Show us your vintage headphones! - Page 36

Quote:

Originally Posted by GREQ 

 

For a DIY project you'll probably need to spend more than $15 to get them in a decent working shape with recabling, new drivers, maybe a new headband. These types of projects are for the love of the hobby, as the drivers inside them are usually rated 2000 ohms and sound worse than anything... if you can even find something powerful enough to run them. 

I saw one thread where a guy refurbished a bunch of these super vintage headphones with almost new everything, so they were perfectly functional and very pretty, but then gave them to family and friends as gifts. 
That kind of project only lowers the value (for collectors) as original parts are damaged or discarded, but it looked like a really cool idea. 

The last time I asked about the price of one of these in a flea market, the guy wanted 60 euros...  ... and it was in bad shape....so from my perspective it's not a terrible price, unless German super vintage headphones are worth more than American....  ... just make sure it's not one-of-a-kind-super-rare before you rip it's guts out. 

Yeah itd be a very long term project with a lot of research involved on my part, but it would just be for fun i think haha.I think i'll pick it up if its still there when i have some extra money and see what i can do with it, if nothing i end up with some cool headphone history  I dont imagine it to be very rare but yeah i'll do some research on it juuuust incase 

More details and pictures on the Reference One.

The driver, as you can see, is quite large: 55mm in diameter. It has a huge magnet on the back which I have found to be quite powerful in comparison to my other vintage cans. The driver shell is made entirely of metal and it is held down with a metal plate that is bolted into the baffle plate. Looking from the front, the diaphragm appears to be made of a glossy black material that I have never seen used before. 

Finally hit that "eureka!" moment last night when I listened to one of my metal songs. These things are <really> fast. They are extremely upbeat and have a lot of energy. They have lots of detail, more than any headphone I have. They also have a good deal of micro-detail in the attack/decay department. They are relatively neutral with maybe just a <tiny> tilt towards the bassy side of things. They have a very wide expansive soundstage and great imaging, instrument placement, instrument separation, etc. 

Keep in mind that this is all out of a lowly E7. I can only imagine what these might sound like out of a higher power amp.

I can't believe it, and I almost don't want to, but these things are my best headphone. I'm stunned. They are absolutely ridiculously good. If you see a pair of these, anywhere, grab them. I can't believe I got them for $20. 

@takato14

Those drivers/magnets are colossal! I bet those things can go loud! Great find. I'm pretty sure large magnets like that and a full metal body would have made these quite a bit more expensive to produce back in the day.

Congratulations on those Koss. The drivers look exactly like what i remember are in my two Koss KRD-711 Red Devil pairs. I also have a spare driver i will see if I can remember to find it and take a picture, for sure it's the exact same metal clamp there, and also the wiring terminating in the pin connections at the driver.

 I had toyed with the idea of placing some small and very powerful neo magnets on the rears of them to increase their force, as the age of the stock ones should put them about half the strength of modern stuff. Helper magnets might boost them to the sweet spot, or it may do nothing.

 Only thing I know about the Red Devils is that their strange foam rubber pads can be interestingly uncomfortable for a few minutes until they warm up. Sort of like squishy windshield wiper blade pads.   I will also see about trying them on the beastly integrated I use and check them out again. I recall some really decent bass for their time.

I assume you have already checked out the dirt cheap replacement pads from Koss for them if you find the pads less than giving due to age. If you are wanting to hear them for what they really are you should make sure the pads are up to snuff to get a proper sound.

One of the Pro4xxx ones may fit.http://www.koss.com/en/products/accessories#?filters[0].key=Accessory%20Type&filters[0].value=C88B6D4C43204B3AB6475BD4110B35A0

Quote:

Originally Posted by nick n 

Congratulations on those Koss. The drivers look exactly like what i remember are in my two Koss KRD-711 Red Devil pairs. I also have a spare driver i will see if I can remember to find it and take a picture, for sure it's the exact same metal clamp there, and also the wiring terminating in the pin connections at the driver.

 I had toyed with the idea of placing some small and very powerful neo magnets on the rears of them to increase their force, as the age of the stock ones should put them about half the strength of modern stuff. Helper magnets might boost them to the sweet spot, or it may do nothing.

 Only thing I know about the Red Devils is that their strange foam rubber pads can be interestingly uncomfortable for a few minutes until they warm up. Sort of like squishy windshield wiper blade pads.   I will also see about trying them on the beastly integrated I use and check them out again. I recall some really decent bass for their time.

