unicord superfuzz caps?

[hellwood]

does anybody know why unicord's schematics dont show polarized caps and every single other schematic does?
http://www.univox.org/pics/schematics/superfuzz.gif
http://www.univox.org/pics/schematics/superfuzz2.gif

[smnm]

It's indicated on the second version - the straight side of the symbol is positive, like this:

[hellwood]

It's indicated on the second version - the straight side of the symbol is positive, like this:

thanks, im aware of that symbol and its meaning, but im interested in the first schematic.

[slacker]

I don't know why the hand drawn version doesn't show polarised caps. Perhaps it's because the circuit doesn't need polarised caps, it would work exactly the same if you used non-polarised electrolytic caps or even film caps (they'd be huge though). I also thought that maybe the originals might of been built with non-polarised caps but looking at the pictures here they are clearly polarised electros.

[Sir H C]

I have one of the early Super Fuzzes.  They used polarized caps from the beginning.  They didn't put the + direction in, it is pretty obvious which way they go from the schematic (some don't matter).  Lazy person drawing up the schematic.

[smnm]

thanks, im aware of that symbol and its meaning, but im interested in the first schematic.

sorry - I misunderstood your question slightly. One other reason  might be that schematics were provided for servicing and repairs, not cloning - you wouldn't need to know the polarity if you just had one to fix...

[hellwood]

thanks for the info! im goin for it!

[R.G.]

Maybe I can clear up some of the FUD.

I drew the second drawing. I drew it based on tracing a unit. Actually a couple of units over a few years. I had never seen the first schemo until after I drew up the second one.

The differences in the two are almost nil. The biggest one is the inclusion of a trimmer pot in the first one to semi-match the octaving transistors for a more prominent octave. I think every polarized cap in my drawing matches one in the Unicord drawing.

All of the uF and up caps in the SF were always polarized.

does anybody know why unicord's schematics dont show polarized caps and every single other schematic does?

It's most likely as Sir HC said - Unicord didn't make that schemo for your education, it was for field repairs.

[hellwood]

well, i guess i couldnt have asked for a better answer. while you are at it, what top secret Hfe's do you think will work the best?

[hellwood]

The differences in the two are almost nil. The biggest one is the inclusion of a trimmer pot in the first one to semi-match the octaving transistors for a more prominent octave. I think every polarized cap in my drawing matches one in the Unicord drawing.

one difference i noticed is a .002 cap missing between Q1's collector and Q2's base. so, if you were to use the cap , would it be a polarized cap?

[R.G.]

what top secret Hfe's do you think will work the best?

It makes almost no difference with any hfe over 100-200. The only two transistors that might cause a difference in sound is the two face-to-face ones. And matching of part to part is more important than the actual gain.

one difference i noticed is a .002 cap missing between Q1's collector and Q2's base. so, if you were to use the cap , would it be a polarized cap?

No, it wouldn't.

In general, polarized caps are not available below 1uF. Yes, there are exceptions at high voltage and with tantalum, but no, not for values like 2nF. Take it as a rule that no cap under 1uF is aluminum electro/polarized unless it's marked differently.

Here's the scoop: if there is always a polarizing voltage across a given capacitor as used in a circuit, you can use either a polarized or a non-polarized cap. If the voltage ever reverses, even by a fraction of a volt, you MUST use non-polarized.

And the polarity must be as the circuit makes it. Frankly, I suspect that one reason that Unicord didn't bother with polarity markings is that it's fairly obvious from the circuit which way has to be positive.

[hellwood]

thanks RG!

[Mark Hammer]

does anybody know why unicord's schematics dont show polarized caps and every single other schematic does?

It's most likely as Sir HC said - Unicord didn't make that schemo for your education, it was for field repairs.

That's the part a lot of folks forget.  The factory drawings were intended for people who had the darn amp/pedal sitting on the bench in front of them and the lighting and angle was poor enough that they needed something to tell them what the writing was on the side of the component.  They are NEVER intended for people who wish to build their own!