# Distortion / Boost Pedal build



## Milkman (Feb 2, 2006)

If this is not the proper area to post this please feel free to move it.

I received two of these nifty kits from Next Gen today. They were promised to ship by May 1, and instead I received it May 1 so I'd call that better than promised.

I ordered the unpainted pre-drilled version. The factory paint job that you can order looks great, but I'm having my daughter Amanda paint these ones, which should add some cool factor.

So, the kits are well packaged. They didn't ship a bunch of air as the saying goes.

I'm going to get Amanda kicked off on the enclosures before I start assembling them, but my 1st impressions are very positive.

The quality of the PCB, if you can judge such a thing by sight, is really nice.

Anyway, I'm looking forward to a fun project.


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## mhammer (Nov 30, 2007)

You'll have fun with it. The documentation is clear and thorough. The result is not likely to kick any higher-end pedals off your board, because it is a simple design, but the result is more than serviceable. The most important aspect is that it makes a great learning platform, and the board layout and design is amenable to tons of useful and practical mods.

I built it from scratch on perfboard, rather than from the kit, and explored some mods not listed in the documentation. I'd be happy to walk you through them at some point if you're game for it.

Once you get DIY in your blood, and enough chops and courage to mod, it's hard to go back. One also begins to adopt a "Well that's just a <insert commercial design here> with <insert design aspect here> changed" attitude about many commercial pedals.

But congrats.


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## Milkman (Feb 2, 2006)

I'll be happy to hear your recommendations, but please know that you'll have to dumb it down considerably.

I'm definitely interested in understanding what I'm doing and how the entire circuit works, but (and please keep this strictly confidential) I'm not the sharpest tool in the shed when it comes to this stuff and many would argue, in general.

I _can _follow clear instructions and solder a decent joint, but that's about the extent of my electronics knowledge.

I'm thinking I'll build two variations of the distortion option. I'm dropping the enclosures off with Amanda in an hour or so. She'll do something very cool with them.


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## mhammer (Nov 30, 2007)

If you have a toaster oven in the garage that isn't in use, or can pick up a used one at Value Village, baking finishes tends to make them hardier. 150 degrees for 45 minutes tends to do the trick.


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## Milkman (Feb 2, 2006)

Would baking two boxes ruin my wife's toaster oven?


Not that I'm considering doing that



but if I did consider it...…

I planned on just putting a couple of coats of poly on them but as long as the heat doesn't wreck the acrylic paint Amanda uses I could bake them as well.


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## mhammer (Nov 30, 2007)

Acrylic may not last that long, unless you clear-coat it. The difficulty with applying laquers to bare aluminum boxes is that the surface of the laquer dries first and prevents what's underneath from fully curing. I find I have to apply 3 light coats and bake each one to have a durable finish.

I doubt anyone would want to eat anything prepared, or even heated up in, a toaster oven used to bake paint finishes.


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## Milkman (Feb 2, 2006)




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## nnieman (Jun 19, 2013)

Milkman said:


> View attachment 308646


Good lord those are amazing!!

She should start selling empty pedal cases painted that like!!

*going to search kijiji for a cheap wah to send your way*

Nathan


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## Milkman (Feb 2, 2006)

nnieman said:


> Good lord those are amazing!!
> 
> She should start selling empty pedal cases painted that like!!
> 
> ...


She would love to do it for you Nathan, and it's awfully hard for me to disagree with you.

I'm blown away by the beauty of her art and she's my daughter. I'm unable to be unbiased.

I'll pass the compliment on to her.


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## Milkman (Feb 2, 2006)

By the way, my hope is that I'll do a good job assembling these, which I will then auction off with the proceeds going to our local food bank.

Amanda is a young mother and not working due to the Covid-19 situation so I'll pay her (if she'll accept) a small fee but the rest will go to the food bank.

A little black and white...


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## mhammer (Nov 30, 2007)

Not any sort of criticism of the finish itself, which is beautiful, but do you have plans for legending it in some way, or is two knobs one of those self-evident things that requires no legending?


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## davetcan (Feb 27, 2006)

Outstanding looking boxes, really outstanding.

As for applying some script I think I'd be tempted to just put it right on the knobs if necessary. A simple "V", "T", "G", or "B", "M", "T" should get you by.


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## Milkman (Feb 2, 2006)

mhammer said:


> Not any sort of criticism of the finish itself, which is beautiful, but do you have plans for legending it in some way, or is two knobs one of those self-evident things that requires no legending?


