in his bonnet for all things Slee..?

It's obvious he hasn't actually listened to a current model UL which is strange since I'm told they are very popular in China... Wink


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Solo UL=Kingrex HQ1=NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero
LCD2F=HD600=SR207=DT990 600Ω=TH-X00=K612Pro=K240S=K171Mkll=M4U2=Y50
RCF Ayra 5=Mogami/Sommer->Neutrik/Amphenol


Posted By: jupiterboy
Date Posted: 05 Jul 2020 at 4:12pm
A little science is a dangerous thing. 


Posted By: patientot
Date Posted: 05 Jul 2020 at 4:43pm
I do look at this site from time to time but I really only focus on the measurements posted by Amir and a couple other people that test gear with an Audio Precision analyzer. I try not to get into the weeds of the discussion boards too much. I'm not even sure at this point if one of the users at the thread in question even interpreted the GS product specs correctly. 

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Reflex M + PSU-1 used with AT VM95ML, Stanton 680mkII + Ogura, and Shure M35X cartridges.


Posted By: capetownwatches
Date Posted: 07 Jul 2020 at 3:45pm
"Plus they don't specify output impedance, but I imagine it will be very high."

"The Solo is 120 Ohm out. This also explains why it sounds different."

Two responses from that thread that I would love to respond to but just couldn't be arsed frankly...there really is no point.



-------------
Solo UL=Kingrex HQ1=NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero
LCD2F=HD600=SR207=DT990 600Ω=TH-X00=K612Pro=K240S=K171Mkll=M4U2=Y50
RCF Ayra 5=Mogami/Sommer->Neutrik/Amphenol


Posted By: Fatmangolf
Date Posted: 07 Jul 2020 at 4:59pm
Agree with you. Welcome to the internet.



-------------
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: lfc jon
Date Posted: 07 Jul 2020 at 8:33pm
For some if you can't push this, turn that and tweek something it's not worth buying
To me I like the plug it in and play some music with great sound quality and THATS what I get with Graham Slee. I have a CD player with a load of digital filters and things and I only use the default setting, could not hear any difference with the other filters settings
KEEP IT SIMPLE THAT'S WHAT I SAY


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Pro-j tt,Ortofon 2m Bronze cart,Audiolab 8300CD,GS Reflex M. Solo headphone amp both with PSU1,MF M2si amp,Monitor audio silver 100 speakers, Atlas cables


Posted By: southall-1998
Date Posted: 07 Jul 2020 at 11:59pm
Originally posted by lfc jon lfc jon wrote:

For some if you can't push this, turn that and tweek something it's not worth buying
To me I like the plug it in and play some music with great sound quality and THATS what I get with Graham Slee. I have a CD player with a load of digital filters and things and I only use the default setting, could not hear any difference with the other filters settings
KEEP IT SIMPLE THAT'S WHAT I SAY

Agreed.

S.


-------------
Shane Lonergan.


Posted By: RichW
Date Posted: 09 Jul 2020 at 11:34am
Open the door for views and comments from 'fellow' hifi enthusiasts and it's almost inevitable that there'll be those barging in, elbows out, with strong opinions to belittle any other opinion.
That spec-quoter hasn't even heard one...


-------------
Elevator, Accession M, Majestic/Enigma, Reflex M, CuSat & Lautus.


Posted By: lfc jon
Date Posted: 09 Jul 2020 at 8:11pm
I have never looked at spec's of any bit of HiFi that I have had in the past only can I plug (CD Turntable or tape) into the amp but then most you can anyway, but best to check .
Spec's mean nothing! If it sounds cr-p. If you are going Digital then yes I think you have to (don't know much about that side of thinks) as I only have a CD player.
Listen with your ears not the spec's   THATS what say


-------------
Pro-j tt,Ortofon 2m Bronze cart,Audiolab 8300CD,GS Reflex M. Solo headphone amp both with PSU1,MF M2si amp,Monitor audio silver 100 speakers, Atlas cables


Posted By: Fatmangolf
Date Posted: 09 Jul 2020 at 10:18pm
Agreed. Listening is believing as I wrote on the forum some years ago.



-------------
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: jupiterboy
Date Posted: 10 Jul 2020 at 1:37am
I'm far from an "objectivist" (whatever that is), but I have found that some consideration of gain matching with my turntable and in-room measurements have helped optimize the gear I can afford. 

I say this because these things are virtually free, and I see people who roll new gear in and out of their rooms. 

I'll also say that the cable debates are THE MOST TEDIOUS dead horse in audio, but I do tend to look to other industries—like medical and defense. If these industries are paying up for technology, then one can certainly argue that they don't apply to audio because nobody can hear the differences, but trying to argue that these technologies are snake oil and that the medical and defense industries are being defrauded really takes the cake.


