I ordered it from Advanced Circuits using wayne's gerbers.
Typically I agree with you on the LM4562 but It sounds good on this. I prefer it over the OPA2132 I had here also. Unfortunately, my dual OPA627 adapter board is acting up and I only had one channel so I couldn't compare that also. The Burson looks like it will be here Wednesday so I will have another datapoint then.
I made a small change to the boards and should have some shortly green 1.6 mm FR4 with 2 ounce copper white silk screen.
The change is two resistors in series with the input pot it makes it a bit more stable if the pot is rotate to the extreme and allows for setting attenuation if you want.
The change is two resistors in series with the input pot it makes it a bit more stable if the pot is rotate to the extreme and allows for setting attenuation if you want.
diyAudio store is planning to have a chassis for low level projects. Our standard for mounting holes for PCB's is a grid of 10mm x 10mm so if the PCB's had mounting holes at some multiple of 10mm in each direction, that would be helpful to builders, esp. in Europe where its easy to to get a HiFi 2000 chassis.
Also kind of too bad the output devices are set back so far from the edge of the board which keeps them from being attached to a single heatsink or the inside of the 10mm thick front chassis panel but I can see that's so there can be individual heatsinks for the devices. I guess the only way then is something like that alu channel shown on that chassis photo.
Also kind of too bad the output devices are set back so far from the edge of the board which keeps them from being attached to a single heatsink or the inside of the 10mm thick front chassis panel but I can see that's so there can be individual heatsinks for the devices. I guess the only way then is something like that alu channel shown on that chassis photo.
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OK circuit gurus ...
I got my Burson V5i today and it sounds TERRIBLE! Turn-on noise, turn-off noise, hum and noise with no source playing. The noise increases with volume until about 1/3 volume then levels off. The ODD thing is that the noise increases faster in the L vs R until 1/3 then L noise drops to match R until about 3/4 volume then R increases until full as I slowly turn the volume up and down.
I had a similar issue with my dual OPA627 on an adapter board where I had no left channel until I turned it down to a certain level and then it would come back but only at VERY low volume. I chalked it up to a bad op-amp but now I am not so sure.
To throw a wrench in it, the amp works FLAWLESSLY with NO noise using an LM4562 with a normal linear volume response as it is turned up and down. I have also tried an Analog Devices op-amp that also behaved fine.
FWIW, I did install the optional stabilization caps on the feedback loop.
Any ideas? Am I oscillating? I do have a scope but not sure how to test it and/or resolve it.
I got my Burson V5i today and it sounds TERRIBLE! Turn-on noise, turn-off noise, hum and noise with no source playing. The noise increases with volume until about 1/3 volume then levels off. The ODD thing is that the noise increases faster in the L vs R until 1/3 then L noise drops to match R until about 3/4 volume then R increases until full as I slowly turn the volume up and down.
I had a similar issue with my dual OPA627 on an adapter board where I had no left channel until I turned it down to a certain level and then it would come back but only at VERY low volume. I chalked it up to a bad op-amp but now I am not so sure.
To throw a wrench in it, the amp works FLAWLESSLY with NO noise using an LM4562 with a normal linear volume response as it is turned up and down. I have also tried an Analog Devices op-amp that also behaved fine.
FWIW, I did install the optional stabilization caps on the feedback loop.
Any ideas? Am I oscillating? I do have a scope but not sure how to test it and/or resolve it.