Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: rzenc on September 20, 2010, 11:32:18 am

Title: PEAVEY WINDSOR O.T.B.
Post by: rzenc on September 20, 2010, 11:32:18 am

A friend brought this to me, Peavey Windsor 100W. This is the first time he takes it outside his house. Never made a show, neither a rehearsal.
Here are the complaints:

1- 3 out of 4 EL34's are redplating - RUBY STR EL34;
2- The amp makes noises, like cracks;
3- Amp lost volume;
4- There is more distortion than before.

I checked voltages and bias. Everything looks fine. There are some suspicious solder joints which will be reflowed. There are pesky ribbon cables which makes noises by itself when you touch the solder joint with meter probe.
He asked me about changing it from EL34 to 6L6GC. The amp comes stock with EL34's. So I checked the schem to see if this was a plug and play mod. Schem shows pin 1 - supressor grid G3 - connected to bias supply thru 10K resistor. I thought about removing the mentioned 10K resistor from G3 circuit in order to use 6L6GC. Would it be the 'right' move??

Thanks in advance.
Best Regards,

Rzenc

Title: Re: PEAVEY WINDSOR O.T.B.
Post by: sluckey on September 20, 2010, 11:44:07 am

Quote

I thought about removing the mentioned 10K resistor from G3 circuit in order to use 6L6GC. Would it be the 'right' move??

I'd just leave the resistors in the circuit. The 6L6s won't care and the owner can switch back to EL34s if he wants to.

Title: Re: PEAVEY WINDSOR O.T.B.
Post by: rzenc on September 21, 2010, 12:29:34 pm

Thanks Steve!
I checked 4 different brands of 6L6GC tubes - modern production - and they don't have PIN 1 and PIN 6. So the mod is not necessary and your advice was right on!

Thanks a lot!
Best Regards

Rzenc