Sony MXP3000 Mic Pre

Hey everyone,

I'm building 8 of these into a 2 space rack. Does anyone know what kind of a power supply I need for these? Is there a design that's already in place that will work for these? Any idea of what torroid to use?

Thanks,
Siegfried

read this

http://www.johnhardyco.com/pdf/MPC3000.pdf

his preamp fits into a 3000 slot and has the same pinouts. so your looking for a supply that will give you +/- 18V and 48 V for phantom. Are you planning to use stock cause the output will be unbalanced as is normal for in the 3000 console. easiest way is to use a trafo and balance the output. :thumb:

AS for PSU's read the meta and make a universal PSU there is schemo and parts list and PCB layout. it will work for your needs...


BTW which mic pre version do you have? IS it the one with the trafo on the input that has 5534 opamps in it?

Thanks for the info. It's just the regular electronically balanced version. By this, I was under the impression that the outs were indeed balanced. Are you saying that I still need a transformer for these then? Damn.

Thanks again.

Siegfried

I'll have to go back and double check my scemo's but they made a version with an input trafo and a transformerless input version. Each will have an unbalanced out as they go into the rest of the console.

The output is unbalanced.

[quote author="Mike Keith"]The output is unbalanced.[/quote]

I knew it but wanted to double check. :thumb:

Siegfried,

I just racked 8 of these along with 8 of the MXP EQs. I used this power supply:

http://www.beatbazar.com/guests/ssltech/kps-1/index.htm

I built four - each supply powers 4 pres or EQs. Works great. Here's a tip: When I tried to use a 20-0-20 (RMS) secondary trafo as specified, my rectified DC before regulation was at about +-27VDC. This caused the 7818 and 7918 to get HOT. I finally ended up using 15-0-15 (RMS) secondary trafos, which rectified out to about +-21VDC and let the regulators run nice and cool. Maybe the 20-0-20 input on the schemo means peak AC, not RMS. Also, I did have to adjust R1 to get the 48V correct. The units are sealed now, and I can't remember what I used for R1, but I'm pretty sure it was a value quite a bit higher (maybe 20K or so?). With a little experimentation, you wont have any problem with that - check the LM317 data.

The trafos I used are Digikey part # TE62083-ND. I used 2 for this project and ran 2 PS boards off of each.

Glenn

Thanks for the info. Glen, did you balance the output of each mic pre? If so, what did you use?

Thanks,
Sig

I did bought 2 MXP-3000 preamps and just arrived last friday.
Today i did tried them with the B*ringher 2200 power supply at 14volts and they sounded just fine. although i think they should sound better at 18 volts.


I am looking for the best power supply to build for those pres.

Gltech your power suplly looks complicated in the 48 volts section , for my small kwnoledge in electronics. It looks to me like the LM317 is 37 volts max??

18V will give you more headroom

Siegfried, the preamps just have unbalanced outs just as Mike said, and I did not add any balancing circuit of any kind - I just use the unbalanced outs. The pin connections are:

2 "low" input
3 ground
4 "high" input
11 ground
12 +18V
13 -18V
14 output
15 +48V

3nity, that power supply is SSLTech's. He hangs around here. I haven't studied the 48V circuit and don't really know anything about it. I only know it's some form of a Cockroft-Walton voltage multiplier, and that you can adjust the output voltage with R1 and R2. I just consulted the LM317 data. I even remember experimenting with some resistor values that gave me over 50 volts.

I've also had some PMs requesting I put up a pic of my unit. As is usually the case, I just barely got it working for a big session, so it's not very aesthetically pleasing yet (well it is to me). I didn't even have time to drill rackmount holes and put it in the rack. But it serves the purpose well!

Pic here:
http://www.glt1.com/gl/Misc/SonyMXPRackUnit.jpg

Oh yeah, and instead of soldering right to the pins on the pres and EQs, I made some little PCB cards (using Press-n-Peel) for each module, on which I mounted 15 pin female connectors that mate with the pres and EQs (they're both the same). Then I did all my wiring to these little cards and just plugged the modules into em'.

15 pin connectors: Digikey S7048-ND

Here's my little connector card for the pre (pin 1 of the 15 pin connector at top):
http://www.glt1.com/gl/Misc/SonyMXPPreConnCard.bmp

And the one for the EQ (pin 1 of the 15 pin connector at top):
http://www.glt1.com/gl/Misc/SonyMXPEQConnCard.bmp

You can see that there are two solder pads on each type of card for the power connections so I could run power from one card to the next.

If anyone uses these card PCB layouts, keep in mind that you will have to shrink or stretch them on your computer/printer so that the 15 pin connectors will fit.

Glenn

Ahh I see. So it's cool to use it unbalanced if the wiring is relatively short. Interesting. Anyone else using it this way? Any problems with it?

Also, I'm curious as to your pinout:

2 "low" input
3 ground
4 "high" input
11 ground
12 +18V
13 -18V
14 output
15 +48V

What do you mean by "low" input and "high" input?

Thanks,
Siegfried

High input usually means hot or you + signal unless it's old gear usually pin 2/tip. Low Input usually means cold or your - signal unless old gear usually pin 3/ring and ground is your ground which is usually pin 1/sleve.

Actually the sound i got from the MXP had enough headroom.
At 18 it would have more than enough.

I'm looking for a way to not solder directly in the pin outs....maybe some kind of socket connector....

I'm heading out to the store and take some trannies...and some switches for phase.

[quote author="3nity"]Actually the sound i got from the MXP had enough headroom.
At 18 it would have more than enough.

I'm looking for a way to not solder directly in the pin outs....maybe some kind of socket connector....

I'm heading out to the store and take some trannies...and some switches for phase.[/quote]

Phase? the mic pre should already have a phase button are you looking to replace or change the button style? If your looking to not solder directly to the pinouts you need an edge connector. read the postings above it is talked about.

Mic pre doesn't have the phase button - that's further on down the console, from what I remember.

Sig

ah yes.

ah yes.

ah yes.

ah yes.