(Can) You Make My Dreams Come True! (?)

Coda

Well-known member
When I was young (20 years ago, or so), I got into The Doors. At the time (Sophomore) I thought that I was into some proper adult/mature music. As a result, I became a fan of the tones of Robby Krieger, especially his fuzz tone. For ages I was under the assumption that he used a Maestro FZ-1A...because he had said as much. Then, one rainy night (for dramatic purposes, anyway) I discovered never before seen (by me) photos of a concert at some place called The Hollywood Bowl. What did I see?....a Vox Tonebender. So what did he use? Maestro? Vox? The question haunted me, and still does to this day. I have come to the conclusion that the Maestro was never used by the Doors in the studio. The Tonebender was definitely used live, and probably in the studio. However, while the Tonebender nails the solo tone in My Eyes Have Seen you, it is nowhere near Hello, I Love You. In fact, the fuzz tones on the Waiting for the Sun album (as well as The Changeling, on LA Woman) sound nothing like the Vox Tonebender. What, then, is the mystery fuzz? Krieger himself is no help. In recent interviews (within the last year) he can only vaguely remember using a fuzz pedal, let alone which one it was specifically...

A month or so ago, I found a clue. Last October, I became the proud owner of a 1972 Acoustic Control Corp. 134, 4x10 combo amp. I then dove into the history of the company, and searched for ads, manuals, etc. I had known that the Doors used Acoustic amps live for a while (260), and never thought anything of it. Thing is, the Acoustic 260 had on-board fuzz.


There it is...the mystery fuzz tone. It is my hypothesis that Robby Krieger, beginning in 1968, used the Acoustic 260 in the studio for the fuzz tone...

So mystery solved. But that's not the end of the story. Now I'm obsessed. I would love to get a 260. Not particularly feasible at the moment, due to both price and availability issues. However, I do have a schematic. And in that schematic is the mystery fuzz. Attached you will find the fuzz section of the circuit. The issue is, however, that the things is just too damn blurry. I have done my best to identify the various components. My goal is to breadboard this circuit. But I need some help. Below is the BOM as best I can figure:

Resistors:
R30 - 22k
R31 - 100k
R32 - 470k
R33 - 680k
R34 - 22k
R35 - 1M
R36 - 100k
R37 - 47k
R38 - 22k
R39 - 6k8
R42 - 1M
R44 - 10k
R45 - 100k

Capacitors:
C21 - 100n
C22 - 100n
C23 - 150n
C24 - 100n
C25 - 100n
C26 - 2n5
C27 - 1n
C28 - 1u
C29 - 100u
C30 - 1u

Transistors:
Q8, 9, 10 - 2n3391 (maybe?)

Attack - 500k
Gain - 500k

I'm sure there are a few things that aren't necessary (Q7?), and I guessed on the transistors. This is where I could use an extra set of eyes. Another thing that jumps out is that, as you will notice (or not, there is no guarantee that anyone will bother), there is 25v at the power rail. If I were to try this as a pedal circuit, and went with the standard 9v, would I have to change some of the component values?

So...I could use an extra set of eyes with this. Who knows, this could turn into a Big Monk-esque PCB giveaway (just the giveaway part, not the "mod everything not nailed down," nor the endless revisions). I'll post the full schematic once I find a place to host a .pdf...
 

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I know nothing about this amp but after a quick search I found this about the 360 - http://moosapotamus.net/ideas/acoustic-360-bass-fuzz/

Are they similar? This may be a good reference point.
I believe the 360 was the exact same amp, but with one channel and more power, as it was intended for bass. Frank Zappa used one in his early-70's rig. That schematic matches with the version for the 260. So that helps tremendously. Looks like that one lists the transistors as 2N2906 (Q8 and Q10), and a 2N1306 for Q9. Q's 8 and 10 do not look like 2N1306 on the 260 schematic, from what I can tell.
 
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i built the moosapotamus 360 bass fuzz with substitutions : Q3 12N1306 ( ge. NPN 60-300 Hfe) = 2N2369A (si. 40-120 Hfe)

It' s great and I strongly recommend it as a "vintage" fuzz sound, I wonder how it would be with a 12N1306 ge. Do you think it's a big difference ?

Edit : I found a good combo connecting it before a Bass Amuser circuit, then cutting some mids with a Tech21 VT bass DI acting as preamp.

build report : https://www.diystompboxes.com/smfforum/index.php?topic=36392.29620 reply #29636
 
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i built the moosapotamus 360 bass fuzz with substitutions : Q3 12N1306 ( ge. NPN 60-300 Hfe) = 2N2369A (si. 40-120 Hfe)

It' s great and I strongly recommend it as a "vintage" fuzz sound, I wonder how it would be with a 12N1306 ge. Do you think it's a big difference ?

Edit I found a good combo connecting it before a Bass Amuser circuit, then cutting some mids with a Tech21 VT bass DI acting as preamp.

build report : https://www.diystompboxes.com/smfforum/index.php?topic=36392.29620 reply #29636

That looks intriguing. There are a few things there, though, that I think are a bit overkill for a guitar pedal...mainly the blend. I totally get its purpose in a bass fuzz, though...
 
You reminded me that i didn't try it on guitar yet.

