Skreddy - Mayo

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
Post Reply
nokaster
Solder Soldier
Posts: 153
Joined: 07 Oct 2007, 17:46
Contact:

Post by nokaster »

i got the info from the schematic in the first post of this thread...

User avatar
Gila_Crisis
Resistor Ronker
Posts: 366
Joined: 01 Jul 2007, 09:37
Has thanked: 1 time
Been thanked: 67 times
Contact:

Post by Gila_Crisis »

all the 100ohm resistors are marked as 120ohm and then there is a 100pF cap marked as a anfi rfi, which i don't know where you got it.... :?
Zwischen Ordnung und Chaos fangt die Musik an

Skreddy
Resistor Ronker
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Been thanked: 225 times
Contact:

Post by Skreddy »

Gila_Crisis wrote:all the 100ohm resistors are marked as 120ohm and then there is a 100pF cap marked as a anfi rfi, which i don't know where you got it.... :?
Right. Plus I don't use a pull-down resistor (the way the bypass switch is wired obviates this), my dc-protection diode scheme is not the standard 1N4001 to ground (it's either a schottky or a germanium in-line), and the led resistor is way too low for any modern bright led.

vanguard
Posts: 44
Joined: 20 Apr 2008, 15:16

Post by vanguard »

so, skreddy...when's your next big muff iteration coming out? i'm so impressed by the mayo circuit and your handling of this thread i want to buy one of your pedals, and not off ebay. any chance of a custom build?

Skreddy
Resistor Ronker
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Been thanked: 225 times
Contact:

Post by Skreddy »

vanguard wrote:so, skreddy...when's your next big muff iteration coming out? i'm so impressed by the mayo circuit and your handling of this thread i want to buy one of your pedals, and not off ebay. any chance of a custom build?
When I'm done with the rollout of my echo, I was planning to finish designing and tweaking my version of the FSB.o opensource fet overdrive aka "mosfet madness". And then maybe dial in a new muff design using whatever decent-sounding, modern transistors win my taste test. I'm trying to get away from NOS transistors, 'cause they always seem to run out just as a product achieves its highest popularity.

But Scotty at ProAnalog has sent me 4 sample bags of transistors, most of which are hard to find, when-they're-gone-they're-gone kind of things, and I'm really taken by one particular model. What I'll do with them is probably make an intentionally-overpriced Mayo-esque limited-edition reissue kind of thing, just to pay the tax bill. Oh yeah; riding a small-hobby-turned-business into profitability without hiring a certified public accountant is not advisable.

Custom builds are possible.

nokaster
Solder Soldier
Posts: 153
Joined: 07 Oct 2007, 17:46
Contact:

Post by nokaster »

Skreddy wrote:
Gila_Crisis wrote:all the 100ohm resistors are marked as 120ohm and then there is a 100pF cap marked as a anfi rfi, which i don't know where you got it.... :?
Right. Plus I don't use a pull-down resistor (the way the bypass switch is wired obviates this), my dc-protection diode scheme is not the standard 1N4001 to ground (it's either a schottky or a germanium in-line), and the led resistor is way too low for any modern bright led.

I didn’t have any 100R’s, so i used 120R’s in my build. Forgot to change that in the list.
CRFI = anti Radio Frequency Interference
Pulldown resistor, polarity protection diode and power filtering cap were added as I’m used to.
All in all I’ve posted the wrong emitter resistor values, all the other stuff is added protection/filtering etc…
So excuse my mistake on the 100R's.
Change RLED to taste...
Hope someone finds the layouts and list usefull.

User avatar
RiGLEY
Posts: 32
Joined: 08 Sep 2007, 11:43
Location: Budapest, Hungary
Has thanked: 1 time
Contact:

Post by RiGLEY »

I have finished this pedal, it's a very mean little machine, and it's working great! Thanks to all who have contributed. I've used 120 Ohm emitter resistors. How does this affect the sound? Should I try to get some 100 Ohm's and replace?

Skreddy
Resistor Ronker
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Been thanked: 225 times
Contact:

Post by Skreddy »

RiGLEY wrote:I have finished this pedal, it's a very mean little machine, and it's working great! Thanks to all who have contributed. I've used 120 Ohm emitter resistors. How does this affect the sound? Should I try to get some 100 Ohm's and replace?
What'd you use for transistors? The 120 Ohm emitter resistors will just calm it down a bit, make it more controlled-sounding, and probably reduce the noise level slightly compared to 100 Ohms. Who knows if its better or worse than stock unless you experiment; likely just a matter of taste and also on whether the transistors you used benefit from this kind of treatment. Probably very subtle regardless.