Posted By: Ash
Date Posted: 10 Jul 2020 at 7:53am
I do think cables between major components matter, not that I could hear the differences clearly as it is not as easy to do thorough side-by-side comparisons like with headphones or speakers. Their impedance, capacitance, inductance, material, length and EM shielding may be able to affect the audibility of frequency balance, phase problems and distortion and stereo image changes.

I bet my system would sound really off if I removed all my Lautus interconnects and replaced them with cheap alternatives or those of silver construction. It would be like changing the PCB layouts of the circuit boards if you introduce antenna-long cables with no shielding at all. The characteristics of a cable would have to be drastically unsuitable for me to hear a difference though I think. Asking me to differentiate between a Lautus and CuSat50 interconnect in a blind test would likely be inconclusive, seeing as they are almost of equal construction.


Posted By: capetownwatches
Date Posted: 10 Jul 2020 at 1:49pm
And yet some (many) would argue that every cable has it's own "sound" and there have been reams of drivel written about how a particular cable improves (always improves) the system it's used in!

Now...I have heard differences. Subtle differences that even one as loquacious as I would have extreme difficulty describing or quantifying. But not placebo. I think. 

And there I shall leave it for now, because cable debates are so outré...Wink


-------------
Solo UL=Kingrex HQ1=NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero
LCD2F=HD600=SR207=DT990 600Ω=TH-X00=K612Pro=K240S=K171Mkll=M4U2=Y50
RCF Ayra 5=Mogami/Sommer->Neutrik/Amphenol


Posted By: fluddite
Date Posted: 10 Jul 2020 at 2:12pm
Originally posted by jupiterboy jupiterboy wrote:

but trying to argue that these technologies are snake oil and that the medical and defense industries are being defrauded really takes the cake.

Hi Mark!

From a GB perspective, I can only add that our "defence" industry is regularly defrauded (and worse) by suppliers such as BAe, Siemens et al - see Private Eye passim, ad nauseam.... AngryShockedEvil Smile

f.


Posted By: Ash
Date Posted: 10 Jul 2020 at 3:15pm
I gauge a product's true worth by whether I enjoy listening with it or not. If I'm not enjoying what I'm hearing as much, there's my answer, regardless of its expense. I've never been someone who likes to write pages and pages of pretentious bollocks to try to delude myself and others that something is better than it actually is. A recent headphone comparison I did several weeks back between two earspeaker headphones was summed up in pretty much one paragraph. Good thing I didn't write it on head-fi; all the fakers would have been like: "well this 'review' sucks..." because I just skipped to the conclusion and said "Yep, one sounds better than the other. I know because I enjoy music more through one than the other".

With cable comparisons, I would just say: "Yeah, the sound has improved purity and resolution when I use this cable in place of the other one" or "I can't hear any difference in the sound through either". The comprehensive story-telling reviews tend to piss me off because they rarely give the reader anything conclusive or truthful, sometimes leaving them more confused or with more questions. Maybe it's just me but there are very few audio "professionals" that I trust online. I can count them on one hand and struggle to count them on two.


Posted By: Fatmangolf
Date Posted: 10 Jul 2020 at 5:52pm
I like Ash's approach, keep it simple and to the point. I can usually tell quite quickly whether I prefer the new item to what I have already, generally more clarity/separation and a natural sound is my preference. If there is an improvement a lot of listening follows with the temptation to describe it at length and justify the expense. Of course it is cheaper if the test outcome is the other way round!



-------------
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: jupiterboy
Date Posted: 10 Jul 2020 at 6:01pm
Originally posted by fluddite fluddite wrote:

Originally posted by jupiterboy jupiterboy wrote:

but trying to argue that these technologies are snake oil and that the medical and defense industries are being defrauded really takes the cake.

Hi Mark!

From a GB perspective, I can only add that our "defence" industry is regularly defrauded (and worse) by suppliers such as BAe, Siemens et al - see Private Eye passim, ad nauseam.... AngryShockedEvil Smile

f.


No doubt, and in all sorts of ways. 

What I'm not saying explicitly is that I have a real interest in the design of speakers and cables and all this stuff. I also tend to listen closely and hear issues that I don't know how to solve. When I find a product that fixes an issue that's bothering me, I tend to go to their marketing and pick through what might be responsible for what I'm hearing. I think that's very different than taking a top down reductionist position.

I also have pretty much zero faith in the idea that AB testing has any degree of validity in terms of these audio nuances. I feel like that assumption is the real leap of faith.

Also, every industry in the world uses inflated marketing copy to present their product in the best light. I am thoroughly confused at why one tiny industry would eschew this trend and only present their products without hyperbole. 


Posted By: Fatmangolf
Date Posted: 10 Jul 2020 at 6:10pm
Why: large profits!



