MN3007 version eh clone theory...

[pinkjimiphoton]

okeedokee...
got this thing working, and it's working great.. i am surprised in fact just how much quieter it is now!!

i went to 47k(!!!!!!) believe it or not for the current limiting resistor. that helped... they're still bright enough (at 18v from the power supply) to be almost painful... knocked out A LOT of the noise. also added resistors to the cathodes of the led's. that helped too...those were 4.7k.

next up, replaced what's on my redraw of cathexis's vero resistor r42.. went from the 1meg resistor, to a 500k trimmer wired as a simple variable resistor. i back it off just a little bit to get the output the right level.

i replaced either r 12 or 13 with a pot... sorry, i don't have it here and i forget!! on one of the threads related to this, either paul or rg had reccomended replacing this resistor to get more volume out of the pedal. i feel like an idiot for not writing it down, sorry!!
should be fairly easy to figure which one once someone with more knowledge than me looks at it. it DOES work. you can even dial in a slightly crunchy overdrive here that sounds imho pretty sweet.

replaced ALL the opamps with tlo82, may try some lower noise 5532's (if them are the ones i think they are.. i have a huge bagfull a friend gave me).
worked much better than the 4558's and 1458 i used initially.

re-wired the switch, now i've got it working right... i can switch from chor/vibe to flange/vib. used a 3pdt, and a bi-color led. definitely reccomend the footswitch over a toggle.

the dead side of the chor/vibe pot was cold solder on the vero... took a little while to figure it out, but as of last nite it's permanently on my pedal board.

speaking of which, i tried putting it last in line, and it was noisy as hell and unusable... bummed. then i tried it near the beginning of the signal chain, just after my fuzz. that was it, it came to life, and very little noise.  so i guess it's finally done!!

here's a quick shitty ms paint drawing of the footswitch, for posterity. i believe i got it right. if i didn't, someone please yell at me so i can fix it.



also, i believe as shown, the 1 + 3 poles on the depth pot need to be reversed!! if ya build this and it seems strange, check that. most of the effect of the depth control is right around 70%...above or below there, it has less effect.

i DID use the specified jfet for the depth control, and own an original (the one with the brite switch, i also owned the original with the vib/flange switch) and the depth control is just funky, so i don't know if it's the jfet or mike mathews was doing really GOOD acid that day.

[Scruffie]

also, i believe as shown, the 1 + 3 poles on the depth pot need to be reversed!! if ya build this and it seems strange, check that. most of the effect of the depth control is right around 70%...above or below there, it has less effect.

i DID use the specified jfet for the depth control, and own an original (the one with the brite switch, i also owned the original with the vib/flange switch) and the depth control is just funky, so i don't know if it's the jfet or mike mathews was doing really GOOD acid that day.

I've tried every combination of pot tapers etc on the depth pot, it's just weird in general and there's not really any getting round that, think it's just because FETs are FETs.

I recommend a delay time control on this, just replace R36 with a 25k Pot with a small resistor in series.

[pinkjimiphoton]

i dunno if i can fit another pot in this thing!!

well.. maybe!

but it sounds so good i am happy with it like it is.

the depth pot is always just weird, i used to ride it with my toe to make it sweep back in the day.. there's a definite sweet spot.


thanks for the tip on the delay time pot scruffie!

[Scruffie]

i dunno if i can fit another pot in this thing!!

well.. maybe!

but it sounds so good i am happy with it like it is.

the depth pot is always just weird, i used to ride it with my toe to make it sweep back in the day.. there's a definite sweet spot.


thanks for the tip on the delay time pot scruffie!

If ya can't fit a pot you can switch that delay time cap (620pF) with an On/Off/On switch between 3 values, it really does offer some great new sounds and works like... well a depth pot in this case almost. Very useful and can take it from thin and settled watery to thick and my glass of water is near jurassic park watery or even my chorus got left in the stone tile bathroom if the filtering is good enough to not whine.

It really does have a sweet spot, using it i've often wondered if it's worth even being there, seems to have mild chorus/ awesome chorus/ some other chorus as its settings.

[pinkjimiphoton]

fwiw, the info on this appears to be wrong .... power supply is not 15v, it's 18v... 36-0-36 transformer.
i just bought a non working one from britain on fleabay, and after repairing some damage (someone had cut in a buffered clean blend with the clone's fx'd output) i checked the transformer... was reading 9v,  or 18-0-18...because it had a transformer for brit power (240) not yank (115). just to be sure i opened up my good clone, same board (series 300) and sure enough, we're not running these clones right..it should be run at 18v, not 15.
not quite savvy enough to understand the diff in hooking up the power supply, as i didn't see any difference in the secondary, like, no -/+ voltage.

or maybe i'm clueless? probable...

i ordered the 36vct transformer... will report back when it's up and running.

[armdnrdy]

Here's a schematic of the Clone Theory that shows the "proper" power supply that includes a 15 volt regulator.

It looks like the schematic posted at the beginning of this thread left out that little detail.

[Scruffie]

Yes it does get 18V, which goes through a 15v regulator to give the board 15V.

Hook up 18V you risk killing the BBD, 18V MAX if I recall, so an 18.1V supply could be bad news.

Check the original schematics, 15V regulator  

Edit: Or you could read armdnrdy's post as he beat me to the punch 

[Fender3D]

Hook up 18V you risk killing the BBD, 18V MAX if I recall, so an 18.1V supply could be bad news.

15V max

[pinkjimiphoton]

i dig the regulator, but what i don't get is why use a center tapped transformer for the power supply if all you need is 18v, why put in a 36v transformer? seems like it would have been cheaper to put in a simpler transformer...
or is there a reason it's worth adding ?

[Scruffie]

Hook up 18V you risk killing the BBD, 18V MAX if I recall, so an 18.1V supply could be bad news.

15V max

I could have sworn it was 18V terminal...

Oh well, doesn't matter that much, still a bad idea.

i dig the regulator, but what i don't get is why use a center tapped transformer for the power supply if all you need is 18v, why put in a 36v transformer? seems like it would have been cheaper to put in a simpler transformer...
or is there a reason it's worth adding ?

They probably just had a lot of those transformers for there other products, why buy 2 different kinds if you can buy one type in bulk and still use it.

[pinkjimiphoton]

shoot, the transformer i ordered arrived. sadly, it's as big as the dang unit!!

anybody know where i can find the proper transformer for one of these?

i could go with a charge pump if i have to i guess, but i'd rather put in something close!!

[armdnrdy]

shoot, the transformer i ordered arrived. sadly, it's as big as the dang unit!!

anybody know where i can find the proper transformer for one of these?

i could go with a charge pump if i have to i guess, but i'd rather put in something close!!

I would look through the transformers that Mouser offers. They have PDFs with foot prints for all everything they stock.

That alleviates the "surprise" factor. 

EHX and many other companies used center tapped transformers for single supplies for a few reasons.
As Scruffie stated, order in bulk at a discounted rate...one size fits all.

But in this case there's something more important in the mix. Using a center tapped transformer to create a single supply allows for full wave rectification. (the two diodes)

Full wave rectification provides twice the AC smoothing than half wave, allowing for smaller (by half) filter capacitors which used to be more expensive at the time of the Clone Theory's inception.

So...to sum it all up....it's just better!