Boss - FZ-2 Hyper Fuzz [schematic]
- Ice-9
- Transistor Tuner
Information
Nice pics and schematic, i might have a go at building one of these , i have been impressed by the sound. Thanks
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !
No silicon heaven ? preposterous ! Where would all the calculators go ?
No silicon heaven ? preposterous ! Where would all the calculators go ?
- dune2k
- Breadboard Brother
They're about 40€ used around here. Wouldn't built one for that price...
JOHNO wrote:P.S Great pedal for playing 70's porn music.
The boost was huge... and clean. Unity was like 9 O'clock. The eq was quite powerful too. How it would sound with an OCD would be speculation. I do plan on breadboarding this circuit and mess around with it.
Although I "plan" on doing a lot of things too.
This circuit has got my curiosity though.
Although I "plan" on doing a lot of things too.

Sorry for the 5 year thread necro, but is there a way to build this without the switching scheme? I cant really tell where theswitch ends and the effect begins. Im fine with leaving all the buffers in that arent driving the bypass switch, flip flop 9v etc.
Another bump to an old thread...
I just got one of these, and I was thinking of making some slight modifications to get a bit more high end sizzle from Fuzz I. I'm far from an expert, but doesn't the schematic above have the two fuzz modes mixed up? It shows Fuzz I as having the notch filter, and Fuzz II with a regular RC low-pass filter. But on the pedal, it's Fuzz II that has the scooped sound, which should be the result of that notch filter, right? Or am I completely misunderstanding what the notch filter is doing?
I just got one of these, and I was thinking of making some slight modifications to get a bit more high end sizzle from Fuzz I. I'm far from an expert, but doesn't the schematic above have the two fuzz modes mixed up? It shows Fuzz I as having the notch filter, and Fuzz II with a regular RC low-pass filter. But on the pedal, it's Fuzz II that has the scooped sound, which should be the result of that notch filter, right? Or am I completely misunderstanding what the notch filter is doing?
For anyone still reading this thread, I can confirm that the schematic above does indeed have Fuzz I and II mixed up. The one with the notch filter is Fuzz II, and the one with the regular lowpass filter is Fuzz I.
Here's a litte mod I did:

- The highlighted 15nf cap (C31 on the board) was changed to 3.9nf to bump the corner frequency of the lowpass filter after the clipping section on Fuzz I from 1kHz to 4kHz. This makes Fuzz I almost as bright as Fuzz II (but with the mids intact).
- The highlighted 33nf cap (C33 on the board) was changed to 18nf to bump the corner frequency of the lowpass filter going into the octave section from about 480Hz to 880Hz. This gives you more picking attack and makes it more useful for playing with the guitar's volume knob (IMO anyway). You could go even lower, I tried 10nf, but it changed the character of the pedal a bit too much for my taste.
Here's a litte mod I did:

- The highlighted 15nf cap (C31 on the board) was changed to 3.9nf to bump the corner frequency of the lowpass filter after the clipping section on Fuzz I from 1kHz to 4kHz. This makes Fuzz I almost as bright as Fuzz II (but with the mids intact).
- The highlighted 33nf cap (C33 on the board) was changed to 18nf to bump the corner frequency of the lowpass filter going into the octave section from about 480Hz to 880Hz. This gives you more picking attack and makes it more useful for playing with the guitar's volume knob (IMO anyway). You could go even lower, I tried 10nf, but it changed the character of the pedal a bit too much for my taste.
Information
Did anyone ever end up creating a vero layout or PCB for this one? I can't seem to find a layout, specifically the FZ-2 (not the FZ-3, which is IMO very different-sounding).raindog wrote:My favourite commercial fuzz.
Loe Sounds
- Cub
- Cap Cooler
Our breadboard brother bugg from PedalPCB has one, the "Hyped Fuzz" project. https://www.pedalpcb.com/product/hypedfuzz/aishabag23 wrote:Did anyone ever end up creating a vero layout or PCB for this one? I can't seem to find a layout, specifically the FZ-2 (not the FZ-3, which is IMO very different-sounding).raindog wrote:My favourite commercial fuzz.
I wish I were a chestnut tree, nourished by the sun.
With twigs and leaves and branches and conkers by the ton.
With twigs and leaves and branches and conkers by the ton.
- Hanky-
- Breadboard Brother
Can anyone share the value of R52? it's located near Q12. It's not visible in the images I could find online. The schematic doesn't have a value mentioned for it either, its blank, I thought it was a jumper connection but looking at the components side pics, there seems to be a resistor in place there.
I'm trying to work out the sf300 clone circuit to get it to be close to the FZ2, so far the progress has been good. In that unit the value is 10k, from the pics of the FZ2 the shape of the resistor is like ~1k size compared to the 10k ones used in there, can't tell for sure. The SF300 has around five or six values different & a slight altered path in the circuit otherwise its a close copy.
I would have liked to tinker around with it to see how far it can hold up to the original, I don't have the FZ2 in my hands or I'd take a look inside to find that resistor.

