Complete circuit/preamp tweaks for acoustic guitar pickup?

[Bananafist]

I have several tube amps, VVT Lindy Fralin, SFDR, homebuilt Tweed Deluxe clone,Quinn octal Derby, etc. Can anyone point me towards a circuit for a tube acoustic amp? Or failing that some tweaks to, say, the SFDR preamp to match it up better with an acoustic pickup.
The pickup is either a DiMarzio D139 soundhole model, or K&K mounted inside the guitar.

Thanks

[Bob-I]

A few years ago I built an amp for a friend who builds solid body acoustic guitars. http://www.electrocoustic.com/index.html

After a lot of breadboarding and experimentation I found that getting the purest tone for these beautiful instruments required a clean straight forward signal path. It's a simple 2 gain stage, single knob tone control which balances the signal through 2 caps. LTP into 2xEL-34 power amp. Also very important was limiting the gain in the various stages so each stage pretty much distorted at the same time. The amp can be run up to about 35 watts with no noticeable distortion in any stage and that's at about 3:00 on the volume knob.

The most important part of the amp was the speaker. We tried several but settled on an Eminence full range 12 with a whizzer cone. I don't remember the model right now.

[Bananafist]

Thats interesting, I had a Wendler system installed in an archtop acoustic.
Though I built my tweed deluxe clone, I was following a how-to article, so my theory knowledge is not extensive. Is the one tone knob/preamp similar to one channel of the tweed deluxe?
Phase inverter, etc, similar to usual, Fender style?
Do you still build the amps for Wendler, as they don't appear on his site, currently. Do you build them, or one like them, to sell?

Thanks

[BTF]

It's interesting that you brought up this subject. I just recently completed a rack mount acoustic preamp which functions as a blender/preamp for a Baggs M1 pickup and Schaller soundboard transducers. The preamp is based on the 5F6A topology, but the values of the components are tweaked for the individual pickups. It works very well at small room levels, but I have yet to try it in a live-sound situation. It uses a modified Bassman-style tonestack, so I use an outboard processor to limit feedback (fortunately, if you're careful, the preamp circuit design can help cull feedback tendencies).

Regards, BTF.

[Bob-I]

Thats interesting, I had a Wendler system installed in an archtop acoustic.
Though I built my tweed deluxe clone, I was following a how-to article, so my theory knowledge is not extensive. Is the one tone knob/preamp similar to one channel of the tweed deluxe?
Phase inverter, etc, similar to usual, Fender style?
Do you still build the amps for Wendler, as they don't appear on his site, currently. Do you build them, or one like them, to sell?

Thanks

The Wendler was a one time thing.

The phase inverter is a Long Tailed Pair, values tweaked for max clean headroom. You can't really say Fender style because they used several.

The tone control was similar but not exactly the same as a Tweed Deluxe but the PI and gain structure is completely different, plus it uses EL34's not 6V6's.

[Drumslinger]

Funny that this subject comes up because i was thinking of building an acoustic amp for my home studio.