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Proprius Amp tweaking......

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ROMPerformance View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ROMPerformance Quote  Post ReplyReply Direct Link To This Post Topic: Proprius Amp tweaking......
    Posted: 21 Feb 2016 at 4:07pm
These little gems need no tweaking whatsoever.  

They are driving my 6Ohm Harbeths with ease and then some srtrapped to the back with super sticky velcro.  It's just amazing how quality sound travels at normal listening levels.  

It's fair to say everything else sounds poor to middling by comparison.
Francis :0)
Majestic DAC, Proprii, Solo ULDE, Voyager, Libran, Lautus, Spatia,, Cyrus CD XT SE2, Cyrus PSX-R, Sennheiser HD 800 and 540 Ref2, Harbeth SHL5
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 20 Feb 2016 at 6:08pm
Yes, it's a 48 volt bought-in switched-mode with built-in short circuit protection and excellent regulation. Does 120 (real) watts.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Richardl60 Quote  Post ReplyReply Direct Link To This Post Posted: 20 Feb 2016 at 1:47pm
Hi, pictures in new website great and notice the Proprius has a different power supply to the normal psu. Is it a different case or differing supply?

Richard
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 2016 at 9:05pm
Originally posted by Richardl60 Richardl60 wrote:


Well made and think another good Yorkshire company!


Neh, t'badlands! (Lancashire) Wink

Originally posted by Richardl60 Richardl60 wrote:


In my experience I agree that the 'best' sound tends to come when preamp volume control is 10.30 to 12.00 o'clock best balance between openness, power, dynamics and clarity. This has been subjective on 4 amps over the years and whilst not fully sure on the science suspect may be related to minimising possible preamp overload in some cases and allowing the power amp to function properly I am sure the more educated may be able to clarify.


Another Neh. They make them do nearly full output at around 1 o'clock to sound impressive! Been there - didn't like it - resigned.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote BAK Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 2016 at 8:33pm
Make sure any and all attenuators used are completely 360 degrees shielded (encased in metal on all sides with no gaps) or you may get extra noise and a possible radio station.
#1 Any attenuator needs to be matched to the impedance of the input it is connected to at a minimum.
    It would be best to match to the impedance of the preceding stage's output, too.
BUT, matching it to the input of the following stage will be very close to the same frequency response and clarity.

NOTE: The attenuators used for Mic inputs are at a very low impedance, say 100 to 600 ohms and will not work good when connected to a 10k to 100k ohm input. Valve (tube) circuits can be as high as 1 MegOhm or more, but most valve amp inputs are 50k to 250k ohms.

Those impedance specs should be given by the unit manufacturer... many do not state the true output impedance.
 The impedance of a circuit's input and output are an AC impedance and not purely resistive.
      Any coupling capacitors and cable matching caps and coils are included with resistors in the AC impedance specs... a complicated calculation.

For those that cannot turn up the volume above "1" on a "1 to 10" volume scale, use a 20 dB attenuator.
    (For limited to "2" or "3", use a 10 dB.)
This will bring your volume control range close to the middle, "~4 to ~7" (between 10 o'clock and 2 o'clock).
    ( In scientific math, the tilde ~ symbol = approximately)

Guitar players will remember some amps having a volume scale of "1" to "11"Wink. (Making one think they had "1" more volume step above "10" .)

I had a high end 90w per chan amp in the 1980's that had a 20 dB attenuator built in. I always used it to keep my volume range close to the middle. With 97 dB @ 1w/1m sensitive speakers I couldn't turn it up above 1/10 watt before the neighbors complained.
 I can give you more info on the science of the volume control next.


Edited by BAK - 11 Jan 2016 at 8:57pm
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
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DaveG Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 2016 at 7:59pm
Aah, yeah - I used to have some of those attenuators - I wonder if I still do Confused
Dave

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Richardl60 Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 2016 at 7:43pm
I am not sure whether Graham produces anything but Rothwell produce plug in attenuators that are very effective in providing greater volume range by attenuating the input signal. This my be more prevalent with Some CD players and may are likely to reduce some of the often found CD hardness. Were around £40 a pair when I last bought some some years ago.

Well made and think another good Yorkshire company!

In my experience I agree that the 'best' sound tends to come when preamp volume control is 10.30 to 12.00 o'clock best balance between openness, power, dynamics and clarity. This has been subjective on 4 amps over the years and whilst not fully sure on the science suspect may be related to minimising possible preamp overload in some cases and allowing the power amp to function properly I am sure the more educated may be able to clarify.

Richard


Richard



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