-------------
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Aussie Mick
Date Posted: 11 Jul 2020 at 12:57am
Everything sounds different to everything else. Lots of reasons based in science to tell us why. Mostly noise reduction, EMI rejection, reduced microphone, etc. All very believable and repeatably demonstrable. Good. 

Use the bits you find make listening enjoyable. Leave everyone else alone to do the same. Job done.

Music is absolutely objective, but our perception is not. My two best friends have become investors in hifi because of their experiences in my listening room. Great! But listening to their seriously researched and auditioned systems, it’s very clear they value a different experience than I do. I reckon that’s how it should be. 

Cheers,
Mick.


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Rega RP8 - Apheta 2 - Accession MC Enigma PS -Solo ULDE (Focal Utopia) - Proprius - PMC Twenty5.22


Posted By: Graham Slee
Date Posted: 11 Jul 2020 at 10:02am
Wumaos?

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Not simple enough for Google-Bot to understand...


Posted By: BackinBlack
Date Posted: 11 Jul 2020 at 10:26am
Originally posted by Graham Slee Graham Slee wrote:

Wumaos?

Clap
 
They're everywhere, trying to influence everything that appears to have been reviewed. Usually lauding cheap clones from you know where.


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Just listen, if it sounds good to you, enjoy it.


Posted By: Ash
Date Posted: 11 Jul 2020 at 11:15am
The post-Truth era is here. Question everything.


Posted By: Fatmangolf
Date Posted: 11 Jul 2020 at 5:58pm
Yes, it feels like a mass version of being contrary. Throw in a remarkable ignorance of science, history, human knowledge and a tendency to believe utter nonsense... welcome to the Internet!

-------------
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: jupiterboy
Date Posted: 12 Jul 2020 at 12:11am
I'd really like to hear a discussion wander into the applications of conductive and semi-conductive dielectric materials. The whole idea of addressing EM field outside the cable—that never, ever gets any reasonable light.


Posted By: Graham Slee
Date Posted: 12 Jul 2020 at 9:58am
Originally posted by jupiterboy jupiterboy wrote:

I'd really like to hear a discussion wander into the applications of conductive and semi-conductive dielectric materials. The whole idea of addressing EM field outside the cable—that never, ever gets any reasonable light.


I once tried to do that, but the Advertising Standards Agency (UK) told me I was in breach of their rules, and I had to take it down. They told me that they'd had a complaint by a college lecturer (no other information supplied), and that was good enough for them to find against me.

Freedom of speech?


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Not simple enough for Google-Bot to understand...


Posted By: Ash
Date Posted: 12 Jul 2020 at 11:15am
You're allowed to talk about the Lautus etc, just don't say anything about it improving sound quality and you're good to go?

Better yet, make the Lautus interconnects a "forum members only and private message request" purchase and say nowt.

If you're not "advertising" a specific product for financial gain, they have no grounds to make a claim against you and seeing as there are plenty of genuinely "sh*te" products out on the market being sold, such as cable pylons et al, they would be utter hypocrites to do so.


Posted By: Fatmangolf
Date Posted: 12 Jul 2020 at 12:55pm
If only the genuinely sh#te products were labelled as such!

-------------
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Graham Slee
Date Posted: 12 Jul 2020 at 3:01pm
Originally posted by Ash Ash wrote:

...plenty of genuinely "sh*te" products out on the market being sold, such as cable pylons et al, they would be utter hypocrites to do so.


It would seem that the college lecturer hasn't complained about those products Wink


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Not simple enough for Google-Bot to understand...


Posted By: Ash
Date Posted: 12 Jul 2020 at 3:42pm
Probably wasn't even a "college lecturer". If so, I would love to read any of the scientific papers they've published about techniques to suppress EMI in cables. Could provide some insightful wisdom. What I suspect is that as the UK is a very class-divided society, an individual with power and influence who has taken a dislike to you or your activities has decided to influence an official body to take action. So keep your head down and sell them on the sly; be dishonest about it if you have to. It's not like our country is a shining beacon of honesty and good intentions. If the Lautus is identical to the CuSat50 in construction apart from the addition of one or more ferrites, perhaps sell them as CuSat50 and offer the inclusion of a ferrite filter in the sheath as an option in the drop-down menu for an additional charge. Add disclaimer "may or may not improve signal fidelity"

F*** the aristocracy.


Posted By: fluddite
Date Posted: 12 Jul 2020 at 7:37pm
Originally posted by Ash Ash wrote:

Probably wasn't even a "college lecturer"....

What I suspect is that as the UK is a very class-divided society, an individual with power and influence who has taken a dislike to you or your activities has decided to influence an official body to take action....

F*** the aristocracy.

Amen to all that! Thumbs Up


Posted By: Graham Slee
Date Posted: 12 Jul 2020 at 10:24pm
Originally posted by jupiterboy jupiterboy wrote:

I'd really like to hear a discussion wander into the applications of conductive and semi-conductive dielectric materials. The whole idea of addressing EM field outside the cable—that never, ever gets any reasonable light.


