Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: bbirling on May 18, 2011, 01:40:06 pm

Title: One tube Reverb in a 6G6-B
Post by: bbirling on May 18, 2011, 01:40:06 pm

If Tubenit has a few minutes. I am looking at adding a one tube reverb to a 6G6-B circuit. I have been reviewing some of the circuits but could use a little assistance with the insertion point into the 6G6-B. Below is the circuit I have bee looking at.

Bruce

Title: Re: One tube Reverb in a 6G6-B
Post by: tubenit on May 18, 2011, 02:02:50 pm

This would be my first effort to do that with the presumption that I will need to tweak something. I probably personally would change the 470k mixing resistors to 330k or 270k as my first attempt also.

With respect, Tubenit

Title: Re: One tube Reverb in a 6G6-B
Post by: bbirling on May 18, 2011, 02:06:46 pm

Thanks for the quick response. I will give it a go and see what happens. May take a day or so.

Bruce

Title: Re: One tube Reverb in a 6G6-B
Post by: tubenit on May 18, 2011, 05:21:07 pm

You're welcome.  Please keep in mind that while I genuinely prefer the one tube reverb to the Fender reverb (I owned a PR), it's strictly a preference thing.   It is a more subtle reverb with a warmer and more mid-ly verb.

With respect, Tubenit

Title: Re: One tube Reverb in a 6G6-B
Post by: topbrent on May 19, 2011, 02:39:59 pm

Check out the Nocturne "blondshell" amp.

It is a 6g6-b with the 1 tube reverb.

Tavo Vega makes/sells this amp.

Perhaps you can glean some info from these pics

Title: Re: One tube Reverb in a 6G6-B
Post by: bbirling on May 19, 2011, 05:09:45 pm

Topbrent, nice photos very helpful.

However I wired it in but I seem to have 114V at the R2. Which I believe to be the first blade on the reverb pot. Via the 330K resistor. This dosen't seem right to me.

Bruce

Title: Re: One tube Reverb in a 6G6-B
Post by: tubenit on May 19, 2011, 08:20:06 pm

Quote

but I seem to have 114V at the R2

IF I am understanding you, that is NOT right at all.  Something is wired wrong or you have a defective cap somewhere or something?

With respect, Tubenit

Title: Re: One tube Reverb in a 6G6-B
Post by: VMS on May 20, 2011, 01:59:41 am

I think the problem might be on tubenits drawing. There is DC-voltage on the added 100k resistor because the 6G6-B doesn't have caps before 470k mixing resistors.


With respect,
VMS

Title: Re: One tube Reverb in a 6G6-B
Post by: tubenit on May 20, 2011, 04:48:26 am

Quote

I think the problem might be on tubenits drawing. There is DC-voltage on the added 100k resistor because the 6G6-B doesn't have caps before 470k mixing resistors.

I think you're right! Maybe reduce the 470k resistors to 270k or 330k and add a .02 after the juncture of the mixing resistors

With respect, Tubenit

Title: Re: One tube Reverb in a 6G6-B
Post by: bbirling on May 20, 2011, 07:16:41 am

That makes more sense. I will give this a shot sometime today.

Thanks for all the help.

Bruce