 

I assume you have already checked out the dirt cheap replacement pads from Koss for them if you find the pads less than giving due to age. If you are wanting to hear them for what they really are you should make sure the pads are up to snuff to get a proper sound.

One of the Pro4xxx ones may fit.http://www.koss.com/en/products/accessories#?filters[0].key=Accessory%20Type&filters[0].value=C88B6D4C43204B3AB6475BD4110B35A0

I would appreciate the pictures of the drivers, and perhaps of the Red Devil set itself: I can't find that set on google or Koss's site. If they're the same driver then I can get some specifications for these. They're not on Koss's site, anywhere. Not even in the product registration list.

I have considered trying the whole "helper magnets" idea. I have a couple neodymium fridge magnets that would fit on these... I might try it when I get home.

The pads I have are actually in phenomenal condition, and none of the pads on their site are quite the right type... Thanks though!

<3

Quote:

Originally Posted by GREQ 

My closed vintage cans - Manta 7000 (probably manufactured by Calrad)

 

-Volumes knobs on both sides

 

Super cool pressed aluminium grills and foam around the sides

 

...and a carry case.

 

At first they seem very comfortable, but the clamping pressure gets really annoying after about 5 minutes - the headband is similar to a Grado with a single metal rod, so I assume it can be bent to adjust the pressure.

I think they're very pretty, and they feel very well made. I wish I could get inside, but under the earpads I saw that the front grill plate is connected with small pop-rivets, so to open it requires destruction 

 

I wish the sound was as good as the looks, but there's not enough detail retrieval to keep me listening to them. There's plenty of bass, with a noticeable hump in the mid-bass, but it does extend well and responds very well to EQ. It's very treble shy which also responds very well to EQ which helps bring out more detail, but not completely to my liking. These are definitely low-mid heavy with a very rich emphasis on the lower vocal/cello range. This natural sound works VERY well for old jazz recordings which are often very thin sounding like Louis Armstrong, but doesn't work so good for female vocals or good/modern recordings. 

I suspect there might be a pretty good (in comparison to other) full size paper cone speaker inside as it sounds fairly similar to my Sony DR-7, but with more details and range. 

Those LOOK LUSCIOUS!!! nice find!

KOSS sent an email back to me.

Apparently, the specs are as follows:

10-25000 Hz

250 ohm voice coil

They said "Same specs as the Pro 4AA". This makes me wonder if it's the same driver unit or just coincidence. Does someone here have a PRO 4AA? I wanna see if the driver is the same. 

Looks to be the same driver. It's 2 inches across so around 53mm thereabouts. This one had the crumbled deteriorated foam which gummed onto the magnet rears and you can see a slathering of adhesive from the factory.

This particular one is the black-cabled one, I also have the red-cabled one. My thinking is that the red cabled one wasn't so hot for quality so they redid it with the thicker black version. From taking one of the red-cabled ones apart for an ortho donor shell ( it had  a bad driver don't get mad haha ) I found the red cabled one seemed prone to oxidation way down into the wires.

So basically i have3 of these (!!) but only two are stock. Somehow I seem to find the rare stuff in multiples at times.

Have to try them again on the amp but right now I am enjoying another thing I just got. I'll check in when I get to it.

yeah these drivers are beefy for sure.

 The headband is one piece with a pad of foam, you can also see the unique pads that are made from a softer foam rubber. I have replaced all inner foam as well as the earside foams directly over the driver.

If I get around to it i might even retrofit ( reversibly ) the other set when i get them cleaned up with modern pads to see how things sound and the fit improves.

I'm not entirely sure what the difference is between these and the excellent looking tan-greenish coloured KRD-7's is, it may in fact have the exact same driver.  The  KRD-7 differs only externally in that it has a dual entry instead of the single entry cable like these and regular style vinyl pads. Otherwise it has an identical headband and cups.

Anyhow here are some pics of the rare Koss KRD-711 "Red Devil"

Quote:

Originally Posted by nick n 

Looks to be the same driver. It's 2 inches across so around 53mm thereabouts. This one had the crumbled deteriorated foam which gummed onto the magnet rears and you can see a slathering of adhesive from the factory.

