Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: worth on November 23, 2012, 08:07:11 am

Title: Dougs "adding reverb" to Western Electric circuit ?
Post by: worth on November 23, 2012, 08:07:11 am
I'd like to add reverb to a 5F6-A , BUT I don't want the additional gain that you find with this circuit on later Fenders. Would this reverb circuit boost the gain in Tweed amps ? I'm assuming I'll have to go the 1-tube reverb route if I don't want the added gain.
Title: Re: Dougs "adding reverb" to Western Electric circuit ?
Post by: clyde on November 23, 2012, 09:06:55 am
No added gain.
Title: Re: Dougs "adding reverb" to Western Electric circuit ?
Post by: TIMBO on November 23, 2012, 03:30:45 pm
I'll second that, I've added REVERB to all my builds and 1 or even 1 1/2 tube verbs don't add any extra gain and all sound great.  :icon_biggrin:
Title: Re: Dougs "adding reverb" to Western Electric circuit ?
Post by: HotBluePlates on November 23, 2012, 09:26:31 pm
I'd like to add reverb to a 5F6-A , BUT I don't want the additional gain that you find with this circuit on later Fenders. Would this reverb circuit boost the gain in Tweed amps ?

This reverb circuit isn't the same as what's in a blackface and later Fender amp.

And despite what Gerald Weber says, those won't necessarily have more dry gain. And if they do, there's a simple way to trim it back.

Regardless, note that this circuit ditches 1 channel if you start with a 5F6-A Bassman. If you're starting with a different amp, you'll have to look at how the reverb circuit is added and adjust to suit your amp.
Title: Re: Dougs "adding reverb" to Western Electric circuit ?
Post by: sluckey on November 24, 2012, 07:44:12 am
Here are two approaches that are specific to adding reverb to the 5F6A or Plexi. Neither of these circuits use an additional gain stage in the dry signal path like the AB763 (and later) Fender designs.

The attached pdf is Doug's "Add Reverb to the western electric circuit " as applied to his Plexi-50 design. It also includes the schematic so you can see how it operates. This was part of a project that bnwitt and I were working on at one time. This circuit design sacrifices one of the Plexi channels and requires an additional tube.

The jpg shows another approach to adding reverb to a 5F6A or Plexi. I don't recall where I picked up this circuit. This design requires two additional tubes but does not sacrifice either of the Plexi channels.

If you would be satisfied with a good sounding reverb that doesn't get into surf territory, consider Tubenit's one tube reverb. You may even find a schematic specific to the 5F6A.

Title: Re: Dougs "adding reverb" to Western Electric circuit ?
Post by: tubenit on November 25, 2012, 05:51:37 am
Regarding the "one tube" reverb.

Look in ARCHIVES.

Regarding adding to a 5F6-A,  Look at Plexi 25w with reverb  in the SCH library of schematics.

With respect, Tubenit