Tweed deluxe half power options

[A.M.]

Hi everybody, I'm currently building a 5E3 amp and would like to incorporate a power/volume reduction feature. To give you a reference, my main current amp is a Victoria 5112, which is plenty loud for the type of gigs that I do (rockabilly, rhythm and blues, jazz).

More than actual volume reduction, I’m thinking more of a "headroom" reduction.
I know there are different master volume types or more advanced power scaling options available, but what I’m looking for is kind of a switch arrangement, that lets me knock down a few dBs when needed.
I'm not looking for bedroom level attenuation, what I would like is a low power option that I can activate to get the amp to distort at a comfortable stage volume level for small gigs. Believe it or not for some of the indoor gigs I play even the beefed up 5 watts that the Victoria puts out are too much (I don't play clean and I don't use pedals).

The closest thing to this I’ve tried so far was a Pentode/Triode switch, which didn’t sound spectacular, but sounded more musical than the various master volumes I’ve tried.

I’d be grateful if you had any input on that, thanks!
Arrigo

[martin manning]

Which master volumes have you tried? Based on what you're asking for, I'd think a fixed pre- or post-PI MV would work for you.

[A.M.]

Which master volumes have you tried? Based on what you're asking for, I'd think a fixed pre- or post-PI MV would work for you.

In various amps I tried both the "type 3" (single 1meg pot) and the "type 2" master volumes, but I didn't find them to be particularly good sounding : (

[bepone]

More than actual volume reduction, I’m thinking more of a "headroom" reduction.
Arrigo

use celestion rocket 50 like dumble, this is like reduced power 3x, and is nice sounding speaker

[martin manning]

Which master volumes have you tried? Based on what you're asking for, I'd think a fixed pre- or post-PI MV would work for you.

In various amps I tried both the "type 3" (single 1meg pot) and the "type 2" master volumes, but I didn't find them to be particularly good sounding : (

You could try a pre-PI MV then, replacing the 1M PI grid leak with a 1MA pot, and taking the wiper to the PI grid. This is a very easy and cheap experiment. The pot could go in the Aux. speaker jack hole, and you could probably get a finger in there to adjust it through the vent cut-out. Having added this feature you could do some things to overdrive the preamp like using a clean boost, or maybe try a higher mu tube in V1, like 5751 (70) or 12AX7 (100) instead of 12AY7 (40) in V1.

[A.M.]

Which master volumes have you tried? Based on what you're asking for, I'd think a fixed pre- or post-PI MV would work for you.

In various amps I tried both the "type 3" (single 1meg pot) and the "type 2" master volumes, but I didn't find them to be particularly good sounding : (

You could try a pre-PI MV then, replacing the 1M PI grid leak with a 1MA pot, and taking the wiper to the PI grid. This is a very easy and cheap experiment. The pot could go in the Aux. speaker jack hole, and you could probably get a finger in there to adjust it through the vent cut-out. Having added this feature you could do some things to overdrive the preamp like using a clean boost, or maybe try a higher mu tube in V1, like 5751 (70) or 12AX7 (100) instead of 12AY7 (40) in V1.

Interesting, I might give it a try. Thanks for the layout!

While searching on the web I found this video: https://www.youtube.com/watch?v=wnnA2Cqs9cs
That sounds nice, at it looks exactly like the type of low power switch option I would love to have on my amp... I wonder how he does that!

[sluckey]

Look at Da Geezer’s Bypass Cap attenuator on page 6 of my Amp Scrapbook. I've not tried it but several others did about 15 years ago when Da Geezer first posted this circuit. I don't remember the comments about it but it's easy to try.

[A.M.]

Look at Da Geezer’s Bypass Cap attenuator on page 6 of my Amp Scrapbook. I've not tried it but several others did about 15 years ago when Da Geezer first posted this circuit. I don't remember the comments about it but it's easy to try.

Thanks Sluckey, I'll check it out!

[Stevem]

You might find some interest in visiting the London power site and checking out there power scaling kit.

You would likely want to check out there SV2 kit.

[A.M.]

You might find some interest in visiting the London power site and checking out there power scaling kit.

You would likely want to check out there SV2 kit.

Interesting, it looks like the same type of power scaling offered on the Surh Badger amp. It's a bit more involved than I wanted but I'll check it out, thanks!

[A.M.]

Look at Da Geezer’s Bypass Cap attenuator on page 6 of my Amp Scrapbook. I've not tried it but several others did about 15 years ago when Da Geezer first posted this circuit. I don't remember the comments about it but it's easy to try.

Hi Sluckey, is this the correct way to implement the bypass cap circuit shown in your amp scapbook? I'm a total novice so it's likely that I'm not understanding it right.

[sluckey]

Hi Sluckey, is this the correct way to implement the bypass cap circuit shown in your amp scapbook? I'm a total novice so it's likely that I'm not understanding it right.

Basically right, but you must remove the wire connecting pin 8 of the two tubes. And there will be no wire between pin 8 and the board.

[A.M.]

Hi Sluckey, is this the correct way to implement the bypass cap circuit shown in your amp scapbook? I'm a total novice so it's likely that I'm not understanding it right.

Basically right, but you must remove the wire connecting pin 8 of the two tubes. And there will be no wire between pin 8 and the board.

Thanks Sluckey, I think I'm starting to get the gist of it: instead of a single 250 ohm bias resistor shared by both output tubes, each tube gets its own 500 ohm resistor (since bias resistor value has to be two times the value of a single resistor, according to your scrapbook). Do you think this layout would work well for the tweed deluxe?

[sluckey]

Layout is fine. You may want to see if you even like this circuit before drilling a hole to mount the switch.

[LOUDthud]

See if you can find an Eminence "Maverick" speaker. As you twist the magnet structure on the back, (I know this seems weird) you can dial in about 8.5dB of attenuation.

Link to info: https://www.sweetwater.com/store/detail ... hm/reviews