I'm still tossing that around in my mind. It's a simple enough pedal that it _could _be ok without a little D and V or I could annotate the knobs themselves or hand paint little letters over the art.

TBD

What would you do?


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## mhammer (Nov 30, 2007)

I'd probably opt for knobs that had a flat surface on the top, and get your daughter to paint V and D/F/G (drive/fuzz/gain) on top of each knob.


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## knight_yyz (Mar 14, 2015)

Just watch a bunch of acrylic youtube videos. It is not a hard thing to do. You would just have to scale down the amount of paint used.


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## vadsy (Dec 2, 2010)

reminds me of the old Rockbox Boiling Point pedals


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## davetcan (Feb 27, 2006)

vadsy said:


> reminds me of the old Rockbox Boiling Point pedals


Yep. There was also a girl that sold painted housings on ebay called "Lucibox" or something like that. She did nice work.


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## davetcan (Feb 27, 2006)

mhammer said:


> I'd probably opt for knobs that had a flat surface on the top, and get your daughter to paint V and D/F/G (drive/fuzz/gain) on top of each knob.


What a great idea


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## oldjoat (Apr 4, 2019)

a cheap hair dryer ( thrift store ) can also help speed up the drying time between coats ... 
just make sure you let 'em cool off before re-painting.


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## mhammer (Nov 30, 2007)

davetcan said:


> What a great idea


Thanks. Necessity, mothers, inventions, and all that. I was going to suggest he get a pair of Fender Volume and Tone knobs, which have the full word printed on top, but felt it was likely an aesthetic mismatch, and Tone was maybe a poor choice of descriptor. White painted lettering atop a knob like this might be a nice match, but I see the indicator slot runs across the entire top, so maybe not. I guess it would depend on the paint used.


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## davetcan (Feb 27, 2006)

LOL, completely missing the fact I'd already suggested it  It's OK, my wife ignores me too.



mhammer said:


> Thanks. Necessity, mothers, inventions, and all that. I was going to suggest he get a pair of Fender Volume and Tone knobs, which have the full word printed on top, but felt it was likely an aesthetic mismatch, and Tone was maybe a poor choice of descriptor. White painted lettering atop a knob like this might be a nice match, but I see the indicator slot runs across the entire top, so maybe not. I guess it would depend on the paint used.


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## Milkman (Feb 2, 2006)

The knobs that came with the kits are actually quite nice, (set screws and inserts) and I think the flat sections are wide enough to fit a decent sized V or D.

I wonder if I could imprint the letters with heat and then fill with white paint.....

Too much?


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## vadsy (Dec 2, 2010)

Milkman said:


> The knobs that came with the kits are actually quite nice, (set screws and inserts) and I think the flat sections are wide enough to fit a decent sized V or D.
> 
> I wonder if I could imprint the letters with heat and then fill with white paint.....
> 
> ...


the heat is a cool idea


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## oldjoat (Apr 4, 2019)

possibly a set of cheap letter punches ( princess auto) 
clamp in a pair of vice bites (locking pliers)
a small propane torch to heat the metal punch tip and burn away...

or shorten and turn the shanks down , and insert into a wood burning iron.


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## Milkman (Feb 2, 2006)

oldjoat said:


> possibly a set of cheap letter punches ( princess auto)
> clamp in a pair of vice bites (locking pliers)
> a small propane torch to heat the metal punch tip and burn away...
> 
> or shorten and turn the shanks down , and insert into a wood burning iron.


Option A was basically what I was thinking, then a little white paint in the impression.

If so I’ll test it on similar material first.


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## greco (Jul 15, 2007)

vadsy said:


> ... heat is a cool idea


Groan...


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## Hammerhands (Dec 19, 2016)

You can have knobs laser etched.


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## davetcan (Feb 27, 2006)

I still have one of these kicking round somewhere.


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## Milkman (Feb 2, 2006)

Hammerhands said:


> You can have knobs laser etched.



Dang, you're right and I know a place here in the city that does that sort of thing (trophy maker).

Good idea, thanks.


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## Milkman (Feb 2, 2006)

I took a whack at assembling the PC Board for the first distortion pedal.

I had to go back and correct (add a couple of missing resistors) but although it may not be pretty I don't think I have any cold solder joints or shorts.

We'll see.


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## mhammer (Nov 30, 2007)

Looks okay to me.

