Pedal manufacturers in here...

Moderators: Slowy, Capt. Black

User avatar
BY Shimmer
#770254
I am currently breadboarding this very cool fuzz
http://www.generalguitargadgets.com/eff ... es/rocket/
I have so far omitted the Drive control, because when I hooked it up as shown, it didn't seem to work as expected. In fact it seemed to act more like a volume control. Is it specified correctly? I am pretty new to pedal building and cant figure out what the Drive pot is actually meant to achieve.
Cheers
Andrew
Attachments
rocket.jpg
ADD_DESCRIPTION
User avatar
BY Snarblinge
#770501
Did you use a 50k pot? The drive I like a pre amp volume, the first transistor is a little gain, the drive controls the level fed into the second stage, where the fun happens, hotter signal in creates more chaos, just like hotter pickups drive fuzz harder. So kinda like a volume. How does it sound without the drive control? You may have a problem in the distorting part of e circuit if the drive wasn't really working.
User avatar
BY Shimmer
#770733
Snarblinge wrote:Did you use a 50k pot? The drive I like a pre amp volume, the first transistor is a little gain, the drive controls the level fed into the second stage, where the fun happens, hotter signal in creates more chaos, just like hotter pickups drive fuzz harder. So kinda like a volume. How does it sound without the drive control? You may have a problem in the distorting part of e circuit if the drive wasn't really working.

Thanks heaps for your replies. I am currently using BC550 transitors as I cant find the 5088s that they recommend. So maybe that had something to do with it. On my breadboard version I have actually modified that part of the circuit to instead blend between the thin sounding 0.01uF capacitor and a much larger value one (a 124 - which sounds heaps fatter and nicer to my ears), using a b50K pot. So not a Drive control, but I guess something of a "Fatness" control :)
User avatar
BY Snarblinge
#770738
the 2n5088 has a gain range of 300 - 900 and the bc550 100-800, so untested you may be a little low, which would explain the lack of excitement from the drive control, sounds like a tone control as you have is a better option anyway.

pictures?
User avatar
BY Shimmer
#770849
Snarblinge wrote:the 2n5088 has a gain range of 300 - 900 and the bc550 100-800, so untested you may be a little low, which would explain the lack of excitement from the drive control, sounds like a tone control as you have is a better option anyway.

pictures?

Here is the bit of the breadboard where I will have to add the pot to be able to 'turn-on' the 683 capacitor. (I did add it previously but then a wire broke off, so I have to resolder it and plug it back in)

A sound clip of sorts here... first 15 secs are the 222K capacitor, the rest is the 683. I prefer it best with the neck pickup on.
Attachments
small20180116_072359.jpg
ADD_DESCRIPTION
User avatar
BY Shimmer
#770878
sizzlingbadger wrote:You could try increasing the value of the 47K feedback resistor, it may help offset the reduced gain from the BC550's

Thanks! I will give that a go. I am still very new to this stuff, and am only very slowly working out what the components do and why they are needed (or otherwise). Every time I breadboard something and it works, I feel like a wizard!
User avatar
BY Optical
#771082
The circuit looks like a slightly tweaked fuzz face (second and third transistors) and a generic unity gain input buffer (first transistor) that allows for the input volume/gain control pot.

You could connect your guitar to the input of C3 and tweak the circuit to your liking first - check out all of the fuzz face circuits and variations. Then add the input buffer and gain control back in. The input buffer isnt needed if you went with the traditional fuzzface gain control, but is needed if you want to use a knob on the pedal to control input gain rather than say the guitar volume.

Also note the tone control is only cutting high frequencies. Fuzzfaces are typically a bit of a dark sounding pedal hence no one ever bothered putting treble cut tone controls on them before. Interesting to see that here - is it much use?
User avatar
BY Shimmer
#771184
Optical wrote:The circuit looks like a slightly tweaked fuzz face (second and third transistors) and a generic unity gain input buffer (first transistor) that allows for the input volume/gain control pot.

You could connect your guitar to the input of C3 and tweak the circuit to your liking first - check out all of the fuzz face circuits and variations. Then add the input buffer and gain control back in. The input buffer isnt needed if you went with the traditional fuzzface gain control, but is needed if you want to use a knob on the pedal to control input gain rather than say the guitar volume.

Also note the tone control is only cutting high frequencies. Fuzzfaces are typically a bit of a dark sounding pedal hence no one ever bothered putting treble cut tone controls on them before. Interesting to see that here - is it much use?


Thanks for that - I will try that suggestion this weekend of connecting to C3 and having a play.
The tone control seems to make a bit of a difference, but the circuit itself is not that trebley. I did play with changing around C4 (the high-end rolloff cap ?) - removing it make things quite trebley and scratchy sounding. I tried other values but ended up coming back to the 0.1uF