Colorsound Fuzz Test Results

[AM]

I'm sure many of you have built the Colorsound One Knob Fuzz. There is an excellent layout at Dragonfly's gallerry. He uses an 820 ohm resistor before Q2. There is another schematic at Fuzz Central where instead of the 820 ohm they have used an 82 ohm one. That caused me some confusion. From what I know their first schem had also an 820 ohm resistor but they changed it later on. Anyway, I built the fuzz and wired both resistors on a dpdt toggle and tested it through two different guitar amps, and through a multi fx with amp simulations going to board and studio monitors. My observations:

I didn't notice any difference in sound character worth talking about. With the 820 ohm R you get unity gain with your bypassed signal at around 3/4 of the drive of the volume knob. With the 82 ohm R you get it at just above 1/4.
I personally like more the way the volume knob works using Dragonfly's resistor value. There is still a bit of spare gain available but not too much. Enough for some extra boost though. Please note that the volume control only affects output level. The gain is fixed. With Fuzz Central's layout there is mucho volume boost on tap but not all that useful in my opininion since you also amplify a lot of noise.
I feel that Andrew's resistor value allows for a smoother operation of the volume knob.
I haven't measure voltages etc. My observations are based on auditioning the circuit through different amps etc. If anybody has any suggestions of what correct voltages should be I would be happy to try them out and report which resistor gives results close to those voltages.

This is a very "retro" sounding fuzz. Sputtery and a bit on the bright side even with the guitar tone knob rolled off. The effect on the decay of the notes is pretty groovey. Hard to describe, but lets say that the transition from a sputtery fuzz sustained tone to clean is pretty smooth. It cleans up when using the guitar volume knob but I thought that there is a much steeper curve between 9 and 10 on the guitar volume knob than up to 8-9. I don't think it's my cup of tea but it would be great for garage and the similar styles.
I thought of posting my test results in case there were other people wondering about those resistors.

[foxfire]

well i suggest that the "correct" value for that R is the one you think works better in the circuit. unless you're going for an exact clone of course. as for it not being your cup of tea i'd suggest breadboarding the hell out of it until it is. i've found that to be one of the best ways to learn. who knows what you'll end up with?

[newfish]

...or using a 1K trimpot?

Recently built a Fuzz Face that was gating before the notes had really started to die away - no sustain at all, so put a trimpot as the bias for Q2 - and adjusted to taste.

Taking measurements and using maths is all well and good - but I reckon a half decent pair of ears is the best judge of some things...

incidentally, I tried various Rangemaster / Octave Fuzz / Fuzz pedals (all homebrew) through a friend's setup - Line 6 and lots digital stuff - and it sounded totally different to what I was used to (straight into a valve combo) - might be worth a try through a straight amp to see what difference that makes - although kudos for using your Monitors for auditioning pedals - there's surely no better way to hear 'everything'...

[AM]

as for it not being your cup of tea i'd suggest breadboarding the hell out of it until it is. i've found that to be one of the best ways to learn. who knows what you'll end up with?

I agree with you. I do that with everything I build. I have already tweaked this unit a bit. Made it a bit smoother. When I'm saying it's not my cup of tea I mean not as my main distortion unit. I find it very good for certain sounds but I have already found my meat and potatoes overdrive/distortion sounds some time ago and I'm very happy with them. So after finishing tweaking this one it will be in my studio for when I want that sound. It's just not kicking my main dirtboxes out of my pedalboard.

incidentally, I tried various Rangemaster / Octave Fuzz / Fuzz pedals (all homebrew) through a friend's setup - Line 6 and lots digital stuff - and it sounded totally different to what I was used to (straight into a valve combo) - might be worth a try through a straight amp to see what difference that makes - although kudos for using your Monitors for auditioning pedals - there's surely no better way to hear 'everything'...

.
Yeah that's what I did already. I tested it through two different guitar amps, AND through an amp modeller AND straight to the monitors. These were all different setups. Maybe it wasn't very clear in my earlier post.

