Marshall - Supa Fuzz (196x) [gut shot picture thread]

phibes · Post by **phibes** » 30 Nov 2011, 17:53

The transistors definitely look resoldered.

How big is your Tone Bender database these days EW?

Electric Warrior · Post by **Electric Warrior** » 30 Nov 2011, 19:08

37 Sola Sound made MKII types (Sola/Vox/Marshall/Rotosound/Fuzzbug), 20 Marshall made Supa Fuzzes. You can tell I'm not too interested in the Marshall made variant. It's much more common than the Sola Sound one.

phibes · Post by **phibes** » 01 Dec 2011, 16:19

Sola's are always better eye candy. You should archive all those on a website some day.

Nyquist5 · Post by **Nyquist5** » 05 Dec 2011, 09:45

Electric Warrior wrote:You mean the Erie electrolytic on the right? That one's contemporary to the pedal. I think Marshall even used that type in some amps.

Yes, I know, I have a marshall superlead with those in

. But the way it has been installed on this board tells me it was soldered later on in the pedal's life.

JVanDe7 · Post by **JVanDe7** » 27 Jan 2012, 14:04

I just built a Marshall Supa Fuzz clone using this Bender layout...
http://www.aronnelson.com/gallery/main. ... o.gif.html

To make it a Supa Fuzz and not a Tone Bender, I changed R1 to 10K and R5 to 470 ohm. Also changed C1 and C3 to 10uF.
I changed R6 to a 20K trimpot for biasing.

It sounds great but that layout has a minor mistake - Fuzz 3 should be Fuzz 1 (and vice versa), and Volume 3 should be Volume 1 (and vice versa). Oh and that 11x11 vero is a bit small for this build. Luckily I had radial caps. I socketed the transistors too, just in case.

Got my matched set of germanium from SmallBear. Everything's from SmallBear actually. Was going to use a GGG TB board but they're all out of stock until further notice, so went with Vero instead.

Does the fact that it's negative ground change the tone/sound at all? Usually they're positive ground, no?

JVanDe7 · Post by **JVanDe7** » 27 Jan 2012, 14:36

Also, can I change the 100K log volume pot to 50K for more output? Or is that not a good idea?

JVanDe7 · Post by **JVanDe7** » 27 Jan 2012, 16:53

Looks like I can change the input resistor back to 100K and I'll get more output.

Anyone want to weigh in on positive ground versus negative ground? I don't see why it would make a difference but I'm curious...

kaycee · Post by **kaycee** » 27 Jan 2012, 19:14

JVanDe7 wrote:Anyone want to weigh in on positive ground versus negative ground? I don't see why it would make a difference but I'm curious...

No it doesn't.

LucifersTrip · Post by **LucifersTrip** » 27 Jan 2012, 21:48

voltage police alert! hahahah...

Did this thread really go 5 pages long with no mention of proper transistor voltages for a good sounding build?

Electric Warrior · Post by **Electric Warrior** » 27 Jan 2012, 22:54

We discussed this in detail on the Tone Bender Professional MKII thread.
Collector voltages should be around -8.5V (Q1),- 0.13V (Q2) and -8.5V (Q3).

JVanDe7 · Post by **JVanDe7** » 28 Jan 2012, 01:54

Really? Man, I've got mine biased at 4.5v at collector of Q3 and it sounds awesome. I'll try bumping that up to 8.5 and see how that grabs me...

I think there may need to be a bit more discussion about the circuit. Specifically, I've seen various schematics on the web and some have two .01uF caps and some do not. The ones that do not, they omit the .01uF cap to ground at the input. I built mine with both .01uF caps in place but removed the one at the input and I like the sound much better without it. Although I'm afraid it may have made the pedal more susceptible to picking up radio interference.

Also, I saw on the web that someone changed the input resistor from 10K to 100K and it gave the pedal much more output. Well I tried it and it definitely does give more output but it also cuts a bunch of lows and makes the pedal sound more modern and thin. It's very noticeable. The pedal gains a bunch of volume but it also loses a bunch of the woofy-ness/thickness that makes it special. I tried a 22K and it sounded much better but still lacked some of the really low boomy bass that it had with the 10K there. I settled on a 15K for a tad more output but still plenty of boom. But I may go back to the stock 10K value.

This is a great fuzz though! Getting some great Black Keys Rubber Factory fuzztones from it. It's nice and dynamic/touch-sensitive. Can do some great stoner rock fuzz but can also clean up, and do vintage Sabbath sounding stuff too.

JVanDe7 · Post by **JVanDe7** » 28 Jan 2012, 01:59

Can anyone suggest a value for that .01uF cap to ground at input that will kill radio interference but not remove so much treble? Maybe .022uF?

JVanDe7 · Post by **JVanDe7** » 28 Jan 2012, 02:21

8.5v bias is not correct. It's 4.5v

Anything anywhere near 8v is just noise-gate sounds. Fuzz decays immediately. Not a good sound at all.

phibes · Post by **phibes** » 28 Jan 2012, 05:58

Go read the MKII thread, it's the same circuit. The first SupaFuzz's were a MKI variant, second were MKII (identical to the SolaSounds) and the third had the 10u electros and dropped cap to ground on the input. I think your building the third which will still apply to all the MKII rules.

