yamaha pm700 info needed

You know I thought of that, I think it's on the output side though.

Maybe that's OK?

I guess my main question is if I can just wire the input tranny to the amp card as is. I think my cinemags would sound best, but the yammys could be cool too. They're small looking.

So, I just had it open. There are actually six opamps in here, I thought there were four.

I traced out the signal flow as best as I could and here's what I think:

After each micpre card the signal hits the R and L makeup gain amps, each with one opamp. this is where the R/L master fader is connected.

From there, the signal goes to another card with four more opamps. Two of these clearly feed the output transformers, the other two feed the unbalanced monitor output.

So I just keep wondering if I can't put input transformers in front of the first set of makeup gain cards and have myself a couple pres? I'd still have them run out through the second set of opamps pretty much maintaing the yamaha design except ditching the routing and the actual IC based preamp cards.

If anybody else wants to go down this road, these are cheap on ebay and there's one right now.

[quote author="Bear"]The input channels have a TA7136P single opamps, in a 7 pin in-line package, as the first gain stage, and they're also in the aux in's. echo return, and talkback circuit.
Bear[/quote]

Hey there--

Anybody ever come up with a replacement or work around for these?

Would bypassing be suitable if using the mixer for summing and EQ?

Thanks,

Liam

rattleyour - Did you ever make a preamp from the output section? Did you have enough gain to drive the signal? Just wondering.

jvanslem - Did you ever get around to building the JLM99v project with the yamaha opamp and transformers?

Looking for updates,

Jason

Nope haven't done anything with it yet.

Still trying to figure out the best option.

Anyone still working on PM700's?

I'm working on one right now, and it's coming together ok. Want to see what it's capable of before I strip it for opamps and output trafos.

Goals of the project are to add direct outs on a few channels and
figure out a replacement situation for the TA7136

So far I've added the direct outs, and that turned out okay.

I also made some adapters for the TA7136's and tried using a 5534 in its place. I'm guessing I'm missing something about the 7136 because this didn't sound good at all. I'm thinking it's time to look at the channel schematic and the Toshiba datasheet.

Anyone have those docs handy?

hmmm the link to the pm 430 schematics is gone does anyone have it?
thanks

Personally I dont really see the point of trying to replace the HA ICs. They run on +/- 24v and dont seem to have any problems passing lovely sounding audio thru my PM2000, so why change them? Id be changing all electro and tant caps before even thinking about opamps anyway.

I reckon if you dont like the sound of these amps, dont bother with PM mixers..

..but thats just me.
:wink:

M

Actually I think the SIP IC's in the PM-430 run on 15v, but I'll have to dig out that schematic again to check.

I mean theyre capable of running on +/-24, as they do in the PM2000. Actually I think the PM1500 uses +/-25v rails...not sure if it uses the same HA ICs but it would be interesting if it does.

M

:shock:
Hi
I'm new on this forum and was wondering if anybody has a schem for the PM700 Yamaha Mixer.
I just bought one and would like to install direct outs.
Any info would be appreciated.
Thanks