It absolutely pains me to sell this, but it needs to go for the reasons I outline below.
I bought this in August 2019, and gave it to David Brett at Essex Amp Repairs to look at. David is a service agent for Icon Audio, so knows his stuff. He is absolutely diligent in the work that he does.
The instructions I gave David below were put together with the help of an Audiokarma member in New Zealand, who services Perreaux amps and also has a direct line of communication with Peter Perreaux (the founder of the company).
Check the electrolytics for value and ESR, including the power supply caps: replace components as necessary with highest quality replacements.
Do a visual inspection for any issues - loose machine screws on terminals, any burnt components
Quiescent current should be set using a distortion meter. If your tech doesn't have one then it can be set to about 350mA and should be close enough.
There is a preset to adjust for distortion null (RV2):
o Connect outputs to 8 ohm resistive loads.
o Apply an input sine wave of 20 kHz and adjust the input level for 300 watts (49 V RMS) output on each channel.
o THD should be 0.03% or less.
o Adjust RV2 on each channel for minimum distortion.
Fit speaker protection circuitry.
[SIZE=11pt]NB DC offset isn't adjustable on this amp. [/SIZE]
David's report to me after doing the work was:
All done for you with reference to these key points. Most of these are standard practice for us whenever an amplifier is in for service, but always useful to see what the designer / manufacturer recommends.
All capacitors were checked and found to be in good condition, so no replacements required.
All other components checked and confirmed to be in tolerance and in good condition. No need for any replacements.
All screws, connectors solder joints etc. checked and corrected as required.
Bias current set as recommended. Power output tested good. This is a very good sounding amplifier.
Top and bottom cover screw holes worn causing the screws to be loose. Replacements fitted.
DC offset was too high. This was due to deterioration of the long-tail pair transistors. These have been replaced and the performance checked and tested good.
Considering the power of the amplifier and the capability of the power supply, I think speaker protection is important. I tested a speaker protection circuit and it appeared to work very well. Since it was relatively straightforward and economical to fit, I thought it best to complete the installation. I am pleased to say that the installation looks as far as can be expected as if it was factory fitted. Hopefully, you will never know it’s there, but as far as possible your speakers will be properly protected.
I have run this amp with a Sansui CA-F1 preamp, and it sounds superb. However, I am now selling all of my vintage collection as I have acquired a Vitus amp (from another HFW member).
The 3150 uses class A in the driver stage, and 'extended' class A/B in the outputs. My Audiokarma contact has an email from Peter Perreaux which discusses the exact design philosophy behind this amp, which I can send to serious buyers.
Note that the amp emits a small amount of hum when switched on, from its massive transformer. This is not audible (to me, anyway) when music is playing, even quiet passages.
From a smoke-free and Covid-free household in Colchester.
Price is £995 plus postage. Collection from the doorstep is fine providing masks are worn etc.
Further photos are available on request.
I bought this in August 2019, and gave it to David Brett at Essex Amp Repairs to look at. David is a service agent for Icon Audio, so knows his stuff. He is absolutely diligent in the work that he does.
The instructions I gave David below were put together with the help of an Audiokarma member in New Zealand, who services Perreaux amps and also has a direct line of communication with Peter Perreaux (the founder of the company).
Check the electrolytics for value and ESR, including the power supply caps: replace components as necessary with highest quality replacements.
Do a visual inspection for any issues - loose machine screws on terminals, any burnt components
Quiescent current should be set using a distortion meter. If your tech doesn't have one then it can be set to about 350mA and should be close enough.
There is a preset to adjust for distortion null (RV2):
o Connect outputs to 8 ohm resistive loads.
o Apply an input sine wave of 20 kHz and adjust the input level for 300 watts (49 V RMS) output on each channel.
o THD should be 0.03% or less.
o Adjust RV2 on each channel for minimum distortion.
Fit speaker protection circuitry.
[SIZE=11pt]NB DC offset isn't adjustable on this amp. [/SIZE]
David's report to me after doing the work was:
All done for you with reference to these key points. Most of these are standard practice for us whenever an amplifier is in for service, but always useful to see what the designer / manufacturer recommends.
All capacitors were checked and found to be in good condition, so no replacements required.
All other components checked and confirmed to be in tolerance and in good condition. No need for any replacements.
All screws, connectors solder joints etc. checked and corrected as required.
Bias current set as recommended. Power output tested good. This is a very good sounding amplifier.
Top and bottom cover screw holes worn causing the screws to be loose. Replacements fitted.
DC offset was too high. This was due to deterioration of the long-tail pair transistors. These have been replaced and the performance checked and tested good.
Considering the power of the amplifier and the capability of the power supply, I think speaker protection is important. I tested a speaker protection circuit and it appeared to work very well. Since it was relatively straightforward and economical to fit, I thought it best to complete the installation. I am pleased to say that the installation looks as far as can be expected as if it was factory fitted. Hopefully, you will never know it’s there, but as far as possible your speakers will be properly protected.
I have run this amp with a Sansui CA-F1 preamp, and it sounds superb. However, I am now selling all of my vintage collection as I have acquired a Vitus amp (from another HFW member).
The 3150 uses class A in the driver stage, and 'extended' class A/B in the outputs. My Audiokarma contact has an email from Peter Perreaux which discusses the exact design philosophy behind this amp, which I can send to serious buyers.
Note that the amp emits a small amount of hum when switched on, from its massive transformer. This is not audible (to me, anyway) when music is playing, even quiet passages.
From a smoke-free and Covid-free household in Colchester.
Price is £995 plus postage. Collection from the doorstep is fine providing masks are worn etc.
Further photos are available on request.
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