Yamaha PM430 Summing Mixer mod/restoration with pics!

[Humner]

I thought I would share my recently restored/modified Yamaha PM430 mixer.

I choose the PM430 as its a small compact unit perfect for my summing needs. I did the usual recapping and changed all IC's to Burr Brown OPA134 chips with custom made adapters.

Its default configuration includes a passive high/low EQ, but I wanted more, so I took this further and modified the EQ to include a MID band with frequency switch between 5k, 3k, 1.5k, 615hz and 330hz. Also installed EQ bypass on each channel.

I also wanted to have some different summing flavor so I included the Classic API ACA-BO summing buss - this is switchable between the original summing buss and the API buss. I also installed TASCAM DB25 connector for input channels.

The last bit of the puzzle was having laser etched panels made up to overlay onto the existing desk to show the new features and what they did. I left a little window to show the original Yamaha logo/model.

Excuse the wiring, bit of a mess but it is secure.

 

[Whoops]

Nice one,
at the same output volume do you notice any difference at all when changing the summing switch?

 

[warpie]

wow! excellent job. Looks lovely 

 

[Humner]

Nice one,
at the same output volume do you notice any difference at all when changing the summing switch?

I haven't done any formal testing, but my initial observations are...

During listening the first noticeable difference is more bass extension on the API buss.

When I compare wave forms visually, I can see more compression with the API buss.

 

[Whoops]

Nice one,
at the same output volume do you notice any difference at all when changing the summing switch?

I haven't done any formal testing, but my initial observations are...

During listening the first noticeable difference is more bass extension on the API buss.

When I compare wave forms visually, I can see more compression with the API buss.

Thanks nice to know.

 

[berkleystudios]

cool project. thinking of doing something much like this with a yamaha m.1532 needs a complete restoration, which leads it to be perfect for complete modification. thinking of a complete custom sum buss and monitor section.

inspiring build

 

[ruffrecords]

I notice you said "The last bit of the puzzle was having laser etched panels made up to overlay onto the existing desk " What material did you use for this? How thick was it? How did you attach it to the existing panels? How much does this process cost?

Sounds like it might be a good low cost way of making neat front panels, hence all the questions!

Cheers

Iana

 

[Humner]

I notice you said "The last bit of the puzzle was having laser etched panels made up to overlay onto the existing desk " What material did you use for this? How thick was it? How did you attach it to the existing panels? How much does this process cost?

Sounds like it might be a good low cost way of making neat front panels, hence all the questions!

Cheers

Iana

Its a 2 tone plastic, 1.6mm thick. Its attached by the Pot bolts and other pre-existing screws from the mixer. They also do an option to include a sticky backing.

Cost wise is dependent on material type and time on the machine. I don't remember exactly how much it was to get all that done, maybe $150 AUS?

It was done by a local laser etching place near me.

 

[mobknarly]

Awesome build man looks great, super clean! Love the little window you left for the original name.

 

[L.warwick]

That looks incredible!
I just tracked one of these down and picked it up, I need to find a good schematic for it though as there are a few issues that need resolving.

Would love to know where you got the custom made connectors for the Burr Brown OPAs as well.


cheers!

 

[Whoops]

Just had a look again at this after some years,
this project looks great. Really nice work

Congrats

 

[rock soderstrom]

Just had a look again at this after some years,
this project looks great. Really nice work

Congrats

+1

 

[PPG]

I thought I would share my recently restored/modified Yamaha PM430 mixer.

I choose the PM430 as its a small compact unit perfect for my summing needs. I did the usual recapping and changed all IC's to Burr Brown OPA134 chips with custom made adapters.

Its default configuration includes a passive high/low EQ, but I wanted more, so I took this further and modified the EQ to include a MID band with frequency switch between 5k, 3k, 1.5k, 615hz and 330hz. Also installed EQ bypass on each channel.

I also wanted to have some different summing flavor so I included the Classic API ACA-BO summing buss - this is switchable between the original summing buss and the API buss. I also installed TASCAM DB25 connector for input channels.

The last bit of the puzzle was having laser etched panels made up to overlay onto the existing desk to show the new features and what they did. I left a little window to show the original Yamaha logo/model.

Excuse the wiring, bit of a mess but it is secure.

hello I have a pm and I would like to use it to connect synthesizers, in what way would you advise me to do it by means of a direct box? Greetings is your beautiful

 

[mpagel]

Just got a Pm400 was wondering if I could get a copy of your eq mod schematics?

 

[Humner]

hello I have a pm and I would like to use it to connect synthesizers, in what way would you advise me to do it by means of a direct box? Greetings is your beautiful

The "gain" control is really just pads in front of the mic transformers so you could connect the Synth's to the mic inputs and keep the volume down on the Synths. Or use DI boxes in front of each mic input.

If you want to bypass the mic transformer, you may need to mod the first gain stage to switch to a lower gain as its fixed and set rather high.

Just got a Pm400 was wondering if I could get a copy of your eq mod schematics?

I don't really have a schematic available as I basically have taken what they did on the PM700 and then for each frequency changed the inductor/capacitor values to suit.