6G2 build!!!!

[Curranproducer]

SO I build a lovely little 6G2 princeton brownface yesterday using the classic tone 40-18019 power tranny, which kicks 650V w/70mA CT. Hitting the rec tube 5Y3 at 330V per side and it comes out at 406V and goes on down the line. for the schematic the is WAAAYYYYYYYYY to high. Everything thing aboot the amp is built to spec from the original fender schematic, only with beef on all the parts(F&T filter caps, 5watt drop resistors, and 1watt Vishay brown pill resistors, Orange Drop caps) all really good nice stuff. SO, the tone if pretty angry and blocky distortion sounding when you crank it. In addition if you slam the volume it get a UBER-compressed and yuck distortion(I think more blocking type) I am going to "assume" that the excessive voltage is making this happen. My plan is to put one resistor on each side of the HV(330V) PT at 25watts each BEFORE the rec tube, to limit the Voltage getting to the tube. I my head this should NOT affect the actual tone of the amp beyond getting it back to spec and getting me a REAL 6G2 voiced amp. let me know what all your thought are on this adventure! I have played it a bit and the tremolo is AMAZING!!!!!!!!

[ToneMerc]

Well something does not seem quite right considering you have 330V at the input to 5Y3. Is the rectifier a vintage 5Y3?

I would drop voltage with a Zener or 25W finned resistor in the HT center tap

TM

[Curranproducer]

does? or doesn't seem quite right? I agree. the spec for the tranny is 650V(325 per side) on the HV with a CT of 70mA's. so the tranny is in spec from classic tone. so popping a metal fin resistor ala trainwreck-ish-ness to bring it down would be fine? That Zener idea, what kind of spec would that require, and would I run that inseries with the CT to ground or something different?

[ToneMerc]

does? or doesn't seem quite right? I agree. the spec for the tranny is 650V(325 per side) on the HV with a CT of 70mA's. so the tranny is in spec from classic tone. so popping a metal fin resistor ala trainwreck-ish-ness to bring it down would be fine? That Zener idea, what kind of spec would that require, and would I run that inseries with the CT to ground or something different?

Sorry, does not. The PT voltage output you have would be correct for around 122V input. Nevertheless, if you have 330 at the rectifier you should not have 406V loaded for a true 5Y3. So again, is the 5Y3 that you used a true vintage tube?

TM

[pdf64]

I would expect bias shift and blocking distortion from overdriving that power amp, with it getting extreme at high trem intensity settings, even with the trem switched off.

Regarding the high HT, what idle current are the power tubes drawing? With saggy tube rectified supplies especially, as the idle current decreases, HT will increase; aka regulation.
Screen grid resistors may help with the buzz.

[Curranproducer]

OH NO, not vintage, it is a sovtek from CEDist. just a 5Y3GT.

[pdf64]

It's regrettable / unfortunate that they are labelled / marketed as 5Y3.

[johnnyreece]

I had one of those Sovtek tubes before. If I remember right, it's really just a 5AR4 with 5Y3 stamped on it...looks like that hasn't changed.

[Curranproducer]

awwwwwww boooooooooooooooooo, so what is my best solution? should I just diode rectify this amp then? I would like to get it to not have that blocking distortion on there, and to sound like a nice little "boingy" fender that also breaks up a bit when you dime it! hahahaha

[ToneMerc]

awwwwwww boooooooooooooooooo, so what is my best solution? should I just diode rectify this amp then? I would like to get it to not have that blocking distortion on there, and to sound like a nice little "boingy" fender that also breaks up a bit when you dime it! hahahaha

First, put a real 5Y3 in it and observe the voltage change.

TM

[Curranproducer]

the voltage kicks down to 387-ish with an old GE5Y3 it cleans up the blocking and all of that quite nicley

[ToneMerc]

the voltage kicks down to 387-ish with an old GE5Y3 it cleans up the blocking and all of that quite nicley

Solder free rectification (no pun intended) of the issue!

TM

[martin manning]

A JJ 5Y3 will match the vintage spec.

[Curranproducer]

I have had so much bad luck w JJ's I stopped buying them for builds and repairs. have they cleaned up their act a bit? what about working with what I have how would I want to run a zener diode in there?

[xtian]

I have had so much bad luck w JJ's I stopped buying them for builds and repairs. have they cleaned up their act a bit? what about working with what I have how would I want to run a zener diode in there?

Check out my implementation of the MOSFET B+ reducer. Really great stuff.