The switched PSU chirps
Printed From: Graham Slee Hifi System Components
Category: And the rest
Forum Name: Power Sources
Forum Description: Where the power comes from has always been a hot topic - even more so now with new World legislation
URL: https://www.hifisystemcomponents.com/forum/forum_posts.asp?TID=108
Printed Date: 27 Mar 2026 at 5:57am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: The switched PSU chirps
Posted By: FritzS
Subject: The switched PSU chirps
Date Posted: 24 Mar 2008 at 8:30am
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One disadvantage of all "Green" products I have - the switched PSU chirps, the new from Reflex more than which from the Solo. I want to make my own dual 24V PSU - one for both amp's. With two separated transformers (a good with EI core!?) and the WNA cascode circuit (I have a PCB) - use two cascoded LM317 for each channel. I have some LM350 in my stock ... Or should I use the JLH design that Sandy suggested? ------------- AKG K812, K872, K712, Q701, K701, K501, K550, K271, Denon AH-D 7000 "Green" SOLO (with LME49860NA), WNA MKII Marantz SA7001 KI, Philips CD650 Revox B790, G1042, Reflex |
Replies:
Posted By: Graham Slee
Date Posted: 24 Mar 2008 at 1:54pm
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Hi FritzS, Please explain further if you can this chirping. I know they make a high pitched sound that can be heard at close quarters, but I've never heard them chirping (like birds do?). I realise there have been about 3 or 4 people who took part in the "green" trial who have said the same, but there were over a hundred who have not. Maybe it could be the polarity? In Austria you can plug them in either way? Maybe they need to be plugged so each is in the same phase? This is the reason why we were selling them so cheaply - to get feedback so we could effect a cure for these "teething troubles" - this is why several companies do product trials before general release. I would really like to fully understand this problem (if it is a problem) so I can put the SM-PS powered products on general release. As for a dual 24V PSU, I wouldn't. All our products use single rail. And as they're designed to work properly on SM-PS it would make sense for us to effect a cure so they remain on SM-PS. Please try and describe the problem in greater depth, and if language is a barrier do you have somebody who can assist with communication? I don't mind it being discussed here as we are an open and transparent manufacturer. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: FritzS
Date Posted: 24 Mar 2008 at 3:04pm
The chirping comes direct from the SM-PS, and I hear this wihout connect to the Reflex, only a bit quieter without load. I turnded arround in connector, it's the same. The Solo SM-PS chirps too but silent. Next time I will precise analyze this problem. If I run the burning in I hear the silent chirping on every side in the sitting room. I must see if I have a mic to record this ....
I know you use single rail - I mean a dual single rail 24V PSU = two separeted conventional 24V PSU's in one case. Your "Green" products working with a conventional 24V PSU too, or? ------------- AKG K812, K872, K712, Q701, K701, K501, K550, K271, Denon AH-D 7000 "Green" SOLO (with LME49860NA), WNA MKII Marantz SA7001 KI, Philips CD650 Revox B790, G1042, Reflex |
Graham Slee wrote:Posted By: Graham Slee
Date Posted: 25 Mar 2008 at 10:29am
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FritzS, does the SM-PS PSU chirp once connected and powering the products it is intended for?
