Definitive Yamaha PM-1000 Information and Discussion Thread

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tablebeast

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I have messed with these PM1k modules from Yamaha for years. I've found bits and pieces of info from all over the net in addition to my own experimenting. But it seems like as time goes by the best information gets harder to find. Some of the info I have seen before even seems to have disappeared completely as well. So, all this considered, I figured I would take on this project as a video series and put as much info as I can in one place. I started a YouTube playlist of some videos that I have made documenting my current project, which is turning into a 4U monster with all kinds of circuit changes and mods that I usually don't see in a lot of the rack jobs out there. I welcome anyone to help add to this thread any pertinent information that they may have. I will be adding more info, pics and videos as I move forward with my own project here as well. Here is a link to the vids I have up already. I will be adding to them as the project progresses.

https://youtu.be/puLBnUS_Jes

Now that I have some Monitor/Master, Headphone/Echo, and Talkback/Oscillator modules to go along with the Pre+EQ ones, I will be doing a video series for each. A few quick notes on my plans...

The Preamp modules will get everything optimised for channel strip use. Phase switch is moved to the input. Phantom power will be rewired in the standard way. The EQ values are all changed: making the low cut filters 75hZ and 150hZ instead of 40hZ and 80hZ, mid range EQ points are moved down a bit: closer to 800hZ, 1.6khZ, and 3.2khZ, and the high freq shelf is moved out to 12k. The echo sends will be placed in series in front of the output line amp as an fx send/return that can be cranked for some drive. Pan pot will be swapped for the output fader pot. The four switches from the channel sends will be repurposed for: +48v phantom, EQ bypass, FX loop bypass, and feedback mode. GA80080 output transformer will be added.

The Master modules will be converted to high gain mic preamps. The monitor gain block is put in series in front of the other two stages and a feedback pot will be added. It will also have an FX loop that can be bypassed. Pad, phase, +48v, and line amp feedback mode switches will all be added.

The echo section will have the 8 white pushbutton switches repurposed for a passive mixing bus. The 2 blue pushbuttons will patch the headphone feed in parallel ahead of the output line amp. The headphones will be rearranged with a hardwired booster section ahead of the IC stage.

Not sure what to do with the talkback/oscillator circuit yet, but something fun will be done with it! I'm open to suggestions.
 

tablebeast

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Oh yeah, these things really are the best bang for the buck once you recap them. Larger caps on the rails and coupling really open up the bottom end. Some guys like to swap out transistors for a more modern, faster slew rate, but I prefer the originals exactly FOR their slower nature. The inductor EQ also is made way more useful with just a few tweaks. I'll show you exactly what I'm talking about with the video series. I plan on covering everything I can! If anyone has any suggestions for video content lets hear it.
 

tablebeast

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No, sorry. I don't have any plans to visit the PNW. Though I bet there is a way I could take it apart if you wanted to optimise the cost of shipping and have me send it.
 

jazzcrisis

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Dec 20, 2013
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Virginia, USA
Hi Tablebeast,

I need a few of the female edge connectors that live on the backplane of the console chassis. Can you make that happen?
 

FS nuke

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Dec 19, 2020
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Hello eveyone, I am looking forward to buy a couple of master channels. Better with their own bigass Tamura, but I will consider also without the trafo.
Also, what is the best VU replacement for the original? I am digging the sifam, are there any alternatives or someone got some spares? I need 8 big ones and 2 little for the aux/echo.
Thank guys.
 

JMan

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Sorry to be slightly off topic here... Does anyone know if much of the same information for the PM-1000 also applies to the PM-430?  I have one sitting in my studio that is like 75% functional, but I haven't looked too deeply into fixing/modding it as I'm somewhat intimidated by something as large as [even a relatively simple] mixer like this.  Is the 1000 just a big brother?

I'm aware of Humner's beautiful work on his 430, but unfortunately the discussion on that one was not specific enough for me to find a real jumping-off point for looking at my own.

Looking forward to checking out OP's videos!
 

FS nuke

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JMan said:
Does anyone know if much of the same information for the PM-1000 also applies to the PM-430?

I do not really understand what you mean. I had a look at the schematics and the pm430 uses different components than the PM1000.
I am not a guru at all but I can assume that every machine has its own math. Said that it looks like a nice project to jump in. Looking forward to further development, keep us posted.  ;)
 

JMan

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FS nuke said:
JMan said:
I do not really understand what you mean. I had a look at the schematics and the pm430 uses different components than the PM1000.
I am not a guru at all but I can assume that every machine has its own math. Said that it looks like a nice project to jump in. Looking forward to further development, keep us posted.  ;)

Well, that pretty much answers my question.  I had't looked at the PM-1000 schematic and I was hoping maybe it was the same basic circuitry as the PM-430 but with some extra channels and features. (There seems to be more info available about modding the 1000, hence my curiosity).  I guess not. 
 

FS nuke

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Tablebeast are you active?
No, sorry. I don't have any plans to visit the PNW. Though I bet there is a way I could take it apart if you wanted to optimise the cost of shipping and have me send it.
Tablebeast are you active?
 

tablebeast

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Forest City, NC, USA
The PM 430 is a completely different animal than the pm1k. I have both. I recently went through and ordered caps to redo my 430. Ill report in when I'm done. Right off the bat, the caps are way different, lots of bipolar type caps, ICs, sealed discrete opamp modules, 2 band eq
 

JW

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Portland USA
Curios, since this is the definitive PM1000 thread. Can someone point out the caps that effect the low end on the PM1000. I always hear something like this 'I increased the cap sizes and it really opened up the low end' Okay. Well I know that if you're wiring a direct out, C37 needs to be increased from 33uF to even 10 times that. Other than that I have found one of the .47uF tants to be a culprit (not the input cap. That, in practice is usually a 3.3uF) But there is one somewhere I forget that seemed to cause a high pass filter, perhaps useful for live use. Replacing it with 3.3uF gets a more flat response. I've seen this cap as both .47uF and 3.3uF in practice. It's the only other 3.3uF tant besides the input cap, should you have it.

Anyway, I'd still like more low end. Is it the case that raising the 47uF filter caps actually opens up the low end? Or any of the other electrolytics?
 

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