Skreddy - Mayo

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

Re: Skreddy Pedals - Mayo

Postby kismet78 » 14 May 2008, 21:07

Marc has set the bar really high for BM clones.
kismet78
 
Posts: 14
Joined: 13 May 2008, 17:04
Has thanked: 0 time
Have thanks: 10 times

Re: Skreddy Pedals - Mayo

Postby Omar Bagh Dad-A » 14 May 2008, 21:48

:secret: The Skreddy Ernie is farking amazing. It seems to be beyond what I thought a Big Muff could be.
Omar Bagh Dad-A
 
Posts: 6
Joined: 10 Nov 2007, 20:04
Has thanked: 0 time
Have thanks: 0 time

Re: Skreddy Pedals - Mayo

Postby Zero » 15 May 2008, 00:09

Here are some guts shots from the pedal that was used to trace the schematic that you can see in page 1: http://www.mediafire.com/?bizddxltpok

And here are the voltages of each transistor:
Q1 :
e : 28.9 mV
b : 0.613 V
c : 3.96 V

Q2 :
e : 26.3 mV
b : 0.627 V
c : 6.37 V

Q3 :
e : 28.3 mV
b : ? (==> unable to reach the lug with my DMM)
c : 3.79 mV

Q4 :
e : 1.090 V
b : 1.668 V
c : 4.68 V

Enjoy :wink:

PS: I traced the schematic and took the pictures a long time ago, but I never wanted to make them public for respect to Marc Ahlfs as I think he is doing a great job. I happened to give the schematic to ech0es and he posted it. Now that the Mayo ain't in sale anymore, I can post the gut shots without doing any harm to Marc (I hope so).
Zero
 
Posts: 5
Joined: 29 Oct 2007, 00:13
Has thanked: 0 time
Have thanks: 1 time

Re: Skreddy Pedals - Mayo

Postby Greg » 15 May 2008, 00:26

Omar Bagh Dad-A wrote::secret: The Skreddy Ernie is farking amazing. It seems to be beyond what I thought a Big Muff could be.


So is the Zero !
culturejam wrote: We are equal opportunity exposure artists.
User avatar
Greg
Old Solderhand
 
Posts: 3319
Joined: 03 Nov 2007, 10:35
Location: Australia
Has thanked: 77 times
Have thanks: 195 times

Re: Skreddy Pedals - Mayo

Postby stefcuypers » 15 May 2008, 10:00

Thanks for the package zero!
User avatar
stefcuypers
 
Posts: 24
Joined: 29 Sep 2007, 18:14
Location: Belgium
Has thanked: 0 time
Have thanks: 2 times

Re: Skreddy Pedals - Mayo

Postby nokaster » 16 May 2008, 16:32

i for one would be very interested in schematics and detailed component list for the ernie and the zero...
if i'm allowed to say so.
nokaster
Solder Soldier
 
Posts: 153
Joined: 07 Oct 2007, 17:46
Has thanked: 0 time
Have thanks: 0 time

Re: Skreddy Pedals - Mayo

Postby Skreddy » 16 May 2008, 23:44

nokaster wrote:i for one would be very interested in schematics and detailed component list for the ernie and the zero...
if i'm allowed to say so.

Same layout. Transistors are 2N5088 (NOS circa 1980?). All original "triangle knob" specs otherwise, except that the input cap is a .1uf tropical fish, the coupling cap between stage 2 and 3 is also a tropical fish .1 (and there's that 100uf power-supply filter and polarity diode and tbp and led).
Image
Skreddy
Resistor Ronker
 
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Have thanks: 225 times

Re: Skreddy Pedals - Mayo

Postby nokaster » 16 May 2008, 23:52

thx marc! you are very kind!!!
nokaster
Solder Soldier
 
Posts: 153
Joined: 07 Oct 2007, 17:46
Has thanked: 0 time
Have thanks: 0 time

Re: Skreddy Pedals - Mayo

Postby Skreddy » 19 May 2008, 19:25

Seen any of these?
Image
I don't know if they're made by Central or by CDIL...
Skreddy
Resistor Ronker
 
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Have thanks: 225 times

Re: Skreddy Pedals - Mayo

Postby The Rotagilla » 19 May 2008, 22:36

Skreddy wrote:Seen any of these?
Image
I don't know if they're made by Central or by CDIL...

Where were you when I tossed a load of these about a year ago? :slap:
The television will not be revolutionized.
User avatar
The Rotagilla
Diode Debunker
 
Posts: 727
Joined: 20 Aug 2007, 19:24
Has thanked: 6 times
Have thanks: 56 times

Re: Skreddy Pedals - Mayo

Postby seniorLoco » 20 May 2008, 02:56

Skreddy wrote:Seen any of these?
Image
I don't know if they're made by Central or by CDIL...


