Recent content by RussB

Looks really good!

I bought a used '89 back in '91 or so. I had that amp for 16 years. I had to sell it (and a lot of other gear) when my son had health issues and we needed the money more...

I notice that photophuckit hijacked my pictures, so I'll repost... I installed a bias pot in my Single Recto today. I used a 50k pot with a 1/2 watt 47k resistor in parallel with the two outside legs. Leg 1 and 2 of the pot are tied together. I used the legs of the resistor to attach the pot...

FWIW, I recently bought a 5-25+ head. I have an Ampeg 1-12 open back cab, and installed a Celestion G12-35XC. It is a very even speaker but retains the Celestion character. The Celestion A type sounds great in the clips I've heard, being a smoother, darker speaker.

What's NOT to love! The flames are a nice touch

Here it is. I've been trying it though all my cabs. So far I'm liking the Lopo 2-12 (looks like a recto cab) with an M65 Creamback and an M75-65 Scumback. It's been a fun day!

Play loud and often, and that V30 will sound better and better. It also works well in the context of a band

All I know is I got a great deal on a 5-25+ from Humbucker :mrgreen:

That would last about 5 minutes in the MKV

And I figured, in for a penny, in for a pound! I bought all the components in the switching and mute circuits. Even in multiples of 10, it cost less than $30 delivered from Mouser.com Tonight I replaced the 4N33 IC, 4 2N6426 and 2 J175 transistors. Noise is gone. Life is good

I wrote this while the board was down... And of course, you are correct. Swapping the relay did nothing to eliminate the buzz/hum that is entering the circuit. I see the noise on pin 1 and 8 of V3, pin 6 of V4 and of course pins 1 & 6 of V5 where the noise is carried into the power tubes...

I had a 22+ for 15 years, and tried many speakers. The EVM12L was awesome in that amp. I also really liked the Weber Silver Bell 50w ceramic.

As mentioned, I am not sure if it is the relay. The issue lies around relay1b. The amp has a 120hZ hum/buzz being introduced in the first gain stage. It increases as you switch through the 5 modes. The 100 ohm resistor after RY1b and before V1b is hyper sensitive. The relay itself is hyper...

Thanks for the tips. I wouldn't unsolder all the pots, just unscrew them. My single rec no longer has the PCB power tube board. The sockets are now attached to the chassis which will make things a real challenge

I don't know for sure, but I'm not going "in" without a new relay available. I can't see a way to solder/unsolder the relay without removing all the pots from the face and lifting the board up. I did order 2 relays from Mesa today