I'd learned a bit about radio frequencies studying for my 2m radio amateur license exam with the RSGB (early 1980's). However, other things got in the way, and I never sat the exam. My interest in radio communications fell away, as I had to concentrate harder on earning a living.

My next brush with radio frequencies was at the beginning of the EMC regulations, starting about 1995. I had already spent four years in broadcast, but working on audio, not the RF end. However, I knew about over modulation, and the audio circuitry had to meet tests regarding retransmission. So I had an understanding of EMC already.

I attended EMC seminars and was given the responsibility of keeping abreast of EMC in a freelance position in 1997.

The products I design have also to comply with EMC legislation, and they do. Although I have never been able to demonstrate it by third party laboratory testing (except for the PSU1), I have used the same self-declaration approach of most in the audio industry.

Our full range of products was EMC tested in South Korea, by a distributor who was required by law to do so. Every product passed.

When designing the Accession, I wanted to ensure its EMC credentials were squeaky clean and having read about Cherry Clough Consultants, and their work for the Advertising Standards Authority, I thought I could not go wrong in hiring them (quite expensive).

I was also developing the Lautus interconnects, and under the same consultancy costs, these were discussed.

Cherry Clough had reported on the false advertising as an expert witness, of another hi-fi firm for the ASA. After being hauled over the coals by the ASA for my explanations about the Lautus USB cable design, I explained that I was using their chosen consultant, but that made no impression on them. They'd had a complaint from a college lecturer, which topped my use of one of the most well-known names in EMC.

I am willing to discuss the thought process involved in anti-nodes, which isn't a secret by the way, and the way a half-turn ferrite core works on RF attenuation. Or I can guide you to resources about it. Just let me know.



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Not simple enough for Google-Bot to understand...


Posted By: Ernie
Date Posted: 13 Jul 2020 at 12:51pm
Hi Graham,
What did you say that the Lautus did that was objectionable?

According to BS EN 61000-5-2 we need parallel earth conductors for all signal cables. We need to fit segregated trunking to our racks to get signal, ac power, and dc power cables separate then bond the equipment chassis’ to the trunking with earth straps or braids (not round cables as they don’t have sufficient surface area.

The trunking (galvanised steel) forms the parallel conductor for us and having a high surface area provides a low impedance bond at high frequency. All equipment will be on the same equipotential ground plane, audio nivarra surely. Yes I am joking.


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There are 10 kinds of people. Those who understand binary and those who don't.


Posted By: Graham Slee
Date Posted: 13 Jul 2020 at 2:07pm
Chris,
Firstly, the Accession C has a solid ground plane, but after supplementing it with 7/0.2 equipment wire between input ground and the 0V connections local to each op-amp, the noise and distortion measurements improved. Allegedly, and according to every EMC engineer who has published anything about ground planes, what I have said is not possible.

PS, dare I say it? It sounded better too!


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Not simple enough for Google-Bot to understand...


Posted By: Graham Slee
Date Posted: 13 Jul 2020 at 2:45pm
Chris,
Secondly, in answering your first question, I cannot recall the exact text because I deleted the lot in a fit of rage.

Graham in error #1:

It had to do with the signals seen on the scope, which everybody seems convinced are neat square waves. Either every function on my scope is/was buggered, or the signals from USB (and even S/PDIF) are a tangle, which somehow, the decoder chip manages to sort out to eventually become, as near as damn it, music.

Graham in error #2:

My thoughts turned to the placement of ferrites on the cable and what effect it could have in cleaning up the signal.

Having helped a pal out of a spot of bother at one of Nottingham University's lecture theatres (2003, when I also did pro installs), I had fitted the ends of a rather long composite video cable (ridiculously long) with ferrites. It was good enough to sharpen the image from the roof-mounted projector, which was being fed by a posh DVD player run by automation from a lectern console. I'd had thoughts of him having to use amplifiers to boost the rather weak signal, but the ferrites did the trick. I was taken aback or gobsmacked at the result. It also saved my pal's profit margin for his install.

I wanted to know how such a "half turn" RF transformer had worked, and the theory is that at some (unknown) frequency, there would be an RF short circuit - the transformer producing the short. Understandably, it would not be an actual short at that frequency but would offer some attenuation.

In RF a few units of dBs seem to make quite a difference and recalling how YRN's engineering chief had solved a cross-channel conflict on an outdoor broadcast - by tying a knot in the transmitter feed cable at a point he measured (the guy being a Home Office approved engineer) - it seemed that there was something about cables I needed to know.

I did a lot of research online, but since I was told to take my explanation down, the online sources also disappeared. You might wish to explore the power the ASA has over the UK internet.

The one thing they cannot remove is cable velocity, simply because manufacturers like Belden, quote velocity factor. However, my work was based on the lengths of the cable where the anti-nodes of particular frequencies occurred. This was how Derek knew where to tie the knot in the transmitter feeder.

