FZ-1B observation.

[digi2t]

I came across this FZ-1B on the Bay, the seller is nice enough to post a pic of the schematic inside. Take note of the two resistors next to Q4, the 680K and the 3.3M;



Intrigued, I did a little more research, and the I found this. Again, note the same two resistors;




HUH? 

Whazzap with that? Typo? or production mod?

[Govmnt_Lacky]

Whazzap with that? Typo? or production mod?

Why would you think it's a typo  

EDIT: NEVERMIND! Duh 

[Mark Hammer]

Damn near a decade back, forum member Rick Lawrence sent me a wad of Maestro "factory" schematics.  A lot of them had errors, even though they were ostensibly service manuals.

Remember that short-lived Andy Richter sitcom "Andy Richter Controls the UNiverse"? ( http://en.wikipedia.org/wiki/Andy_Richter_Controls_the_Universe ).  Part of his job in the show was going over technical support information for his employer and checking for errors; document quality control.   My guess is that Norlin/Maestro had somebody like his character on the payroll...part time.

[digi2t]

Whazzap with that? Typo? or production mod?

Why would you think it's a typo  

EDIT: NEVERMIND! Duh 

No worries pal!

Damn near a decade back, forum member Rick Lawrence sent me a wad of Maestro "factory" schematics.  A lot of them had errors, even they were ostensibly service manuals.

Remember that short-lived Andy Richter sitcom "Andy Richter Controls the UNiverse"? ( http://en.wikipedia.org/wiki/Andy_Richter_Controls_the_Universe ).  Part of his job in the show was going over technical support information for his employer and checking for errors; document quality control.   My guess is that Norlin/Maestro had somebody like his character on the payroll...part time.

Sorta like a factory version of "The Office"?

I guess I'll have to breadboard this sucker one day to find out which one goes where  .

[LucifersTrip]

if you need a bigger, cleaner ver of the schematic:
http://www.luciferstrip.com/fuzz/fz-1b-4tran.jpg

I actually didn't try that one yet since the 2 tran ver:
http://www.luciferstrip.com/fuzz/fz-1b-2tran.jpg

...was one of the rare few circuits I could not get to sound good enough to be boxed. I still have the parts in a bag waiting for another try.

[mac]

My schem says 3m3 between diode and base, and 100k from base to gnd... 

I'd trim both resistors, and the 330k too. I'd also play with the 0.1 cap.

It looks like the diodes charges the 0.1 cap, and depending how much voltage it gets, Q4 is on or off, that is, its resistance goes from zero to a high value controlling the gain of Q3... Pick sensitive gain, "envelope follower"?... not sure...

mac

[Solidhex]

 Its a simple noise gate. Q3 and Q4 depend on each other to turn on. When no signal is present Q4 shuts off eliminating the Q3 emitter's connection to ground killing all signal. When a note is played current travels through the diode and raises the voltage on Q4's base turning it on. With Q3's emitter grounded through Q4 it then is on as well. The correct schematic is the first one with the 680K to ground and 3M3 to diode. I believe the .1 cap is just there to insure only direct current is traveling to the base. Its a cool idea but the circuit has a sort of anemic sound to it. Would like to hear an original unit. Its basically a Fuzzrite with some fun stuff added

[digi2t]

Many thanks Solidhex for the description, and the setting the record straight on the resistors.

Greatly appreciated!

I'm going to breadboard this one day, just to satisfy my curiousity.

Cheers,
Dino

[petey twofinger]

i got an original fz-1 , not sure which model , its 9 volts . my step dad found it in his old stuff and gave me it !


that was a real thrill .

[digi2t]

my step dad found it in his old stuff and gave me it !

I'm very adoptable, you know. 

That's super Petey. Good on ya!