This is something I could find out at home with a screwdriver and some wine, but I'm away so I thought I'd post this...

I am trying to sell my Mackie 1642 vlz pro (it's in reader's ads... nudge nudge...) to raise money for either another mic or towards some rackmountable pres. I'm trying to build a completely portable multi-track set-up.

But then I got thinking - what would really sort me out for now would be to be able to just remove the pre circuits from the desk and botch them into a 1U rack with a power supply.

The general word on Mackie seems to be that they tend to make stuff on one big inconvenient board and are a nightmare to dismantle/mod/fix. But a brief google image search threw up a couple of blurry close ups that suggested that maybe the pres are actually separate inside and each one has a fairly simple-to-access harness attaching it to the main board.

Does anyone know? Is this a ridiculous idea? I realise the man-hours involved prob don't work out in my favour but I'm up for a little electronics project anyway, I need the practise...

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Anto mo Ninja, Watashi mo Ninja

No chance.. As you said everything is on one circuit board pretty much. You could remove the pre-amp IC's but why bother? You could make a better pre-amp from scratch.

Here is a pic of my SR-32-4 VLZ Pro, the 8 Bus looks pretty much the same as does your mixer I think.

I have a DJ mixer from 1976 which uses Beyer input transformers and discrete circuits.
It sounds 1000000000000 times better than the Mackie pre amps (To my ears) quieter too, albeit no Phantom power.

Just copy some current pre-amp designs and build them on bread board and stick em in a case or something.

Yeah, VLZ Pro pre-amps are not worth that much effort.

If you want a project like this then you need to find an old desk with one PCB per channel. They needn't be expensive as older desks are often larger and more cumbersome than people want nowadays - you'd probably get 24 or 32 modern channels into a desk the size of my old MM 12 into 2. I'm sure there are plenty of possibilities around if you keep an eye out for them.

James.

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JRP Music - Audio Mastering and Restoration.
http://www.jrpmusic.net

Yea pick up something old and modular or make from scratch..

This is the phono board in one of my mixers



From left to right: 3 Phono boards, 2 Mic pre's, EQ board, Summing amp board, Booth out board, Main Out L board, Main out R board, PSU


Input transistors for mic cards

Brilliant - well, not brilliant news but thanks for the help!

I'll leave the mackie on sale and keep my eyes out for something else.

If anyone has any suggestions for a pretty cheap diy kit as well (i.e. I don't have the cash right now to start building a Seventh Circle rack) - but one that's actually useable, or at least on a par with the VLZs, feel free to make suggestions.

Cheers for now!

H.

EDIT: - actually, scrap that, I haven't had a proper search through the electronics forum lately so I'll be over there if I need any more help!

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Anto mo Ninja, Watashi mo Ninja

Edited by molecular (07/07/12 09:38 PM)