Power amplifier Fostex 600?

[DanielT]

(not mine in the picture, same modell)

Anyone have experience with, know anything about a vintage power amplifier Fostex 600?

https://www.hifiengine.com/manual_library/fostex/600.shtml

Got it very cheap this summer. It's right with my friend for a recap operation now. I'll see how it turns out.

Do you think it's worth spending some money on new capacitors on an old Fostex 600?

 

[AnalogSteph]

Found a diyAudio thread on this one. Seems to be a generally solid construction. Since the filter caps are no doubt going to be expensive (18000µ/100V if I can decipher that correctly?), I would consult an ESR or even LCR meter regarding their health first... they may actually still be fine depending on the amplifier's previous life.

The wiring is interesting, not sure it would be 100% Douglas Self approved but it is quite tidy-looking in any case.

The inputs seems to be all unbalanced, which is not the most ideal thing in an IEC Class I device. Also, the modest SNR spec suggests a rather high-impedance feedback network. Both are things I would be looking into, not saying it would be easy though. It's probably not going to be a world-beater for slew rate given the undegenerated BJT input.

Not sure how old these actually are, but I'd say the construction is defintely pre-1980, maybe 1975-78.

 

[DanielT]

Thanks for the information!

Very interesting. It will be one, recap that is. . It may cost a little, because I want good ESR value. Quick withdrawal from the bank.

My friend, who will recap it, has as a hobby vintage hifi. Luckily, I think he gets good prices on ... I think the place is called Farnell.

Speaking of Douglas Self. I saw his Audio Power Amplifier Design
Sixth Edition is available to download (legally) online now.

The inputs seems to be all unbalanced. Okay but purely practical, how do you proceed if you are going to plug in a Topping e30 DAC (which I have) or a regular CD player, my Marantz CD5001? Something special one should do, think about?

https://www.hifiengine.com/manual_library/marantz/cd5001.shtml

Edit:
I also have a Yamaha CD player/changer, with adjustable bias, output level on the remote control. Maybe should test it together with Fostex 600 .

Recap in mid-November. Can put some pictures on it after it is ready.

 

[DanielT]

Recap earlier than planned.

My friend said:

Plays music through it now, speaker on Sonab OA14.Can easily fire up all the elements and get the emergency service here, (Neighbors can call if loud music is played in an apartment, for example)

Power and dynamic. Quiet when no signal. Hum and noise free in other words.

He He

 

[tomtoo]

Cool robust Eisenschwein.
A macho amp.