------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: FritzS
Date Posted: 25 Mar 2008 at 10:46am
It chirp (more a higher frequent tone 5 .... 10 kHz) with powering the Reflex, and it chirps a bit softener if nothing powered. Turn arround in main-power socket - it's the same. The other from Solo chirps more silent. I reckon a wire in the tranducer "sings"  I measured about 80 ... 90 VAC between the output and main-ground (protection-earth), but this at all of my three SM-PS PSU's (two from you, one from WNA). ------------- AKG K812, K872, K712, Q701, K701, K501, K550, K271, Denon AH-D 7000 "Green" SOLO (with LME49860NA), WNA MKII Marantz SA7001 KI, Philips CD650 Revox B790, G1042, Reflex |
Posted By: Charley Phogg
Date Posted: 27 Mar 2008 at 6:40am
I've only unplugged my Solo a few times,and from what I gather in doing so, it seems to me that it depends on how you plug it in. Example, into outlet first then into Solo, or Solo first then outlet. I just can't bare to umplug it. Maybe I should try and see what I come up with. I'll do my best to trey and be without it and take notes to inform what I find. I'd take a day to evalute it, but thats a tall order  considering how much I listen to it  . |
Posted By: FritzS
Date Posted: 30 Mar 2008 at 6:41am
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The SM-PS “chirping”
nasty quite alone too – without any amps to load – it’s only a SM-PS problem,
that have nothing to doo with the Solo or Reflex amps, nothing to do with
grounding to earth! One building component inside the SM-PS, transducer or cap,
chirps. I think it’s a series-fault
of the SM-PS. Sometimes I read about similar “chirping”
in notebooks, SAT receiver, DVD player, etc. that use switching regulators – some shift for
oneself – a drop of coating on the transducer wires helps mostly. But I cannot
open the SM-PS without destruct. ------------- AKG K812, K872, K712, Q701, K701, K501, K550, K271, Denon AH-D 7000 "Green" SOLO (with LME49860NA), WNA MKII Marantz SA7001 KI, Philips CD650 Revox B790, G1042, Reflex |
Posted By: ServerBaboon
Date Posted: 30 Mar 2008 at 8:09pm
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I have a chirping SMPS as well, I have a green solo and a green reflex and one smps is noisier than the other. It is not the solo or relex it is definately the SMPS. Curiously I am decorating at the moment and have unplugged everything for a week or so and have plugged them back in so I can listen my CD player through the solo and the chirping does not seem as loud. I will check back tomorrow. One SMPS has tone you can hear with your ear next to it but the other has a louder tone which is lower in frequency than the other, and less 'pure' and louder. It seems to be an occilating frequency (does that come under 'you don't say banner'?). It doesn't matter if I plug the SMPS directly in a wall socket or in a surge protected strip block. |
Posted By: Graham Slee
Date Posted: 30 Mar 2008 at 10:08pm
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Rather frustrating this chirping is. I have had 5 of the same SM-PS powered up here all day and not one single chirp. I've even had the room temperature go from 15 to 27 degrees to see if it's a temperature thing. The next stage is to put them on a variac and test them at several voltages in the region 200-260V ac. There is always the possibility that these are four faulty ones out of some 150 in use around the world. And we will send out two to each of you. However, please send the suspect ones back once you receive them. They will be from the five we're testing here. One other question to ServerBaboon and FritzS, are they plugged direct to mains or via a conditioner/filter? This is important and it will help greatly to here your experiences with both. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: ServerBaboon
Date Posted: 31 Mar 2008 at 9:44am
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I have tried it in a mains wall socket and a surge protected mains block which may have some filtering in it, it's one of those cheap ones from maplins or somewhere (lost in the dim regions of time). I will try and pop it in the post this week since my HiFi is in bits. I have kept up the chirping phrase on the basis that it is trying to describe the audible noise (from more than a few feet) from the smps as I have tried to say above it does seem to be some high frequency vibration from inside the device but it is not a constant single tone. |
Posted By: FritzS
Date Posted: 01 Apr 2008 at 8:33am
I have similar feeling about the tone, if I hold my hand on the PSU the tone varies a bit. I use a power strip with a switch lighted with a glow-discharge lamp - in line before are two surge arresters - one in power outlet, one in breaker panel - both use varistors. This are a common configuration in houses here. ------------- AKG K812, K872, K712, Q701, K701, K501, K550, K271, Denon AH-D 7000 "Green" SOLO (with LME49860NA), WNA MKII Marantz SA7001 KI, Philips CD650 Revox B790, G1042, Reflex |
Posted By: Charley Phogg
Date Posted: 02 Apr 2008 at 5:51am