[axg20202]

...or using a 1K trimpot?

Recently built a Fuzz Face that was gating before the notes had really started to die away - no sustain at all, so put a trimpot as the bias for Q2 - and adjusted to taste.

I think this makes sense. Actually, the Fuzz Face layout at Fuzz Central (and maybe others?) includes a 10K trimpot to adjust bias on Q2. Works well. I wonder though, do you think it would be worth making this an external pot? Does bias drift THAT much with temperature changes etc using Germ trannies or can you set and forget? Not sure I can be arsed to yank the trimmer off the board in my FF and try it, so I thought I'd ask first (so I'm lazy...see you in court!).

EDIT: I know the Analogman Sun Face pedal has an external bias pot (as an example), but is it really worth the bother? Is 10k the best value for this?  Sorry to derail the thread, but it's sort of relevant.

[foxfire]

...or using a 1K trimpot?

Recently built a Fuzz Face that was gating before the notes had really started to die away - no sustain at all, so put a trimpot as the bias for Q2 - and adjusted to taste.

I think this makes sense. Actually, the Fuzz Face layout at Fuzz Central (and maybe others?) includes a 10K trimpot to adjust bias on Q2. Works well. I wonder though, do you think it would be worth making this an external pot? Does bias drift THAT much with temperature changes etc using Germ trannies or can you set and forget? Not sure I can be arsed to yank the trimmer off the board in my FF and try it, so I thought I'd ask first (so I'm lazy...see you in court!).

EDIT: I know the Analogman Sun Face pedal has an external bias pot (as an example), but is it really worth the bother? Is 10k the best value for this?  Sorry to derail the thread, but it's sort of relevant.

if you care about every detail of your sound then i think it would be worth it. or if your just a knob guy then why not add it. a bias knob can be very useful depending on the circuit and or the trannies your using. i'm tending to use fewer and fewer knobs the more and more i get broke.   

[superferrite]

I'm going to build one tomorrow, if I have time.  I bought the trim pot but it looks a bit tight on that veroboard.
Thanks for the info (i've been specifically lurking for this advice for a week or two), and I think a 100 ohm resistor might be just right by your description.

[AM]

I'm going to build one tomorrow, if I have time.  I bought the trim pot but it looks a bit tight on that veroboard.
Thanks for the info (i've been specifically lurking for this advice for a week or two), and I think a 100 ohm resistor might be just right by your description.

Hey, I remember you asking about sound samples a couple of weeks ago. This is the exact reason I posted my observations on this pedal. Not to review it as a pedal. I just thought that there might have been some other people except me wondering about the same thing.
If you have already bought the trim pot you might as well use it. I don't think it will change much in the sound character of the pedal but by adjusting it to taste you could get the feel that suits you most on the volume control. Good luck and have fun building.

[superferrite]

I ended up finding a salvaged 820 ohm resistor and used it in my build today.  Cool fuzz--right between my smooth Fuzz Face and the noisy insanity of the Fuzzrite.
Thanks for post and I hope this helps other n00bs too!

[drewl]

You have a link to a schematic?
thanks.

[superferrite]

Here is Dragonfly's wicked cool tutorial on the subject.  May be a bit too much info but you get the gist!
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album20/album21/

[drewl]

Thanks, but is there a schem?

[Dragonfly]

Thanks, but is there a schem?

In the very first post.....

There is another schematic at Fuzz Central ...

Which brings us to....

http://fuzzcentral.ssguitar.com/schematics/oneknobfuzz.gif

[drewl]

Thanks, but is there a schem?

In the very first post.....

There is another schematic at Fuzz Central ...

Which brings us to....

Where in the first post?
Am I missing something or stupid today?
I'd like to see or build some of the projects that get mentioned but I can never find the schems. (well not never)


http://fuzzcentral.ssguitar.com/schematics/oneknobfuzz.gif

[Dragonfly]

Where in the first post?
Am I missing something or stupid today?
I'd like to see or build some of the projects that get mentioned but I can never find the schems. (well not never)

first post in the thread.

