6G3 / 6G11 Build

[dr.barlo]

Hi guys,

I would like to ask for your feedback about an amp that I and a friend of mine are thinking of building (he is gonna be doing the "building" actually). We are at the stage about choosing parts and all.

The amp would have 2 channels, the first would be the bright of 6G3 and the second the bright of 6G11. It would have the vibrato as well. We are thinking of doing the amp with Hammond 370HX PT (275-0-275V with 200mA ... quite powerful!) and Allen Amps' TO40:

http://www.allenamps.com/parts.php#transformers

and again their bigger choke. The plate voltage with a Gz34 would like ~360V, and it'd be sorta "fluid" amp...

We thought that switching between JJ6V6 and TungSol 5881 for the 40/20W thing. Of course also being careful about the speaker taps. We are doing this, in order to have a bit more headroom and bass.

Any feedback?

I really would appreciate it.

Best,

B

[collinsamps]

My 2 cents

The channels are so similar that the sonic difference between them would be minimal at best. The switch between 6v's and 6L's will give you more headroom and less breakup, but at the same plate voltage you can expect minimal differences in tone.

If you are dead set on a two channel design, I'd personally pick the favorite between the two, or even a hybrid and use it for one side, and then do something tweed or blackface(or more dirt) for the other side to at least give you tonal options.

[dr.barlo]

Thanks for the feedback. I appreciate it.

The power amp section of a 6G3 and 5E3 are different no? Wouldn't I have to choose one if I were to go with you suggestion? (BTW I would love to do that! It is just that, I thought doing a 6G3/5E3 is sorta impossible -without using a crazy big relay-, because the power sections are a bit different.) The way we read it, the preamp section of the Browns is sorta identical or very similar with Blackfaces, and the difference lies in the differences in the negative feedback (with which I could play) and maybe more importantly, the plate voltage.

See?

Best,

B

PS I do not want to imply that I have some deep knowledge and all... In fact, I am well aware that I do not know sh*t when compared to folks here... Hence, would appreciate the feedback!

[collinsamps]

It depends on what you want to do with the tremolo circuit that feeds the output tube bias pertaining to the 6G3, but the major difference is fixed/adj or cathode bias. switching between the two is easy, as is building a fixed biased 5E3, or cathode biased 6G3. The plate voltage difference between the two isn't enough to make a big difference in overall tone.

Sticking with stock values, Its either going to have the headroom of a fixed bias amp, or the breakup of a cathode biased amp. Once you determine that, your tone is essentially defined and established by your preamp design.

[dr.barlo]

Thanks for the feedback. I am going to be checking this in detail.

B