Thunder Tomate schematics

[amz-fx]

Schematics from Thunder Tomate:

http://www.thundertomate.com/overdrivep/odp_sch.jpg
http://www.thundertomate.com/tdriver/TDriver_SCH.jpg
http://www.thundertomate.com/Distortion/Distortion_SCH.jpg
http://www.thundertomate.com/principal/ebay/cow_SCH.jpg
http://www.thundertomate.com/DIY/BMP81/BigMuff1981SCH.jpg
http://www.thundertomate.com/DIY/DISPLUS80/DistPlus1980SCH.jpg



regards, Jack

[petemoore]

  Sextuplet
  A group or combination of six, associated by common properties or behavior.
  Most Excellent !!!
  *Interesting placements you've figured out for the "CTS" components, It appears they were chosen as lower tolerance% for noise reduction.
  I haven't quite figured out yet what is happening with the power supplies and the 1n4148 diodes, etc.
 
 
 
 

[Mark Hammer]

A Rat with LEDs.  A Big Muff with a tone bypass.  A TS9 with a larger value gain pot.  Straightforward enough, I guess.  Thanks, Jack.

BTW, how's the cleanup going, or is it done?

[Roberto]

The Distortion+ and the Big Muff  are schematics I extracted from original pedals, the tone bypass switch was an original feature of the Big Muff, and I think that is a desirable mod for the new ones.       

I've some info about the original BMP with tone bypass here, including audio signals and spice model:   

http://www.thundertomate.com/DIY/BMP81/BMP81.html

and here  it's possible to appreciate the effect of assymetrical opamp distortion in the Distortion+ (fuzzy sound when the     distortion is maximized). The Ge diodoes can't soften that opamp distortion:

http://www.thundertomate.com/DIY/DISPLUS80/DistPlus.html

Probably the most interesting is the schematic of the "The Cow " fuzz:


Thanks jack 

[Mark Hammer]

The Distortion+ and the Big Muff  are schematics I extracted from original pedals, the tone bypass switch was an original feature of the Big Muff, and I think that is a desirable mod for the new ones. 

Agreed.  I've never seen a BMP with a tone bypass.  I know the Little Big Muff had a 2-position toneswitch, and the Hot Tubes had a BMP-style tone control and tone bypass, but I've never seen a tone bypass on a BMP.  On the other hand, there were many features on E-H products that, if you blinked your eyes or went to the bathroom for a minute, you missed.

Probably the most interesting is the schematic of the "The Cow " fuzz:

Also true.  Should I assume that 2N5088/89 and MPSA18 will work for this circuit or are the transistors special in any way?

[MartyMart]

Great stuff, I love that "Taxi" design   

Marty.

[toneman]

U say "tomate" , I say "tomatoe"..

from the capital of California, Sacatomatoe..

stayred
tone

[Roberto]

Thanks MartyMart, It's like a small model car. 

Should I assume that 2N5088/89 and MPSA18 will work for this circuit or are the transistors special in any way?

I had some bad experiences with high gain transistors in silicon fuzz pedals, specially the MPSA13 [edited] (it's a darlington, it has a very high gain).  My favourite transistor for "The Cow" is the BC109B, It has a low noise figure and a moderate amount of gain. I   always adjust the value of R8 to achieve   3v / 3.5v Vce(Q3) , It's less than the teorical 4.5v but with that voltage the Vc(Q2) is greather and has more clean headroom, so the fuzz cleans very well and  has a nice decay.

[Mark Hammer]

Don't confuse an MPSA18 with an MPSA13.  The first one is just high gain (and pretty low noise).  The second is Darlington.

If lower hfe units seem to work best (my datasheets show BC109b having typical hfe of 200-450), then units like 2SC1815, 2N4124, 2N3392, 2N4401, and maybe BC549, 2N5210, 2N3391.

[Roberto]

Don't confuse an MPSA18 with an MPSA13.  The first one is just high gain (and pretty low noise).  The second is Darlington.

If lower hfe units seem to work best (my datasheets show BC109b having typical hfe of 200-450), then units like 2SC1815, 2N4124, 2N3392, 2N4401, and maybe BC549, 2N5210, 2N3391.

Sorry for the mistake, I was thinking in the MPSA13.  I Believe that any NPN silicon transistor with a moderate amount of gain and low noise will do the job pretty well.

[amz-fx]

Great looking pedals, both inside and outside!  Very neat construction. 

regards, Jack

[Roberto]

Thanks again, Jack.

Mark, I have a couple of pics from an old BMP with tone bypass:





Regards.

[Hal]

what is the point to the paralell caps in the feedback loop of the taxi driver?  Is it just to make a certain value, or for some other reason...?

[Bernardduur]

parallel caps add up

[Paul Perry (Frostwave)]

Those parallel caps are pretty odd, I wouldn't have expected the smaller ones to make an audible difference.
A 47nF 5% cap can have about 2nF variation in size anyway..

[Roberto]

The paralell caps are here only to make a certain value. (there is no "mojo" stuff). C4´ and C5´ are market as 2n2 because in most cases it's the correct value, but it depends on the real value of C4 and C5.             

The values of C4 and C5 are important and small changes have an audible effect.

[Bernardduur]

OK, just to let you know I just modded my new NYC BMP to the 1981 specs.

WOW........ the result is HUGE.......

Once I had a thin sounding pedal that I liked, now I have a HUGE sounding pedal that I love

Thanks for the schematic!

[TELEFUNKON]

wha`appened?

[Steben]

Interesting you say,that COW looks on the other hand "just" like a modified silicon tonebender MKII to me.

[Kornell]

wha`appened?

He said on a spanish forum that he was going to start another activity and he didn't have enough time to build so many pedals.

We miss you tomate!