Rewiring V1 for full use of both triodes?

[JDW3]

I have a Traynor Bassmate that uses half of V1. I'm trying to find a schem to copy, just to have a little bit more gain. Everything I've seen is kind of close. A 5E3 Deluxe has 2 volume pots from it's V1. On a single volume amp, how do I wire this?

The bassmate has 2 input jacks, volume, bass and treble. Tubes are 2 12ax7 and 2 6v6.

It's a bass practice amp and I just want to get it into guitar territory.

It does sound simple! I just want it right the first time.


http://rawsoulfolk.com/images/YBA-2A...A-Web-TEXT.jpg

[JDW3]

Can I run both sides of the tube from one R/C setup? Join or parallel the triodes?

[chocopower]

Hi.

you must tie together pins:
1-6
2-7
3-8

halve the value for the plate resistor (R8. 100K to 50K) and for the cathode resistor (R4. 1K5 to 820).

Teory said you must double the value in the cathode cap (C1), but if it is 22uf or more, you are not going to ear any change in sound.

I make something similar in a Bassman blackface with good results.

Adios!!

[Bruce / Mission Amps]

Originally Posted by JDW3

I have a Traynor Bassmate that uses half of V1. I'm trying to find a schem to copy, just to have a little bit more gain. Everything I've seen is kind of close. A 5E3 Deluxe has 2 volume pots from it's V1. On a single volume amp, how do I wire this?

The bassmate has 2 input jacks, volume, bass and treble. Tubes are 2 12ax7 and 2 6v6.

It's a bass practice amp and I just want to get it into guitar territory.

It does sound simple! I just want it right the first time.


http://rawsoulfolk.com/images/YBA-2A...A-Web-TEXT.jpg

Are you trying to get two channels with two separate volume pots or use the other triode in cascade (with a new volume pot) for TONS of preamp overdrive?
Is the schem for a YBA-2a/b what you are looking at?

[JDW3]

Originally Posted by Bruce / Mission Amps

Are you trying to get two channels with two separate volume pots or use the other triode in cascade (with a new volume pot) for TONS of preamp overdrive?
Is the schem for a YBA-2a/b what you are looking at?

Yes, that is the schem. I don't need tons of overdrive, or the second volume pot.

I was hoping I could just somehow use the other half of the 12ax7 for added power basically. It's a simple amp; volume, bass and treble. Looking at the 5E3, it appears pretty close. But maybe not? I guess that's why I'm here!

I want to power the tube up, and then just change a couple caps and resistors to get more guitar frequencies out of the bass amp. That much is pretty clear to me. I want to power the tube up correctly. That's where I'm stuck.

Bruce, is it possible to do this without cascading?

[JDW3]

Originally Posted by chocopower

Hi.

you must tie together pins:
1-6
2-7
3-8

halve the value for the plate resistor (R8. 100K to 50K) and for the cathode resistor (R4. 1K5 to 820).

Teory said you must double the value in the cathode cap (C1), but if it is 22uf or more, you are not going to ear any change in sound.

I make something similar in a Bassman blackface with good results.

Adios!!

I ended up not joining the 2 triodes. I did reduce the Cathode resistor to 820 from 1500 ohms.

I raised the plate resistor to 150K from 100K.

Any harm in this? In theory, should the plate resistor have been reduced? I know the tube should be "biased", but I'm not sure how to do it. Is biasing a preamp tube mostly a hifi thing to do? I'm going by what I have been reading on the internet.

FWIW, the amp sounds great. I reduced the coupling cap to .022 from .1. Also brought the slope resistor down from 220K to 47K. So, lots more mids. Kinda tweedy, although I've never had a tweed amp!