I deleted the whole input board(pre amp). Which had a blocking cap on it. Its been running for days. No problem. Infact that board caused a slight turn on thump that is now gone. There is no need for all the junk on that board. Or those bad volume pots that fail on many I have seen for sale. It sounds far better. It will be worth seeing what happens when I change out the electrolytics. But, I don't expect much there. People over rate the change of power supply caps. The good thing about oil caps is they seem to last forever. Which you can't say for electrolytics.
Paul, with these changes the amp has to sound different. However, since you do not have any measuring equipment it could easily be that you just like the new sound, even if it has far more distortion and a havoced frequency response.
Reducing/removing the feedback loop will definitely boost distortion. I can't imagine that distortions are beneficial for sound quality.
While you ask for advice, you don't care at all about it at the same time. This makes helping you difficult.
Have fun, Hannes
Reducing/removing the feedback loop will definitely boost distortion. I can't imagine that distortions are beneficial for sound quality.
While you ask for advice, you don't care at all about it at the same time. This makes helping you difficult.
Have fun, Hannes
removing feedback from a class B solid state amp may cause a few problems. with no feedback, the amp is running at it's open loop gain, which could be anywhere from 1000 to 1 million depending on the design. this means that the bias current in the input stage could be enough to cause the amp to latch to a rail, even with no input. a small input (a few microvolts) would drive the amp to clipping. distortion would be excessive even with the input at a useable level, since there is no corrective action taking place.
McIntosh mc602
Hi!
Suppose this thread is dead by now - but on Taobao.com there is a mc602 clone for sale. Unbalanced input and seemingly without output transformer.
So maybe not a true clone, close enough that I bought myself a couple of PCBs. Made a quick drawing and it seems to be true to the original.
Note that the transistors shown are just available models from KiCAD which I use.
Hi!
Suppose this thread is dead by now - but on Taobao.com there is a mc602 clone for sale. Unbalanced input and seemingly without output transformer.
So maybe not a true clone, close enough that I bought myself a couple of PCBs. Made a quick drawing and it seems to be true to the original.
Note that the transistors shown are just available models from KiCAD which I use.
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