In view of how much of a flexible platform for modding it is, I will suggest that you connect in and out jacks, and power, to the board, for the time being, and try it out. That way, if you'd like a little more of this or less of that, you can do the changes without having to disassemble and reassemble it in the enclosure. Saves wear and tear on a nice paint job, too. Once you have it sounding the way you like, THEN you can add all the bells and whistles like stompswitch, status LED, etc.


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## Milkman (Feb 2, 2006)

mhammer said:


> Looks okay to me.
> 
> In view of how much of a flexible platform for modding it is, I will suggest that you connect in and out jacks, and power, to the board, for the time being, and try it out. That way, if you'd like a little more of this or less of that, you can do the changes without having to disassemble and reassemble it in the enclosure. Saves wear and tear on a nice paint job, too. Once you have it sounding the way you like, THEN you can add all the bells and whistles like stompswitch, status LED, etc.


The first one will be built to the specifications in the manual.

I would like to do the second one per the Rat-esque modification Mr. Beal mentioned that you had a hand in developing.

Are you able to tell me which components to replace, and with what please?


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## Dorian2 (Jun 9, 2015)

So far so good man! Hoping for a recording of the pedal when all is said and done.


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## Milkman (Feb 2, 2006)

Dorian2 said:


> So far so good man! Hoping for a recording of the pedal when all is said and done.


If I plug this in and it works, count on a clip for sure and some of my normal pic whoring.


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## mhammer (Nov 30, 2007)

Milkman said:


> The first one will be built to the specifications in the manual.
> 
> I would like to do the second one per the Rat-esque modification Mr. Beal mentioned that you had a hand in developing.
> 
> Are you able to tell me which components to replace, and with what please?


First, a disclaimer. It doesn't _sound_ like a Rat (although I imagine one could move it in that direction), but rather borrows a trick _used_ in the Rat for a punchier harder sound.

I hope Jon and Tom will forgive my shuffling around of the schematic. I like to squish them so that when I print them out in landscape, they come out large on the sheet.

Shuffling aside, cast your gaze down to C6/R8. Those two components play a role in setting both the low-end rolloff and the range of gains achievable. As shown, they provide gains of a little over 1x to a bit over 22x, which is suitable for a simple cleanish booster (power chords will likely clip a little bit). If one increases the value of the Gain pot to 500k, then the gain range becomes 1x to just under 108x, which puts you within spiting distance of the gain range of a Tube Screamer. Using a 1meg Gain pot puts you in the range of a Distortion+ and DOD250. C6 sets the low-end rolloff at around 7hz, which is much better than either of those pedals, but a lot lower than one really needs. If C6 = 0.47uf (470nf), that bumps your low-end rolloff up to 72hz, which is comfortably low, but still has some heft to it.

The Proco Rat has a second pair of components in parallel with the functional equivalent of C6/R8. It involves a smaller value cap and a smaller value resistor. The specific value are different than what I'll describe and am showing here. What matters is that they end up providing _*much*_ more gain for content above 1540hz; in the thousands. I'm not aiming for that here; just for a slightly more vicious bite.

If you connect a 100nf (0.1uf) cap in series with a 1k resistor, and connect that pair in parallel with C6/R8, that provides greater gain (about 5x more) for content above 1590hz. So if the drawing shown here gives a max gain of 22x for everything down to 7hz, the two extra components hike that up to 101x for stuff above 1590hz. If you used a 1meg Gain pot, to get a max gain of 214x for full bandwidth, the two extra components would push that up to 1002x for the upper mids and treble.

The venerable Tube Screamer, SD-1, and many workalikes use a different strategy, by making the part equivalent to C6 a much smaller value. It provides a bass rolloff beginning around 720hz. While that certainly affords an "advantage" to mids and highs, in terms of clipping as easily as lower notes do, it's not "flat". The dual-path approach has no bass rolloff to produce the annoying "mid-hump". It keeps the bass solid, and simply gooses that part of the spectrum that has a disadvantage in clipping, because it is normally a lower amplitude coming into the pedal. Of course, because we've goosed the top end so much, we've also increased the gain applied to any hiss coming in. In which case, C7 is called for to smooth out the brittle edges. I'll suggest 47pf. With a 1meg Gain pot that provides a rolloff starting around 3380hz at max gain, and starting much higher up as the Gain is decreased. That still leaves plenty of sizzle, so I supplemented it by sticking a 500k pot, in series with a 15nf cap, where C9 goes. That provides a Treble cut, similar to what your guitar Tone control does.

But, like I say, fire it up stock, to confirm your build and how it sounds, before you start implementing any mods.


