Mystery Yamaha component?

[the_merv]

Any music experts out there, need help identifying what this Yamaha NP00268 is, only marking on chassis?
Circuit board ID = Yamaha LC26041-1/3 Elna F45 94V-1.
Is a schematic available? Worth fixing? Much thanks in advance.

 

[Pio1980]

Looks like a power supply, possibly for a Yamaha organ.

 

[Lavane]

Power supply me thinks.

 

[Robisme]

Vol adjust. I'll go with PA amp.

I would think a power supply wouldn't have two transformers.

Rob

 

[the_merv]

Thanks for the pointers. I read in a Yamaha Electone Organ forum, the older models did have a main power supply (PUM) and a secondary power supply (PU) using two transformers, that's probably what I have here.

 

[Robisme]

I'm guessing that Tamradio transformer is an audio output transformer. You could see if it's primary side is wired to the AC input or the output of an amp.

Maybe it's both a power supply and an amplifier.

Rob

 

[Pio1980]

Hard to tell, the heat sinked devices could be voltage regulators.

 

[reydelaplaya]

Beyond the PA Outputs in the back, you've got an output labeled 'Tremolo'. IDK if it helps or not, but googling the definition gives this:

trem·o·lo
/ˈtreməˌlō/
noun
Music
noun: tremolo; plural noun: tremolos

1. a wavering effect in a musical tone, produced either by rapid reiteration of a note, by rapid repeated slight variation in the pitch of a note, or by sounding two notes of slightly different pitches to produce prominent overtones.
   • a mechanism in an organ producing a tremolo effect.
   • a lever attached to the bridge of an electric guitar and used to vary the pitch of a note.
     noun: tremolo arm; plural noun: tremolo arms

 

[the_merv]

The 2 transistors on the heat sink, attached board labelled PU3 are 2SA1106 and 2SC2581 (see description).
All the circuit boards are labelled PU, with 9 fuses, sort of points towards power supply. It does have 2 blown fuses, and a severely burnt small film capacitor.

DESCRIPTION 2SC2581
·With TO-3PN package
·Complement to type 2SA1106
·High power dissipation
·High current capability
APPLICATIONS
·Audio power amplifier
·DC-DC converter

Any other suggestions?

 

[the_merv]

Here's a pic of the underside. It's well constructed and probably weighs close to 20lbs.

 

[Pio1980]

View attachment 1396895 Here's a pic of the underside. It's well constructed and probably weighs close to 20lbs.

It still looks like a power supply with a couple series pass regulators to me.

 

[slimecity]

Yup - tremelo is a volume modulating effect - something Id expect to see in an old organ- and in those days it was probably mechanically actuated. Its a common guitar effect and sounds GREAT. My guess is this is a multiple PS feeding a lot of voltages to different sections in an organ



.............................I want to see if I can get banned from here for posting inappropriate nudity.........

 

[the_merv]

I think we got it pegged as a power supply. Thanks for the great assistance. AK rules. Love the photo, simply hilarous!

 

[Anti_Skate]

And now for something completely different.