| Fritz and Serverbaboon, my appologize , I thought you were talking up strictly on power up. |
Posted By: Tarkovsky
Date Posted: 08 Apr 2008 at 11:38am
| Hi there everyone, first post. I own a pre 2008 green solo and it's a beauty. However I'm having this exact same power supply issue i.e. a constant whining from something that's gone microphonic in the power supply. So it's buried under some bubble rap and clothes. Are suggestions as to what kind of supply I should replace this with? |
Posted By: Graham Slee
Date Posted: 08 Apr 2008 at 1:47pm
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Hi all, We had some back from Serverbaboon the other day, and it looks like the main thing the EU hasn't considered is the high pitched emissions of SM-PS. True, the one in your computer doesn't do the same audibly (maybe your dog is being driven wild by it...) but that's because it's big and butch! (I didn't mean your dog, unless that is, he's big and called butch). The plug top variety mostly suffers the same problem as the energy saving light bulb - they run at just above 20kHz, which means along with other normal sounds in a household, you'll hear them at a lower frequency caused by a thing called "beating". As I've explained countless times, beat frequencies are set up in all walks of life - it's the reason why your car engine seems to emit a throbbing or wobbling sound in traffic jams - it's even why Steve McQueen's motorbike spokes seem to show the wheels revolving in the wrong direction in "The Great Escape". Apart from doing a super high frequency SM-PS of the type used in computers, which would "cost the earth" in world-wide approvals packaged as an external power supply (but hey, I guess some manufacturers don't give a toss about safety, energy efficiency limits and EMC rules - but we have to because there are plenty of people willing to blab on us), we are stuck with little plug top switchers that sing. The younger you are the more you'll hear the high frequency whine that sounds similar to a flash gun charging. In some circumstances the sound can be a chirping - it all depends on the many sounds surrounding you and your own hearing sensitivity. The only way I know how to remove the sound is to place the SM-PS in a bell jar and attach a vacuum pump to it and evacuate all the air - what a jolly good idea for the latest Slee product  ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: ServerBaboon
Date Posted: 08 Apr 2008 at 10:43pm
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In the end, although we talked on the phone about returning just the one to check, I did send both back as a comparison of one which I wasn't sure was a problem (Suppose I should be happy my HF hearing is still intact at 40) , and the other which I felt was significantly louder (noiser) which I attached the tape to. Did you not detect any difference between the two smps, one is a flash gun and one 'chirps' for want of a better phrase. Is/has Fritz returning/ed his yet? As I said since I returned a smps I wasn't sure about I'm quite happy to stand the postage cost back just PM me the costs. |
Posted By: Graham Slee
Date Posted: 08 Apr 2008 at 11:40pm
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Hi Steve, I can hear the one with the tape on the lead. It emits a high pitched whistle to my ears. During the day when I listen to Radio 4 in the workshop I have to listen hard for it, but this evening with nothing switched on but the test gear (silent) and the soldering iron (silent too) I could easily hear the whistle seated within 18 inches of it. The other one that's on another wall socket a further 2 or 3 feet from my seated position I can't hear at all - probably drowned out by the first one. I last measured my hearing a few years ago (age 50 ish then) and I could hear up to 13kHz. John is bringing Leo tomorrow and they'll be testing their own hearing with the test gear oscillator. John is about your age and Leo is early 30's. I'll report back on that shortly. As for the exchange, don't worry, they'll be sent in the next few days. Postage cost is not a problem. I'm grateful for the feedback, but I am frustrated, not with you but the idiots we somehow elected to govern us for their incompetent handling of the green issue. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: dvv
Date Posted: 10 Apr 2008 at 7:17pm
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I think the chirping noise comes more often than not from the ferrite rings in the PSUs. There are two things you can do about this.
One is to use larger output signal capacitors, e.g. if you currently have sau 100 uF, try with a 220 uF cap, that sometimes cures things and provides the added benefit of still cleaner power.
The other is to use some silicon paste/glue compound on the wirewound ferrite rings. Make VERY sure you are using thermally insensitive (400 deg. centigrade) compound. It's the same stuff they use to fix the large capacitors to the PCB, milky white, takes a few days to harden. But when it does, it kills chirping on the ferrite rings stone dead.