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## Milkman (Feb 2, 2006)

mhammer said:


> First, a disclaimer. It doesn't _sound_ like a Rat (although I imagine one could move it in that direction), but rather borrows a trick _used_ in the Rat for a punchier harder sound.
> 
> I hope Jon and Tom will forgive my shuffling around of the schematic. I like to squish them so that when I print them out in landscape, they come out large on the sheet.
> 
> ...


I'll need to read this over carefully to make sure I understand everything you've said.

I appreciate the input and advice. I am after all, trying to gain some understanding as a part of this little project.


Thank you!!


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## mhammer (Nov 30, 2007)

Not to worry. We'll get you there. If any part of what I posted is unclear, just let me know and I'll make it clearer. And we can certainly discuss any other changes you're thinking about making to the circuit as you explore it.


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## keto (May 23, 2006)

mhammer said:


> First, a disclaimer. It doesn't _sound_ like a Rat (although I imagine one could move it in that direction), but rather borrows a trick _used_ in the Rat for a punchier harder sound.
> 
> I hope Jon and Tom will forgive my shuffling around of the schematic. I like to squish them so that when I print them out in landscape, they come out large on the sheet.
> 
> ...



It would be much clearer, I hope you don't mind me saying, if you said
'replace C6 with XXXXX' - does THIS'
'replace R92 with XXXXX - does THIS'

The way it's written is hard to follow.


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## mhammer (Nov 30, 2007)

Noted.


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## Milkman (Feb 2, 2006)

There's a great part of the Rush doc Beyond the Lighted Stage, where Ted Colbert asks the guys if they've ever written a piece so epic, that by the time they got to the end of the piece, they were being influenced by themselves because it took so long to write.

I followed it, but I like to read things several times and consider them.


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## Paul M (Mar 27, 2015)

Milkman said:


> There's a great part of the Rush doc Beyond the Lighted Stage, where Ted Colbert asks the guys if they've ever written a piece so epic, that by the time they got to the end of the piece, they were being influenced by themselves because it took so long to write.


Reading this post,I immediately thought of both Frank Zappa, and The Roots. I've read an argument that FZ's body of work could be considered to be one long piece if music. The Roots numbered the tracks on their 1st albom 1-10, the 2nd 11-20, etc......the idea being that each album doesn't stand alone, but is a continuation of the previous one. 

What I take from that, and what I hear in the music of groups like RUSH!, FZ, The Roots, is that there is very little happenstance or luck involved. The music is *very* carefully considered and crafted.

Other groups, (Allman Bros., Phish, The Grateful Dead), are much looser, taking chances, and often getting a bit lucky. 

Both ways can create some beautiful music. I find it easier to study and arrange well crafted music, (for lack of a better term), but wish I had both the technical skill, and creative freedom to just freely play.

FWIW, I am also unable to colour outside the lines. 

Sorry for the de-rail.


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## Milkman (Feb 2, 2006)

The two enclosures are now in my daughter's hands and I should have them back tomorrow.

I'm inclined to complete one full assembly before starting on the second just to refine my method a little.

Again, if I eff this up, it's not because the instructions were unclear or inaccurate. That alone is refreshing.


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## Milkman (Feb 2, 2006)

1st Coat of poly.


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## Milkman (Feb 2, 2006)

I applied the third coat of poly and I'm using an incandescent light to apply a little gentle heat to help dry things more quickly.

The surfaces will have texture. I'm not level sanding these. They'll be well protected.

I also have another enclosure which I'll stay mum about for now.

I hope to get to work on the assembly of the first distortion pedal this afternoon.


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## mhammer (Nov 30, 2007)

Well that settles it. Now you HAVE to get some of those illuminated stompswitch rings. The question is, though, what colour should they light up as?


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## Milkman (Feb 2, 2006)

Ok, all assembled and it's trouble shooting time.

I have a good clean bypass signal. LED lights up, but weak signal and no effect when engaged. Both pots seem to have an effect. If both are off no sound when engaged. Turn the pots up and you get the weak signal.

I haven't tried it with a battery yet.


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## jbealsmusic (Feb 12, 2014)

Milkman said:


> Ok, all assembled and it's trouble shooting time.
> 
> I have a good clean bypass signal. LED lights up, but weak signal and no effect when engaged. Both pots seem to have an effect. If both are off no sound when engaged. Turn the pots up and you get the weak signal.
> 
> ...


Looking at the picture, you have what appears to be a 4.7uF electrolytic cap at C9. That one should be a 4.7nF Polyester Film Box cap (found in the "Bonus Parts For Distortion Configuration" bag). Perhaps that is the culprit?


