Skreddy - Mayo

Whoismarykelly · Post by **Whoismarykelly** » 29 Jun 2009, 03:57

Electric Warrior wrote:
Krinkle wrote: So the originals used ALL ceramics? Wow, I'll have to try that. Thanks so much for all of the sharing.

Darrin
There's some with electrolytics, too. check this one out: https://cgi.ebay.com/70s-Electro-Harmon ... 1|294%3A50

I would wager that its a transition pedal with a ram head circuit in a triangle box.

Electric Warrior · Post by **Electric Warrior** » 05 Jul 2009, 00:59

Weren't they all transistion models?

Whoismarykelly · Post by **Whoismarykelly** » 05 Jul 2009, 02:13

Electric Warrior wrote:Weren't they all transistion models?

More or less lol.

Beedoola · Post by **Beedoola** » 05 Jul 2009, 21:29

I'm having a problem with mine, the sustain pot isn't working properly, there isn't enough gain, the max amount - which isn't what it should be, is only there when the sustain pot is all the way up, when I back it off the gain goes away.

Any thoughts?

Rocket Roll · Post by **Rocket Roll** » 06 Jul 2009, 09:00

Beedoola wrote:Any thoughts?

Wrongly orientated transistors. Rotate them for 180 degrees and see what happens.

Vegas513 · Post by **Vegas513** » 18 Jul 2009, 12:51

Hi, all!

This is my first non-kit build...
Thank you to everyone who contributed, especially Marc!

Pedal is finished and working, but I have a few issues.
1. There is quite a bit of hiss when the pedal is switched on. (A bit more than the GGG BMP I just built.)
2. I need to either keep the sustain cranked, or boost the input with a compressor, otherwise it seems that the incomming signal is just not enough for the pedal to work properly.

Any help or suggestions will be appreciated!

Vegas513 · Post by **Vegas513** » 18 Jul 2009, 13:12

Rocket Roll wrote:
Beedoola wrote:Any thoughts?
Wrongly orientated transistors. Rotate them for 180 degrees and see what happens.

Didn't see the post before I posted...

Sounds FANTASTIC now!

95strat · Post by **95strat** » 28 Jul 2009, 18:54

Just completed my "mayo" build thanks to Spencer's layout. Great sounding muff. Thanks Marc for sharing all of your knowledge. I sort of made mine a hybrid between the Mayo and Pink thanks to the info on page 6 of this thread. I didn't do a switch, but did opt for more mids with an increase of the capacitor value in the tone stack.

My only issues are my sustain is pretty much all or nothing. There's not much range in the pot. I'm wondering if it's the pot itself or if I've got something else going on? And the tone knob works in reverse? I've double checked my wiring and the orientation of my trannies, but all looks good. I may try to post a pic if anyone willing to help me out.

Whoismarykelly · Post by **Whoismarykelly** » 28 Jul 2009, 19:06

95strat wrote:Just completed my "mayo" build thanks to Spencer's layout. Great sounding muff. Thanks Marc for sharing all of your knowledge. I sort of made mine a hybrid between the Mayo and Pink thanks to the info on page 6 of this thread. I didn't do a switch, but did opt for more mids with an increase of the capacitor value in the tone stack.

My only issues are my sustain is pretty much all or nothing. There's not much range in the pot. I'm wondering if it's the pot itself or if I've got something else going on? And the tone knob works in reverse? I've double checked my wiring and the orientation of my trannies, but all looks good. I may try to post a pic if anyone willing to help me out.

Reverse your leads on lugs 1 and 3 of your tone pot.

If you used all linear pots your gain control will not have an even taper. Its a super high gain circuit anyway though so you aren't going to get great low gain tones. Just crank it and smile.

bucksears · Post by **bucksears** » 30 Aug 2009, 20:17

Anybody else 'Pink' up a Mayo per the page 6 tips? I finished up my Mayo and PF this weekend; the Mayo works well (need to decide on which trannies to go with - so far the 5089's have the biggest 'wall 'o fuzz'), but the PF has very little signal. The volume is very low and there isn't a LOT of distortion, more like an overdrive.
Big question: which way do you have the 10uF (electrolytic) cap oriented? With the (+) toward the 33k, or the opposite (flowing with the signal)?

Thanks,
Buck

tschrama · Post by **tschrama** » 31 Aug 2009, 10:09

Hi,

I made a 'pinked' mayo and it really is a very nice version too..

The 10uF (electrolytic) cap should be oriented with the (-) toward the guitar pivkup, and the (+) toward the transistor base connection.

