Isolator integration for DIY Bozak (Pathos) DJ mixer

[f.aiseur]

Hi everyone!
I asked on the dedicated facebook group but no one answered me there so i will try my luck here...

I am finishing some build of a bozak clone made by Miles Stevens, but i'd like to add an isolator.
Here is the full documentation with schematics and gerber files :
https://fabricastronautblog.wordpress.com/2017/02/14/pathos-pt-5-the-pitch/

The solution to take the Main output from PGM card and put the ISO between here and the actual output is not satisfactory for me because then, it wouldnt affect the CUE and the REC out. Only Main out. Not great for djing.

So I am thinking about taking the negative leg out of C207 at the end of the EQ section, send the signal from here to the ISO, then back to the same pad.
Somehow it seems odd to me, but the pcb layout doesnt allow me to have a very clear idea of what to do...

Here are schems of the EQ section and the PGM card...

If anyone has some suggestion, i'm all ears!
Thanks!

F.

 

[Newmarket]

By ISO do you mean an output transformer ?

 

[f.aiseur]

Hi Newmarket,
No i mean a 3 band « dj isolator »

Since i posted i actually tried something else by taking the signal directly from c207 negative pin, to iso and sending it back directly to master volume/cue/tape out.

It seems to work like this, after cutting a few tracks from c207

 

[Newmarket]

No i mean a 3 band « dj isolator »

Okay - got it.

 

[boombipbass]

Hi everyone!
I asked on the dedicated facebook group but no one answered me there so i will try my luck here...

I am finishing some build of a bozak clone made by Miles Stevens, but i'd like to add an isolator.
Here is the full documentation with schematics and gerber files :
https://fabricastronautblog.wordpress.com/2017/02/14/pathos-pt-5-the-pitch/

The solution to take the Main output from PGM card and put the ISO between here and the actual output is not satisfactory for me because then, it wouldnt affect the CUE and the REC out. Only Main out. Not great for djing.

So I am thinking about taking the negative leg out of C207 at the end of the EQ section, send the signal from here to the ISO, then back to the same pad.
Somehow it seems odd to me, but the pcb layout doesnt allow me to have a very clear idea of what to do...

Here are schems of the EQ section and the PGM card...

If anyone has some suggestion, i'm all ears!
Thanks!

F.

Did you find a solution? And which isolator project did you use? Also the one from F.A.?
Also curious how you got it in the same case he proposed

 

[f.aiseur]

Did you find a solution? And which isolator project did you use? Also the one from F.A.?
Also curious how you got it in the same case he proposed

Hi!
Well the solution i described in the previous post seems to work for me - at least on oscilloscope check.
But i’m still curious to know another approach of this!
The iso card i got from oudin cien, he was selling some stuff on the facebook group.
I wish Miles released the pcbs for his iso tho, really neat and tiny project!
And for the case i made my own as i wanted also VU meters, ISO and two slide pots, here it how it look like now.
Cheers!

 

[fragletrollet]

Very cool!

I'm also planning to build the bozak clone, a tad worried about finding the right transistor sub for the long gone ones specified in the original. Might be easier than feared, but the equivalents suggested on various transistor equivalent finder pages have suggested other, long gone parts. I don't have the experience or knowledge involved in determining what specs of the transistor is essential to match, and which aren't, but I'm sure there are plenty modern equivalents.

Anyhow, here's a great resource on frequency isolator design:

https://sound-au.com/project153.htm

 

[f.aiseur]

Very cool!

I'm also planning to build the bozak clone, a tad worried about finding the right transistor sub for the long gone ones specified in the original. Might be easier than feared, but the equivalents suggested on various transistor equivalent finder pages have suggested other, long gone parts. I don't have the experience or knowledge involved in determining what specs of the transistor is essential to match, and which aren't, but I'm sure there are plenty modern equivalents.

Anyhow, here's a great resource on frequency isolator design:

https://sound-au.com/project153.htm

Hi fragletrollet,
you should definitely jump in and start this project! I have a leftover PCB set if you want.
Dont be so worried about the transistors, i found the russian equivalent pretty easily on ebay and most of them were fine (buy a bunch more so you can match them. I didnt do that on my first build but i matched everything on my second, including the BD139/140, resistors, capacitors....and the difference is really noticeable!)
Regarding the Isolator and Rod Elliott link, i actually designed a PCB straight from his (amazing!) website!
I will make a post for it on the forum but you can already check it out here :

https://github.com/faiseur-cz/DJ-ISOLATOR

I build one and it works really good, its open-source so you can roll your own pcb - or i can send you, as i have 3 extra pcbs that i wont be using anytime soon

cheers!

 

[boombipbass]

Hi!
Well the solution i described in the previous post seems to work for me - at least on oscilloscope check.
But i’m still curious to know another approach of this!
The iso card i got from oudin cien, he was selling some stuff on the facebook group.
I wish Miles released the pcbs for his iso tho, really neat and tiny project!
And for the case i made my own as i wanted also VU meters, ISO and two slide pots, here it how it look like now.
Cheers!

it looks great nicely done!!

what did you mean by cutting the traces on the eq section in the previous post?
also did you cut the wood yourself too and the faceplate?

are those pcbs still available or are there gerber files? i'd love to mke one too!