The college lecturer objected to this part of the explanation, although it seems regular radio communications practice. Obviously, talking about audio, and audio not being radio, I suppose he had a point, but my interest was the higher speed signals on USB.

I will continue this in a bit. I need coffee!


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Not simple enough for Google-Bot to understand...


Posted By: jupiterboy
Date Posted: 13 Jul 2020 at 3:36pm
Originally posted by Graham Slee Graham Slee wrote:

Originally posted by jupiterboy jupiterboy wrote:

I'd really like to hear a discussion wander into the applications of conductive and semi-conductive dielectric materials. The whole idea of addressing EM field outside the cable—that never, ever gets any reasonable light.


I'd learned a bit about radio frequencies studying for my 2m radio amateur license exam with the RSGB (early 1980's). However, other things got in the way, and I never sat the exam. My interest in radio communications fell away, as I had to concentrate harder on earning a living.

My next brush with radio frequencies was at the beginning of the EMC regulations, starting about 1995. I had already spent four years in broadcast, but working on audio, not the RF end. However, I knew about over modulation, and the audio circuitry had to meet tests regarding retransmission. So I had an understanding of EMC already.

I attended EMC seminars and was given the responsibility of keeping abreast of EMC in a freelance position in 1997.

The products I design have also to comply with EMC legislation, and they do. Although I have never been able to demonstrate it by third party laboratory testing (except for the PSU1), I have used the same self-declaration approach of most in the audio industry.

Our full range of products was EMC tested in South Korea, by a distributor who was required by law to do so. Every product passed.

When designing the Accession, I wanted to ensure its EMC credentials were squeaky clean and having read about Cherry Clough Consultants, and their work for the Advertising Standards Authority, I thought I could not go wrong in hiring them (quite expensive).

I was also developing the Lautus interconnects, and under the same consultancy costs, these were discussed.

Cherry Clough had reported on the false advertising as an expert witness, of another hi-fi firm for the ASA. After being hauled over the coals by the ASA for my explanations about the Lautus USB cable design, I explained that I was using their chosen consultant, but that made no impression on them. They'd had a complaint from a college lecturer, which topped my use of one of the most well-known names in EMC.

I am willing to discuss the thought process involved in anti-nodes, which isn't a secret by the way, and the way a half-turn ferrite core works on RF attenuation. Or I can guide you to resources about it. Just let me know.



That's interesting background. I had the sense that something had happened, but had no idea. I am also not clued in to the politics, so it's an interesting insight. 

I come at this as a simple enthusiast who doesn't have the cash to entertain a parade of audio components in and out of my home. Over the years I've kept and idea of the sound I like, but that has evolved along with my understanding of the design parameters that work for me. That said, gear wears out, and not being able to afford big mistakes, I tend to try and educate myself so I make better purchases.

You have given me a few new concepts to read up on—overmodulation and anti-nodes! Thank you for taking the time to respond.

What I can say is that an easy way to experiment with cables without spending much is to buy some bulk wire, terminate it, and see what happens. After making many of the basic discoveries, like heavier wire does change the way the low end sounds; I arrived at trying to mitigate the transient and very hot moments in recordings—like when a horn player goes into the red or sibilance. I started to realize that, particularly with valve amplification and its various added distortions, that the bloom that was generally romantic was not good when the recording was at its worst. I started reading up on true Litz wire, and the compromises and benefits of running wires in parallel—higher capacitance, lower inductance. That led me into discussion of EMC and the idea that magnetic forces outside the wire were in play. I also quickly figured out this was a big taboo in online discussion. Those that stopped with Ohms law were having nothing to do with it, and those who just liked to listen to differences did not seem to distinguish it from other marketing hyperbole. About that time I found an inexpensive wire with individually insulated wires run in parallel ribbon form. This wire really seemed to neutralize the bloom, but also reduce the added artifacts at distorted moments that were baked into recordings. I was super happy, but as I read, I realized that discussions of ideal dielectrics—those that had the least interaction with the wire—had nothing to say about conductive and semi-conductive dielectrics, which is exactly what the cheap and cheerful wires I was listening through employed. 

Anyway, that's more than enough insight into my comments. What I'm amazed to learn from your response and should have been obvious is that EMC applies to wires but also to the circuits of components. I suspect it also applies to a system as a whole from transducer to transducer, which I also suspect has to do with phase integrity of the sound. 


Posted By: Graham Slee
Date Posted: 13 Jul 2020 at 3:43pm
It may be recalled by some that bass loss can be the result of high-frequency instability, or other high frequencies wasting power. Going on what I have read in hi-fi, the correct solutions might not be understood.

