Vintage Koss pro 4aa specs.....

[jameselmer66]

I've looked everywhere that I know for the spec sheet for '70's built Koss pro 4aa headphones. If anyone might have that info or could point me in the direction to find it. I would appreciate very much. I've acquired a pair and like the sound so far. Pretty darn heavy and clunky but not too uncomfortable. I have found that these cans do not like mediocre or bad mastered CD's or vinyl. I listened to a Phil Collins CD which the mastering was of so-so quality. And they sounded terrible. But I played Dave Mathews Band, Crash CD and Wow! Very nice indeed. Nice tight bass and smooth mids to nice highs. I am pleased. But I would really like to have the specs. Thanks

 

[nitrous]

This info is from the insert which came with my set of Koss Pro-4AA headphones purchased in the spring of 1973 for $31.88 from Lafayette Radio (list price $60):
Frequency response: 10-20,000 Hz (no +/- info listed).

 

[jameselmer66]

This info is from the insert which came with my set of Koss Pro-4AA headphones purchased in the spring of 1973 for $31.88 from Lafayette Radio (list price $60):
Frequency response: 10-20,000 Hz (no +/- info listed).

Thank you

 

[tom3]

Brought back by Koss, look to be near original design too.
https://www.walmart.com/ip/Koss-Pro...MInYn-6q6-3QIVDtbACh0ShgNrEAQYBCABEgIDrfD_BwE

 

[jameselmer66]

Brought back by Koss, look to be near original design too.
https://www.walmart.com/ip/Koss-Pro...MInYn-6q6-3QIVDtbACh0ShgNrEAQYBCABEgIDrfD_BwE

Yeah, I appreciate the effort but those specs are for the modern Pro 4aa. They don't hold a candle to the vintage. If I remember correctly the vintage 4aa impedance is 32 but the modern 4aa are a whopping 250. So if you don't have a headphone amp or a decent home amp you can't get sound your looking for out of them. And from what I understand the drivers are way different. I think I've pieced enough 8nfo to cover the specs I'm looking for. Again thanks for the help.

 

[ra.ra]

Specs attached for original Pro-4AA headphones, circa 1975.

 

[jameselmer66]

Specs attached for original Pro-4AA headphones, circa 1975.
View attachment 1284499

Thank you

 

[Boonaroo]

My very first pair of headphones. Wish I still had them. They were some great cans!!!

 

[mhardy6647]

Pro-4AA (and AAA) manuals at:
https://www.hifiengine.com/manual_library/koss/pro-4.shtml



Specs on the last page of the PDF (and as posted earlier in this thread).

 

[Rey1]

I have a pair of the old ones, mine must be first generation or so because they have honking big speaker magnets jutting out from the sides. I mean almost like Frankenstein's neck bolts. Damn uncomfrortable but they do sound good on some recordings. I just need to do more neck work outs so they don't tip me over when I'm using them.

 

[red 111]

had the originals also ...sound was good but uncomfortable to wear for extended periods...lent them to a acquaintance & never got them back...still looking for the dude!

 

[twiiii]

I will admit I mixed a lot of live recordings using Pro 4 aa headphones. My last pair failed me about 5 years ago. Now I use Sennheiser 598, they are more comfortable and easy to listen too. They have better highs and bass even though they are open air headphones. They wouldn't be acceptable for live recording like the 4aa because they aren't sealed. In fact none of my 6 headphones are sealed anymore. Wonder how that happened? By looking for the best sound I guess. I will admit the 598's don't have the highs of my electrostatics or quite the clarity, but they are easy to live with and work well with my 10X iPhone. Yeah I had to spend $9.00 for the head phone adapter. Those ear plug things suck. Over the years I can't remember how many times I had to repair my 4 AA's. It was either the cross over cable, the fluid filled ear pads or the coiled cable. Only once or twice did I have to replace an ear speaker. Probably due to physical damage from transportation or dropping them on concrete floors. For the money they did a heck of a job. My portable Nakmichi 550 could blow you ears with 4AA's. My early favorites were my Model 9 electrostatics, but having to haul around my MC 240 to run them was a pain in the neck. But they sounded great with the old tube amp, something I couldn't say for a lot of early SS amps. My Crown D 150'As just didn't compare either.