Category Archives: non-mojo components

Ram’s Head Battersea Power Station Big Muff ₽i

    

When i was a Londoner, id often catch the 24 bus on sunday mornings from Hampsted Heath to its final destination, Pimlico. There was a pub there, next to the bus station where we would go have brunch and shoot pool. In the afternoon we would visit the Tate, usually.

And we would enjoy the beautiful, post modern view of the Battersea Power Station from Pimlico.

Gilmour used a rams head Big Muff on Animals.

Built for a friend on a pcb by OP ELECTRONICS, IT. Transistors BC239C from ebay seller, Whazzgroover. Sprague caps, etc

First time i mess with a hot glue gun, and i guess you can tell! 🐣

Messin with the Klon

Yesterday i was busy making two Klon Centaur clones.

Months ago i bought the last two Chimaera pcbs from the cat over at Grind Customs Fx.
Very well made boards i must say.
I got me some 50 x D9E germanium diodes, the latest darlings of klon builders the world over and plunged into this build, keeping in mind and on the bom the latest (2014) discoveries by the byoc guys on the silver klon (the golden enclosure came first, the silver came later, improving on tone and volume control).
Elna electros, philips, greenies, etc caps.
Metal and carbon film resistors, 1590BB build #1:

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I had to lower the value of a 20k log pot down to 10k for the volume knob using a resistor across pins 1-3.
This was made for my friend Luca.
Next, it’s mine:

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Same caps n resistors chan pon here.
This time to make the volume pot a log, i used a 10k lin, a 2k resistor from pin 2 to ground.
Same blue minotaur lsd blotter art employed..

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On the first build, the gain pot would run funny: regular until 3/4 its taper, then volume would drop.
Heres what i found out about the klon:
YOU MUST audition/measure LOADS of TL072 to get the right balance of clean/gain/volume in general. I have some Texas Instruments and some ST, all of the TI sounded way too “weak”, alas noise would slip through, not enough power, etc. ST’s are better but still, you have to choose the right ones. I did this by ear.
Good TL072s are the secret to this pedal: i tried a bunch of germanium diodes: lots of the aforementioned russian ones, both matched and unmatched, but also Valvo OA81, OA91, RL32S11, AAY22.. guess what? They didnt impart any specific tonal character to the pedal.

As it is, the Klon is a good, clean, very musical buffer/overdrive.
Without a strung out, breaking amp though, i have my doubts it would save the day.

I prefer the good old dirty Rangemaster to the Klon i suppose.

bea!
yours truly

Two pedals for my bro

My brother took up playing electric guitar again. He asked me for some boxes..

2n1307 texas instruments fuzz face
Q1 hfe 200
Q2 hfe 198
(leakage, wartsnall measurements)

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This Fuzzface sounds GREAT. The best i built so far, possibly. Very subtleties responsive, can be hard, soft, gainy, bluesy. Amazing basses.

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The other box is a repeat percussion-using BC547 instead of mpsa18.. very quiet sounding, no ticking.
Very happy about these two.

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Golden: fuzzface; toy car green: repeat/percussion.

bea!
yours truly

Turning a jimmy dunplop High Gain pedal into a vintage specced wah wah

Oh well.. i got this volume pedal for cheap. I also rescued some BC173B and 4x early 70es italian inductors (red, white) from a Farfisa organ i recently dissected.
I bought a vox v847 pcb from a reputable greek seller on ebay.
After cross checking caps and resistors differences, i took the plunge to make a mccoy of sorts.

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The mccoy calls for a bipolarised 4uF cap. Somewhere i read the original also used a 3.9uF so a tropical fish of this value was chosen.
I also tried to change the resistance value of the pot from 250k down to 100k as called for by putting a 166 resistor between the lugs 1 and 3 of the stock hotpotz.
Transistors measured hfe: 395 and 320. I used the gainier one for q1.
Upon firing it, the wah was almost non existent.
Measuring the inductor, it appeared to be the same Henrys value as the black 80es inductor of my dunlop crybaby so possibly it’s not the inductor’s fault.
I changed the 3.9uF tropical fish for a 4.7uF blue polarised Philips.
Much better..
I also changed the pot’s range of sweep, using the “pinion mod”, adding more bass to the curve.

To be contd

bea!
yours truly