Maestro fz-1b has sharp decay

[rockman627]

I see this was previously posted but with no resolution. Hopefully this schematic should help.

I read elsewhere that the squelcher is basically a noise gate. If so, the threshold is set too high and the the signal sustains a while, then cuts off abruptly. I'm hoping a resistor replacement is all that's necessary.

[rockman627]

Here's a photo of the fuzzbox

I don't see a diode. There is a component with color stripes like a resistor, but a glassy body. Look at the left screw, then go right. I'm going to have to figure out a layout for this.

[mozz]

Glass body with colored stripes sure sounds like a diode.

[Helmholtz]

Here's a photo of the fuzzbox

No picture showing.

[g1]

I think raising the value of the 0.1 cap (at D1 cathode) would delay the squelch.

[rockman627]

From diystompboxes.com

Re: Maestro FZ1-B 4 trans restoration, factory schem and pcb photos inside
#3
July 04, 2012, 09:56:37 AMLast Edit: July 04, 2012, 11:33:15 AM by joegagan
brad and gus have both commented on this section.

brad/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"

here was gus smalley's take:
"If you look close the circuit is a lot like the foxy lady, Shin EI, fuzrite and other cascaded gain stages two transistor fuzzes.

This one has an input emitter follower buffer and and the added squelcher section. The mixing with this one is a dual pot the others have the outer legs of the mix pot to the collectors and the wiper to the volume pot

The circuit change I read in the ampage posts are

anode of diode stock connection

cathode of diode to 3.3meg to ground and .1uf to ground(3.3meg with a .1uf across it)

The cathode and 3.3meg and .1uf node to a 680K the other side of the 680K to the Q4 base

It looks like a balancing act. It looks like you want enough current to barely turn on Q4 when not playing.
When playing and the signal going more positive the increased current though the diode raises the voltage across the 3.3meg and the hold cap the .1uf(one of the RCs). The node voltage increases and causes more current to Q4 base via the 680K turning it on. The 3.3meg and .1uf and 680k control the turn off time and the turn on is faster via the diode.

[rockman627]

I hope all can see this. If not, I don't know what to do.

[mozz]

Those caps are probably good. If the transistors are good, chances are your original assumption is correct and a resistor have drifted out of tolerance.

[J M Fahey]

I think it is working as designed, period.
It IS a very abrupt noise gate.

Think about late 60s fuzzed solos, not modern metal use or whatever.

Think Rolling Stones or The Kinks, not Jimi Hendrix which was the exception.
"Choppy chops", not liquid sustained solos

Also: average guitar quality was very low, those would have hummed/buzzed a lot.

Not everybody had a Fender or Gibson, MANY had cheap Silvertone, Danelectro, Mosrite Harmony, Kay, Guyatone, Teisco, Supro and similar average quality ones (to say it politely).

Single coils hummed buzzed, humbuckers were patented and only available on Gibson, amps were cheesy, Fuzz solved many problems at once.

Even mighty Jimmy Page started recording none less than Led Zeppelin 1 with a humble Telecaster (all he could afford), a Fuzz box and a small practice amp. Was it a Silvertone or similar?

A very popular pickup, available on a Ton of American Guitars and almost all Japanese or Italian ones was the very weak so called "Gold Foil" pickup.






These would benefit a lot from a noise gate

Or user should have to switch Fuzz OFF instantly when not needed any more.

EDIT: in the Rolling Stones biography, at one point Keith Richards was asked "which was the first Electric Guitar you bought?"

"Oh, you did not buy an Electric Guitar , you took your (plain vanilla Acoustic or Spanish) guitar to a shop, and had a pickup installed"
"I took mine to Mr xxxxxxxxx shop for it"

And they plugged it anywhere, many record players or radios had an auxiliary input.opr they modded one.

Kids today have NO IDEA on how EASY they have it now, tons and tons of Guitars, Amps, Effects, whatever at burger prices.

[rockman627]

The 3.3m resistor measured almost 7meg, so I changed it. The signal lasted much longer before cutoff, but it was still abrupt. Then I started thinking, 60's songs like Dirty Water, Heartful of Soul etc, didn't have super long sustains, so maybe this pedal is working like it is supposed to.
But JM Fahey stated it much better, so thanks.
I will explain this to the user and give it back. Thanks again.

[Mick Bailey]

Even mighty Jimmy Page started recording none less than Led Zeppelin 1 with a humble Telecaster (all he could afford)......

USA guitars were very expensive in England due to high import tariffs that made them around 10 week's pay (before stoppages) for the average worker in the late 60s. Most music catalogues didn't start listing them until the 70s.

[rockman627]

Jimmy wasn't paid well as an in demand session player? Didn't he have a 3 pickup Les Paul which was later stolen?