Hidrosis fuzz, no fuzzing happening.

[sengo]

Hey guys,

    I just built the Hydrosis fuzz according to this schematic,

http://www.diystompboxes.com/smfforum/index.php?topic=50984.0

When I hook it all up I don't get any distortion, but the gain pot works fine as a volume control .

My voltages are as follows,

Battery - 8.10V

Voltage divider section - 4.05V

Pins,

1 - 4.03V

2 - 4.05V

3 - 3.66V

4 - 0V

5 - 4.02V

6 - 4.05

7 - 4.03V

8 - 8.10V

I've checked the pin outs of everything and they seem fine. The only modification I made was that I ran out of 2.2uF electrolytics about half way through my build, so several of them are only 1uF, could this be the cause of no fuzz? I wired the whole thing "Manhattan Style" so its pretty cramped on the board, but I've had no luck finding shorts so far.

I'll keep checking for soldier bridges I suppose, but if anyone sees any huge flaws in anything so far your help will be appreciated.

Thanks!

Nick

[sengo]

*bump*

[ambulancevoice]

breadboard it and see if it works then
if it does, than its probably just the Manhattan version that has problems

[sengo]

Hmm, I guess I'll have to try that when I get a chance. Do you think the voltages look alright atleast? I think it's pretty much what a typical dual op-amp distortion is suppose to be, but I'm not sure.

I also forgot to mention that I did not have a 120pF cap, so I used a 100pF cap instead.

Nick 

[ambulancevoice]

well, i dont know anything about the way the voltages should be

some of those 2.2uf caps look rather necessary , i would probably get some and replace the 1ufs with them
www.smallbearelec.com will have em

also, check that everything is orientated correctly (polarity and pin outs and such)
did you do a layout of the Manhattan before you made it? or did you just go and build it from scratch?
if you didnt id would do a layout first, on paint or photoshop or something similar.

For this type of circuit, I probably wouldnt use Manhattan style with it, perf or vero would be a better choice
but you can use it if you want, because it is pretty cool!

[gutsofgold]

I built this on an etched pcb and it turned out fine, I will get some voltages later on today and see if they match up.

I would have to agree that those 2.2uF electros seem necessary in that value. And do not worry about the 120pF cap, thats just there to cut the highs so you'll have more high end in the sound with 100pF.

[brett]

Hi
Do you definately have a 1M resistor between pins 6 and 7 , and a 2.2k resistor and cap from pin 6 to ground ? These components control the gain in the second stage.  If the gain is good, check the diodes.  After that, check that the gain pot is a 10k, not a 1k.

Also, there's something fishy with the voltage on pin 3.  The voltages on pins 2 and 3 should be almost exactly the same.

RE: the caps
I suggest that the 2.2uF caps shouldn't be changed to 1uF.  Use 3.3 or 4.7uF (or even 10uF) instead.  1uF will cut some bass.
cheers

[sengo]

Ahh, as would be expected... I accidentally used the wrong value for the 2.2K resistor in the second stage 

Fuzzes good now, Cant wait to really try it out.

Nick

[brett]

Let us know what you think.
I suspect that not too many have been built. (Hidrosis circuits)
cheers

[sengo]

I like it 

It has a definite Black Keys vibe. Reminds me a lot of my Jordan Bosstone, but more stable, quieter, with more bass. I think I'm going to mess with that 120pF cap in the feedback loop, because the 100pF cap made it a bit too raspy, but when I added a 20pF cap in series with the first it cut a bit more fuzz than I wanted, so I'll be doing some tweaking.

Nick

[gutsofgold]

It definitely does the black keys thing pretty well. I think it helps to have the amp already overdriven a bit with the pedal too.

I just changed out the 120pF for a 150pF and also used a 1uF for the input this time, hopefully that gives me some more bass.