User avatar
RiGLEY
Posts: 32
Joined: 08 Sep 2007, 11:43
Location: Budapest, Hungary
Has thanked: 1 time
Contact:

Post by RiGLEY »

Skreddy wrote:What'd you use for transistors? The 120 Ohm emitter resistors will just calm it down a bit, make it more controlled-sounding, and probably reduce the noise level slightly compared to 100 Ohms. Who knows if its better or worse than stock unless you experiment; likely just a matter of taste and also on whether the transistors you used benefit from this kind of treatment. Probably very subtle regardless.
Q1 (BC549B) :
e : 33 mV
b : 0.6 V
c : 3.91 V

Q2 (BC238B) :
e : 32 mV
b : 0.62 V
c : 6.23 V

Q3 (BC547B):
e : 31 mV
b : 0.61 V
c : 3.79 V

Q4 (BC238B):
e : 1.05 V
b : 1.64 V
c : 4.78 V


I have tried to match the mayo voltages measured by Zero. I like how it sounds with these.

vanguard
Posts: 44
Joined: 20 Apr 2008, 15:16

Post by vanguard »

so i think my volume problem may be due to using an incorrect cap somewhere? i can't figure out how to read them accurately. first person to tell me if the following guesses i used were correct wins my thanks.

first cap says "110k". i assumed this to be 100pF?

47k = 47pF ???

472M = 4.7nF ???

Skreddy
Resistor Ronker
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Been thanked: 225 times
Contact:

Post by Skreddy »

vanguard wrote:so i think my volume problem may be due to using an incorrect cap somewhere? i can't figure out how to read them accurately. first person to tell me if the following guesses i used were correct wins my thanks.

first cap says "110k". i assumed this to be 100pF?

47k = 47pF ???

472M = 4.7nF ???
The schematic at the beginning of this thread has the correct values in it.

vanguard
Posts: 44
Joined: 20 Apr 2008, 15:16

Post by vanguard »

oh, snap. i just had v2 in the wrong place all this time. it just fired up like a monster out of hell. thanks a million billion and great work here.
:applause:

nokaster
Solder Soldier
Posts: 153
Joined: 07 Oct 2007, 17:46
Contact:

Post by nokaster »

somehow the edit button wasn't where it should be.

here's an update on the big muff versions list.

Image

swt
Breadboard Brother
Posts: 113
Joined: 07 Sep 2007, 17:52
Has thanked: 4 times
Been thanked: 13 times

Post by swt »

fact is...buy an original today, and you'll have to wait for 20 years, and if it was a good one (luck on your side), you can sell it on ebay ( or whatever at the moment), for good bucks.
But you buy something from a booteeker, and the worst deal will be have your money back from a resell. But chances are you'll get more than you pay for it.
SO... i'm glad there are lots of chances on the market. each one knows where to invest their money. Anyway, thanks to skreddy for the good info and good vibe, and please try to stay on the market. good luck!.

Brian M
Cap Cooler
Posts: 532
Joined: 10 Nov 2007, 09:37
my favorite amplifier: Vintage Twins
Location: Oregon, USA
Been thanked: 47 times
Contact:

Post by Brian M »

Greg_G wrote:Marc's one of the good guys in the industry.
He's honest about his designs, reasonable pricing, no goop, and his stuff sounds great IMO.
The Screw Driver is a classic.

Marc is one of my favorite people in the stompbox market. He's a sharp guy on many other topics as well.

He's also willing to deal with buying and testing obsolete parts. That's something I've never wanted to even try beyond building one or two pedals.

vanessa
Cap Cooler
Posts: 468
Joined: 08 Jul 2007, 18:51
Been thanked: 10 times

Post by vanessa »

Skreddy wrote:
vanguard wrote: But Scotty at ProAnalog has sent me 4 sample bags of transistors
I wonder where he got a hold of an original MK1 Tonebender to dissect for his MK1 clone? $250? :roll: Maybe I should get a kickback for providing him with the schematic? :lol:

User avatar
Gila_Crisis
Resistor Ronker
Posts: 366
Joined: 01 Jul 2007, 09:37
Has thanked: 1 time
Been thanked: 67 times
Contact:

Post by Gila_Crisis »

nokaster wrote:i want to post a V2 for my layout, which can be used by those who don't want the split up resistance from 9V to C of Q4.
Image
i just wanna say thank you a lot for this layout. i just built a Green Urss Big Muff with it and it sounds awesome!!!!!
:cheers :cheers :cheers
Zwischen Ordnung und Chaos fangt die Musik an

Cow4prez
Resistor Ronker
Posts: 269
Joined: 11 Jul 2008, 19:01
Been thanked: 5 times

Post by Cow4prez »

I dunno, based on this youtube clip, it's probably better to not build a mayo... and you can save yourself $300 USD.

https://www.youtube.com/watch?v=X8qEp-fHNK4

JimiB
Solder Soldier
Posts: 205
Joined: 31 Dec 2007, 03:57
my favorite amplifier: AC30
Been thanked: 5 times

Post by JimiB »

I think the mayo in that clip sounds way better thatn the EH
JMHO
YMMV
:thumbsup

nokaster
Solder Soldier
Posts: 153
Joined: 07 Oct 2007, 17:46
Contact:

Post by nokaster »

Gila_Crisis wrote:
nokaster wrote:i want to post a V2 for my layout, which can be used by those who don't want the split up resistance from 9V to C of Q4.
Image
i just wanna say thank you a lot for this layout. i just built a Green Urss Big Muff with it and it sounds awesome!!!!!
:cheers :cheers :cheers

it is my pleasure!
i see pics popping up of muffs build with my layout, but people don't tend to share there opinions or results, so many many thx for your kind words!
so far i've build the mayo... sounded wicked!
and i've got the boards finished for a ram and a triangle, but i've been lazy with the off board wiring. :oops:
should finish those soon!

Post Reply