Graham, I have had this problem as well, it's in the domain of sympathetic vibration, and that you can never foresee, it just happens under certain conditions and that's it. ------------- True audio lives on the fringes of the industry. |
Posted By: FritzS
Date Posted: 17 Apr 2008 at 7:24am
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Hi Graham, what`s the latest knowledge about? Should I send back this one PSU and you give me a new and tested? ------------- AKG K812, K872, K712, Q701, K701, K501, K550, K271, Denon AH-D 7000 "Green" SOLO (with LME49860NA), WNA MKII Marantz SA7001 KI, Philips CD650 Revox B790, G1042, Reflex |
Posted By: Graham Slee
Date Posted: 17 Apr 2008 at 8:05am
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Hi FritzS, We've had the ones back from Serverbaboon plugged-in for near on two weeks now, and admit they do make a noise. But they don't do "chirp, chirp, chirp". Three of us have listened to them at close quarters, aged mid thirties to mid fifties, with keen to average listening abilities, and we can report that they whistle quietly. We've yet to hear them chirping like a canary. We agree to replacing your SM-PS and will send Serverbaboon two to replace his. I have three plugged in permanently here for my own audio system. If I listen closely to them, yes they do emit a whistling sound, but even in the dead of night, a couple of metres away and nobody here hears them - not even my 9 year old son. I guess if we had a dog it could be different. My Nokia mobile phone charger does exactly the same. Unlike computer switched-mode supplies, these plug tops work similarly to energy saving light bulbs (which are becoming mandatory in places like Australia) where the frequency of operation is just above the audio spectrum. The operating frequency lies between 20 and 40 kHz. Components within the plug top will mechanically resonate (even if they're glued down) at such a frequency, just like glass can break with a good female opera singer! FritzS, I will send you a new tested one, but if that develops the same whistle then I'm sorry - it's simply a fact of life. It's a fact of life brought on by EU, Australian and Californian politicians. If the second one is not to your liking would you please plant it in the cranium of one of the EU instigators? After all, the seat of EU power is easier to get to from Austria than it is from here (by car). At the end of the day, the "green" Solo was always advertised as a pre-release product pilot sold at a highly discounted price - not a mainstream product, and as such some imperfections are to be expected. To say there are no imperfections like this in the item we make, but just the little power supply, isn't bad? And for a few Euro's it can be cheaply replaced by a linear plug top power supply that doesn't whistle - I'd say you've got a bargain  (the emoticon means "hug")------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: ServerBaboon
Date Posted: 17 Apr 2008 at 12:46pm
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Ok, I think in my case it was more of a
cccccccccccccchhhhhhhhhhhhhhhhiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiirrrrrrrrrrrrrrrrrrrrrrrpppppppppppppppppp
than a chirp, chirp, chirp which I assumed was some sort of resonance.
I may have jumped on the chirping bandwagon assuming that they were
talking about the louder than average (to my ears) noise one of my
units was making. It will be interesting to see what you think of Fritzs to see (hear) if it is a beating tone or a constant tone. I guess other smps do makes noises, I did feel the example I sent back (taped one) was louder than most though and could be heard from 2+ meters. Not sure if this general noise is noticable due to the proximity though, afterall you are chained by the length of your 'cans' lead and so you are limited to how far away you can place the smps, certainly a complainent on 'another forum' was talking of his situation of the green solo in their bedroom. Sat on my sofa listening to records through the green reflex I can confess not to hearing anything. Is the frequency and amplitude of the noise generated related the voltage/current capacity out? Yes the green series was a fantastic bargain and was the only way I could have got hold of a Reflex and certainly try the Solo (a successful gamble) and I hope I haven't come across as a complaining git. Has the fact it was such a bargain affected peoples perception/acceptance of the smps, have people been more accepting of the whistling than they would be at full price? I suppose my concern would be if a magazine reviewer ended up with one they thought was 'too audible' and passed this comment. Whether this is relevant or not is yet another matter... have you seen an increase in demand after the HiFi World Voyager review? ..... does good review make a difference. I know you have passed comment on magazines and reviewers before but surely a positive review good? It would be interesting to see if there are any studies on the affect magazine reviews on sales of products. |
Posted By: Graham Slee
Date Posted: 17 Apr 2008 at 9:47pm
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"hope I haven't come across as a complaining git." (more big hugs)... Don't get me wrong - you don't come across as that. To be perfectly honest, the whole SM-PS thing ****** me off. OK, it'll save the world about 18 power stations of the size of Ferrybridge in West Yorkshire. IMO carbon emissions and their link to "global warming" are a mere diversion - a conjuring trick to disguise the real purpose which is security of supply (as the Eco Design directive partially admits) - in otherwords it's political, and you and I will foot the bill as we usually do. I could have designed a range of equipment by now, but for RoHS, WEEE and the "rolling" Eco-design directives. Why do you think I hate politicians? Hope no one here's one! They get 40 grand a year plus 160 grand expenses and what do they do for it? Yes! They make sure people like you and me don't get anywhere near what they get! Anarchy? You're b****y well right!
