X FUZZ

[seedlings]

I'm out and about coming back from work when I get home ill post a simplified version with the combined XFuzz/ rock and only Robs output.
The low end of the dial of the bias knob should be an aggressive fuzz with no gating. That thing should sing.  Do you have the clipper section feeding a tone and then feeding your output section?

This is what is on my breadboard, except Q3 is a 3904 with a 3k emitter.  I've got something wrong because the aggressive fuzz is missing, and there is one more problem.  With a partial turn of either guitar volume or the pre-gain knob, the signal goes to nothing... I'll be back at the breadboard tonight.  If I can't find the problem, I'll post pics.

CHAD

[karbomusic]

This is what is on my breadboard, except Q3 is a 3904 with a 3k emitter.  I've got something wrong because the aggressive fuzz is missing, and there is one more problem.  With a partial turn of either guitar volume or the pre-gain knob, the signal goes to nothing... I'll be back at the breadboard tonight.  If I can't find the problem, I'll post pics.

CHAD

I had the exact same issue in my layout/physical build. I found that in addition to sending Q3's emitter through the 3.3K to ground, I had also inadvertently sent it directly to ground. I cut the trace that provided the direct ground path and fixed the issue. My build is basically the same except, I subbed Q1 with a 3904 instead of Q3 as an FYI and didn't lose the aggression in gain.

[seedlings]

This is what is on my breadboard, except Q3 is a 3904 with a 3k emitter.  I've got something wrong because the aggressive fuzz is missing, and there is one more problem.  With a partial turn of either guitar volume or the pre-gain knob, the signal goes to nothing... I'll be back at the breadboard tonight.  If I can't find the problem, I'll post pics.

CHAD

I had the exact same issue in my layout/physical build. I found that in addition to sending Q3's emitter through the 3.3K to ground, I had also inadvertently sent it directly to ground. I cut the trace that provided the direct ground path and fixed the issue. My build is basically the same except, I subbed Q1 with a 3904 instead of Q3 as an FYI and didn't lose the aggression in gain.

If you (or anyone) has a working circuit, and would be willing to post clips, it would be very helpful to hear a chord strum once each:
1) pre-gain full, bias at 7:00 (~500k) max
2) pre-gain full, bias at 12:00 (~220k) middle
3) pre-gain full, bais at 5:00 (10k) minimum
4) pre-gain at 3:00, bias at 5:00
5) pre-gain at 9:00, bias at 5:00

Thanks!

CHAD

[karbomusic]

It's in my pedal board, in my car being carted "to and fro" for rehearsal. Translation: Might be a few days before it's back in the house where I can play around with it. I do remember however, that there is such a thing as the bias being "too low". I was simply going to either not set it too low or do some type of compensation on the pot. It's just for me so not sure I'll tweak it too much more.

[deadastronaut]

CHAD.

here is the xrock on breadboard still ...clips as you wanted, if it helps ya..    Q1-2 5088's, Q3 3904.  250k bias trim

https://dl.dropboxusercontent.com/u/7464107/XROCKTEST.mp3

[seedlings]

CHAD.

here is the xrock on breadboard still ...clips as you wanted, if it helps ya..    Q1-2 5088's, Q3 3904.  250k bias trim

https://dl.dropboxusercontent.com/u/7464107/XROCKTEST.mp3

Helps tons  .  Means something is critically wrong with mine  with heavy gating and synthyness all around.  My breadboard has 'the tone' of yours, but not the attack and decay.

CHAD

[WhiskeyMadeMeDoIt]

Are you sure your LEDs are in the right direction? 

[seedlings]

 

5088s were in backwards...  I had the 5088 handwritten wrong for reference 

And now she's just like the clips!  I don't feel the need for the recovery stage- even keeping the tone control, so this just may be a 1590A build.

Thank you so much DA Rob!

CHAD

[deadastronaut]

 aha...cool, glad you got it going man. 

