DIY amp attenuator for Fender Hot Rod Deluxe

[WholeLottaDimitri]

I'm looking into building an amp attenuator as a summer project.
Can anyone recommend a schematic or something that will be compatible with my fender hot rod deluxe?

[aron]

Something like this will work. Over the years we found that regulator resistors work fine for the sound.
http://www.regiscoyne.com/ampoline/

You can also use the "motor" of a speaker like the MASS:

http://www.diystompboxes.com/smfforum/index.php?topic=16235.0

IMO the resistor will work ok and be easy to build.

[GibsonGM]

I have a HRDx too, and want to try Yellowjackets some time.  They adapt your output tube sockets to take EL84s (and bias them too), which have far less gain that 6L6s.  Therefore, they turn your amp into about a 20W instead of 40W.      Might be work looking into...

[midwayfair]

I have a HRDx too, and want to try Yellowjackets some time.  They adapt your output tube sockets to take EL84s (and bias them too), which have far less gain that 6L6s.  Therefore, they turn your amp into about a 20W instead of 40W.      Might be work looking into...

You can run JJ 6V6s (has to be JJ or you'll fry the tube) to knock it down to about 20W as well, with no other changes to the amp. It's a lot cheaper than the yellow jackets and won't drastically change the character of the output section.

I use a voltage starver (Hall Device) in mine, I liked it better than any other type of attenuator.

[GibsonGM]

I have a HRDx too, and want to try Yellowjackets some time.  They adapt your output tube sockets to take EL84s (and bias them too), which have far less gain that 6L6s.  Therefore, they turn your amp into about a 20W instead of 40W.      Might be work looking into...

You can run JJ 6V6s (has to be JJ or you'll fry the tube) to knock it down to about 20W as well, with no other changes to the amp. It's a lot cheaper than the yellow jackets and won't drastically change the character of the output section.

I use a voltage starver (Hall Device) in mine, I liked it better than any other type of attenuator.

Really? I've 'heard a rumor' about that (probably on the old Justin Houlton site), but can't figure out what the difference is with the JJ 6V6s vs. others.   Do ya know what's different?

[Tall Steve]

The JJ's are more like a low wattage 6L6 rather than a 6V6.

[Tall Steve]

Also, IIRC, Yellow Jackets run EL84s in triode mode instead of pentode. I don't know the technical details, but I believe I remember reading somewhere that was the only way they could work with the mechanism they do.

[GibsonGM]

Also, IIRC, Yellow Jackets run EL84s in triode mode instead of pentode. I don't know the technical details, but I believe I remember reading somewhere that was the only way they could work with the mechanism they do.

Yup, I think you're right.   They sound pretty good, for what they are, but are not (to me) like 6L6's or 6V6's. 

I have thought a couple times about maybe power scaling the HRDx, but haven't taken it farther than that.   Wonder if there's any promise in that?

[Tall Steve]

Power scaling only scales the power section. I think a VVR system would be more flexible IMHO. If the chassis of the HRDx is anything like the Blues Dlx internally, there should be enough room to mount a VVR internally. You could put it in as a sort of 'set and forget' to lower the B+ south of 400V and re-bias for 6V6's or 5881's .