Maestro FZ-1B - schematic errors?

[Mark Hammer]

Going through the dreaded bin of unfinished perf projects last night and came across a board with this circuit on it.  It may not be that fabulous a fuzz but it's virtually done, and I have the later issue FZ-1S too, so I figured I take it down the home stretch.  Looks really close to being ready to install but I wanted to verify that what I changed was changed appropriately.

The "factory schematic" just doesn't look right, but I'm not knowledgable enough about discrete circuits to determine what the alternative ought to be.  In particular, the connection between C3 and R9/R11 just seems wrong. I'm guessing that the connection ought to be between C3 and R4 rather than going back to +9v.  Is my guess correct?  Or should the correct path be to just break the connection shown between C3 and +9v?  I'm sort of leaning towards the latter simply because there would be no other DC-blocking cap in the signal path if C3 was not connected to the R9/R11 junction.  Is there anything else drawn wrong here?

[mountainking]

Hey Mark, I seem to remember that you already mentioned the error in this schem alittle while back and I think, as mentioned before, that breaking the connection to 9v+ is probably all you need to do to get it working right. Best to just breadboard it first.

[R.G.]

At least the connection between C3 and +9 is incorrect. That's all that jumps out.

[jaytee]

R8 looks a bit high at 22k compared with 15k for R7 unless it's intentional mis-biasing?

[Mark Hammer]

Thanks for the feedback, gents.  Is the single diode correct or is it missing a partner?  Safe to assume its silicon?

[R.G.]

I'd try it with only the one diode as shown. There's precedence. Leave space beside it on the perf for another, and try it both ways maybe. Add salt to taste.

As to whether it's silicon - probably. Both would do something audible there, but there's no evidence I can think of that would separate the two with no more information than this.

[vanessa]

Hello Mark! Is this supposed to cop the tone of the original germanium version?

[Mark Hammer]

Don't know for sure, but probably not.  The FZ-1B uses the 2N3392 is as silicon-laden as they get (cousin of the 2N3391).  More than likely you are thinking of the FZ-1A, which uses 2N2613/2614 transistors, both of which are Ge types.  My guess is that the FZ-1B is "the disappointment" fuzz rather than the "satisfaction" one. 

[vanessa]

Now that's funny! 

I never really could get that tone with any of them (fuzztone's and clones). If Keef was using one like shown in schematics I think a lot can be attributed to it, the reverb (for sustain), amp and guitar on that track.

[sshrugg]

Is C3 connected to R7, or is that wire supposed to hop over?

I kinda want to make one, too : D

[Mark Hammer]

It hops over.

[g3rmanium]

The "factory schematic" just doesn't look right, but I'm not knowledgable enough about discrete circuits to determine what the alternative ought to be.

I have an FZ-1B and can send gut shots.



Also here are sound clips of the Maestro Fuzz-Tone FZ-1, FZ-1A and FZ-1B.

[sshrugg]

 

WOW, Johann!!! Can you send those when you're through with them? 

[g3rmanium]

WOW, Johann!!! Can you send those when you're through with them? 

I can take photos this evening.

[Sir H C]

Watch out, there are two completely different circuits for FZ-1Bs out there, that the two transistor version, and the 4 transistor version that is more common with the squealch control.

Here is a pretty poor shot of the insides of the 2 transistor one:



The dang thing won't open further because of the jack placement.

[jaytee]

I suspect R8 labeled as 22k is really 2.2k?

[sshrugg]

I can take photos this evening.

You rock.

Here is a pretty poor shot of the insides of the 2 transistor one:

You too!

[g3rmanium]

You rock.

Thanks, uploading photos as we speak.

[g3rmanium]

Maestro Fuzz-Tone FZ-1B photos

or alternatively on flickr.