Univox - Superfuzz  [schematic]

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sonicvi
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Post by sonicvi »

Here's my Superfuzz clone. I used 2SC828's.
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theehman
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Post by theehman »

I've just been assembling an original Super Fuzz and took some time to compare it to the schematics found at univox.org. My unit matches the original Super Fuzz schematic on everything (except the on/off power switch). The redrawn schematic found here: http://www.univox.org/pics/schematics/superfuzz2.gif has several differences in resistor values, all of which seem to be switched around with other resistors. My unit has 1N34A diodes and 537G transistors.
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Post by theehman »

Minor difference I found:

The unit shown here: http://members.fortunecity.com/uzzfay/s ... fuzz2.html has a 3.3K resistor to ground from the Expander pot, as is shown in the schematic.

This unit: http://members.fortunecity.com/uzzfay/sf3/sf3in.html doesn't have that. Instead, the Expander goes directly to ground.
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Post by Bside2234 »

theehman wrote:Minor difference I found:

The unit shown here: http://members.fortunecity.com/uzzfay/s ... fuzz2.html has a 3.3K resistor to ground from the Expander pot, as is shown in the schematic.

This unit: http://members.fortunecity.com/uzzfay/sf3/sf3in.html doesn't have that. Instead, the Expander goes directly to ground.

I had the 3k3 resistor to ground on mine and the expander didn't really do much. I removed it and put a jumper there and the expander pot works great now.

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Post by Dan N »

A really cool mod for these is putting the diodes on a switch to lift them from ground.
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Post by Solidhex »

Dan N wrote:A really cool mod for these is putting the diodes on a switch to lift them from ground.
Yo

yeah the three way germ/silicon or led/ no diode thing is fun in the superfuzz. Stock is my favorite though. I think leds are too harsh.

--Brad

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Post by roseblood11 »

Hi,

1)
someone wrote above that he has a superfuzz with an internal trimpot to adjust the octave. I´d like to add that to Mike Livesley´s Layout. Which resistor do I have to replace with a trimpot and which value should I use?

2)
Is it possible to add a switch to swich of the octave completely?

regards,

Sue

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Post by analogguru »

roseblood11 wrote:Hi,

1)
someone wrote above that he has a superfuzz with an internal trimpot to adjust the octave. I´d like to add that to Mike Livesley´s Layout. Which resistor do I have to replace with a trimpot and which value should I use?

2)
Is it possible to add a switch to swich of the octave completely?

regards,

Sue
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Post by yeeshkul »

sonicvi wrote: Image
hey man, how did you fix the battery clip on the box?

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Post by sonicvi »

3M double sided gray acrylic foam tape. It can hold just about anything to anything. Automotive stores usually have it.

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Post by metulmykul »

graemey wrote:https://uk.youtube.com/watch?v=BPBn1VK8C ... annel_page


Finally got round to posting a youtube video of my Superfuzz.
Big thanks to Shortscalemike for the vero layout and, as you may see, I pinched the 'Starve' control idea also. :applause:

I used 2N3904 trannys in mine.

Check the link above. Fuzzchaos!
Been lurking for a bit here now...

Awesome build and vid graemy.

Just finished a "Leeds Fuzz" good but not in the same league as your Super.

I'm sourcing parts as we speak.

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Post by ShortScaleMike »

The Leeds should sound pretty similar, I believe it's based on the same circuit - does it not use the 2C828s?

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Post by metulmykul »

ShortScaleMike wrote:The Leeds should sound pretty similar, I believe it's based on the same circuit - does it not use the 2C828s?
Yep, that what she's got. And yes it does sound similar. Have A-B'd it with ChinaFuzz and it's pretty darn close to my ears with a couple of mates preferring it to the MJM.

But Graemey's build seemed to show a hell of a lot more tweakability due to the little extras, no doubt.

I'm thinking of changing the trannies and adding a footswitch for the scoop and the sag.

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Post by graemey »

metulmykul wrote:
ShortScaleMike wrote:The Leeds should sound pretty similar, I believe it's based on the same circuit - does it not use the 2C828s?
Yep, that what she's got. And yes it does sound similar. Have A-B'd it with ChinaFuzz and it's pretty darn close to my ears with a couple of mates preferring it to the MJM.