It might stand to reason that a subjective improvement to the bass - in other words, it sounds nicer - might indicate that the high-frequency problem had been solved or mitigated. It appeared that way to one eighties reviewer who produced 3D RF plots of amplifiers to try and understand why one might sound better than another. I recall the Kraken, which had a following, but I also remember others saying it was as bright as ****. The RF plot of that amplifier was a complete mess.

It turned out that my only point of reference in researching the Lautus (all of them) was their subjective bass response. The reason being that I had no objective way of measuring the differences.

I had started to equip myself with an RF spectrum analyser. Still, I was unable to "drive it" but had started taking an interest in the work of Keith Armstrong (Cherry Clough), and I was going to continue studying how to get to the measurements required. Having had the wind blown out of my sails by the ASA, the RF spectrum analyser has been collecting dust.

This goes to show that the research was based on subjective findings. Still, then it was reverse engineered by mathematics and the physics of cable velocity, and in particular, the frequencies where nodes and anti-nodes would appear.

I had thought the ferrites would attenuate interference frequencies of things like switched-mode power supply harmonics and mobile phone interference. However, the calculations pointed to 100MHz and 200MHz.

The ferrite positions were adjusted to the calculated nodes or anti-nodes (by now, I forget which, because I lost interest, but they are whatever 90 degrees occurs at). The conclusion of more listening tests was setting ferrites at the exact distance from the enclosure's emergence, that the 90-degree point of the waveform of 100MHz and 200MHz, related to the cable velocity, the better it sounded.

The cables were then loaned out to members, and the general comment was of a bass improvement, with one or two disliking this.

I then decided to take a stock USB cable, investigate its construction, using the type of dielectric (PVC) research its velocity, and then use the result to set the ferrite to the calculated position.

We heard an improvement here, and owners club/forum members commented positively, so I started to market the Lautus USB cable.

The explanation, which went along the lines described above, was questioned as being false advertising by the college lecturer. The ASA rejected the forum members' subjective findings and stated that I must prove what I had said by measurement or remove the explanation.

The ruling only applied to the Lautus USB, but I removed references to the same description on the other Lautus pages, just in case.


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Not simple enough for Google-Bot to understand...


Posted By: Ash
Date Posted: 13 Jul 2020 at 8:46pm
Thanks for taking the time to rewrite this. I find this topic interesting and would like to understand it in more detail.

I think:
Anti-node = region of peak amplitude
Node= region of zero displacement


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Lautus USB or S/PDIF>Majestic>Lautus-R3 TRS-XLR>2xProprius>MySphere 3.1


Posted By: Fatmangolf
Date Posted: 13 Jul 2020 at 10:09pm
It will be the anti-nodes, my notes from October 2012 have:

velocity factor, VF = speed of light in dielectric / speed of light in vacuum = 1/sqrt(e) where e is the dielectric constant

Reception is zero at beginning of cable so quarter wavelength (antinode) out from shielded source is the key position, that is the first peak in the wavelength or lamda /4

For 100 MHz in vaccuum would get 75cm for lambda = 3m, adjust for the VF of PE cable and you get 50cm for antinode/ferrite position (using PE which has VF 66%) - put the ferrite bead there

Halve this for 200MHz, it has half the wavelength so 25cm. This would be at lambda/8 of 100MHz so one bead at 25cm and one bead at 75cm (i.e. 50cm further on from the first one)

Foamed PE has VF 82% so increase the spacing in proportion. Nylon and PVC (in some mains cables) is around 50% so closer than solid PE.

Graham was right and it worked! The theory made sense to me back then and still does. Science and good engineering put a ferrite in the right place on an audio or SPDIF cable for known radio interference, better than randomly chucking a ferrite on a cable as seen elsewhere which makes no sense if your aim is to protect an unbalanced signal by stopping a RF signal imposing itself on the ground/return so it appears on the signal too and overloads the input of the next piece of equipment.

Hope that helps Ash and my acknowledgement to Graham for repeating what he worked out and shared.



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Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: jupiterboy
Date Posted: 14 Jul 2020 at 1:19am
Can you only tune the ferrite core by position for one frequency, and how do you choose that frequency?


Posted By: Ash
Date Posted: 14 Jul 2020 at 2:16am
A particular frequency is attenuated based on its wavelength. The attenuation curve is a phase-shifted sine wave?? A range of frequencies in the region are reduced in amplitude, with the frequency at 90 degrees receiving the highest reduction.

100MHz region of the radio band is chosen as likely has the best potential for attenuation as it is the typical frequency area used in FM radio transmission so contains the most radio interference to suppress.

If you wish for signal attenuation at an alternative frequency region, the ferrite position is moved to reflect this. The cable has to be connected the "correct" way around (marked arrows on sheath) for the signal attenuation to be in the "culprit" region chosen. It is not a "palindromic" distance.