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## mhammer (Nov 30, 2007)

If Jon's observation is accurate, oh yeah that would do it. If R9 = 10k and C9 = 4n7, you get a treble cut starting just under 3.4khz. If C9 = 4u7, which is 4n7 x 1000, you lower the rolloff point by 1000, down to 3.4hz. That would provide a barely audible output, even with gain and volume dimed.

And, to make sure you don't feel like an idiot, I'll simply note that I've lost track of the number of times I've said to myself "What the hell is THAT part doing there?", when troubleshooting builds.


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## Milkman (Feb 2, 2006)

jbealsmusic said:


> Looking at the picture, you have what appears to be a 4.7uF electrolytic cap at C9. That one should be a 4.7nF Polyester Film Box cap (found in the "Bonus Parts For Distortion Configuration" bag). Perhaps that is the culprit?


Looks like a likely candidate. Thanks very much.

I found one, but I may have put it into the wrong baggie.

The label says 47nF but I already have that one in C7.

The electrolytic cap I have is annotated (on the cap itself) 473J100.

Is that the correct cap for C9?


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## Milkman (Feb 2, 2006)

Well, if the goal is to learn while doing, I'm learning.

That did change things, but not 100% where it should be.

Now I have a bit stronger signal when engaged (no change to the bypassed signal which is still ok), but no real effect and when I max the gain pot it sounds like a poorly tuned 4 cylinder ICE.

No crazy hums or anything, but I've obviously goofed something up somewhere in the process.


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## jbealsmusic (Feb 12, 2014)

Milkman said:


> Is that the correct cap for C9?
> 
> View attachment 310882
> View attachment 310884


C5 = 47nF Polyester Film Box Cap (looks like you have the 4.7nF cap in that position in the picture you provided)
C7 = 47pF Ceramic Disc (you've done that one right)
C9 = 4.7nF Polyester Film Box Cap (the one you seemingly have soldered in at C5)

To fix:
- Remove what you currently have soldered into C5 and C9
- Solder the 47nF Polyester Film Box cap (labelled 473J100) into C5
- Solder the 4.7nF Polyester Film Box cap (labelled 472J100) into C9

You're so close! You'll get there.


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## Milkman (Feb 2, 2006)

Ok, I may have figured this out.

This one should go in C9

I wondered why it looked different.

Back to the workbench.
View attachment 310894


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## davetcan (Feb 27, 2006)

Boy, they turned out terrific, I absolutely love what she does.



Milkman said:


> I applied the third coat of poly and I'm using an incandescent light to apply a little gentle heat to help dry things more quickly.
> 
> The surfaces will have texture. I'm not level sanding these. They'll be well protected.
> 
> ...


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## jbealsmusic (Feb 12, 2014)

Milkman said:


> Ok, I may have figured this out.
> 
> This one should go in C9 and was missing from the 1st kit.
> 
> ...


If the "1st kit" you're referring to is the PCB you already completed and pictured earlier, you mistakenly soldered that into C5 by mistake.

To fix:
- Remove what you currently have soldered into C5 and C9
- Solder the 47nF Polyester Film Box cap (labelled 473J100) into C5
- Solder the 4.7nF Polyester Film Box cap (labelled 472J100) into C9

You're there man. You're there!


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## mhammer (Nov 30, 2007)

That third digit on caps (e.g., 473 vs 472) is as much of a pain in the butt as the often negligible difference in hue between orange and red "third stripes" on resistors. Those sorts of things are precisely why it is good to have:
a) good lighting,
b) a magnifier of some kind
c) a meter
...handy when building stuff. As the saying goes, "Trust, but verify".

Probably one of the handiest bits of math you will need is the formula for calculating corner frequency of rolloffs. Frequency = 1 / (2 x pi x resistance x capacitance), where R is in megohms, and C is in microfarads. So, consider R8/C6, which are .0047megohms and 4.7uf.

2 x pi x .0047 x 4.7 = .139 Take the reciprocal on your Windows calculator (1/x) and you get 7.2hz. If we made C6 47nf (473), just like the Tube Screamer, we'd get: 

2 x pi x .0047 x .047 = .00139 Take the reciprocal of that and we get a rolloff starting around 720hz.