But Graemey's build seemed to show a hell of a lot more tweakability due to the little extras, no doubt.

I'm thinking of changing the trannies and adding a footswitch for the scoop and the sag.

Thanks man! I was very pleased with the way mine turned out, insane!
The starve is a simple but effective addition, quite 'sitar' like :wink:

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Post by metulmykul »

Newbie question:

would using NTE 289A's (537G equivalents) on Shortscalemike's vero layout require any other changes?

cheers

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Post by roseblood11 »

Hi,

I built a superfuzz using Mark Livesley´s stripboard layout.

But it only produces a moderate, dark overdrive and octave is not to be heard at all. The level is hardly above the bypass signal.

Have gone through with audio probe:

- If I measure the signal in the Expander-Pot, one hears aforesaid moderate distortion and the level is raised. I think, that means that Q1 and Q2 work correctly.

- measured in the Balance-Pot or in the Tone-Switch the sound is nearly identical, but the level clearly reduced. Whether the clipping diodes are soldered in or not, makes nearly no difference. Suppose mistake in the area around Q3, Q4, Q5.
-The level at the output connector is higher again, so Q6 should also function.

What gives to think to me, is the following: If I simply pull Q5 out of it´s socket, the signal gets much louder, more distorted and with a strong octave (it sounds broken and unstable, but closer to the typical superfuzz sound). Suppose, that Q4 and with it probably also Q3 also function, the mistake is to be searched in the area around Q5 .
However, I find absolutely nothing. I have checked the board several times for wrong connections, have cleaned it with acetone, have checked all component values, on suspicion have changed condensers in the doubtful area, have changed all transistors... The result stayed always the same :-(

Measured voltages:

Battery voltage: 9.79 V

-------C-----B-----E--------
Q1: 5.63 0.71 0.14
Q2: 9.76 5.69 5.08
Q3: 7.46 2.79 2.31
Q4: 3.61 2.00 3.60
Q5: 3.60 4.35 3.59
Q6: 3.71 1.21 0.59

Particularly the big difference of the base voltages of Q4 and Q5 surprises me...
And I think the emitter voltages of Q4/5 should be lower

Can anybody help me??

regards, Immo

PS: I used an online-translator... :shock:

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Post by Dan N »

Just to be sure, have you double checked your track cuts? There are three that might be hard to see. Under R9 (just to the right of the top of C5), under R19, and under R23.
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Post by ShortScaleMike »

I would:

1. Check all the cuts, I mention a few of the tricky ones on the layout.
2. Check orientation of all electrolytics. I drew the layout using the shaded end to mean the cathode end, with the stripe on most caps
3. Check for any tracks that are linked by solder bridges
4. Check all your jumpers are jumping the correct tracks

Also are you using 2SC828s? My layout is for these transistors, they have an odd pinout.

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Post by R.G. »

roseblood11 wrote:Hi,
What gives to think to me, is the following: If I simply pull Q5 out of it´s socket, the signal gets much louder, more distorted and with a strong octave (it sounds broken and unstable, but closer to the typical superfuzz sound). Suppose, that Q4 and with it probably also Q3 also function, the mistake is to be searched in the area around Q5 .
You're correct, it is around Q3. Something is pulling up Q5's base to too high. On another of these recently, the builder mixed up the 100K and 22K bias resistors. Another used a 220K.

Check that over very carefully. The base should sit at the voltage-divider level for the bias resistors. In this case, with 9.7Vdc for a power supply that is 9.7* 22K/(100K+22K) = 1.6V more or less. Both Q4 and Q5 should be at about that voltage. If you built the version with the balance trimmer pot, it will be a little higher, maybe up as much as 2.0V. But Q5s base is way too high in your circuit.

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Post by roseblood11 »

I found the mistake :D
A very little piece of copper was hiding in a trace cut next to C7... :roll:

It´s a really great sounding machine, thanx for the layout, Mark!

But how can I switch off the octave totally? I read that a switch should be added between "the 10µF and the 470R", but there are two possible positions: Before the base of Q4 or before the base of Q5 ?

Immo

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