4.5V on Q3's is not correct. Are you bias'n with a trimmer to Q3's collector? If so, you will probably get the gating. Instead, ditch the 47K on Q2's collector for a 100K trimmer and put the 8K2 back on Q3's collector. This way effects both Q2 and Q3 appropriately and you'll get a better fuzz. The voltages EW listed are from patterns off actual units. I'd also change the resistor to ground on the input back to 10K to keep the SupaFuzz sound.

Anyway though, read the MKII thread, lots of good discussion in there.

LucifersTrip · Post by **LucifersTrip** » 28 Jan 2012, 07:45

Electric Warrior wrote:We discussed this in detail on the Tone Bender Professional MKII thread.
Collector voltages should be around -8.5V (Q1),- 0.13V (Q2) and -8.5V (Q3).

...and that's why it should be one of the 1st things discussed at the beginning of each thread.

Thanx much...I knew your answer was gonna stir things up a bit. I was pretty sure it was going to be in that 7v+ range like the MKII, but I wanted to hear it from the man.

thanx again

LucifersTrip · Post by **LucifersTrip** » 28 Jan 2012, 07:57

ps: from the DAM site admin, after someone wrote: "I was told the collector should be biased to read 4.5V"

http://dam.10.forumer.com/viewtopic.php ... or+voltage

"Not in a MKII. On vintage units it varies from around -7.6V - -8.9V.
Even seen em with 9.1V! I take measurements with Zinc Carbon batteries which are around 9.6 Volts when fresh. The original batteries used in the MKII's and its variants were PP4's (Eveready 226) which also read high at around the 9.6V level.
Hfe levels are usually higher also. For example my '67 Supa Fuzz measurements...

Q1 - 174
Q2 - 208
Q3 - 194"

JVanDe7 · Post by **JVanDe7** » 28 Jan 2012, 14:30

And THAT is why I come here. Thank you guys for clearing that up.

@Phibes - I did change the 8k2 into a 20K trim but I'll put it back and use the 47K to bias instead (with a B100K trim or pot, not sure what I've got laying around). I'll also return the input resistor to 10K as you suggested. I'll report back once I've done the deed and the wife gets out of bed (can't test anything until she's awake)

JVanDe7 · Post by **JVanDe7** » 28 Jan 2012, 14:32

@Lucifer's Tip - very interesting! I'm using standard tonebender hfe trannies. Ordered from smallbear so that's all I could really do. Very interesting to know that they could/should be higher gain.

Electric Warrior · Post by **Electric Warrior** » 28 Jan 2012, 15:06

phibes wrote:Go read the MKII thread, it's the same circuit. The first SupaFuzz's were a MKI variant, second were MKII (identical to the SolaSounds) and the third had the 10u electros and dropped cap to ground on the input. I think your building the third which will still apply to all the MKII rules.

4.5V on Q3's is not correct. Are you bias'n with a trimmer to Q3's collector? If so, you will probably get the gating. Instead, ditch the 47K on Q2's collector for a 100K trimmer and put the 8K2 back on Q3's collector. This way effects both Q2 and Q3 appropriately and you'll get a better fuzz. The voltages EW listed are from patterns off actual units. I'd also change the resistor to ground on the input back to 10K to keep the SupaFuzz sound.

Anyway though, read the MKII thread, lots of good discussion in there.

Stu was kind enough to provide measurements of his vintage units on the D*A*M forum: http://stompboxes.co.uk/forum/viewtopic ... 99#p110299

The earliest and the last units made by Sola Sound didn't have the cap from input to ground either, so the only thing that Marshall actually changed for the third version was to use 10µF electrolytics instead of 5µF - and they went back to OC75s of course (and the 10k/47k bias resistors that OC75 units always had).

LucifersTrip wrote:ps: from the DAM site admin, after someone wrote: "I was told the collector should be biased to read 4.5V"

http://dam.10.forumer.com/viewtopic.php ... or+voltage

"Not in a MKII. On vintage units it varies from around -7.6V - -8.9V.
Even seen em with 9.1V! I take measurements with Zinc Carbon batteries which are around 9.6 Volts when fresh. The original batteries used in the MKII's and its variants were PP4's (Eveready 226) which also read high at around the 9.6V level.
Hfe levels are usually higher also. For example my '67 Supa Fuzz measurements...

Q1 - 174
Q2 - 208
Q3 - 194"

I wonder if they always used hfes as high as that. Later ones used slightly different looking OC75s than what is in Dave's old Supa

JVanDe7 · Post by **JVanDe7** » 28 Jan 2012, 15:15

Phibes - I changed the input resistor back to 10K, ditched the 20K trimpot and replaced it with the stock 8K2, then ditched the 47K and replaced it with a 100K pot but I don't think it sounds better. When I tweak the 100K it does nothing to Q3's collector reading. It stays at 2v basically, and the fuzz sounds a bit weaker than it used to. The 100K does change the sound of the fuzz but no matter where it is set, it doesn't do the trick.

I'm pretty sure I've got the transistors oriented properly. I am assuming the tab on the metal can is the emitter leg. And when I had it set up before, using the 8K2 for bias, it was sounding great and working good so I think the transistors are all good. What could be the problem?