------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Tarkovsky
Date Posted: 18 Apr 2008 at 5:12pm
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Hello Graham, is there any chance my PSU could be replaced also? It's really not just a quiet noise but fairly obvious within the confines of any quiet room. Both units chirp when the power is onned as well. Either that or could you recommend an alternative PSU to buy? Cheers Zak |
Posted By: Graham Slee
Date Posted: 20 Apr 2008 at 6:25am
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To all participants of the "green" offer made at Rockgrotto forum. As I've stated above, all SM-PS plug top power supplies produce noise. The very idea of forcing a distorted squarewave through an inductor, which in the simplest of terms is what these EU preferred SM-PS do, causes ringing. If I did replace an SM-PS I would be in effect dealing the same card again. This will be the case where I have exchanged the three units so far because although they may be slightly quieter in two weeks of testing, they may also result in the same noise, which is within reason IMO when compared to similar SM-PS sold by other manufacturers. The "green" offer was made based on a product pilot and that means each unit was effectively a prototype. Each person taking part paid me for the value of the parts and labour without any profit, and obtained a good experimental amplifier using a "green" technology power supply. I had voiced my opinions about such power supplies on numerous threads at the forum where the offer was made. The offer was made to members only of that same forum. The offer wasn't made anywhere else because to do that could have been to mislead, for such people would not have been able to read my views (or should I say: I could not be certain that non-members would not be conversant with my views). Therefore my conclusion is that all those who partook of the offer were aware of the limitations of the SM-PS? If each person who took part is now going to expect a replacement SM-PS or other satisfactory replacement after explaining the gist of that offer, I would think that was against the spirit of the offer. However, if it could be shown that even after stating that this was a product pilot, I have been in error with this offer, then it may take me a few years to replace each power supply because the average cost including shipping will be in the region of 30 GBP each. With over 100 of these offers having been taken up all around the globe the cost will therefore be in the region of 3,000 GBP. Apart from the final few "green" Solo's, I did the offer out of my own pocket, so that will mean I personally would have to pay some £3,000 out of my own pocket. People reading this may think I would find that easy, but unfortunately that isn't the case on my salary. I have placed the above on record here for all participants of the offer to decide whether I forfit 3,000 GBP of my own income or whether they accept that it was part of the bargain? Fair? As for an alternative, any half decent DC supply capable of supplying 24 volts (nameplate rating) to 35 volts (measured offload maximum) DC at 250mA or above will power the "green" Solo. As these units are comparatively cheap, users may find they can try a few and post their thoughts. For anyone wanting to upgrade their "green" Solo to a PSU1, this would only be a good idea if the output stage bias resistors are changed to value 1k6. We will not be offering this service so it will be a DIY decision. I will publish information about this modification shortly. I feel I must now announce that the "green" Solo offer is now suspended for the reasons as set out above. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: dc2
Date Posted: 22 Apr 2008 at 10:42pm
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Graham,
Tried a Mascot 2183, 24VDC 1A linear regulated PSU (centre +ve) http://www.mascot.no/pdf/2183.pdf - PDF document Measured offload voltage 23.752 volts LED barely lit no sound output? 250mv? what's wrong? # 0110-010 |
Posted By: Graham Slee
Date Posted: 23 Apr 2008 at 1:21am
Does it still work with the SM-PS? ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: dc2
Date Posted: 23 Apr 2008 at 5:48am
NO the unit is working 100% on a SMPS.  I had one of these PSUs at hand so gave it a try after reading your comments, curiosity that was all.