I have been using those on my muff builds for the last three years :thumbsup
...guess that 'C' is for China :mrgreen:
"Curiosity may have killed the cat, but it saved the mice, who ate the cheese."
User avatar
seniorLoco
Resistor Ronker
 
Posts: 343
Joined: 05 Nov 2007, 10:43
Location: ASIA
Has thanked: 0 time
Have thanks: 10 times

Re: Skreddy Pedals - Mayo

Postby Skreddy » 20 May 2008, 03:05

Anyone have a bunch with gains ranging from 600 to 800 for sale? I like 'em.
Skreddy
Resistor Ronker
 
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Have thanks: 225 times

Re: Skreddy Pedals - Mayo

Postby seniorLoco » 20 May 2008, 03:19

Skreeedddy ... you got PM :D
"Curiosity may have killed the cat, but it saved the mice, who ate the cheese."
User avatar
seniorLoco
Resistor Ronker
 
Posts: 343
Joined: 05 Nov 2007, 10:43
Location: ASIA
Has thanked: 0 time
Have thanks: 10 times

Re: Skreddy Pedals - Mayo

Postby alteredsounds » 20 May 2008, 12:19

sorry for butting in here but transistor's on my rams head clone, I've used 4 old can bc109's that all measure between 350 and 370, i notice that ur asking for 600 - 800, interesting how would that affect the sound?
User avatar
alteredsounds
Resistor Ronker
 
Posts: 256
Joined: 01 Oct 2007, 13:28
Has thanked: 0 time
Have thanks: 6 times

Re: Skreddy Pedals - Mayo

Postby analogguru » 20 May 2008, 14:23

....interesting how would that affect the sound?

that´s a real good question since in every gain stage is current AND voltage feedback..... AND the gain of each stage is far below the ß of every si-transistor.

analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.
analogguru
Old Solderhand
 
Posts: 3285
Joined: 26 Jun 2007, 14:58
Has thanked: 0 time
Have thanks: 116 times

Re: Skreddy Pedals - Mayo

Postby Skreddy » 20 May 2008, 16:28

alteredsounds wrote:sorry for butting in here but transistor's on my rams head clone, I've used 4 old can bc109's that all measure between 350 and 370, i notice that ur asking for 600 - 800, interesting how would that affect the sound?

Higher gain transistors result in a more "biting" sound (more aggressive attack, more sensitivity to high frequencies, boosted mids/upper mids content), all other things being equal, in the BMP. Lower hfe's render a mellower sound, more natural attack, a bit darker response, all other things being equal. But the nature of the transistors themselves, owing to the maker, the process, the materials, etc., is more significant usually than the gains. E.g.; old, circa 1970, 2N5133's with gains in the 500's sound smoother, creamier, more dynamic, and sweeter than newer versions of the same with gains in the 300's.

Certainly all the nice biasing and feedback built into the gain stages of the BMP ensure that nearly any BJT will work; but that doesn't mean they'll all sound alike.

For this message the author Skreddy has received thanks: 2
PokeyPete (25 Feb 2011, 23:28), protakill (25 Jun 2014, 20:20)
Skreddy
Resistor Ronker
 
Posts: 419
Joined: 11 Nov 2007, 05:22
Has thanked: 12 times
Have thanks: 225 times

Re: Skreddy Pedals - Mayo

Postby alteredsounds » 20 May 2008, 23:02

Thanks, I'm gonna throw a load of different ones at it over the w/e, see what I come up with.
User avatar
alteredsounds
Resistor Ronker
 
Posts: 256
Joined: 01 Oct 2007, 13:28
Has thanked: 0 time
Have thanks: 6 times

Re: Skreddy Pedals - Mayo

Postby noelgrassy » 21 May 2008, 09:03

Great zip file! Thanks Zero (the Hero).
Copyright does not protect facts, ideas, systems, or methods of operation, although it may protect the way these things are expressed. US Copyright Office
User avatar
noelgrassy
Resistor Ronker
 
Posts: 388
Joined: 28 Nov 2007, 03:43
Location: Vacuum Tube Valley, Cali
Has thanked: 11 times
Have thanks: 3 times

Re: Skreddy Pedals - Mayo

Postby noelgrassy » 21 May 2008, 09:14

Big thanks to Skreddy for sharing your hard work. :thumbsup
I enjoy reading your observations in the various threads around here. Your posts evidence a gentleman &
mature personality sporting an obviously skilled pair of ears. I really liked some of your comments on the
"Fuzz" movie I just bought. You never appear as self absorbed as some of the other interviewed builders.
Copyright does not protect facts, ideas, systems, or methods of operation, although it may protect the way these things are expressed. US Copyright Office
User avatar
noelgrassy
Resistor Ronker
 
Posts: 388
Joined: 28 Nov 2007, 03:43
Location: Vacuum Tube Valley, Cali
Has thanked: 11 times
Have thanks: 3 times

Re: Skreddy Pedals - Mayo

Postby nokaster » 27 May 2008, 16:48

i wanted to and succeeded in understanding the big muff circuit. knowing what each component does etc...
making a vero layout thought me a lot.

but on the mayo i still have a few questions...
- why a higher collector voltage on Q2?
- why split the collector resistor on Q4 in 2 resistors with the output at their joint?
- i guess the 47pF after the tone section filters some highs?

i love the sound of my clone A LOT!
AB'd it with a little big muff last week... LBM s*cks...

8)
nokaster
Solder Soldier
 
Posts: 153
Joined: 07 Oct 2007, 17:46
Has thanked: 0 time
Have thanks: 0 time

PreviousNext

Return to Boutique Stompboxes dissected...

Who is online

Users browsing this forum: fredmerts, J0K3RX, lukatosh, vws7 and 14 guests