trinityamps.com

Hello

I have a late '80's early '90's Fender "Red Knob Twin" that I really don't play ever since I built by 18watt. There are a lot of mixed reviews on this amp. They are known for having a lot of issues and the tone seams to be a love/hate thing.

Personally I find it too clinical sounding. It's missing that vintage vibe. It's really not worth selling since they seem to sell for around $400.

I am seriously considering gutting the chassis and transplanting a Bassman 5F6A circuit. I think I could do this and reuse some of the existing parts. I might be able to reuse the Power Tranny and choke as long as I add a separate small transformer for the 5V rectifier heater.

Before I take such a radical step I am considering trying a GZ34 rectifier in place of the current SS to see if this will add some "sag" and therefore sound less clinical. I only run the amp with 2 of the 4 6L6's so I have the extra tube socket. I will never use all 4 because I don't need that much power. I think the GZ34 will do for 2 6L6's ala Bassman.
This way If I still don't like it I can gut the amp and do the Bassman or even Tweed Twin thing.

Now comes the question. Do I just basically just substitute the 4 rectifier diodes with the GZ34 and re-bias??

You could do the solid state/tube rectifier on a switch thing.

Personally I would sell the amp for 400$ and that would allow you to get most if not all the parts to start a scratch build. It would probably save you a lot of headaches.

Ya. The more I think about it the more I am leaning toward gutting the amp. I can reuse tube sockets, chassis, cabinet, speakers and switches. I would just need board, pots, sockets and tranny's. It would cost me more than $400 for new tube sockets, chassis, cabinet, speakers and switches.

I have been studying the 5E8A and 5F6A circuits. Leaning toward the 5F6A.

You could start here...
http://www.turretboards.com/

These guys are a great source as well...
http://www.tubesandmore.com/

Be sure to post pictures of the project

Joe G

_________________
Some assembly required,
Brain sold separately...

Thanks.

I will start a new thread and post pictures of the build. It will be a slow build as I will be purchasing the parts a bit at a time. I have decided on the 5F6A Bassman circuit.

I have decided on the following components.

Hammond PT (available locally)
MM Choke and OT
5F6A Eyelet board from turretboards.com
Sozo Blue Molded coupling caps
Resistors and caps from multiple sources
Chassis, Sockets, Switches, Speakers, Cabinet reused from Twin (I may make a new speaker baffle board out of 5/16 pine to get some Bassman mojo)

Make sure your GZ34 can handle the filtering the SS recto had stock. I forget now without looking at the datasheet but I think a GZ34 can handle 33mF on the input filter.