I just did and it's great too ! Splattery, crackling, squishy and fat... I compared with the closest thing I have in hands : a BM Ram's head set with 2 leds as clipping diodes : 360 fuzz sounds less compressed, more "vintage". Then, I tried both at the same time, 360 before BM, and... wahouuu... this is it !
I wouldn't get rid of the clean control, it's quite useful : It fattens the guitar signal and the fuzz sound going CW. CCW I only have the fuzz setting i dialed, which is great but very tight, like some useful frequencies has been cut.

I will give you sound samples if you want, recording on an RC-3. I won't go through the trouble if you don't really care though...
 
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You reminded me that i didn't try it on guitar yet.

I just did and it's great too ! Splattery, crackling, squishy and fat... I compared with the closest thing I have in hands : a BM Ram's head set with 2 leds as clipping diodes : 360 fuzz sounds less compressed, more "vintage". Then, I tried both at the same time, 360 before BM, and... wahouuu... this is it !
I wouldn't get rid of the clean control, it's quite useful : It fattens the guitar signal and the fuzz sound going CW. CCW I only have the fuzz setting i dialed, which is great but very tight, like some useful frequencies has been cut.

I will give you sound samples if you want, recording on an RC-3. I won't go through the trouble if you don't really care though...

Clips would be appreciated.
 
Clips would be appreciated.

This is based on an Acoustic 260 Amp Fuzz


hph5z8q6exbjsmcymq76.jpg
 
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Ok i am done. I ended up recording a whole song's outlines, I thought it would be best to get this circuit in a musical context. I did simple things though, nothing fancy or very complex. Tracks are splitted : one side is drum line & bass, other is guitar alone with drums. (you can pan between one or the other for a more accurate listening). I hurried the process, transitions are... there aren't any transitions. Please enjoy, and turn up the volume ! IMG_20220501_055141.jpg


4 movements bass & guitar. Everything is done with Moosapotamus circuit, I really tried to preserve the 360 sound all the way, except in the end, for the guitar ( BM). GE-7 is flat, only used as volume pedal (no volume pot on 360 fuzz, and it was too loud).

Bass =

1/ 0 : 12' = 360 acting as preamp all controls CCW, Clean CW
2/ 0 : 37' = boost (out of the picture, Musikding Bass Overdriver) + preamp mod
3 & 4/ 1 : 20' = Fuzz + enveloppe filter (Aion Spectron) and Fuzz only

Guitar =

1/ Fuzz (Clean CCW = full effect)

2/ chords neck pickup + fuzz w/ Clean CCW

3/ notes w/ Clean at 12' , with and without boost. Then (1: 53')chords w/ Clean fully CW (more clean signal).

2: 20 = notes w/ clean CW with and without boost (Aion Sapphire = BD-2 w/ Galaxie mod, that's a big mod).

2 : 35 = chords with clean CW : I select the bridge pickup while playing. Higher notes played with and without enveloppe filter reverse wah, over the chords (i like this part).

3 : 18' = chords with Clean CCW

4/ 4 : 00' = Big Muff Ram's Head alone and then 360 Fuzz into Big Muff until the end.
 
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Ok i am done. I ended up recording a whole song's outlines, I thought it would be best to get this circuit in a musical context. I did simple things though, nothing fancy or very complex. Tracks are splitted : one side is drum line & bass, other is guitar alone with drums. (you can pan between one or the other for a more accurate listening). I hurried the process, transitions are... there aren't any transitions. Please enjoy, and turn up the volume !View attachment 25806


4 movements bass & guitar. Everything is done with Moosapotamus circuit, I really tried to preserve the 360 sound all the way, except in the end, for the guitar ( BM). GE-7 is flat, only used as volume pedal.

Bass = 1/ 0 : 12' = 360 acting as preamp all controls CCW, Clean CW
2/ 0 : 37' = boost (out of the picture, Musikding Bass Overdriver) + preamp mod
3 & 4/ 1 : 20' = Fuzz + enveloppe filter (LectricFX Spectron) and Fuzz only

Guitar = 1/ Fuzz (Clean CCW = full effect)
2/ chords neck pickup + fuzz w/ Clean CCW
3/ notes w/ Clean at 12' , with and without boost. Then (1: 53')chords w/ Clean fully CW (more clean signal).
2: 20 = notes w/ clean CW with and without boost (Aion Sapphire = BD-2 w/ Galaxie mod, that's a big mod).
2 : 35 = chords with clean CW : I select the bridge pickup while playing. Higher notes with and without enveloppe filter, over the chords (i like this part).
3 : 18' = chords with Clean CW (full effect) Bridge pick up died here...recording with an other guitar, Seymour Duncan bridge pickups.
4/ 4 : 00' = Big Muff Ram's Head alone and then 360 Fuzz into Big Muff until the end.

A strange thing happened toward the end of the recording. EMG (81 or 85) bridge pickups stopped responding, no sound, only neck pickups are working now... I changed the battery but it's still the same. Any idea why ?

Very good, thank you for that. It definitely has that vintage fuzz vibe. Looks like I'll have to try this on the breadboard.
 
Very good, thank you for that. It definitely has that vintage fuzz vibe. Looks like I'll have to try this on the breadboard.
Sorry to ping such an old post but found this again digging through my bookmarks this morning. Were you ever able to test the schematic you found for the 260?
 
Sorry to ping such an old post but found this again digging through my bookmarks this morning. Were you ever able to test the schematic you found for the 260?

Of course not. I put it on hold while I searched for the transistors, and never got back around to it. Maybe I’ll start a gofundme for that Creepy Fingers version…
 
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