S-2000 contour repeat issue ?

papz · Post by **papz** » Sat Jul 28, 2018 8:49 pm

Hi
Is it normal that when set to repeat mode both C2 and C3 cycles vary in length and are not regular, without touching anything ?
Thanks

EPTC · Post by **EPTC** » Sat Jul 28, 2018 9:36 pm

Do you mean each contour is pulsing at separate tempos, or the tempo of each is uneven by itself?

On mine, both pulse an even pulse, the speed for each is dependent on its individual rise/fall setting. But they're not synched, so they shift in and out - Does that help?

papz · Post by **papz** » Sun Jul 29, 2018 6:21 am

The tempo of each is uneven by itself. Here's a short video.

On other videos I could see, the tempo looks even, like on yours.
So mine seems to have a problem.

Swap the MC14013BCP with a V4013D (NOS CD4013) helps a bit but the waveform still reminds of a sync or alike. With the MC14013BCP there's also a bottom plateau, not with the V4013D.
Here's a scope display with both pots set to minimum (CCW).

MC14013BCP :

V4013D :

Thank you

EPTC · Post by **EPTC** » Sun Jul 29, 2018 4:28 pm

Huh - wow, that's actually a pretty interesting rhythm sequence ... but yeah that does seem incorrect. Mine pulses evenly for each dial setting.

How's it sound?

papz · Post by **papz** » Sun Jul 29, 2018 4:47 pm

The sound is ok but the modulation follows the LED blink : it's uneven and erratic. Not unpleasant in some cases but I'd like to have it even too. A switchable fix would be great.

No problem triggering from the ribbon or with external keyboard via the gate out.
Hopefully Eric will have a suggestion to fix it.

buzzlegs · Post by **buzzlegs** » Mon Jul 30, 2018 5:17 am

On mine they are un-even too, bit annoying but I got over it!

papz · Post by **papz** » Mon Jul 30, 2018 7:24 am

Interesting, so there may be 2 "revisions" ?

Mine is #38. Yours ?

buzzlegs · Post by **buzzlegs** » Mon Jul 30, 2018 7:40 am

papz wrote:Interesting, so there may be 2 "revisions" ?

Mine is #38. Yours ?

#34.

papz · Post by **papz** » Mon Jul 30, 2018 8:21 am

Pretty close.

How about yours, EPTC ?

Thanks

buzzlegs · Post by **buzzlegs** » Mon Jul 30, 2018 8:24 am

papz wrote:Pretty close.

How about yours, EPTC ?

Thanks

What does EPTC mean?

papz · Post by **papz** » Mon Jul 30, 2018 8:38 am

EPTC is the Wiggler who replied above that on his unit the repeats are even.

buzzlegs · Post by **buzzlegs** » Mon Jul 30, 2018 8:43 am

papz wrote:EPTC is the Wiggler who replied above that on his unit the repeats are even.

oh, haha!:)

EPTC · Post by **EPTC** » Mon Jul 30, 2018 9:57 am

buzzlegs wrote:
papz wrote:EPTC is the Wiggler who replied above that on his unit the repeats are even.
oh, haha!:)

Haha!, sorry - yeah it's shorthand for my website, http://www.ep.tc/

I think my S2000 is around #50 - grey knobs, same style as D2000.

papz · Post by **papz** » Mon Jul 30, 2018 10:15 am

So yours is a later unit in which this may have been fixed.
Any chance you could post pics of the circuit please, to compare with mine ?
I'm afraid Eric will have other things to deal with in the coming days.

EPTC · Post by **EPTC** » Mon Jul 30, 2018 10:51 am

Sure - I can't remove mine from the case for a photo right now but I might have a photo somewhere from when I last opened it up a few years back - will check for you. (will do that tonight) Might not be a clear photo of the traces, though. Will PM you.

Cheers, E

papz · Post by **papz** » Mon Jul 30, 2018 10:58 am

Thank you !

Yes Powder · Post by **Yes Powder** » Mon Jul 30, 2018 1:45 pm

Chiming in here. Mine is #31 and it definitely doesn't do that.

papz · Post by **papz** » Mon Jul 30, 2018 1:54 pm

Damn you just ruined my theory.

darmklacht@gmail.com · Post by **darmklacht@gmail.com** » Mon Jul 30, 2018 2:53 pm

I´ve got number 11

Mine doesent behave like yours mister Papz.

The only thing I can say is that the repeat frequency was slightly unstable the first half minute after powerup. it didnt feel like sync (dont have a scope to check).

EPTC · Post by **EPTC** » Mon Jul 30, 2018 3:03 pm

I'll be able to look for that photo of the board in a few hours (it's 3pm here in texas) but here's a few sound files of the even pulsing on mine.

http://soundcloud.com/eptc/s2000-sequence/s-iyNLP
https://soundcloud.com/eptc/s2000-pulsing/s-TP3oU

papz · Post by **papz** » Mon Jul 30, 2018 4:40 pm

Thanks for the inputs.

By "sync" I meant just that the scope display reminded me of a synced oscillator waveform, not that both contours are synced.

Mine is also more unstable just after power up but it never stabilizes enough to have even contour like on EPTC's tracks.

EPTC · Post by **EPTC** » Mon Jul 30, 2018 10:04 pm

Hey papz, check your PM for a photo of the board. Good regards, Ethan

papz · Post by **papz** » Thu Aug 02, 2018 5:13 pm

It seems related to the +48V supply circuit, without the related 34063 the contours LEDs blink and scope display are clean and even.
Ripple on both +12V and -4.5V rails can be seen when the +48V circuit is working : the line on the scope blinks and this looks synchro with the contours "jumps".
I replaced the 34063 but it doesn't help.

On your photo the 2200pF caps are mylar greenies, on mine ceramics, that I replaced with greenies just in case but of course this didn't help either.

papz · Post by **papz** » Thu Aug 02, 2018 7:49 pm

I found a fix.

I added a 100nF cap between the 48V 34063 pin 5 and 0V. It's the 34063 near the operator one resonance pot.
The 0V connection should be far from the IC, I ran a cable to the audio output jack socket.
Close to the IC, like in parallel with the 2k7 resistor connecting pin 5 to 0V, it doesn't work.

papz · Post by **papz** » Thu Aug 02, 2018 9:53 pm

The fix works without the panel only.
When I put it back in place the uneven contours come back.

MUFF WIGGLER

MUFF WIGGLER

S-2000 contour repeat issue ?

S-2000 contour repeat issue ?