What is this amp, and what do you think of it?

[nannoo]

Without saying too much about the make or model, can those in the know say what they think of this power amplifier? I don't know how much you can tell from a picture, but any observations relating to quality and value of the item would be interesting...

thanks

 

[jacco vermeulen]

Taste like fish & chips.

 

[sreten]

Hi,

Strange choice and use of that heat sink. No apparent
thermal feedback for biasing. Pretty wimpy board
tracks for the high current stuff. No attempt to use
spare board space as a ground or supply plane.
Hard to work out the rectifier arrangements.

Whatever it is I'd say its not mainstream.
Value wise I'd say nothing special, at all.

rgds, sreten.

 

[Fusion916]

Those heatsinks don't look adequate.

Save the caps, xfmr, throw the rest out.

 

[Zen Mod]

power wires ditto to bottom side , there is thermal feedback on heatsink (3 blue wires)

though , info about outputs could say more ......

I think there is something interesting , but hard to say more just from pic

and - that's certainly one of wimpy UK amps

 

[jacco vermeulen]

info about outputs could say more

Darling-ton

(Philips 15000uF/40V, 1992, junk)

 

[sreten]

there is thermal feedback on heatsink (3 blue wires)

Hi, Yes I missed that looking for traces, rgds, sreten.

 

[ostripper]

Looks like the outputs/drivers are point to point wired direct to the PS (on the
heatsinks.

What's left on the board is apparent , LTP , servo, CCS's , VAS. Don't see the
driver pads , but do see the Vbe out on the twisted triple (3 blue's).

A shot of the other side would confirm.

OS

 

[Ian Finch]

The heatsinks look to be substitutions since the output darlingtons are wrongly located on those extruded sections and the narrow ventilation slots don't cover them properly for cooling efficiency. Guessing they could be 72 mm high, would give a free air rating of 2.2°K/W or 2.5°K/W if 55mm high. That's not a lot of cooling when the parts are fitted incorrectly in a poorly vented enclosure.

Even though there is a reasonable sized transformer, perhaps the amplifier should only be rated about 30W/ channel?

 

[anatech]

Looks like a one-off build. For all the previous comments I would have to agree that some parts should be recycled, some shouldn't.

Either that or it's an overbuilt DIY headphone amplifier.

-Chris

 

[jacco vermeulen]

Looks like a one-off build.

Boy, are you in for a surprise.

Barry might even throw in a bottle of toilet wine : https://www.youtube.com/watch?v=QC0V6lf-KVI

(40W, the bridge rectifier is a KBPC type inbetween the lytic cans, wire links to the capacitor solder lugs above it)

 

[anatech]

Hi jacco,
Are you telling me this is a production piece? Wow!
This appears to be very high in assembly labour. Not what I expected.
Would you be willing to PM me about this unit? I am now very curious about it.

-Chris

 

[anatech]

Hi jacco,
I have never seen that brand on this side of the pond. They really produce this and sell it?? Wow. Is it as bad as it looks?

I see someone asking 300 pounds for that exact model.

-Chris

Edit: Does anyone have a schematic for this beasty?

 

[Zen Mod]

nice to see ya mate

 

[jacco vermeulen]

as bad as it looks?

In reality they're even worse than on a picture, imo.

Albarry went bust in the '90s, but relaunched half a decade ago, still the same cheap plastic styling for rather absurd price levels.

The stero power amp is pretty much the integrated (PP1) model of that era, in the same case, minus the preamp hardware (Britannia all the way).
The M408 is half an S508, in a different case.

 

[billshurv]

We did produce some dross in the past.

 

[jacco vermeulen]

Folks who love strapped-down electrolytics could have done a whole lot better with an Audiolab 8000 series, imo.

(for cans in bondage plus darlington output stages, Nytech springs to mind)

 

[anatech]

Mr Zen!
Always a pleasure! Keeping well I hope?

Hi jacco,
Looking at the schematic (many thanks), it's like there was an standard design that had changes strapped onto it to make it better. This is an odd amplifier for sure. The Audiolab 8000 is a much better product! I have seen those come across my bench before. Those amps I don't mind at all.

Hi Bill,
Do you really have a hand in that S508 amplifier? Interesting. We all have to start somewhere, and that place isn't normally something to be proud of.

-Chris

 

[billshurv]

Goodness no, just apologising for the dark days in the 80s where fresh grads often setup a hifi company and foisted some horrible flat earth carp on the world. Then again as you know I made a poor choice of preamp in the mid 90s!

 

[jacco vermeulen]

Looking at the schematic

Do you not wonder where the reset button for the muted input stage is ?