Works exactly the same way for bass and treble rolloffs. In the feedback loop of IC1a, using the stock "booster" values, we have a "mystery cap" and 1k in series with a 100k pot. The lowest point of treble cut will occur when the Gain pot is maxed (i.e., pot + resistor = 101k). If C7 was 470pf, then at max gain, the rolloff would begin around:

2 x pi x .101 x .00047 = 3352hz (3.35khz) Make C7 half the value and the rolloff begins an octave higher. Make C7 double the value and the rolloff begins an octave lower. And so on.

It's one of those formulas that becomes indispensable for drive pedals, because you always want to know "What am I feeding in?" and "What am I letting out?". It's also handy because a great many commercial pedals provide for more bandwidth, whether at the low end or at the high end, than you want or need. Calculating what they provide allows you to know what you can shave off, or even increase, using the parts you have on hand.


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## Milkman (Feb 2, 2006)

Well, ugly soldering notwithstanding I have replaced the incorrect components, I'll seat them down more permanently later, but not until I'm sure it's working right.

I still have no effect and that strange oscillating noise when the pots are maxed.

Clean signal is still fine.

Not to make excuses, but I'm blaming shitty eyesight on some of this, LOL.


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## Milkman (Feb 2, 2006)

One thing I noticed that's a little strange and might help someone more savvy than me to diagnose the problem is that the LED will work when there' nothing plugged into the input jack.

As long as I have an adapter connected the LED comes on anytime I hit the switch.

I don't recall seeing that in any pedal before.

Does that ring any bells?


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## mhammer (Nov 30, 2007)

That's what happens when you use an external supply. In the "good old days", a stereo jack would be used for the input jack, and the black/ground lead from the battery connector wired to the ring lug on the input jack. When a mono lug was inserted into the stereo jack, the ground lead from the battery would be automatically connected to circuit/enclosure ground, to power up the circuit. If you external power jack is _directly_ connected to the circuit board, then as soon as external power is applied, it goes to the board, regardless of whether there is anything plugged in or not.

If you attempt building any other pedals in future, I will point out that not every phone jack model has the lugs in the same location. If one doesn't pay close attention, ground wires from the battery can inadvertently be connected to the wrong lug on the jack. Most often this results in a post containing the phrase "I don't get it. I put in a brand new battery last night, and unplugged everything when I stopped playing, but today the battery is completely drained.".


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## Milkman (Feb 2, 2006)

mhammer said:


> That's what happens when you use an external supply. In the "good old days", a stereo jack would be used for the input jack, and the black/ground lead from the battery connector wired to the ring lug on the input jack. When a mono lug was inserted into the stereo jack, the ground lead from the battery would be automatically connected to circuit/enclosure ground, to power up the circuit. If you external power jack is _directly_ connected to the circuit board, then as soon as external power is applied, it goes to the board, regardless of whether there is anything plugged in or not.
> 
> If you attempt building any other pedals in future, I will point out that not every phone jack model has the lugs in the same location. If one doesn't pay close attention, ground wires from the battery can inadvertently be connected to the wrong lug on the jack. Most often this results in a post containing the phrase "I don't get it. I put in a brand new battery last night, and unplugged everything when I stopped playing, but today the battery is completely drained.".


The input jack IS stereo on this.

And, when I tried a battery the LED only works when there's a cord plugged into the input. That's not a concern, I just wonder if it may shed light on the malfunction I still have.
(I still have that oscillation and no effect.)


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## mhammer (Nov 30, 2007)

Milkman said:


> The input jack IS stereo on this.
> 
> And, when I tried a battery _the LED only works when there's a cord plugged into the input_. That's not a concern, I just wonder if it may shed light on the malfunction I still have.
> (I still have that oscillation and no effect.)


Yep, that's how it's supposed to work. And since the ground connection is generally in place for the external-power jack, plugging an adaptor in allows the circuit to work and the LED to light up even when there isn't a plug inserted to the input jack.

I'm a little concerned about some of the solder joints on the board. It can sometimes be the case that a solder joint is a little bigger than one intended, and a solder bridge is formed between two or more areas that should not be in contact with each other. The solder flux can sometimes make those solder bridges a little harder to see, so what I like to do is take an old toothbrush or Q-tip and brush on some methyl hydrate. It will dissolve the flux, which you can then wipe up with a paper towel or Q-tip. It's not _essential_, merely helpful. Once you've checked each solder joint to make sure it isn't inadvertently shorting anything, then we can start to examine other possible sources.

Incidentally, what value of Gain pot are you using?


