Help me identify my HiFi equipment!

March 28, 2008 2:37 PM

I need help identifying my vintage(ish) HiFi equipment, Especially the amplifier. If anybody has any information on them, it would be appreciated, or does anybody know any useful websites for this sort of thing? (Photos inside)

I have taken some photographs of the items,

posted by sliderjc to technology (7 comments total)

Here are the images, didnt work first time

http://farm4.static.flickr.com/3289/2369784122_27702f7d1d.jpg?v=0
http://farm3.static.flickr.com/2041/2368955073_b67f21be4f.jpg?v=0
http://farm4.static.flickr.com/3183/2369810058_3a83358da6.jpg?v=0
http://farm4.static.flickr.com/3270/2369778082_dabc95ce36.jpg?v=0
posted by sliderjc at 2:39 PM on March 28, 2008

http://farm4.static.flickr.com/3289/2369784122_27702f7d1d.jpg?v=0
http://farm3.static.flickr.com/2041/2368955073_b67f21be4f.jpg?v=0
http://farm4.static.flickr.com/3183/2369810058_3a83358da6.jpg?v=0
http://farm4.static.flickr.com/3270/2369778082_dabc95ce36.jpg?v=0

FTFY
posted by mumkin at 2:41 PM on March 28, 2008

That "Dad" button is unusual, and may be helpful in identification. Tha mind boggles!
posted by fish tick at 2:58 PM on March 28, 2008

Well, there can be no question but that you have a JVC A-G90 Stereo Integrated Amplifier with Dynamic Super-A. It is most decidedly not vintage, though I suppose you could get away with describing it as being old school. Looks to turn up on eBay from time to time. I assume it once was a component in a complete JVC rack system, and has since been separated from its brethren. The speakers are not original to the amplifier, since their inspection tag reads 1971, which has to predate that JVC unit.

Really, that's all you've got to go on? There's not a metal plate on the back of the thing with a serial number and power requirements and watts per channel and all that?

JVC describes Dynamic Super A (in this discontinued amp's specs) as:
Dynamic Super-A: For low-distortion performance throughout the
audible frequency range.

Dynamic Super-A is a refinement of our revolutionary Super-A, the design that offers the distortion-free sound of a class-A amp, and the efficiency of a class-B amp.

Popular class-B amps offer high efficiency, but they achieve it by switching the output transistors on and off. This results in an increase in distortion - switching distortion. Unrelated harmonically with music, switching distortion adds a harsh, metallic or gritty quality to the sound you hear. The alternative is the class-A amp which offers smooth low-distortion switchless sound, yet it requires its output transistors to be always on. This means low efficiency, bulky size and high cost. JVC Super-A is the answer to this dilema - it combines the positive aspects of both class-A and class-B amps. It does not generate switching distortion (like class-B amps). It gives sound a smooth, yet powerful quality.

Dynamic Super-A was developed with the singular purpose of catching up with vast improvements that have recently been made in the dynamic range of new digital technologies.
posted by mumkin at 3:07 PM on March 28, 2008

Oh, and it looks like yours has three Gm settings too, if those buttons are to be believed, so that part of the AX-901's description probably applies as well.
posted by mumkin at 3:23 PM on March 28, 2008

The speakers are definately KEF (as you probably noticed) thankfully KEF is still around and kickin' and they even have a fancy history page. looks like those speakers could be 103's or possibly the Coda, hard to tell how big they are in your pictures. unfortunately, it looks like the speakers have had their drivers replaced at some point, the woofer especially looks to have a butyl rubber surround which so far as i know didn't exist in 1971. The tweeters could be original, it's hard to see exactly what kind they are. I don't have much to add with regards to the amp other than to go out now and get a spray can of contact cleaner from your local radio shack or the like. those slidey pots for bass/treble/balance always seem to get corroded and get all scratchy. the contact cleaner should fix that up although it might be a pain to get the spray in there without opening the case. good luck with it all and keep it around as long as it still sounds good to you.
posted by skatz at 5:13 PM on March 28, 2008

DAD = Digital Audio Disk IIRC, not a bass boost for your parents ;o)

The JVC component is bland and not especially promising. KEF on the other hand are reputable and the speakers might be interesting to someone.
posted by arcticseal at 7:01 AM on March 29, 2008