Custom Rotary DJ mixer.

[tristan.kelly]

OK so I really REALLY want an old school rotary mixer i.e. Bozak/Urei, but they're well beyond my budget. I have kicking around the house a fully working Citronic SM550 remix (back when they were made by hand in England). I fired it up the other day and it still sounds really nice, not Bozak nice, but better than my Rane MP44.

I thought I'd have a poke around inside and it's certainly well put together and is also totally modular, so no drama there. I'm looking to re-house the bits I want in to a new case with ALPS pots. My question is what pots should I be looking to get?

 

[AuroraB]

Alps is usually OK, but I'd look at Bourns conductive plastic.......
what value....?

 

[tristan.kelly]

Well the RK27's I'm thinking of are 100 ohm. This seems to be what most people are using. What would be the benefits to using the bourns over ALPS?

 

[AuroraB]

It's ages since I last saw a Citronic, but if it's the main faders you're looking to replace, 100 ohms doesn't sound right at all......?
Conductive plastic is usually concidered more wear resistant. Which source do you have for he aalps pots?

 

[tristan.kelly]

Haven't sourced the pots yet, there's a place in Germany that list on eBay, which seems safer than getting moody ones from China! I'm going to need around 5/6. How do I work out what size I need? The reason for choosing ALPS is that these are what Bozak used, and most clones released seem to use these.

 

[AuroraB]

If by size, you mean the pot value, the value of the original sliders are printed on them.
They are probably in the range 10-47 kohms.......
I'd strongly suggest that you get hold of a schematic if you are trying to rebuild this....
I googled the SM550, - what about the small sliders for EQ?

 

[tristan.kelly]

Not planning on using the eq boards as I want as clean a signal path as possible. I have an external isolator that I will be using instead.

 

[pern]

ALPS RK27, 50K LOG is the standard volume pot used in most rotary mixers.

 

[AuroraB]

THat's OK, and the pot i probably OK, but it needs to be the same value as the linear pot that's being replaced, as the thing is deisgned as a virtual earth mixer. I think I saw 10k in another Citronic schematic.

 

[pern]

I only got the Citronic SM607 schematic, not the SM550. And there they used 10K LOG as volume fader.

 

[tristan.kelly]

Thanks for the input guys, much appreciated. Just need to locate a chassis now and then we're off!