It should have about the same gain as the mayo, just a different voice....

goodluck!
Thijs

bucksears · Post by **bucksears** » 31 Aug 2009, 12:38

WHEW! Ok, thanks!
That's the problem; I have it oriented the other way. Looking at GGG's Ram's Head schematic, it shows the 10uF with the (-) toward the base and the (+) toward the input. So I did mine the same way. Good to know that it should be other way. I think it WORKS correctly, just next to no volume. I had to max it out to hear anything.
I'll have to try that out tonight. It really makes you guess about a million things when you can't nail down where the problem is (makes you want to take it all apart and start over).

hazelwould · Post by **hazelwould** » 03 Sep 2009, 05:43

I looked through and couldn't find anything about the mid switch. Anyone know how to do it?

Thanks!

edit: Nevermind. Mid switch on page 4!

bucksears · Post by **bucksears** » 09 Sep 2009, 20:20

Just out of curiosity:
How easily are you guys finding 400-500+ hfe transistors in the 5088, 5089, BC550 and BC183 types? I've gotten batches of 50 of each and find that most of them are in the 275-320 range.
I've got some more (100 each) on order from a different manufacturer, so we'll see what those do.

JimiB · Post by **JimiB** » 10 Sep 2009, 04:50

are you paying attention to the A, B, and C designations? C is the highest gain. How are you measuring btw? MPS18's are high gain btw.

tschrama · Post by **tschrama** » 10 Sep 2009, 09:04

bucksears wrote:Just out of curiosity:
How easily are you guys finding 400-500+ hfe transistors in the 5088, 5089, BC550 and BC183 types? I've gotten batches of 50 of each and find that most of them are in the 275-320 range.
I've got some more (100 each) on order from a different manufacturer, so we'll see what those do.

In my BC550b batch I can easely find Hfe > 500.. I haven't kept count, but I gess 30% > 500. meanwhile I have bought MPSA18, which have Hfe of 800 and higher, and like really like how those sound.

bucksears · Post by **bucksears** » 10 Sep 2009, 12:41

JimiB wrote:are you paying attention to the A, B, and C designations? C is the highest gain. How are you measuring btw? MPS18's are high gain btw.

Yes, I'm using BC183C and BC550C; the others are 2N5088 and 2N5089.
I'm using an older multimeter that my GF's father let me borrow, since it has a transistor slot and measures hfe. I thought it might be the multimeter, so I ordered a new one from Futurlec and it should be here in a week or so. I've got other stuff to finish up in the meantime.
I didn't know that the 550C and 183C were oriented differently (EBC are backwards) from the 2N5088 and 2N5089, though. I reversed them and got a much better response out of the Mayo with some 183C's last night. Definite 'wall of fuzz' like I was hoping for. I've got a GGG-tuned one (almost a clone of the Violet Ram's Head) and a Triangle spec one on the bench.

Krinkle · Post by **Krinkle** » 21 Nov 2009, 15:43

Skreddy wrote:
SpencerPedals wrote:
Electric Warrior wrote:has anybody here tried Vishay/Philips mkt 368? they're supposed to be "today's tropical fish caps".
That's actually what I have loaded into my board for this pedal right now; I used three of those for the film caps in the circuit. I have never used them before. I plan on ordering some more and doing some breadboard tests in the future. I'd be interested to see what people have to say, as well. They certainly LOOK sexy. For what that's worth.
I'm going to give some of those a shot as well.

Tried these yet?

bucksears · Post by **bucksears** » 22 Nov 2009, 23:58

Krinkle wrote:
Skreddy wrote:
SpencerPedals wrote:
Electric Warrior wrote:has anybody here tried Vishay/Philips mkt 368? they're supposed to be "today's tropical fish caps".
That's actually what I have loaded into my board for this pedal right now; I used three of those for the film caps in the circuit. I have never used them before. I plan on ordering some more and doing some breadboard tests in the future. I'd be interested to see what people have to say, as well. They certainly LOOK sexy. For what that's worth.
I'm going to give some of those a shot as well.
Tried these yet?

My amp has been in/out of the shop recently getting restored back to its stock config (SRRI); haven't messed with the Mayo or BMP stuff in a while. Hopefully after I'm done editing a DVD and get some other guitar-related projects (loose ends) tied up, I'll mess with them again. FWIW, my Mayo right now has a huge fuzz sound, but it's a bit raw & tight. Don't remember what trannies I've got in at the moment, but I'd like something with the same amount of gain, but a little more musical.

supergigi · Post by **supergigi** » 07 Apr 2010, 16:51

Zero wrote: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

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).

Hi Guys,
thanks for your work.
I'd like make the "Skreddy Mayo" using your schematic. Since the link don't work, please could you send me the Zero zip file with guts shots of the Skreddy Mayo effect ? My e-mail address is supergigi@tin.it.
Thanks in advance.