5E5 transformer?

[jmaf]

Looking at the 5E3 schematic, does this mean that I replace the 2 100K resistors from pins 1 & 6 of V1 with a single 47K to 56K and remove the jumper from pins 3 and 8 and add a separate 820R resistor from pin 3 to earth with a 25/25 cap in parallel?

He's suggesting you jumper pins 1 and 6 together then add a resistor about half of 100k connected there on either pin 1 or 6, the other end of that resistor goes to the preamp's filtered +B.

Yes, separate cathode resistors and bypass caps, thus you get a mixer - the two separate inputs will add up at the plate, one input will not see the other but the outputs mix together going into the tone stack. If I understood correctly.

[stephenhartley]

I tried it and there was hardly any volume on one of the channels. So I've put it back to the original circuit. I've wired the mic channel 68k pair directly to the tube base with shielded cables over to the sockets and this minimises the hum to an acceptable level. The amp sounds great - I'm using an RCA 5v4 and a pair of Russian military 6v6s. It's my first amp build so I'm quite pleased with it.

[Bruce / Mission Amps]

I tried it and there was hardly any volume on one of the channels. So I've put it back to the original circuit. I've wired the mic channel 68k pair directly to the tube base with shielded cables over to the sockets and this minimises the hum to an acceptable level. The amp sounds great - I'm using an RCA 5v4 and a pair of Russian military 6v6s. It's my first amp build so I'm quite pleased with it.

I guess my previous message was a bit cryptic....I've been doing this common anode, triode mixing thing for many years and it works perfectly.... there must have been a wiring error in your layout somewhere. However, if you are happy with what you have, then I wouldn't mess with it anymore.

[stephenhartley]

Yeah, I'm sure you're right. I struggled to work it out exactly. I left the plate wires on the board from V1 pins 1 & 3 then bridged them to one end of the 56K resistor. I removed the jumper between the cathodes and ran a separate 820R cathode resistor & 25/25 bypass cap to earth. The sizzle removal cap from the normal channel went. I probably did something stupid.