This particular one is the black-cabled one, I also have the red-cabled one. My thinking is that the red cabled one wasn't so hot for quality so they redid it with the thicker black version. From taking one of the red-cabled ones apart for an ortho donor shell ( it had  a bad driver don't get mad haha ) I found the red cabled one seemed prone to oxidation way down into the wires.

 

So basically i have had 3 of these, still do but only two are stock. Somehow I seem to find the rare stuff in multiples at times.

 

Have to try them again on the amp but right now I am enjoying another thing I just got. I'll check in when I get to it.

 

yeah these drivers are beefy for sure.

 The headband is one piece with a pad of foam, you can also see the unique pads that are made from a softer foam rubber. I have replaced all inner foam as well as the earside foams directly over the driver.

If I get around to it i might even retrofit ( reversibly ) the other set when i get them cleaned up with modern pads to see how things sound and the fit improves.

 

I'm not entirely sure what the difference is between these and the excellent looking tan-greenish coloured KRD-7's is, it may in fact have the exact same driver.  The  KRD-7 differs only externally in that it has a dual entry instead of the single entry cable like these and regular style vinyl pads. Otherwise it has an identical headband and cups.

 

Anyhow here are some pics of the rare Koss KRD-711 "Red Devil"

 

Wow.

For one those headphones look sweet, and for two that diaphragm is super-beefy looking. Any idea what the diaphragm is made of?

only thing i can think of would be mylar at that time. ( I edited the last post slightly after you quoted not sure whats different if anything ) If I recall correctly these are from around 1971-2 ish. Surprising really.

Quote:

Originally Posted by nick n 

only thing i can think of would be mylar at that time. ( I edited the last post slightly after you quoted not sure whats different if anything ) If I recall correctly these are from around 1971-2 ish. Surprising really.

Mylar is usually transparent though. Any driver I've seen was see-through... 

*shrugs* either way they sound great.

oh these are definitely see-through it's just the camera angle . Also just got out the multimeter and tested the driver it's around 240ish ohms resistance so I would say it is also specced at 250ohms, my meter contacts or the driver pin contacts may be less than ideal.

 Interesting never thought to check before thanks for the idea.

Oh and the 10-25000 rating would explain the deep bass on these and decent highs. You must be getting the same no wonder you like them. Certainly not a muddy sloppy overall sound like one might expect here. Vintage doesn't have to automatically mean garbage.

Just in case you are curious here's the stock insides and then the final finished ortho transplant ( lower pic ) with new pads on that other 3rd spare set .

The 4 baffle screw/bolts were extremely hard to remove they had flat tops and were also tiny hexagonal edged, no screw insertion at all. Basically threaded tiny bolts.

The more I look at you fellers' Manta and Reference One shots the more I want to find one of each, the aesthetics are top notch.

This arrived today... The Watson Mod. 920

Aside from my massive disappointment and anger at the person who sold this, as they described it as 'well preserved', yet I found the volume control to be held together with sticky tape, both plastic gimble arm connectors had cracks, and one has a piece of plastic snapped off and missing, not to mention the complete disintegration of the interior earpad foam, I'm actually really happy with them.

They don't have an ortho SFI driver like the bigger brother Mod 930, but the dynamics inside sounds impressive. This one is actually very difficult to open up, so I don't know how long it will be until I can get photos of the driver. I would love to at some point, so someone can help identify them, as my ears tell me they are too good to be cheap consumer rubbish; probably another mass produced driver by a reputable company sold to 3rd party manufacturers. 

Quote:

Originally Posted by GREQ 

This arrived today... The Watson Mod. 920

 

 

 

 

Aside from my massive disappointment and anger at the person who sold this, as they described it as 'well preserved', yet I found the volume control to be held together with sticky tape, both plastic gimble arm connectors had cracks, and one has a piece of plastic snapped off and missing, not to mention the complete disintegration of the interior earpad foam, I'm actually really happy with them.

 

They don't have an ortho SFI driver like the bigger brother Mod 930, but the dynamics inside sounds impressive. This one is actually very difficult to open up, so I don't know how long it will be until I can get photos of the driver. I would love to at some point, so someone can help identify them, as my ears tell me they are too good to be cheap consumer rubbish; probably another mass produced driver by a reputable company sold to 3rd party manufacturers. 

Awesome headphone, sorry about the lying sack of **** that sold it to you.

And I believe that's an old Pioneer Equalizer in the background, isn't it? :3