Yamaha PM-430 Direct Outs and Console Redesign / Refurb / Mods

I finally was able to get one of these Yamaha Pm430 consoles on the cheap. Its dusty and has tape residue on it, but should clean up nice. Everything seems to work with some pots a bit scratchy. So, I want to couple this console as my analog front end and summing bus, with my Macbook Pro and Metric Halo 2882 doing all the signal capture and mixing respectively.
Now you may scoff at the PM-430E or even just the hype of the Yamaha PM stuff in general, but one thing is for sure, these PMs are each cool in their own ways and VERY easy to work on. I want to use this device more as a starting point and chassis/parts donor and reuse as much as possible, but I plan on tweaking and rearranging nearly everything.
From my examination today it looks like the individual preamp/EQ cards have two TA7136AP Toshiba made sips in the preamp and EQ sections. The Monitor sends and line amp both look to be discrete much like the PM1000. It does have a single inductor in the two-band EQ. The input transformer is a 600 ohm / 3k ohm type and is labeled GA8027. I don't have the schematic but will try to trace it out soon.
If anyone has a schematic for this model please let me know or just post a link to the thread. I have the owners manual for the 430 and the manual + schematics for the PM1000, but the PM-430 manual doesn't have schematics, only a block diagram.
So my mods for now will be:

Recap:
1. Replace electrolytics with Nichicon Audio series caps in bigger sizes.
2. Replace Tantalum and ceramic coupling caps with Wimas, also in larger sizes.
3. Tweak EQ a bit with some different size caps.
4. Rebuild and beef up Power Supply

Stage 1 Mods:
1. Eliminate all analog mixing capability
2. Direct outs from each preamp
3. Build 16 channel Passive mixbus with DB25 connectors feeding Master Section
4. DI input for Two channels

Stage 2 Mods:
1. Utilize the sends with the NE 80100 opamps as line amps for four of the preamp direct outs
2. Cascade monitor send gain stages on other 4 preamps for creative drive
3. Replace monitor master with parallel SSL mixbus compressor
4. Install a modern headphone amp

I think the recap and stage 1 mods should be fairly straightforward but the Stage 2 mods will be considerably more experimental but could be really fun.

It should be obvious that I am not looking for neutral sounds with this unit, instead I am on a search for some color, and unique color at that. I want to embrace the flaws of these circuits, improve and mod it where I can and just have something cool and one of-a-kind when I'm done.

I haven't had a chance to trace out the schematics on my own yet, still hoping someone out there has the proper Yamaha schematic already in digital form for it that they can share. Anyone?

Hey I just ordered a PM-430 service manual, as I'm looking to add direct outs to mine. I will scan the schematic if you're still looking for it.

hi Cuttyup
would you mind sharing the schematic ?
i, too have a PM430 .

Looks like it needs to be sent to the grp archives as well

I think those pm's are a little funky dark grungy & fun
worth having a pair at least

pm 430 might be close enough in design to an m-406. Can get that schematic for free. I have an m-406 that I added direct outs too and moved the phantom power switch to the front.

I would also like a set of schematiocs please.
q dot aeternus777 AT gmail.com

Sorry that took so damn long. Hope this helps.

does anyone know if i can take the signal from the M2 pot on the channel card?? and use it as an direct output attenuator, while keeping the mixing capabilities of the desk.

What does that pot control normally? I haven't touched my unit in ages and am having a hard time figuring out the intended use.

Orpheus said:

What does that pot control normally? I haven't touched my unit in ages and am having a hard time figuring out the intended use.

Click to expand...

it controls the pre fader aux output

you could, but you might find the output low (I did something similar on an M512).  I ended up grabbing the signal at the top of a similar aux output and fed it to a TL071 to give it some gain.  Turned out better and the console busses stay intact.

I've been thinking about what's best to do with the PM-430; direct outs would bypass too much of the good stuff...

So I've pondered a bit; it has a total of 10 outputs, 6 of which are NE80100, two are transformer balanced.

So utilising those 6 separate stages would yield the "nicest" signal processing.

My first idea is adding on/off switches to each channel's PR (Program) line (which feeds the channel to the Master/Program),
the other two (Monitor 1/To Echo and Monitor 2) are more controllable.


The other route would be making Monitor 1 into Pre-Fader (same as Monitor 2).

Any thoughts?

(in the picture, all the "outputs" which have LA =Line Amp? are the NE80100s)

I got lucky and found another output board (the one with the 4 potted opamps).
I stuck it in and wired it up and piggy backed +/-18V into it.

The first four channels go to this board, then into some transformers I had laying around then terminate in a D-Sub. Works nicely...

Except I get bleed from channels 1-4 onto each other..

I lifted the ribbon which interconnects the channel strips and I picked up the individual signals from there..

Any idea what could be causing the bleed? It's a bit weird.