|
Posted By: Graham Slee
Date Posted: 23 Apr 2008 at 8:50am
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Maybe the DC plug isn't making good contact? The little socket on the end of the wire can be problematic on these things - if we use them we squash or bend the pins on the DC plug part to ensure good contact, but be careful... Another thing: Manufacturers often kindly protect metal parts from corrosion without thinking it also impedes electricity. We have to degrease some of the DC plugs we buy (and a sod it is too). None of these things may apply to you dc2, but they could be of benefit to others. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: ServerBaboon
Date Posted: 23 Apr 2008 at 3:25pm
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Perhaps you could tell us what the dimensions of the smps plug should be. Last time I looked on Rapid Electronics a couple of weeks ago I noticed some came in different dimensions. |
Posted By: dc2
Date Posted: 23 Apr 2008 at 5:59pm
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Graham, soaked the plus in isopropyl alcohol (IPA), worked first time.
ServerBaboon, the Mascot comes with 2 interchangable plugs, 2.1mm and 2.5mm. The 2.5mm is the size I am using. The 2.1mm will not go into the socket (to small). |
Posted By: FritzS
Date Posted: 24 Apr 2008 at 1:53pm
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Graham, is the change from 3k to 1k6 really essential if using a conventional PSU? Or the other way around - works Solo with 1k6 and the SM-PSU well? ------------- AKG K812, K872, K712, Q701, K701, K501, K550, K271, Denon AH-D 7000 "Green" SOLO (with LME49860NA), WNA MKII Marantz SA7001 KI, Philips CD650 Revox B790, G1042, Reflex |
Posted By: Graham Slee
Date Posted: 24 Apr 2008 at 11:53pm
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We have had some real difficulties making the green and 2007 models
work the same, and we are still working on a model that will do both
types of power supply. The 1k6 makes it better with our PSU1 power
supply, but may make it less good with the SM-PS. You are free to try
it, but be prepared to have to change it back. And also, please report
your findings here.
------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: Andy9672
Date Posted: 03 Sep 2009 at 11:35am
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Graham, Just reading this thread for the first time as my television (lcd flat screen) has started to chirp! lasts arround 7-10 secconds about every 30 seconds, only notice it now our baby has been born as we are turning it down more than usual! I know on our tv there is not a lot i can do but an idea came to mind that may help with your SMPS problem. How about an extention for the DC cable so that the power supply can be located furhter away from the listener? I also find with my mobile ohone charger that placing it on a granite drinks coaster helps a lot in the whine. I can see that we are going to have huge SMPS cases that are accoustically insulated. oh and i hate energy saving light bulbs, i thought we had left the dark ages!! ------------- Solo psu1 Rega Apollo AT W1000 Technics SL1200 |
Posted By: Graham Slee
Date Posted: 03 Sep 2009 at 12:01pm
I second that last sentence... I will look into the extension cords. I keep 4 or 5 (one from each batch we bought) of the SMPS supplies permanently on within 1.5 metres of where I sit doing the office and design work at my computer and only really hear them when changing a connection on the equipment we have on test - when I'm within 0.5m of them, or in the "dead" of the night if I'm working very late/early - but I hear the computer and fridge more (the computer is one of those low noise HPs) I never heard one chirp even after over a year of usage, but my situation may be a lot different to those who've heard chirping... 1] My electrical wiring is quite close to the consumer unit (in the same room) 2] I don't go via a mains cleaner/conditioner 3] They're hidden behind a cupboard 4] At 54 my high frequency hearing falls at 13kHz but as a child it was nearer 18kHz as I remember my physics teacher did an experiment on us. Unfortunately the world is stuck with an ever growing emphasis on switched mode power supplies which are good from the point of view they save energy, but bad because of the downside of possible noise detection due to their untrasonic "mains" frequency, not forgeting their carbon footprint may actually be very similar to a linear because although they waste less energy, they take a lot more energy in manufacture because of the large number of parts they use. ------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps |
Posted By: bery
Date Posted: 29 Nov 2011 at 11:18am
| I had the Green PSU ( with Solo II ) in my bedroom. My wife was complaining about the chirping ... so I bought PSU1. Problem solved. |
Posted By: Fatmangolf
Date Posted: 29 Nov 2011 at 9:40pm
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Good call! ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |