'Jazz' switch for SFDR

[Bananafist]

I'm hoping someone can point me in the direction of a tone switch schematic to allow selection of the standard tone stack, and also give the option of a smoother,more even, perhaps jazzier sound, with less prominent, sweeter treble and some more mids. I have seen the H*D jazz switch schematic for a twin, but wondered if there were others. Does the H*D jazz switch mod do this?
Thanks

[Structo]

What is H*D?
Howard Dumble?

[Bananafist]

Sorry, yes it is Mr Dumble. I know on certain other forums his full name is not used, I'd forgotten that its not a problem on this one!
The kind of effect I'm after is similar to the jazz switch fitted on some Fargen Blackbird amps.

[ic-racer]

You could try this. (from the "Blue Guitar" site)

[Bananafist]

Yes, thanks 'ic', this is the one I was told was the Dumble mod - anybody tried it?
Are there any others?

[ic-racer]

anybody tried it?

Yes, I did : https://tubeamparchive.com/viewtopic.ph ... sc&start=0

[Firestorm]

If you aren't up for that much of a mod, rig a switch that can parallel a 56K resistor with the stock 100K slope resistor. Reducing the slope resistor value significantly boosts the mids.

Or wire the tone stack as a Baxandall/James stack. Very hi-fi, very jazzy. I could dig up some of the values I've used in mine if you want.

[Bananafist]

Thanks Firestorm,
I'll try the mod you suggested.
If you have the time, I'd certainly be interested to know more of your baxandall tone circuit, I've only seen these in hi fi articles, never related to fender amp mods.
As you probably gather, I'm not that experienced in amp building yet.
Thanks

[ic-racer]

Thanks Firestorm,
I'll try the mod you suggested.
If you have the time, I'd certainly be interested to know more of your baxandall tone circuit, I've only seen these in hi fi articles, never related to fender amp mods.
As you probably gather, I'm not that experienced in amp building yet.
Thanks

Here is a little article explaining amp tone stacks : http://amps.zugster.net/articles/tone-stacks

[Bananafist]

Hey,
Thanks IC racer, that is a really interesting piece, I've bookmarked it for further study!
I find I get so much help in this forum, its great. I hope one day I'll be able to put something back.

[Bananafist]

IC racer,
I read the thread on the super twin conversion you did - I am in awe!

With reference to Ed Jahns at Fender, in 'The Soul of Tone' book about Fender amps, after quite a bit of complimentary text, there is an anecdote of Joe carducci's which made me smile, and says something about the Fender design approach in the 70s.
Freddy Tavares was playing a strat through a cranked up prototype amp plugged in to a dual showman cab, and having a top of the voice very confrontational conversation with Ed Jahns. Freddy kept saying 'but it sounds terrible,' and Jahns kept saying 'but look at the scope - square waveform, its what the kids want....!

[ic-racer]

Glad you liked reading about the Super Twin Conversion.

In terms of a Jazz switch, here is another example.
I was looking for something else on the net and found this. Here is the page and the creator. http://www.qrp.pops.net/jazzamp.asp

Might be of relevance to this thread.

[Firestorm]

Thanks Firestorm,
I'll try the mod you suggested.
If you have the time, I'd certainly be interested to know more of your baxandall tone circuit, I've only seen these in hi fi articles, never related to fender amp mods.
As you probably gather, I'm not that experienced in amp building yet.
Thanks

Sorry this "Baxandall" schemo took so long to dig up. This isn't a pure Baxadall/James stack because it has a mid control and the cap and pot values were selected specifically to make it possible for it produce the characteristic Fender "mid scoop." As a result, the response isn't quite flat with the controls at 50%, but the sound is a little more "familiar" than true Baxandall/James stacks. Something else to play with.

[Bananafist]

Thanks for all the info and suggestions guys, its much appreciated, and probably enough to keep my experimenting for some time!
All the best