I'm sure many of you have built the Colorsound One Knob Fuzz. There is an excellent layout at Dragonfly's gallerry. He uses an 820 ohm resistor before Q2. There is another schematic at Fuzz Central where instead of the 820 ohm they have used an 82 ohm one. That caused me some confusion. From what I know their first schem had also an 820 ohm resistor but they changed it later on. Anyway, I built the fuzz and wired both resistors on a dpdt toggle and tested it through two different guitar amps, and through a multi fx with amp simulations going to board and studio monitors. My observations:

I didn't notice any difference in sound character worth talking about. With the 820 ohm R you get unity gain with your bypassed signal at around 3/4 of the drive of the volume knob. With the 82 ohm R you get it at just above 1/4.
I personally like more the way the volume knob works using Dragonfly's resistor value. There is still a bit of spare gain available but not too much. Enough for some extra boost though. Please note that the volume control only affects output level. The gain is fixed. With Fuzz Central's layout there is mucho volume boost on tap but not all that useful in my opininion since you also amplify a lot of noise.
I feel that Andrew's resistor value allows for a smoother operation of the volume knob.
I haven't measure voltages etc. My observations are based on auditioning the circuit through different amps etc. If anybody has any suggestions of what correct voltages should be I would be happy to try them out and report which resistor gives results close to those voltages.

This is a very "retro" sounding fuzz. Sputtery and a bit on the bright side even with the guitar tone knob rolled off. The effect on the decay of the notes is pretty groovey. Hard to describe, but lets say that the transition from a sputtery fuzz sustained tone to clean is pretty smooth. It cleans up when using the guitar volume knob but I thought that there is a much steeper curve between 9 and 10 on the guitar volume knob than up to 8-9. I don't think it's my cup of tea but it would be great for garage and the similar styles.
I thought of posting my test results in case there were other people wondering about those resistors.

[drewl]

Obviously user error....I was having trouble finding it on the FuzzCentral page,
anyway, I slapped one together and just need to put it in a box and find the right transistors for it.

[Gus]

http://www.diystompboxes.com/pedals/gusFuzzFace.gif

If you look close it is close to the VOX two transistor circuit in  R.G.s writeup

remove R2 and R1 and use a 2.2K for a 1 knob, keep C2.

If you want no bias pot but a gain control use a 1K for R1 or a 2K gain pot.

That is a Si circuit that will bias up with a bunch of Si transistor numbers just drop them in and play.  The bias pot is not a HACK it is an external in my builds it allows different sounds one can make it a fixed and set it for the "WEB says it is best" 4.5VDC point

Been in schematics for years.  C4 and R8 might be the earliest stuff posted on the web to add to a FF IIRC, R8 was before Jack's IIRC, and the lowpass being set by R9 C4 instead of collector to base caps.

This is a simple little circuit Aron placed in schematics years ago.  That old phono pre/audio gain stage amp section circuit the FF is like you can find in  60's books with the math for the emitter resistor at Q1.  In the circuit I used both math and ear to select the 100 ohm and 10K.  I fixed the q2 total collector resistors to fix the collector current I wanted.  I also used a 100K volume and a 47K feedback.  One can change the input and output caps to tune it. 

[Dragonfly]

Obviously user error....

Believe me....I do it all the time ! 

[AM]

I went back to my circuit for some more tweaking. At some point I started trying out dying batteries. I ended up putting an 92 ohm resistor to bias Q2. I ended up liking it the best with some half dead battery I used. This gave me the idea to wire a pot between the 9V+ and the 100uF cap at Dragonfly's layout (which I have actually made a 220 uF). So I thought of using a pot as some sort of "starving voltage" pot and supply the pedal power through my regulated adator but adjust the ammount of voltage through the pot.I have a 10k pot lying around. Does anybody know if it would work for this purpose? Anything that I should be aware of? Thanks in advance for any replies.