What's this valve pre-amp?

[nat8808]

I've just bought a Harmonic Precision KH9 or "Champion" valve pre-amp from ebay for hardly anything - one of those, can't loose, risk buys - but can't find any info on it at all.

I can find Harmonic Precision as a brand of Star Sound Technologies, a US small company who make some well regarded bookshelf speakers but that's all.

It has a thick silver aluminium face plate with dual volume controls and input selector that has Phono, Tuner, Tape, Aux 1 and Aux 2 (note no 'CD' - so could date it?).

Inside it has some nice valves it turns out - don't know about valves, but seem high value when I look them up - 2 x Mullard CV4004s and 1x Mullard E88CC in the phono stage, 4 x Mullard CV4004s and 2 x name-rubbed-off 12BH7A s in the rest.

Judging by the 10 big ITT capacitors at the back, i'm guessing it's 80s.

Any ideas at all??

Here's the ebay listing and one photo HERE (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=140469813121&si=RrjDUYBgpVErGFrDQq3IWPzrHs8%253D&viewitem=)

Something about it told me it was a valve pre even though the listing doesn't give a clue - was obviously a pre to me because of the left and right volume knobs.

I'll post some photos of my own later..

I've not had a chance to try it out yet - it's a bit bashed but all looks in order inside - I'm a bit wary of pluging it in to anything not throw-away. I'll get out the Akai AU-1 I found and plug it into that with some found speakers.

All input greatly appreciated.

[jandl100]

Interesting Nat!

No, I've never heard of it either.

Some pics of the innards would be nice.

I don't blame you for being wary of plugging it to anything worthwhile .... scary!!

Any obvious signs of internal overheating or damage?

[nat8808]

Ooo, a reply. Hi Jerry.

I'll take some in a bit..

No signs of electrical mis-haps. Smells fine (the usual test).

No signs of bodge fixing either that I can tell although there are a couple of RS capacitors on the underside that stand out as being different so it could have been modified? The circuitboard itself though looks very hand made with the tracks looking hand drawn before the etching - a couple of deliberate track-cuts too. An early model of this unknown pre perhaps or recommended mods by the original designer?

The power cable is nicely made and looks recently made so suggests it was still in use despite being physically a bit bashed with odd and missing case screws.

Still, the quality valves, two Alps Black Beauties (one sounds rather scratchy tho), dual volume controls, large bank of PSU caps and heavily engineered front panel all seem promising!

Only one way to find out how it sounds though (or doesn't if it doesn't work).

[jandl100]

Go on, take a risk and plug it in, Nat. :eek:

Must admit I'd get it checked out by a competent electrical engineer before I did anything at all with it.

Just think - it might smoke your kit :doh: ... and for rather less than you paid you could have got a truly wonderful sounding TA2020 T-amp that will almost certainly totally knock the stuffing out of it in terms of sound quality! :eyebrows: (Yeah, I know yours is a pre and the T-amp is an integrated ... but have you tried one of those little TA2020 amps, Nat? - gobsmackingly good! ... see my system list below. ;))

[nat8808]

Reviving this thread...

I never did get around to turning it on - my flat was too messy to even have hifi set up.

I have taken some photos though:

http://img651.imageshack.us/i/sg100660.jpg

http://img822.imageshack.us/i/sg100658.jpg

http://img713.imageshack.us/i/sg100659.jpg

http://img809.imageshack.us/i/sg100661.jpg

Has anyone seen this before or know if it's manufactured or a kit?

Appears to be 3 valves for a phono stage and 6 in the active stage / power supply? There are a couple of 80's ICs too, near the caps - auto bias or regulators?

Dual Alps Black Beauty pots.. perhaps dual mono all the way through?

I guess I will have to plug it in and try it out. Won't be able to do that though till April as I'm going away.

[nat8808]

?? Where are the photos? have used the [IMG] button and entered the imageshack http link... OK, here are the links:

Front (http://img651.imageshack.us/i/sg100660.jpg)

Inside 1 (http://img822.imageshack.us/i/sg100658.jpg/)

Inside 2 (http://img713.imageshack.us/i/sg100659.jpg/)

Back (http://img809.imageshack.us/i/sg100661.jpg/)