[Mario44]

Ok
Thats version of xfuzz/rock that I have on my BB. Gonna make the PCB soon myself.
If someone fancy doing it, here you go. Everything should be good, but it needs verification.
Format A4, PCB and traces, then both mirrored, rdy to print.
edit: it's my first layout 

[seedlings]

Ok
Thats version of xfuzz/rock that I have on my BB. Gonna make the PCB soon myself.
If someone fancy doing it, here you go. Everything should be good, but it needs verification.
Format A4, PCB and traces, then both mirrored, rdy to print.
edit: it's my first layout 

Mario, that looks great.  Were you thinking 1590A?

CHAD

[Mario44]

(Un)fortunately I didn't think of that tiny hammond. I never had opportunity to work with these housings. Just made this board optimum size, no jumpers.
Its more or less 4x4cm. PCB is adapted for using goldpins for pots. Just decided to go more pro and use some connectors.
It will look more aesthetic for me. Power pad will be like that: http://static1.tme.eu/katalog_pics/2/e/7/2e751263292af19fabe21c765db8a459/tb-3.5-p-2p_bl.jpg

If somebody wants it more packed up for hammonds - no problem, just let me know 
I never tried to thermotransfer any PCB, so I have not much experience with creating good layouts for it.

[monksanto]

1) pre-gain full, bias at 7:00 (~500k) max

Man this sounds lush. How simple would the circuit be just to achieve this lol.

[seedlings]

1) pre-gain full, bias at 7:00 (~500k) max

Man this sounds lush. How simple would the circuit be just to achieve this lol.

I think 1) and 3) might be the other way around in the clip... all depends on how the knob is wired.  I'm pretty sure DA's sound sample first chord is with just the 10K collector resistor.  In my mind the 'max' setting on the knob would be most voltage drop (highest resistance), but could easily be the other way around (highest collector voltage).

So, to answer your question:



CHAD

**edit: deadastronaught, at your command I shall remove this image!!!

[WhiskeyMadeMeDoIt]

I knew I was going to screw up that switch layout I built it as posted and discovered my mistake. I had the switches backward for the rock and fuzz caps...here is revised schematic. If you built it and used one 3pdt for the rock/fuzz switch just flip the clipper leads and relabel.

[Jdansti]

Help!  I'm building a version using the scheme above and I haven't gotten my head around the FET switching yet. Could someone please point out to me where the LED and current limiting resistor connect?

[WhiskeyMadeMeDoIt]

That section of the circuit you have marked is just the output amp selector. There are two possible output stages one is the bjt and the other is a bastardized mu-valve.  You wire the input and outputs to your standard 3pdt foot switch and use your favorite wiring method for that.  On that foot switch you usually wire your led and resistor. If you need more help ill post a schematic with off board wiring.  

Edit: are you wanting to use an led as indicator for the amp selection?

[Jdansti]

Thanks, Whiskey- that makes sense.  I thought it looked like another stage (two stages), but also thought it might be DA's FET switching.  I built that section as shown and I hard wired the rock/fuzz options for fuzz.

I tested it without a stomp switch, just wiring the input and output to my breadboard setup, and I didn't get any sound. This actually doesn't surprise me since I built it on perf without drawing it out first. I probably miswired something. I'll draw up a layout and try again after my brain reboots. It's tough trying to remember which transistor is which just by looking at the board without a layout to follow. I spent a lot of time and effort retracing my steps as I went. I've had success dong this before, but on smaller circuits.

Thanks for your help!

[Cozybuilder]

I breadboarded this today (Crossfire schemo)- all sections work great! This is one Kick-A** design, incredible sustain, the tone circuit gives a lot of variation. I had to sub a couple of items- no 8.2nF caps in hand so I used 6.8 (maybe a little more treble, easily adjusted). Lacked a 1.5M so used a 680K/1M voltage divider (1.5:1 ratio, gives same bias voltage to gate of top 2N5457), and I used J201 FETs. Can't wait to stick this in a box- a huge 1590B- thanks to Whiskey for a PC card to make this an easy build. Will post pics when its ready.

[WhiskeyMadeMeDoIt]

Awesome report Russ. John when you get back to the circuit change the 40k on the jfet to a 22k. It makes both stages about the same volume level.  I had switched it around and goofed on the schematic.