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## Milkman (Feb 2, 2006)

mhammer said:


> Yep, that's how it's supposed to work. And since the ground connection is generally in place for the external-power jack, plugging an adaptor in allows the circuit to work and the LED to light up even when there isn't a plug inserted to the input jack.
> 
> I'm a little concerned about some of the solder joints on the board. It can sometimes be the case that a solder joint is a little bigger than one intended, and a solder bridge is formed between two or more areas that should not be in contact with each other. The solder flux can sometimes make those solder bridges a little harder to see, so what I like to do is take an old toothbrush or Q-tip and brush on some methyl hydrate. It will dissolve the flux, which you can then wipe up with a paper towel or Q-tip. It's not _essential_, merely helpful. Once you've checked each solder joint to make sure it isn't inadvertently shorting anything, then we can start to examine other possible sources.
> 
> Incidentally, what value of Gain pot are you using?



Thanks very much. I'll stop by the hardware store and pick up some methyl hydrate. I also need a new solder wick and one or two other little things.

In addition to poor eyesight these days I also have the steady hands of Don Knotts. I'll go over it again with a fresh set of eyes today.

The gain pot is 250k ohm. The volume is 100k ohm.


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## mhammer (Nov 30, 2007)

Milkman said:


> Thanks very much. I'll stop by the hardware store and pick up some methyl hydrate. I also need a new solder wick and one or two other little things.
> 
> In addition to poor eyesight these days I also have the steady hands of Don Knotts. I'll go over it again with a fresh set of eyes today.
> 
> The gain pot is 250k ohm. The volume is 100k ohm.


Just remember that, while it's not acetone or anything that instantly nasty, methyl hydrate is not exactly benign either, so use with care. Sadly, the amount you need for this task is MUCH less than the smallest container size it comes in. I hope you can find other uses for it, like thinning or removing paint.

With a 250k Gain pot, I'd recommend a feedback cap in the range of 150-220pf. At max gain, the treble rolloff with a 220pf cap will be just under 2.9khz. That may seem low, but remember that a) the slope is shallow, still permitting treble to come through, albeit at a lower level, and b) the diode clipping will add harmonic content beyond what you're feeding the diodes. Because of the way feedback caps work, you'll have more bandwidth than 2.9khz at the high end as the gain is turned down. But since lower gain settings will also mean less diode clipping, that improved bandwidth won't translate into annoying harshness.


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## Milkman (Feb 2, 2006)

mhammer said:


> Just remember that, while it's not acetone or anything that instantly nasty, methyl hydrate is not exactly benign either, so use with care. Sadly, the amount you need for this task is MUCH less than the smallest container size it comes in. I hope you can find other uses for it, like thinning or removing paint.
> 
> With a 250k Gain pot, I'd recommend a feedback cap in the range of 150-220pf. At max gain, the treble rolloff with a 220pf cap will be just under 2.9khz. That may seem low, but remember that a) the slope is shallow, still permitting treble to come through, albeit at a lower level, and b) the diode clipping will add harmonic content beyond what you're feeding the diodes. Because of the way feedback caps work, you'll have more bandwidth than 2.9khz at the high end as the gain is turned down. But since lower gain settings will also mean less diode clipping, that improved bandwidth won't translate into annoying harshness.


I appreciate the response. Can you explain where to install the feedback cap please?

I suspect I'll have other uses for the methyl hydrate. I'm sure I've done something glaringly wrong, so I'm hopeful I'll be able to track it down and correct that.

Really I should view the first kit as my basic training. I honestly did learn some basic techniques that I will surely apply to the second one, and I'm fairly confident that the second one will simply work if I apply those improvements. I mean, you _think _you know how to do things but I'm finding gaps in that assumed knowledge.


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## mhammer (Nov 30, 2007)

Whenever I build a pedal, the second one always comes out much better than the first. It's been like that since 1980.

The feedback cap is in parallel with the Gain pot and 1k resistor. It goes between pins 1 and 2 on the chip. Such caps are quite small so you can easily "tack" it on the copper side of the board, with a wee bit of solder to those particular pads. Too easy to lose track of things when flipping the board over and inverting everything, so pay attention to which pad is which.

You're quite fortunate to have such a thoughtful and build document and well-planned circuit-board and kit to start with, and some "aftermarket help" to supplement that. I have little doubt that you'll learn a lot, and very quickly. Won't be long before you're modding your other pedals.


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## Milkman (Feb 2, 2006)

mhammer said:


> You're quite fortunate to have such a thoughtful and build document and well-planned circuit-board and kit to start with, and some "aftermarket help" to supplement that. I have little doubt that you'll learn a lot, and very quickly. Won't be long before you're modding your other pedals.


