JHS Japan Fuzz Veroboard Verification

[ToneRangerAudio]

Hey all,

I just finished the new JHS video on the fuzz he built in Japan. He provided the schematic with the video and I figured I'd attempt to put it on veroboard with a voltage inverter so I can use it with a normal 9VDC jack.

This is my first time attempting a layout like this straight from a schematic, so I was wondering if anyone could just take a look and point out any errors I've potentially made? I am waiting for some germanium transistors to come in, so can't physically verify the layout just yet.

Appreciate any help!

[Mark Hammer]

The omission of an output cap may introduce some "chaos" but not the kind one might necessarily like; especially if this circuit is going directly into an amp where there may be no input cap to block the DC at its input.

Turns out I have a dozen or more TOshiba 2SA49 transistors sitting in a drawer gathering dust.  Many have hfe measurements in the high 40s, but I quickly located a pair of 100 and 130, so I may try this later today.

[ToneRangerAudio]

Definitely! Would changing that 0.05uF cap to an electrolytic solve that?

And let me know if it works!

[PRR]

Would changing that 0.05uF cap to an electrolytic solve that?

No.

[andy-h-h]

There's quite a few errors 

Check the voltage inverter, ground connection in particular, and unfortunately there's quite a bit wrong with the rest of the layout.  example:  how does the signal get from the 2u2 cap to the base of Q1?  How does voltage pass through the trimmer?  The volume will work in reverse.

I'd suggest a fresh start & ignore Josh re adding some chaos.  You need a cap on the output.

[ToneRangerAudio]

There's quite a few errors 

Check the voltage inverter, ground connection in particular, and unfortunately there's quite a bit wrong with the rest of the layout.  example:  how does the signal get from the 2u2 cap to the base of Q1?  How does voltage pass through the trimmer?  The volume will work in reverse.

I'd suggest a fresh start & ignore Josh re adding some chaos.  You need a cap on the output.

You're right! Thanks for pointing that stuff out. Time to start over haha.

[Mark Hammer]

I had a bunch of NOS Toshiba 2SA49 transistors (is there any other type?), so I perfed one up yesterday afternoon (shame on me for abandoning all the pre-built things I have to troubleshoot and get working).  Instead of fixing the gain, I implemented a 1k gain pot, Fuzz Face style, and skipped the weird output pot arrangement that fails to block DC.  Not everything one might plug into has a DC-blocking cap on its input.  Finally, I added an extra switch-selectable 250k feedback resistance on top of the 100k shown, for some added glitchiness.

It's a Fuzz Face.  The transistors I selected from the pile were more or less in Mike Fuller's recommended range, although I never attempted to measure leakage.  I have a bunch more 2SA49s and installed sockets for them on the board, so I may swap some out to see if they make a difference.

[ToneRangerAudio]

Okay, here's attempt #2. Fixed the issue with the 2.2uF cap not getting to the base of Q1. The voltage to the trimmer goes through the 1K resistor if I'm reading it right on the schematic. I've added an output cap, but not sure if the orientation/value. Regardless, I'm having a lot of fun messing around with this stuff! It's a fun puzzle. Let me know what ya'll think.

[antonis]

Let me know what ya'll think.

It's a bit of mess inside the red circled area..

You have to add another column and move columns 11, 12 and 13 righthand..
Then add a jumper between 9B & 9C (to turm trimpot into variable resistor), move cut 11B one column lefthand and move 1μF output cap lower leg to 11B (polarity retained)..

[antonis]

Omitted pic..

[ToneRangerAudio]

Let me know what ya'll think.

It's a bit of mess inside the red circled area..

You have to add another column and move columns 11, 12 and 13 righthand..
Then add a jumper between 9B & 9C (to turm trimpot into variable resistor), move cut 11B one column lefthand and move 1μF output cap lower leg to 11B (polarity retained)..

Okay how does this look? I changed the trimmer to an inline to save some space.

[andy-h-h]

Looking better.   Check your work round the volume pot as mentioned above - not quite right.  You can use a much smaller cap on the output (Fuzz Face uses 10n, you have 1u).  I'd avoid the electro and use a film cap. 

Also note that you have one side of the board labeled as ground, and the other side +GND.

General questions:

• Why try and make the vero layout so small? 
• How are you mounting it in the enclosure?

In DIYLC you can set component size to match the parts that you have.  Your electrolytic caps are probably bigger than what is on your layout.

