Skreddy - Mayo

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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culturejam
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Post by culturejam »

Anybody know what happened to that matrix of parts values of the different Muff versions that used to be in this thread? Now it's just a dead Flickr link. :cry:

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Barcode
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Post by Barcode »

nelson wrote:fuck the mayo
this is just downright unnecessary. please don't bring our forum down to this level.

oh yeah, and what DID happen to that layout and conversion chart?

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Gila_Crisis
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Post by Gila_Crisis »

it seam that you must write to nokaster to have those layouts!
Last edited by Gila_Crisis on 16 Feb 2009, 21:03, edited 1 time in total.
Zwischen Ordnung und Chaos fangt die Musik an

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culturejam
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Post by culturejam »

Many thanks, sir.

:applause:

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L_Z_Nut
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Post by L_Z_Nut »

Over the past few days or so I've been working on implementing the mayo specs to the tonepad and GGG big muff layouts. I was wondering if anyone could take the time and check these over for me. I won't bother posting any parts that have not changed.

Tonepad stock version. http://www.tonepad.com/getFile.asp?id=94

The tonepad layout also has a 2.7k resistor between the emitter of Q4 and C13 R21, a 100uf elec cap going to 9V and ground, and a 47 pf cap going from lug 2 of the volume control to ground, swap R7 with C4, and a 1N400X diode between the board positive and 9V.

R1 - 33k
R4 - 18k
R6 - 820R
R7 - 8.2K
R8 - 56k
R10 - 10k
R15 - 18k
R17 - 33k
R18 - 33k
R21 - 8.2k
R22 - 2.7k

C1 - .01uf
C2 - 470pf
C3 - .01uf
C4 - .22uf
C5 - .22uf
C6 - 470pf
C7 - .2uf
C8 - .22uf
C9 - 470pf
C10 - .0047uf
C13 - .1uf

GGG schematic http://www.generalguitargadgets.com/pdf ... tri_sc.pdf layout http://www.generalguitargadgets.com/pdf ... tri_lo.pdf

The GGG layout has 2.7k resistor between the emitter of Q4 and C13 R24, swap C4 for R8, add a 47pf cap from lug 2 of volume to ground, and add a 1N400x diode between the board positive and 9V.

R1 - 33k
R2 - 100k
R3 - 470k
R4 - 100R
R5 - 18k
R7 - 820r
R9 - 56k
R11 - 10k
R12 - 100R
R14 - 100k
R15 - 470k
R16 - 100R
R17 - 18k
R18 - 33k
R19 - 33k
R24 - 8.2k

C2 - 470pf
C4 - .22uf
C5 - 470pf
C6 - .22uf
C7 - .2uf
C8 - 470pf
C9 - .22uf
C10 - .0047uf

There might have been some mistakes or typos. Thanks for any help.

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Post by SpencerPedals »

I guess I can do you one better: last night I downloaded Eagle and learned to use it by modifying the Gaussmarkov/Nordic layout for the Muff (a very concise and organized layout) to Mayo specs. I used the schematic listed early in this thread. I was already done with the schematic when I saw this addition to the thread. This'll be a standalone Mayo board with adapted parts already integrated. I'm excited to finally be able to contribute something to this site after learning from it for the past few months. So, here's what I came up with:

Layout -
Image

PCB Transfer -
(This looks huge but when you save it and open it in Photoshop or something, it's small)
Image

Parts List -
(Posting as an image because I can't figure out a way to get it to format as text)
Image

That's what I came up with and it looks good after some proofreading. If someone else finds something off, please let me know and I'll correct it. Thanks to Gaussmarkov and Nordic for arranging the board and posting the Eagle files to make way for this layout. This still fits in a Hammond 1590B box. I haven't etched the board yet so technically it is not verified. I'll be doing so later this week and will update the thread when I do so. Until then, comments or suggestions are welcomed. Thanks,

Steve

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Post by SpencerPedals »

I populated the board today and the layout is very clean. I'll be changing some of the cap sizes (physical size, not value) on the layout to make things perfect. I couldn't hook it all up as I don't have a 390K resistor. I'll be making another Mouser order within a few days and will update after I get that.

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Post by JimiB »

whats the board supposed to measure?

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SpencerPedals
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Post by SpencerPedals »

2.16" X 1.81"

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Post by L_Z_Nut »

It looks like you missed a trace from lug 2 of sustain to R7.

