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This board (REV D with 5AR4) is part of a problem child that I think I've beaten almost into submission; however my left channel ( as you look at it from the front w/ the V1/V2 closest to you) is quieter than the right.

I have changed out all the tubes, seemed to make a difference. also, I biased it to 310mv (for some reason the highest I could get on one tube w/in the L channel is 317mv - related? - even after changing)

I had spades for the speakers and dropped those for bare wire connections. I am going to resolder some of the OPTs wires to better connectors (was using crimp so I want to eliminate that possibility - my crimper is horrible, anybody know of a good crimp tool - mine (also strips - sometimes) was $2 and it shows).

With alot of the trouble that I had earlier (see http://www.diytube.com/phpBB2/viewtopic.php?t=4506 question in the hifi section)

The caps I am using in the C1-C4 are non-standard. ,1uf 630v (Russian oil caps) The rest are normal.

I'm going to resolder and then take voltages to see if that gives any clues.

Ideas where to start or an idea on what could be the culprit?

Thanks

Erick

77seriesIII wrote:my crimper is horrible, anybody know of a good crimp tool?

I bought this one from Harbor Fright. Surprisingly, it works pretty darn good.
http://www.harborfreight.com/ratcheting ... 97420.html

Checking for correct voltages is a good idea. At least make sure the voltages on the left channel match the right. While you have the amp powered down, it's probably a good idea to go over every resistor with an ohmeter and check it against the schematic.

You might also consider swapping out the 'X7 and 'U7 for known good tubes, if you've got them.

Good luck!