Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubenit on September 13, 2015, 06:00:22 am

Title: D'Mars SE (clean only) & FX loop
Post by: tubenit on September 13, 2015, 06:00:22 am

Guys, 

My D'Mars uses the CF as the "send" for the FX loop.   Think this would work on an SE version?  I might build this for a friend so he can use a 6V6 or 5881 in it. I've got a bunch of left over parts including a SE OT.

With respect, Tubenit

Title: Re: D'Mars SE (clean only) & FX loop
Post by: JJones on October 19, 2015, 10:36:02 pm

I've got a project under way that is based from some of your other post.

I'd love to see your ideas!

Jim

Title: Re: D'Mars SE (clean only) & FX loop
Post by: Fresh_Start on October 20, 2015, 12:08:43 am

Don't see any reason why it wouldn't work. Looks really neat.

Extra power rail filtering will help in a single-ended amp. An additional C-R-C or C-L-C pi filter before the plate node would be ideal.  C-L-C would be best but choke needs to handle total amp current.  An additional 20uf cap and 1K resistor definitely would help. Your power supply is pretty stiff anyway, and the power tube is cathode biased so it's drawing max current at idle. IOW no "sag" to speak of anyway. Choke between plate node and screen grid node next option.

Elevating heater ground also might help. I'd start with the power tube cathode but think about a higher reference voltage because of the cathode follower.

Chip

Title: Re: D'Mars SE (clean only) & FX loop
Post by: kagliostro on October 20, 2015, 12:59:15 pm

Ciao Tubenit

I will follow you with interest, keep us updated on this project


Franco