Any input would be appreciated.
I'm trying to work out the sf300 clone circuit to get it to be close to the FZ2, so far the progress has been good. In that unit the value is 10k, from the pics of the FZ2 the shape of the resistor is like ~1k size compared to the 10k ones used in there, can't tell for sure. The SF300 has around five or six values different & a slight altered path in the circuit otherwise its a close copy.
I would have liked to tinker around with it to see how far it can hold up to the original, I don't have the FZ2 in my hands or I'd take a look inside to find that resistor.

Any input would be appreciated.
- Hanky-
- Breadboard Brother
The schematic posted here has errors in it, mostly with resistor values. I found a newer one with correct values & seems to have been verified by the user. Its available at madbeanpedalsforum or something, should be easy enough to find on google search.
The cheapest clone out there of the FZ2 is the SF300. Its as close to perfect clone as it can be. The buffer is brighter & overall the sound isn't as dark as the fz2. To get it close change the 1n5 cap to 47pF, its located near tlo64 IC.
The cheapest clone out there of the FZ2 is the SF300. Its as close to perfect clone as it can be. The buffer is brighter & overall the sound isn't as dark as the fz2. To get it close change the 1n5 cap to 47pF, its located near tlo64 IC.
- modman
- a d m i n
Information
- Posts: 4806
- Joined: 19 Jun 2007, 16:57
- Has thanked: 4265 times
- Been thanked: 1970 times
Fair enoughHanky- wrote:The schematic posted here has errors in it,
So it's slight changes as in a version update?Hanky- wrote:mostly with resistor values.
Yes, I googled and only came up with this same non-factory schematic for this unit. Show us the schematic, or indicate the wrong values if you have this info.Hanky- wrote:I found a newer one with correct values & seems to have been verified by the user. Its available at madbeanpedalsforum or something, should be easy enough to find on google search.
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- Hanky-
- Breadboard Brother
I don't think it's a version update if the original version was based on the values in the schematic in this thread that were wrongmodman wrote:Fair enoughHanky- wrote:The schematic posted here has errors in it,So it's slight changes as in a version update?Hanky- wrote:mostly with resistor values.Yes, I googled and only came up with this same non-factory schematic for this unit. Show us the schematic, or indicate the wrong values if you have this info.Hanky- wrote:I found a newer one with correct values & seems to have been verified by the user. Its available at madbeanpedalsforum or something, should be easy enough to find on google search.


But there is link someone posted above to a vero layout "hypedfuzz" offered by pedalpcb.com, that one in its latest pdf file has the correct values.
Anyways, here are the values as per the boss pcb that the schematic by HemmoP has errors with:
R54 should be 1k, it's given as 10k
R53 should be 10k, it's value is missing
R28 should be 10k, it's given as 56k
R47 should be 27k, it's given as 100k
R24 should be 47k, it's given as 10k
R60 should be 1.8k, it's given as 2.9k
I think that's about it for the resistors that are odd from the boss board. The updated schematic is easier to follow. If you guys still want me to mark the locations of the above resistors in the schematic of this thread then I can but I'd just suggest referring to the new one below.
The schematic with the corrected values is found here:https://www.madbeanpedals.com/forum/ind ... c=30455.15 Reply No.17
I haven't found the service manual from Boss for it yet

I think the guy that makes the FZ2 vero layout pcbs has replied in that thread perhaps, not sure, the username seemed to be the same as "BuGG" that someone mentioned in a reply above mine.
- Hanky-
- Breadboard Brother
Can't edit my post so heres the link
https://www.madbeanpedals.com/forum/ind ... c=30455.15
And I marked the wrong ones location in the old schematic & attached it.
By the way any ideas how to get Mode 1 to have less midrange to it, a bit less honk would be nice.
https://www.madbeanpedals.com/forum/ind ... c=30455.15
And I marked the wrong ones location in the old schematic & attached it.
By the way any ideas how to get Mode 1 to have less midrange to it, a bit less honk would be nice.
- Gila_Crisis
- Resistor Ronker
Information
These are the parts of the circuit where the filter (mid cut or boost) is applied in the Fuzz Modes I & II.
The bottom one is mode I, the 10k+15n is a Low pass filter cutting at around 1Khz, so ou could try to rise the capacitor to have a lower cut, hence less high/mid freq.
The bottom one is mode I, the 10k+15n is a Low pass filter cutting at around 1Khz, so ou could try to rise the capacitor to have a lower cut, hence less high/mid freq.
Zwischen Ordnung und Chaos fangt die Musik an