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Lautus USB or S/PDIF>Majestic>Lautus-R3 TRS-XLR>2xProprius>MySphere 3.1


Posted By: Graham Slee
Date Posted: 14 Jul 2020 at 3:05am
The reason for knowing where the nodes and anti-nodes are so the ferrite can be positioned where it counts (I am grateful to Ash and Jon for reminding me which is what).

A node is where the waveform passes through zero. Positioning for that will do nothing because the signal is already zero.

The anti-node is where the voltage rises to maximum, and it needs to be in the first half cycle at the peak of the quadrant, for maximum attenuation.

The frequencies either side, near to that point, will receive some attenuation.

As I've said, I can offer no proof, just the theory, but the circuit is shown in fig 3C on this page ( http://www.compliance-club.com/archive/old_archive/990609.htm - http://www.compliance-club.com/archive/old_archive/990609.htm ). It is the left-hand circuit of the 2-circuit CM choke. The "short" is because the two conductors transform to each other. Its nickname is a half-turn transformer because it isn't a loop-around. Obviously, its efficiency isn't high, but subjectively, it works.

The ferrite bead or tube must be chosen to have maximum impedance for the range of frequencies you wish the filter to work on.

The USB cable I made was based on 200MHz. If made for a lower frequency, it might affect the rise and fall times of the signal. You can get a clue from the clock frequency. A square wave is made up of all the whole number odd harmonics of its fundamental (3, 5, 7, 9, etc.), and the idea is to keep it as square as possible while filtering out higher frequency noise.



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Not simple enough for Google-Bot to understand...


Posted By: gwebster
Date Posted: 14 Jul 2020 at 2:01pm
As Graham found (even though the ASA thought otherwise), the appropriate use of ferrites on cables is definitely a worthwhile thing. Along similar lines, my son made definite and demonstrable improvements to RFI noise picked up by his remotely mounted radio receiver stick being controlled by a Raspberry Pi over his home network. If it's of interest, have a look http://alloutput.com/amateur-radio/ethernet-rfi-noise-reduction/ - here .




Posted By: Ash
Date Posted: 14 Jul 2020 at 3:25pm
Finally getting my head around Jon's mental arithmetic there. Calculating the distances for ferrite placement is one thing; what about the qualities of the ferrite itself? Does it have to be a certain size or have a particular inductance or "crystal" resonance?

Why a 200MHz calculation? For the second harmonic of the fundamental wave?? If you had a 10m cable and the signal amplitude were not significantly attenuated by that length, you could have a series of ferrites along the cable that gradually get closer together by a factor of VF%, as long as they fit on the cable?

The physical contact that the sheath/insulation makes with the EM shield is also important. I assume that is why users were encouraged to gently and carefully bend the cable slightly along different parts of its length to ensure that the sheath is as separated from the shield as possible. If not, could the filter be bypassed to some extent? I understand that I may be asking too many questions...


One more thing, is velocity factor a similar principle to refractive index? A constant between 0 and 1 that considers the speed of light in the medium compared to the speed of light in free space (vacuum).


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Lautus USB or S/PDIF>Majestic>Lautus-R3 TRS-XLR>2xProprius>MySphere 3.1


Posted By: Graham Slee
Date Posted: 14 Jul 2020 at 4:01pm
Originally posted by Ash Ash wrote:

Why a 200MHz calculation?

It worked.

As for the rest of your questions, I'll let Jon answer them LOL


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Not simple enough for Google-Bot to understand...


Posted By: Ash
Date Posted: 14 Jul 2020 at 4:10pm
So by the logic of "it worked", each ferrite point must act like the start of a new cable?

I kind of understand yet am very confused at the same time.

We are so used to visualising currents as direct current rather than alternating current. The energy propagates through the conductor very differently.


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Lautus USB or S/PDIF>Majestic>Lautus-R3 TRS-XLR>2xProprius>MySphere 3.1


Posted By: jupiterboy
Date Posted: 14 Jul 2020 at 4:40pm
Honestly, my room imposes such dreadful nodes and antinodes on the bass that I'd have a hard time telling if I had the ferrite core right. lol


Posted By: Graham Slee
Date Posted: 14 Jul 2020 at 6:03pm
Originally posted by Ash Ash wrote:

So by the logic of "it worked", each ferrite point must act like the start of a new cable?


That was one way I looked at it.


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Not simple enough for Google-Bot to understand...


Posted By: Fatmangolf
Date Posted: 14 Jul 2020 at 6:09pm
Originally posted by Graham Slee Graham Slee wrote:

Originally posted by Ash Ash wrote:

Why a 200MHz calculation?

It worked.

As for the rest of your questions, I'll let Jon answer them LOL


Thanks Graham. I used your formula to position ferrites on some mains cables. It was not always discernible but seemed to sharpen the picture on the TV.


