Hi anyone know where to get an 18v SAD1024A electric Mistress version PCB? Thank!
As far as I know, there isn't one out there..... I know, I looked for about a year for one. I ended up being lucky enough to be able to buy an original pre-populated V2 PCB off a kind soul on the EHX forum. The only component it was missing was the SAD1024 chip, of which I had 2 sitting in a draw at the time.
When I received the PCB I was intending to trace it and create a PCB layout but never got around to it.... I ended up just stuffing a SAD chip into it and building the PCB into a Hammond case. To be honest, It's probably better to just copy the schematic into Eagle and create a brand new layout.... That would likely cut down on the noise these things suffer from.
I don't actually use the Mistress anymore, I find it too noisy with the rest of my rig, so have started using a Donner Jet Evolution instead.... It's not exactly the same but it gets me in the right ball park (I play in a Floyd tribute)
As I don't use it anymore I may at some point pull the PCB out of the case and trace it......
The EM is one of my favorite effects ever and I just happen to have some NOS SAD1024A's laying around. I am not in anyway an electronic expert, just a hack DIY'er. SO anyone with a Perf board EM layout to share would be awesome!
These might help
https://www.diystompboxes.com/smfforum/index.php?topic=119933.0
(https://i.postimg.cc/svL3zgD5/webmistress.jpg) (https://postimg.cc/svL3zgD5)
You may find this of interest if you want a perfboard build ...
https://www.diystompboxes.com/smfforum/index.php?topic=119933.msg1121331#msg1121331
Grab the pictures while you can because the TinyPic site that hosts those images is going to stop hosting images within a month.
EDIT: I just remembered that if you can download VeroRoute (my software for perf/vero/pcb layouts)
https://sourceforge.net/projects/veroroute/
then you wil find that "improved 18V EM" layout included in the "examples" folder, so you can use that to do a perf layout of your own.
Quote from: DrAlx on August 22, 2019, 06:15:27 AM
EDIT: I just remembered that if you can download VeroRoute (my software for perf/vero/pcb layouts)
https://sourceforge.net/projects/veroroute/
then you wil find that "improved 18V EM" layout included in the "examples" folder, so you can use that to do a perf layout of your own.
I've just downloaded that myself..... Really good little software. I might even have a go at making a Mistress myself using this layout :D
Just wanted to add that Ive been looking for this myself. A large lot of SAD1024 chips went up on the big auction site, I took a gamble and bought a few. I found a thread where someone had posted a tracing of an original unit but the image is lost to time. Would be really cool to build a repro of the original, but I have a '77 V2 nowadays to it would largely be for novelty sake. Ultimately any obsolete chip that resides in a DIY build will one day be called upon to repair a vintage unit if needed.
Quote from: miketbass on August 24, 2019, 11:49:15 AM
Just wanted to add that Ive been looking for this myself. A large lot of SAD1024 chips went up on the big auction site, I took a gamble and bought a few. I found a thread where someone had posted a tracing of an original unit but the image is lost to time. Would be really cool to build a repro of the original, but I have a '77 V2 nowadays to it would largely be for novelty sake. Ultimately any obsolete chip that resides in a DIY build will one day be called upon to repair a vintage unit if needed.
Have you tested those batch of SAD1024's yet? I got a few from the same seller!
Maybe we can do a group buy for a smaller version of the 18V EM PCB?
Hello :)
old topic!
i got myseld some SAD1024... and i'd like to build a EM clone
what's the best ressource to use ? is there a way to have a pcb etched from the veroroute example files ? (great software btw!)
Quote from: Piamp on March 23, 2022, 11:34:51 AM
Hello :)
old topic!
i got myseld some SAD1024... and i'd like to build a EM clone
what's the best ressource to use ? is there a way to have a pcb etched from the veroroute example files ? (great software btw!)
Following link has schematic and also Gerber's for my 18V EM with reworked LFO/VCO.
Forget about etching. Just use the zipped Gerber's to get some PCBs made. I've used JLCPCB lots of times with no problems.
The PCB is just 2.1 x 2.3 inches and will easily fit a 1590B, and it provides multiple holes for the pots (so you can use 16mm or 9mm pots)
and also for the trimmers.
https://1drv.ms/u/s!AvrH61utWEtEnRUE-FrwyRWTZeux?e=u3W2Fd
Thanks!
did you compare it to a real EM ?
Quote from: Piamp on March 25, 2022, 02:13:24 AM
Thanks!
did you compare it to a real EM ?
Yes. Audio path is identical (up to the point marked "Test" before the final gain stage that corrects for the volume drop of the original). Sweep range and sweep ratio both match the original EM too. I went to a lot of effort reworking the LFO and VCO to make sure of that, and to have the controls all work the exact same way.
The only difference is that it will be lower noise because it wont have all the unwanted tweets and whistles of the original EM (and that is due to the improved VCO).