The 1k on the emitter of Q2 could happily site anywhere on the bottom right of the board.  The 100k could almost do without a link.   Could align all the cuts under the IC.

[ToneRangerAudio]

Looking better.  Check your work round the volume pot as mentioned above - not quite right.  You can use a much smaller cap on the output (Fuzz Face uses 10n, you have 1u).  I'd avoid the electro and use a film cap. 

Also note that you have one side of the board labeled as ground, and the other side +GND.

General questions:

• Why try and make the vero layout so small? 
• How are you mounting it in the enclosure?

In DIYLC you can set component size to match the parts that you have.  Your electrolytic caps are probably bigger than what is on your layout.

The 1k on the emitter of Q2 could happily site anywhere on the bottom right of the board.  The 100k could almost do without a link.  Could align all the cuts under the IC.

Great!

I'll change that output cap. I want the board small because one it makes me think and little more creatively, and two I want it to go into a 1590B, which now it will without a problem.

And yeah I have the wire pointing to ground, and positive ground is there just for my purposes.

I'll probably mount it with adhesive mounts or superglue on the back of the pots (with covers) like I sometimes do.

What should I change on the volume pot?

[andy-h-h]

Fair enough.    

I've made some really small layouts before and later found that they were unnecessarily small and complicated, which just made them harder to build.   I say if you have the space, use it (within reason).  You still have room for more columns in a 1590B.     

For the volume pot, signal normally enters pin 3, exits pin 2 and pin 1 goes to ground.  If you do the reverse of this (reverse pins 1 & 3) the pot has to rotate counter-clockwise to increase level.  Also look at where the 1u cap is connected.

Good luck   

[ToneRangerAudio]

Fair enough.    

I've made some really small layouts before and later found that they were unnecessarily small and complicated, which just made them harder to build.   I say if you have the space, use it (within reason).  You still have room for more columns in a 1590B.     

For the volume pot, signal normally enters pin 3, exits pin 2 and pin 1 goes to ground.  If you do the reverse of this (reverse pins 1 & 3) the pot has to rotate counter-clockwise to increase level.  Also look at where the 1u cap is connected.

Good luck   

Awesome! Appreciate your help. I changed the volume pot around and adjusted the output cap.

[antonis]

10nF output cap might be OK for 500k Volume pot but can you guarantee for succeeding effect high input impedance..??

[Mark Hammer]

Here's my build.  The 450k volume pot is a weirdo Bourns pot that I found when helping to clean up late forum member Peter Snow's workbench.  I gather he had bought  these as a great E-bay deal, really cheap, because he had at least 100 of them in a bin.  He also had a similar number of 190k pots of the same form.  All came with a nice black control knob.  Good thing too, because the shafts are a VERY non-standard diameter.

[andy-h-h]

Fair enough.    

I've made some really small layouts before and later found that they were unnecessarily small and complicated, which just made them harder to build.   I say if you have the space, use it (within reason).  You still have room for more columns in a 1590B.     

For the volume pot, signal normally enters pin 3, exits pin 2 and pin 1 goes to ground.  If you do the reverse of this (reverse pins 1 & 3) the pot has to rotate counter-clockwise to increase level.  Also look at where the 1u cap is connected.

Good luck   

Awesome! Appreciate your help. I changed the volume pot around and adjusted the output cap.

Hey there - You might want to take another look at the output cap and the schematic.  It's still not right at present.

[ToneRangerAudio]

Fair enough.    

I've made some really small layouts before and later found that they were unnecessarily small and complicated, which just made them harder to build.   I say if you have the space, use it (within reason).  You still have room for more columns in a 1590B.     

For the volume pot, signal normally enters pin 3, exits pin 2 and pin 1 goes to ground.  If you do the reverse of this (reverse pins 1 & 3) the pot has to rotate counter-clockwise to increase level.  Also look at where the 1u cap is connected.

Good luck   

Awesome! Appreciate your help. I changed the volume pot around and adjusted the output cap.

Hey there - You might want to take another look at the output cap and the schematic.  It's still not right at present.

I'm confused on what should be changed. Are you talking about the 0.05uF cap? If so, yeah I need to slide that down.

[Elijah-Baley]

The down side of the 10nF, output cap, should go in Volume 3. You have to change a bit the layout to keep on the board the 0.50uF cap and connected on the Volume 2 and Volume 3... no so much easy, at my first sight (not impossible, of course).

Did you think of put that 0.50uF cap directly on the pot?