You're not kidding. The amount of spoon feeding I'm getting from you and others here is not taken for granted.

I'm also trying to gain some base knowledge by slowly reading Basic Electronics by Paul Daak.


Is there another reference book you would care to recommend, remembering that you're not helping a rocket surgeon here?


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## mhammer (Nov 30, 2007)

Wish I could, but I'm almost entirely self-taught by trial and error and others on the stompbox forum much savvier and trained in these areas than I.

But certainly ask questions as they come up, and I'm sure we'll all do our best to clarify. And, truth be told, you'll actually learn more by having your questions-of-the-moment well-answered than by plowing through a text with theory not particularly well-anchored in your practical concerns.

I'll put in a big plug for the diystompbox forum, literally THE best resource for such matters on the web.


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## Milkman (Feb 2, 2006)

LOL, I drove by the hardware store to look for Methyl hydrate and a new desoldering wick, maybe a better quality "helping hand" device.

The line up was stupid. I kept driving. I'll try earlier in the day tomorrow.

And I'm still shaking my head about Mr. Hammer being self taught.

If I'm learning one thing as I get older (maybe taking longer than some would like) it's that I'm just not quite as smart as I once thought.

That provides me with ample opportunities for improvement.


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## mhammer (Nov 30, 2007)

Do NOT confuse what took me 45 painstaking years to learn with something that "comes easy" or "natural". What took me 45 years will come to you in 2, at most. Really. The same internet that gives us 9 year-olds who can compete with Steve Vai, also makes it possible for people to go from a cold start to award-winning boutique pedalmaker in less time than it takes to get an MBA from University of Phoenix. Read some of the interviews with various pedal makers here: http://www.effectsdatabase.com/interviews/brands and you'll be as surprised as I was to learn how recently they started.


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## Milkman (Feb 2, 2006)

mhammer said:


> Do NOT confuse what took me 45 painstaking years to learn with something that "comes easy" or "natural". What took me 45 years will come to you in 2, at most. Really. The same internet that gives us 9 year-olds who can compete with Steve Vai, also makes it possible for people to go from a cold start to award-winning boutique pedalmaker in less time than it takes to get an MBA from University of Phoenix. Read some of the interviews with various pedal makers here: http://www.effectsdatabase.com/interviews/brands and you'll be as surprised as I was to learn how recently they started.


Well yes, that's the "easy to be tall when you stand on the shoulders of giants" paradigm I suppose.

But no, I won't learn in 2 years what you have in 45.

I definitely WILL shamelessly try to glean what I can from you and others here.

And I do appreciate it.

Thanks


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## mhammer (Nov 30, 2007)

You're welcome. Start yer engines!


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## Milkman (Feb 2, 2006)

I picked up a few supplies and will resume my pedal assimilation next week.


Resistance is futile.


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## mhammer (Nov 30, 2007)

What is that Zemaitis looking thing in the corner?


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## Milkman (Feb 2, 2006)

You kid?

That's a guitar that doesn't get played enough lately.


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## mhammer (Nov 30, 2007)

But what is it? I can't imagine you'd spend good money on a Zemaitis or a Teye and ignore it. The headstock and pickups are intriguing me. Maybe I'd be less intrigued if I saw it more closely with a better image, but for now it tickles my curiosity.


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## Milkman (Feb 2, 2006)

Sorry, it’s a Greco Zemaitis.

I must have posted pictures of it, probably a NGD thead.

Edit: I just found the NGD thread, but all the pictures are gone. I was hosting them on photobucket at the time.

NGD Greco Zemaitis GZ500S Diamond


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## mhammer (Nov 30, 2007)

Hah! Nice score. Remarkable how instantly identifiable it is. I guess that's a testiment to Tony Z.


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## Milkman (Feb 2, 2006)

It's a shameful waste is what it is.

In terms of fit and finish, and overall quality I would rank it among the best instruments I have ever owned, without hesitation.

I'll bet I haven't played it in more than a year. I may have changed the strings on it sometime in 2019 just for something to do.


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## mhammer (Nov 30, 2007)

S'okay. I have a bunch of things I haven't played in ages. Easy to acquire things. Harder to be faithful to them.


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## Milkman (Feb 2, 2006)

mhammer said:


> S'okay. I have a bunch of things I haven't played in ages. Easy to acquire things. Harder to be faithful to them.


It really is one of the finest I’ve ever owned.


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