unknown amp

[amplidude]

hello.
ive been offered this amp cheap, seller has no clue what it is, my guess is hiraga, am i right?

right?

 

[vinylkid58]

No idea, but I like it.

jeff

 

[amplidude]

me too. it looks like lots of thought went into it.

 

[amplidude]

those white centertapped things?? dc link capacitors?

 

[Netlist]

those white centertapped things??

Makes me think of a reostat.

Hugo

 

[amplidude]

Probably right, a fixed rheostat configured in some crc.

 

[Citizen124032]

my guess is hiraga

The 8W version, component count.
The two TO92 near the pot are a 2SK and a 2SJ jfets, their neighbours NPN & PNP cascodes.
The TO92's near the big guys are the drivers, also NPN & PNP.
Get some top & btm and side pictures 2bsure.

 

[Norgaard]

Yes, it also looks like the "Le Monstre" to me. Will be easy to tell from the lower dc voltage also. 12V instead of 21V.
The output transistors are afaik know unobtanium and has been so for quite a while.

 

[amplidude]

We were all wrong, I got told by the builder that it is a scaled down version of Stax DA-300.

 

[amplidude]

Didnt even know stax made power amps hmmm

 

[ctrlx]

looks like lots of thought went into it.

looks like two sinks joined together with each output unfortunately mounted at the extremes of both sinks

 

[Citizen124032]

Now I'm curious what the circuit looks like.
Can you provide detailed photo's of top & btm sides, and component types?
I'll draw the circuit diagram and post it.

 

[amplidude]

Might do better,, have no clue how it sounds but I have an itch to buy it

 

[amplidude]

I did notice the positioning of transistors, if I get hold of it, and it's worth it, a copper bar comes between.
Will read up on the stax amp a bit, I sounds like a monster

 

[Citizen124032]

We were all wrong, I got told by the builder that it is a scaled down version of Stax DA-300.

Curious to notice the values of the various resistors and the layout...

 

[Netlist]

We were all wrong, I got told by the builder that it is a scaled down version of Stax DA-300.

One of a kind... in 1976:
https://www.1001hifi.info/2020/10/stax-da-300-1974-pure-class-a.html

Hugo

 

[amplidude]

Sorry I did not get the amplifier, it was sold when I again approached him.
Looking at post 15, those resistor values correspond almost exactly to a hiraga, I cant see any stax there, it's way more complex with current sources etc.