Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: sclinchy on July 06, 2012, 09:00:34 am

Title: Single Channel 6G6
Post by: sclinchy on July 06, 2012, 09:00:34 am

Anyone have a schematic and/or layout for a single (Normal) channel Blonde Bassman 6G6?  Extra credit if it's got reverb!

Title: Re: Single Channel 6G6
Post by: sluckey on July 06, 2012, 10:06:31 am

Here you go. No extra credit please...

Title: Re: Single Channel 6G6
Post by: phsyconoodler on July 06, 2012, 10:11:22 am

I did one of those a while back.If you simply cut out the portion of the layout you don't need and graft in an AB763 reverb circuit you are done.

  Just take sluckeys layout and move V1 to the right,add the AB763 reverb circuit with two tubes and graft it in at the phase inverter.Fender circuits are easy that way.
 I will show you a picture of mine if I can figure out how to convert my photo into a drawing that will upload.

Title: Re: Single Channel 6G6
Post by: tubenit on July 06, 2012, 11:50:42 am

IF you are NOT looking for surfy reverb ........ you could consider doing a one tube reverb which is quite easy:

http://www.el34world.com/Forum/index.php?topic=7957.0 (http://www.el34world.com/Forum/index.php?topic=7957.0)

With respect, Tubenit

Title: Re: Single Channel 6G6
Post by: jonathan_kea on April 22, 2025, 12:43:11 pm

Would it be possible to build one of these with a 5U4 rectifier tube? I have two old tube organ chassis that run two 6G6's and would like to repurpose. The PT primaries read 335v AC to the 5U4 on the organ schematic i have.

Title: Re: Single Channel 6G6
Post by: TIMBO on April 22, 2025, 02:28:10 pm

Sure will!

Title: Re: Single Channel 6G6
Post by: jonathan_kea on April 22, 2025, 03:48:58 pm

It looks like the 5u4 is rated at 3 amps vs the Gz34 being rated at 2 amps, so my thinking is that the original power transformer should be able to handle it. But a transformer manufactured for the Gz34 may not be able to handle a 5u4.

Title: Re: Single Channel 6G6
Post by: TIMBO on April 23, 2025, 03:17:17 am

That's correct

Title: Re: Single Channel 6G6
Post by: jonathan_kea on April 23, 2025, 03:53:40 pm

What does the diode circuit/arrangemenr  coming off of the enter tap associated with the Gz34 do? I am not sure i've seen that before

Title: Re: Single Channel 6G6
Post by: AlNewman on April 23, 2025, 04:44:16 pm

Might be best to find a schematic for the organ you're repurposing.

I think you're talking about the bias circuit, which in the above schematic is fixed bias.  Your organ may be cathode biased, or already have a dedicated winding for fixed bias.  It might be better, (and likely easier) to use your existing power section and PI, and modify the preamp only.

Title: Re: Single Channel 6G6
Post by: jonathan_kea on April 24, 2025, 09:01:09 am

That makes sense! My princeton reverb has fixed bias.