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Post by SpencerPedals »

Dammit, you're right...I forgot to route that one to complete it. I already have the board etched (that's an easy fix if it's the only one needed) and have it all populated, with the exception of the 390K resistor that I've been short that just arrived today. I also etched the enclosure today. I'll be testing it all out in the next few days. I'm taking off right now but I'll update those files tonight if I'm back by then or tomorrow morning. Thanks a lot for pointing that out.

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Post by SpencerPedals »

A bit late on these and I apologize, but I got the files updated. The trace is updated now and the cap sizes have been changed to more appropriate ones. I populated a board already with the old ones and they all worked fine but some needed excessive bending. The cap size changes allow the few large film caps to fit in better. That's little stuff but it all makes it go more smoothly. I spent today working too much on pedals for other people (note to self: don't tell friends that play guitar that you can build pedals) and didn't get it hooked up yet. I'll post an update when I do. Files:

Image

Image

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Post by Whoismarykelly »

Thats a great looking board. FWIW - most of those large film caps dont actually fit the Skreddy board and have legs bent under to fit pads half as wide as the cap.

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Skreddy
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Post by Skreddy »

SpencerPedals wrote:A bit late on these and I apologize, but I got the files updated. The trace is updated now and the cap sizes have been changed to more appropriate ones. I populated a board already with the old ones and they all worked fine but some needed excessive bending. The cap size changes allow the few large film caps to fit in better. That's little stuff but it all makes it go more smoothly. I spent today working too much on pedals for other people (note to self: don't tell friends that play guitar that you can build pedals) and didn't get it hooked up yet. I'll post an update when I do. Files:

Image
Please don't title that "Skreddy Mayo" 'cause it's not. It's something you created yourself, not something I created. You can attribute me and Mike Matthews, et al, for parts and/or values selection all day long, but in the end it's a "Spencer" artwork.

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Post by mudbuddy11 »

I've just started really diving into building pedals, and at this point I'm really just a copy/paster... taking parts of common circuits and cobble them together, really just understanding enough to be dangerous. I'm impressed by Screddy... to be so open and to actually give pointers on aproximating your tone is wonderful.

I'm wondering about the carbon composition resistors and the tropical fish caps. I've been using metal caps and metal resistors in all my builds, thinking I was using 'boutique' components. Are you using all NOS parts, and is there a big difference in sound between the two types of resistors... and how about the caps? Can you tell me how the sound is different using your tropical fish over my boxed metal film caps?

Thanks for your tips... and just for generally hanging around..

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Post by soulsonic »

Tropical fish caps are metalized film caps, very similar to AVX, Wima, and other "box" caps. They are actually probably closest in construction to "greenies".
I got some tropical fish recently, broke one open, and that's what I found inside.

I think if you want to try something really special, I recommend looking for some film/foil caps. These have the metal electrode as a separate foil, whereas the metalized ones have the metal deposited directly on the film. Polystyrene foil caps are cool for low values and they're not expensive.
"Analog electronics in music is dead. Analog effects pedal design is a dead art." - Fran

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SpencerPedals
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Post by SpencerPedals »

Skreddy wrote: Please don't title that "Skreddy Mayo" 'cause it's not. It's something you created yourself, not something I created. You can attribute me and Mike Matthews, et al, for parts and/or values selection all day long, but in the end it's a "Spencer" artwork.
Sorry for the confusion Marc and everyone. I've removed the title and updated the file to reflect that it is an existing layout modded to Mayo specs - not the layout of a Skreddy pedal.

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Skreddy
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Post by Skreddy »

Caps--tropical fish and others that are close?

Yeah; greenies are close. Tropical fish seem to impart a sweeter, fatter tone; so to emulate that, choose a greenie with a 10% higher value if possible.

As for all-around great-sounding caps, especially in clean applications, I'm liking Cornell Dubilier DME series. They're not fat and round (sounding) like tropical fish, but they have a very transparent frequency response. In fuzz applications, you may need to increase your hf filtering when using modern, metalized caps; other wise you'll get a harsher, fizzier result.

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Post by Electric Warrior »

has anybody here tried Vishay/Philips mkt 368? they're supposed to be "today's tropical fish caps".

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Post by SPeter »

Skreddy wrote:Caps--tropical fish and others that are close?

Yeah; greenies are close. Tropical fish seem to impart a sweeter, fatter tone; so to emulate that, choose a greenie with a 10% higher value if possible.

As for all-around great-sounding caps, especially in clean applications, I'm liking Cornell Dubilier DME series. They're not fat and round (sounding) like tropical fish, but they have a very transparent frequency response. In fuzz applications, you may need to increase your hf filtering when using modern, metalized caps; other wise you'll get a harsher, fizzier result.
http://www.mouser.com/Search/Refine.asp ... d=59850000

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