Acrosound S1001

[hionfi]

We wanted to post this S1001, you don't see them much.

 

[gadget73]

Wow, nice. Never seen one of those before.

 

[hionfi]

We thought it would be fun for members, you'll see Acrosound amps from time to time but not the pre.

 

[diamondsouled]

With built in power supply?

 

[dcgillespie]

Are those the original knobs? They sure look like Heathkit knobs to me -- or maybe they both used the same knobs?

Dave

 

[radioactive]

Are those the original knobs? They sure look like Heathkit knobs to me -- or maybe they both used the same knobs?

Dave

Those are original.

To the original poster :thmbsp: on the preamp and they are quite rare although it probally sounds good with the dynaco st 70 you need the amps to go with it. either the stereo 20 -20 or the 60 w monoblocks.

 

[crooner]

That's a real beauty and rare as hen's teeth!
Are you powering it from the preamp take off sockets on the Stereo 70?

 

[Hionfi2]

Yes it's powered from the st70 and I think everything is original.

 

[crooner]

That unit was Herbert Keroes' swan song in the tube business as it was released shortly before he closed shop.

It is more fully featured and better looking than Hafler's PAS, IMHO. I bet sounds better also.

 

[Hionfi2]

One last note, we're playing the pre with a Dynaco St70 and a pair of Bozak Concert Grands. They fill our store and put a smile on our customers.

 

[BootsyK]

One last note, we're playing the pre with a Dynaco St70 and a pair of Bozak Concert Grands. They fill our store and put a smile on our customers.

Hello,
I know it's been some years, but any chance you have a schematic for the Acro S1001? I picked one up myself, and it's missing it's power transformer. I'm looking for documentation that would let me know what voltage I would need on the secondary to get it back up and running

 

[Dswankey]

@BootsyK

Just so you don't get your hopes up, the member you quoted and asked a question to hasn't posted or been seen since 2015, so I doubt you'll be getting a reply

 

[Dswankey]

Fwiw,

Here's a somewhat more recent thread by AK's noted Acrosound guru not only that he's still active so maybe post a question there as he's quite knowlegable.

Thread 'Acrosound family reunion: S1001/UL120'

Jul 7, 2017

Hello guys,

I did some work on the only Acrosound pre-amplifier ever produced, with the idea of making it work together with it's mate, the UL120. Thanks to Diamondsouled for finding me this one.

First I thought it would be an easy caps swap and go. As usual, it did not happen this way.

First I started to notice some oddities with the boards versus the schematic. After some time, I realized that the model I had did not follow the schematic as it has 2x7199 per board and not a 7199 in low input followed with a 7247.
This is odd but reality: the version I have is not the "regular" model...

• Brice
• Replies: 19
• Forum: Tube Audio

• 

 

[ramjet]

Hello,
I know it's been some years, but any chance you have a schematic for the Acro S1001? I picked one up myself, and it's missing it's power transformer. I'm looking for documentation that would let me know what voltage I would need on the secondary to get it back up and running

The transformer has two secondaries, one at 6.3 vac, current load 1.5A, and the other at 135vac, current load 15ma. The power supply needs to provide 250-350 vdc.

 

[dcgillespie]

So I’m assuming it uses a voltage doubler rectifier? And if so, is it a half-wave or full-wave design? That will figure significantly into the true current drawn from the transformer’s HV winding. Their little 20 watt stereo amplifier uses a half wave design — which is a little strange….

Dave

 

[ramjet]

So I’m assuming it uses a voltage doubler rectifier? And if so, is it a half-wave or full-wave design? That will figure significantly into the true current drawn from the transformer’s HV winding. Their little 20 watt stereo amplifier uses a half wave design — which is a little strange….

Dave

Here is a partial view of the schematic from the assembly manual. It does not show what the self powered unit actually has installed, at least not in the one that I have. No 6X4 rectifier shown.

 

[tubeactive]

Here you go:

 

[tubeactive]

I hope these help your resto of a scarce preamp...

 

[Brice]

Zoomed.

 

[dcgillespie]

Yep. Another half wave voltage doubler rectifier. What Keroes fascination was with them I’ll surely never know…….

Dave