Boneyard suggestions and questions....

[highway jones]

Like mjcyates, I too was underwhelmed with the LEDs in the clipping section.  I wanted more clipping and compression like the BSIAB2 or red channel of the Aristocrat.  I replaced D1 and D2 with BAT41's and D3 with a MA856 (1N914 works well and is not much different, if any).  These changes gave a much spongier feel and sound is somewhat reminiscent of the MI Audio Crunchbox (which has clipping LEDs). 

How much difference would different sizes and types of red LEDs make? 

This pedal is thick!!!.....possibly a bit too thick for my tastes when using humbuckers (even with the tone knob maxed).  Which cap(s) should I experiment with to shift the frequency curve toward the upper mids?

I love the switching ability from low to high gain.  Most brown sound pedals seem to excel in low or high gain but this one seems very well balanced.  After changing the clipping structure and once I get a handle on the tone shaping, I may push the high gain pot up to 500k to see if it can be tolerated without oscillation.

Sorry, no pics yet...  I never box it up or wire in a 3PDT until I am sure I like the circuit.

[mjcyates]

shift the frequency curve toward the upper mids?

This is what I think it needs as well so if anyone has any ideas that would be great.

[stecykmi]

How much difference would different sizes and types of red LEDs make? 

probably very little since the forward voltage (the voltage needed to turn them on), is the same. Clear lens red leds may be different however.

This pedal is thick!!!.....possibly a bit too thick for my tastes when using humbuckers (even with the tone knob maxed).  Which cap(s) should I experiment with to shift the frequency curve toward the upper mids?

you can decrease the input cap and the decoupling caps, they're quite large. i would start with C2, that could be decreased a lot, maybe 0.1uF or less even. For reference, 0.022uF is a fairly common input cap for a lot of distortions, but C2 is an order of magnitude larger.

you can also try fooling around with C7 to change the feel of the tone knob. It's a low pass filter so if you decrease C7, you'll allow more high frequencies through.

you can also try decreasing C1, try something like 100pf or so.

[slimtriggers]

Thanks for the mod suggestions

My biggest complaint is the fizz on the decay.  I think that may be fixed with a diode swap. 

[Myramyd]

I agree with you. I will be trying all these mods this week also so, I will report my findings.

J

[k.rock!]

I agree with you. I will be trying all these mods this week also so, I will report my findings.

J

I'm really interested to hear your findings man...I'm actually following this thread closely cause I'm waiting for the parts to arrive to build my Boneyard and I can see already that apparently needs some work. So hopefully you guys can share your findings and as soon as I get my parts I'll experiment as well and share my results with all of you too

Thanks!

-Kaleb

[Myramyd]

Well...

After doing some experimentation tonight I've come up with a conclusion.

R5 is the key...

I socketed R5 and tried various resistor values. I don't have a 47R but I tried 120R, 100R and 33R. Having done that, I think 47R (the original value) might be just right. In my build, R5 greatly affects the gain level. 33R is quite nice (Hi-Gain is now perfect for shredding) but it starts to oscillate when you click in the boost switch and turn that up a bit, where 100R doesn't osc but isn't enough gain. Right now I'm keeping the 33R in until I can get a 47R to try.

Clipping: LEDs sound best (to me). Diodes sound too "mushy" to me--not crisp. 1N914s produce a great "Wolfmother" type fuzzy Marshall tone but, I like the LEDs better for articulation and with the change in R5, the tone gets a little sharper as well.

I may try swapping out some gain pots too, in order to see if anything changes for the better but, right now the R5 change makes it almost perfect for me. Enough to where now I want to box it!

I will report back if I try anything else.

J

[Myramyd]

When I say oscillate with the 33R, it's very minor but noticeable when you get the boost knob around halfway up.

J

[highway jones]

I will verify that 47 ohms at R5 made it right for me as well.  I also subbed back in the 1M pot for the high gain channel.  Note that I built mine without the boost and I used a MAX1044 for the charge pump.  I haven't had good luck with the TC1044 chip.  It was noisy with the Fatpants so I decided not to use it with any of my other builds.

I threw back in the red LEDs and it kills now!  The EQ has seemed to sort itself out as well.  On the low gain channel it is a bit brighter while switching to the high gain pot you hear more clipping of lower frequencies such that palm muting comes easily.

I'm boxing mine up as well.  Can't wait to crank it once the baby wakes up!

[slimtriggers]

Thanks for the tip!  I'm gonna try the 47R tonight.  I may go ahead and socket the LEDs, anyway.  I should have done that in the first place.  Socket everything

[slimtriggers]

Mine does not work at all with the 47R.  I'm going to go back and verify I didn't break something else when I made the switch. 

[Myramyd]

At the moment I have a 33R in there so, I know it works. On my way to Rat Shack to grab a 47R and pots to try for the 2 gains. I may end up putting the whole thing to "stock" specs by the time I'm done. Although the boost sounds fine as is. Reminds me of a Slambox.

Honestly, before I messed with R5 I was ready to trash this whole project because I thought I messed something up. I was very close to ordering a new board and starting over but they happened to get sold out right before I did. Good timing.

If I swap gain pots I'll report back.

J

[slimtriggers]

OK. It works.  Verified!  I think I shorted something.  When I took the bottom off, it started working again

Way better!   

[JeffdaMaori]

Very cool, thanks for all those hints, I'll try those when I get around building mine!
Muchos gracias!

[highway jones]

....still thinking about decreasing the low end when switching to high gain.  I might play around with the input cap and make it switchable (on the same switch as the low/high gain switch).