Pigtronix - EP-1 ( Envelope Phaser )

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chicago_mike
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Post by chicago_mike »

going to start tracing this and then see what kind of pcb layout I can coax up. Might take me a little time, as im working on a couple others too. But I have high hopes. :)
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Post by Nocentelli »

It's an awesome pedal - It's replaced my smallstone AND boss envelope filter and sounds better than both. The only minor gripe I've got is it would be nice to be able to reverse the sweep direction in envelope mode: I suspect this mod is either impossible or well beyond the scope of my abilities...
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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Post by chicago_mike »

if its at all similar to an envelope filter, than the sweep up / down mod should be a piece of cake, looking at a mutron schema anyhoo, but im not 100% sure yet.
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Post by Liquids »

Nocentelli wrote:It's an awesome pedal - It's replaced my smallstone AND boss envelope filter and sounds better than both. The only minor gripe I've got is it would be nice to be able to reverse the sweep direction in envelope mode: I suspect this mod is either impossible or well beyond the scope of my abilities...
http://www.pigtronix.com/tech/EP-1tech.htm

From this it's probably not major surgury, and if you wanted it done and under warrantee, you could e-mail them and have them do it, it looks like...
Up/Down Envelope Sweep Switch

This toggle switch allows the Envelope Follower to sweep down for that classic Mutron-esque synth tone. It sounds exactly like the intro to Chameleon by Herbie Hancock. A toggle switch at the back of the pedal selects between Up/Down modes.

FYI from what I read, most of these pedals are designed by Howard Davis of EH fame, which explains quite a bit...something I read made me think it's a variation from the EH polyphase?

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Post by chicago_mike »

currently building a polyphase..Ill let you know when Im done. maybe then we can compare sounds and circuits.
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Post by culturejam »

chicago_mike wrote:currently building a polyphase..Ill let you know when Im done. maybe then we can compare sounds and circuits.
Oooooohhhh.

I'm as giddy as a schoolgirl. :applause:

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Post by soulsonic »

chicago_mike wrote:currently building a polyphase..Ill let you know when Im done. maybe then we can compare sounds and circuits.
What are you using for the dual LDRs? I'm wondering what a good replacement part might be for the originals.
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Post by chicago_mike »

well I have Vactrol 5C4/2's Im using. I hope they'll work.

I think 5C3/2's would be better, but I dont really know why. :hmmm:
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Post by chicago_mike »

culturejam wrote:
chicago_mike wrote:currently building a polyphase..Ill let you know when Im done. maybe then we can compare sounds and circuits.
Oooooohhhh.

I'm as giddy as a schoolgirl. :applause:
Are your nip's hard?

Holy fuck thats a sick ass question!!!!!!!!!! :mrgreen: :oops:
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Post by culturejam »

chicago_mike wrote:
culturejam wrote:
chicago_mike wrote:currently building a polyphase..Ill let you know when Im done. maybe then we can compare sounds and circuits.
Oooooohhhh.

I'm as giddy as a schoolgirl. :applause:
Are your nip's hard?

Holy fuck thats a sick ass question!!!!!!!!!! :mrgreen: :oops:
Hahaha. That's funny.

Nips.


Image

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Post by chicago_mike »

well, at least you know what direction she's headed. :applause:
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Post by rocklander »

8) don't look now, but she's smuggling M&Ms
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anybody ever watch that wierd cartoon tranzor z?

Im reminded of the female robot with the boobie missles.
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Post by culturejam »

Mike, any updates on the project you were working on?

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Post by chicago_mike »

Well, the board is populated. 8) I need to find a case for her. Since I finally got a scope here, I can pass signal thru her and see whats working, whats not. I can gte this done this weekend. :)

But from what I have read all over the internet, the polyphase project works. 8)

My real concern is my use of VTL 5C4's. I think the 5C3's would be better, but I didnt have any of those.
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Post by Liquids »

chicago_mike wrote:Well, the board is populated. 8) I need to find a case for her.
My real concern is my use of VTL 5C4's. I think the 5C3's would be better, but I didnt have any of those.
http://optoelectronics.perkinelmer.com/ ... l5c3c4.pdf

These datasheets help. It takes the VTL5C4 a second and a half to reach a resistance of 100k/get the LED dark! I tried is as a sub on my breadboarded trem lune just as a comparison to the 5C3 (or was it a 5C2?) and it couldn't keep up with faster speeds--it likewise had a different 'curve.'

So yeah, it may have a dramatic effect on your phaser...it may 'smear' some of the intricate transients at typical LFO speeds, as compared to a 5C3. Then again, maybe it will have it's own cool sound and benefits, but this way, you know what to expect. It's sensible to stock more than one variety of these at all times if cost permits. Also, the /2 series can always work as a singles, but the opposite is not true.

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Post by soulsonic »

Hey, the old EHX PolyPhase I was working on had this problem... with the phasing effect getting almost no depth at the fastest LFO speeds. I think the speed of the old optos was definitely the problem. They must have drifted off with age or something. So, would the 5C3 possibly be a good replacement? The original Clairex dual optos are nowhere to be found.


edit; typo
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Post by chicago_mike »

Possibly, get the 5C3/2


I think I have enough ldr's to roll my own duals..

so what in the world could my 5C4's be useful for I wonder... :scratch:
I wish the vactrols werent so damned expensive.. :oops:

Yep 10 ldr's in a baggie....well, its worth a shot, they are 1m to 300ohm...
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Post by Nocentelli »

Anybody know how the sweep direction mod is achieved? I've studied a couple of pics, but it's not clear what's going on.
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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Post by Nocentelli »

zenrad wrote:
Nocentelli wrote:
zenrad wrote:I would just get rid of it - the thing is huge - but I like the envelope sound...
Same here - I don't use the phase (i've got a smallstone theat does a much nicer sound) but I dig the envelope sound... if I can get a reverse sweep sound, it might be a keeper.
Pardon my drawing skills - I opened up the unit and this is how the reverse mod is wired.
D1 is removed from the PCB, the red wire is soldered to the anode pad and the black wires + diodes are soldered to the cathode pad.
Both diodes are 1N4001 and the resistor is 680R wired in parallel with one diode (it was obscured in the photo)Image
many thanks to zenrad for providing the sweep mod - Now can anyone shed light on the "marv" mod?
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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