Deltalab Effectron II ADM 1024 MIDI Sync Mod

Started by andrewapeterson, August 10, 2013, 07:55:07 PM

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andrewapeterson

I'm new here.
I have a Deltalab Effectron II ADM 1024 which I believe cannot be midi clock controlled via the "pedalsync" kits, because I think it doesn't use BBD IC's.

I'm wondering if anyone knows what I should be looking into to figure out how to make this thing sync to my DAW, or if it's even possible

Also, I know of one place online that has some really crappy hard-to-read schematics for this unit, but perhaps someone knows where I can find better copies.

Thanks!

g_u_e_s_t

i found some picture online of the effectron, and it looks exactly like a delay unit i worked on a few years ago.  if its the same thing, then it should be able to be controlled with an external clock signal, just like the BBD devices.  it looks like it does 1bit sigma delta into 1b DRAM chips.  the rate at which you clock the data in determines the delay time.  if you get your hands on schematics, it should be possible to find the internal clock source and switch it with an external one.  or if you have an oscilloscope, you can start poking around and find the oscillator that is adjusted by the delay knob

andrewapeterson

q_u_e_s_t,
Thanks for the response.  You have made me more optimistic.

Here's is the place online that has the crappy schematic. 
http://www.stecrecords.com/index.php?RecordId=528

I find it very hard to look at.  Any chance you're able to tell me anything more by glancing at those pictures?  Like is there an IC noted anywhere that you recognize as the clock source?

I'm not afraid to try to mod this thing once I feel like I understand what's going on with it a little better. Once I know what the clock source is, I can read the datasheet on the part Etc and play around with it.

Either way, thanks!

g_u_e_s_t

the clock comes out on pin6 of IC38 (4528B).  it is a 0 to 12v digital signal varying from 250kHz to 1MHz.  it has a fixed pulse width of 0.5us for the high period, and the low period varies in length to make up the remaining time.

it all depends upon how you want to control it.  it has an external CV input for varying the delay time, so you could just use that, although it wouldnt be as accurate.

the schematics arent bad, but there are gaps in the scan, which is a bummer.

andrewapeterson

q_u_e_s_t, you are AWESOME!  Serious wizard stuff.
I hope it doesn't bother you if I keep asking questions.  I guess you can always just stop paying attention :)

I've been emailing with Pedal-Sync, and the person there keeps essentially saying "if your device uses BBD chips then one of our kits can work..."

But I don't think this unit does use BBD chips.  Or does it?

BTW,
Someone I found has modified a very similar unit to double the available RAM and thus, double the max delay/sample time.
http://www.jhaible.com/jh_adm1020_loop.html

Anyway, I've done some reading and it appears to me that BBD chips have RAM built-in, and thus, if my unit is built with several RAM-only chips in series like this, it probably doesn't use BBD ICs.  Right?

But maybe the clocking is still done the same, but in a more convoluted way (a few/several ICs, instead of essentially two, a BBD and a Clock)?  Or am I way off?

Also, for anyone interested, here's a page where someone is replacing some bad RAM in this same unit.
http://obsoletetechnology.wordpress.com/repairs/deltalab/



g_u_e_s_t

the way this delay pedal works is very similar to BBD.  basically, BBD is a long line of buckets that hold an analog voltage level.  but, in this device, its a long line of buckets that hold a digital voltage level.  as a result, it needs to be clocked faster, as 1 bit of data (1 logic level) doesnt carry as much information as 1 analog bucket.  so you need a bunch of digital buckets to get read in the same amount of time.  so, what this means for their kit, is wether or not it can clock fast enough.  ask them what the highest clock rate on the kit is.  it needs to go to 1MHz.

andrewapeterson

Is the top clock speed needed proportional to the max sample time?
If I decide to increase my delay time capability from ~1 second up to ~4 seconds, does that mean I will need at least 4MHz?
(thanks again)

andrewapeterson

It looks to me like the max clock output speed on this thing is 291.3 KHz
http://www.pedalsync.com/pedalsync/documentation/PedalSync_MV-64_BBD_Delay_Controller_Datasheet.pdf

I'm going to ask him if they make a similar IC that outputs higher frequencies.  I think they don't.

It's strange to me that I seem to be the only person in the world trying to do this.  I guess it's because these old DeltaLab Delays are built a bit weirdly.  I love the way it sounds though!

g_u_e_s_t

you could use a PLL to shift the frequency up, but thats starting to get complicated.  the problem with just clocking it slower, is that the sound really degrades.  one of the things i love about those sigma delta delays is they way they distort at lower clock rates, but it would also be good to have the normal mode as well.

i wonder if any of the MIDI to CV kits have autotune functions.  i know MOTU had an application like that for their MK828 i think.  where it sent out a CV, measured the frequency, and compensated in real time to keep it at the frequency you wanted.

you might be able to make your own system with an arduino or similar platform.  all you need to do is output a clock.  the trouble with arduino, is that max clock rate is 16MHz, so the resolution down at 1MHz is only 1 part in 16, which is pretty lousy.