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Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Graham Slee
Date Posted: 14 Jul 2020 at 6:10pm
Originally posted by jupiterboy jupiterboy wrote:

Honestly, my room imposes such dreadful nodes and antinodes on the bass that I'd have a hard time telling if I had the ferrite core right. lol


That's why we go through the pain for you Wink

Room ratios, BBC acoustical engineering guide, rebuilds, laser cut absorbers, lots of wasted effort and materials (an abandoned new building!), and eventually we arrived at the equivalent of a control room regarding how it sounds... or we can use headphones!


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Not simple enough for Google-Bot to understand...


Posted By: Fatmangolf
Date Posted: 14 Jul 2020 at 6:16pm
Originally posted by Ash Ash wrote:

Finally getting my head around Jon's mental arithmetic there. Calculating the distances for ferrite placement is one thing; what about the qualities of the ferrite itself? Does it have to be a certain size or have a particular inductance or "crystal" resonance?

> I bought some ferrite blocks from Maplin that werea about 30mm long and centred them on the cable at the calculated distance.

Why a 200MHz calculation? For the second harmonic of the fundamental wave?? If you had a 10m cable and the signal amplitude were not significantly attenuated by that length, you could have a series of ferrites along the cable that gradually get closer together by a factor of VF%, as long as they fit on the cable?

> Yes, in theory a longer cable needs more ferrites as you create a node and the wave starts there. In practice one or two was enough but I didn't have an oscilloscope to look at the waveforms so very subjective on my part.

The physical contact that the sheath/insulation makes with the EM shield is also important. I assume that is why users were encouraged to gently and carefully bend the cable slightly along different parts of its length to ensure that the sheath is as separated from the shield as possible. If not, could the filter be bypassed to some extent? I understand that I may be asking too many questions...

> Not sure whether if it would make a difference. Your chance to explore...

One more thing, is velocity factor a similar principle to refractive index? A constant between 0 and 1 that considers the speed of light in the medium compared to the speed of light in free space
(vacuum).

> Yes but different frequency range.



-------------
Jon

Open mind and ears, whilst owning GSP Genera, Accession, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Ash
Date Posted: 14 Jul 2020 at 7:13pm
Thanks very much Jon. Thumbs Up

So Graham, if the ferrite position is essentially the end of one circuit and the beginning of another, would it not be wiser to place the next ferrite at the same distance again, to attenuate the fundamental frequency rather than its second harmonic?? The amplitude of the fundamental is also higher than that of subsequent harmonics so more to attenuate?

With all the expense of setting up speakers for optimum performance and reference sound, perhaps £3.5k MySphere is a more sensible choice? An expensive investment but backed up with plenty of R+D and extensive sound measurement techniques.


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Lautus USB or S/PDIF>Majestic>Lautus-R3 TRS-XLR>2xProprius>MySphere 3.1


Posted By: Graham Slee
Date Posted: 14 Jul 2020 at 10:58pm
@ Jon: I wouldn't even try to measure frequency vs amplitude, because the cable reflections will swamp any theoretical attenuation. It is theory after all.

@ Ash: Where a second ferrite is used, the first ferrite is for the upper frequency. The origin for the lower frequency is still at the cable start.

The 2nd harmonic will peak in the middle of the filter frequency's first quadrant, and so, theoretically also be attenuated to a lesser degree.

Hint: wavelength is in inverse proportion to frequency. Higher frequency - shorter wavelength.

For the USB, I decided not to try 100MHz due to the possibility of "rounding-off" the properties of (what should be) the squarewaves. The FFT of a squarewave being the fundamental and all its whole number odd harmonics.

But all this is theory anyway, although I would like to be able to measure it one day.


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Not simple enough for Google-Bot to understand...


Posted By: Ash
Date Posted: 15 Jul 2020 at 7:19am
Yeah, otherwise with digital, you may find yourself attenuating the signal rather than the interference.

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Lautus USB or S/PDIF>Majestic>Lautus-R3 TRS-XLR>2xProprius>MySphere 3.1


Posted By: capetownwatches
Date Posted: 15 Jul 2020 at 10:53am
This thread certainly has veered off course somewhat...did we not begin by discussing Audio Science Review..? Wink

That said, interesting stuff although much of it goes over my head...Embarrassed


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Solo UL=Kingrex HQ1=NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero
LCD2F=HD600=SR207=DT990 600Ω=TH-X00=K612Pro=K240S=K171Mkll=M4U2=Y50
RCF Ayra 5=Mogami/Sommer->Neutrik/Amphenol


Posted By: BackinBlack
Date Posted: 15 Jul 2020 at 11:29am
Originally posted by capetownwatches capetownwatches wrote:

This thread certainly has veered off course somewhat...did we not begin by discussing Audio Science Review..? Wink

That said, interesting stuff although much of it goes over my head...Embarrassed

Like the science and logic goes over the heads of those at Audio Science Review. Geek


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Just listen, if it sounds good to you, enjoy it.



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