[Paulusz]

Would you say they could be the NAF-48490-1 Type 49510, has the same weird top terminated twisted cable. (Im pretty positive it them)

Yep! it's the NAV, it was used on submarines together with the ASDIC sonar system, detail retrieval was a matter of life and death, specifications look really bad but that must not be translated into ''it's a bad headphone'' since it was a 'specialist' and bad specifications can also be a sign of a honest manufacturer..
What I would really like to know is why many ASDIC users turned to ''consumer'' headphones, three of which I'm sure; koss pro 4aa (U.S), AKG K-160 (U.K), and in Europe, guess what, the DT-48!

 

[Carlos42]

US Navy military surplus!

Presumably they were flight communications headphones...

Who would have been the manufacturer?

 

[Carlos42]

US Navy military surplus!

Presumably they were flight communications headphones...

Who would have been the manufacturer? .

These were made by Permoflux.Back in the day, these were the only headphones that were considered to be suitable for accurate monitoring.The picture is of famed recording engineer Rudy VanGelder wearing a pair. Having been around, (as an interested teen) in those days I don't remember any DT-48's being used for that purpose.At this point, I am a old guy of 78.I have a working pair of Permofluxes, bought during that era.They really sound pretty good.Permoflux also made quite a few headphone for the military use. If asked I could get out my Permoflux literature and give you some precise model numbers. The ones made for the military had the terminals on top also but the holes for the cords were larger that the holes for the ones sold later for critical monitoitoring. Otherwise they pretty much looked the same. I don't remember being aware of the DT-48's until Gothem audio started importing them a little bit later. They imported what we know as the "E" series with a separate cord for each phone.They were 5 ohms with one being red and the other one being black.They thoughtfully inculded the resisters for padding down the output of your amplifier. In those days amps had no headphone jacks. I have such a set up on my system today, even though my amp does have a headphone jack and I think it sounds better than the headphone output.I still have and use those DT-48's. I must say that this post is all from memory, which may not be that good, so I welcome any corrections.I do have the old maufactorer's literature so I could look up some better facts if anyone is interested.When the DT-48's first started being imported by Gothem, it was a different world, the US audio guys were just becoming aware of the many things used in Europe that were not used in America,such as Neumann/Telefunken microphones. And Gothem audio was just starting to import and sell this gear,

 

[Carlos42]

I was wrong (again). The first set of dt-48's I bought as a teenager most resembled the "A" series not the e series.

 

[MDR30]

No wonder the DT48 became popular the last decade:

https://www.facebook.com/PBSSoCal/videos/midsomer-murders-a-rare-bird-preview/988627124681337/

 

[mindblownDt48]

No wonder the DT48 became popular the last decade:



https://www.facebook.com/PBSSoCal/videos/midsomer-murders-a-rare-bird-preview/988627124681337/

No way its because of one episode of some small production TV show. Its the sound that separates these with all the rest. DT48 was used in field recording a lot, so maybe thats how they got them- as someone had old pair sitting around and offered them to producer. Or producer himself is knowledgeable and wanted to make realistic scenario.
Also, they have been popular for what, 60 years ? They are by far the most popular professional headphones, since theyve been around since 1937, nowdays its 7506 or hd25

 

[CJG888]

The DT48 was the can chosen by Nagra to go with their R2R decks…

 

[jellyfriends]

Update:
Audio Technology Switzerland has released an updated Nagra headphone: a private-label Audeze LCD-XC. beyerdynamic continues to have nothing offered with Nagra standard certification. Ultimately, has Nagra or beyerdynamic lost credibility in the professional world? The planar technology appears to have succeeded dynamic for studio preference in the USA and Asia; Nagra chooses the Californian manufacturer presumably due to the vacuum of planar manufacturers in Western Europe. Otherwise, Audeze truly has the only monitors worthy of the namesake. After a decade of discontinuation, the DT 48 is admittedly “a dinosaur,” as described by USA beyerdynamic repair service. On the other hand, flat frequency response, phase and impedance are still the top characteristics in high fidelity—the standard since the DT 48 dynamic driver's release. In the interim, Nagra has been photographing their field recorders with HD 25s.

Obscure DT 48 A.?s are appearing-
The Bund is auctioning off surplus medical equipment with a hidden surprise:

The Auritec AT409 audiometer is standard with DT 48 A.00 drivers! These are terminated with 270° 5-pin DIN at 1, 2 and 3. The wiring is the same scheme as the DT 48 E, with blue being left + and transparent as right +. On eBay, 1.bestshop has more than a few, along with other German sellers. The “Vario-Volume 2000” headband and cups are likely the best option for the DT 48 A.00. The pads have similar performance as the EDT 48 R without the accumulation of discomfort. I find the EDT 48 S seal poorly and omit low frequency, but I have not chosen to use the adhesive seal. The initial impression is that staging is enhanced at the expense imaging and texture with the EDT 48 S.

Anyway, a rare headphone is now much more accessible to the few.

 

[Paulusz]

Update:

That is an interesting post! new life for this old design, as an addition I like to present the maybe best sounding DT-48 up till now, the DT-48PE.
Ho ho, stop Googlin', the PE stands for ''Paulusz Edition''.
It's a DT-48A modified to the bone, the butterflynuts; why didn't Beyer think of this? The earpads, nice and thick, I can move around, wear glasses AND ''have my Bass''.
I had to expiriment with different amounts and thickness of foampads behind the grills to ''restore'' the right amount of airresistance behind the driver,
resulting in a colourless sound, the most ''liquid'' I ever heard .
BTW it looks like a open headphone now but afcourse it's not, a pressure-chamber headphone will always be a pressure-chamber headphone....

 

[SHAMuuu]

That is an interesting post! new life for this old design, as an addition I like to present the maybe best sounding DT-48 up till now, the DT-48PE.
Ho ho, stop Googlin', the PE stands for ''Paulusz Edition''.
It's a DT-48A modified to the bone, the butterflynuts; why didn't Beyer think of this? The earpads, nice and thick, I can move around, wear glasses AND ''have my Bass''.
I had to expiriment with different amounts and thickness of foampads behind the grills to ''restore'' the right amount of airresistance behind the driver,
resulting in a colourless sound, the most ''liquid'' I ever heard .
BTW it looks like a open headphone now but afcourse it's not, a pressure-chamber headphone will always be a pressure-chamber headphone....

What pads are those?
Did you take any pics before you put the grill on?

The dt48/480 i've been tinkering with for years now.

Only kmann, me, and I guess you now.

I tried shure 1540 alcantara on 48 but it didn't work out. Though it's been nice on the 480 (which has the 48 driver but has no cover and open fully)

They all seem to behave differently (the 5ohm, 25ohm, and 200 ohm)

Do you have another pair to compare to the stock? Or do you use another reference headphone to tune them?

Thanks

 

[Paulusz]

What pads are those?
Did you take any pics before you put the grill on?

The dt48/480 i've been tinkering with for years now.

Only kmann, me, and I guess you now.

I tried shure 1540 alcantara on 48 but it didn't work out. Though it's been nice on the 480 (which has the 48 driver but has no cover and open fully)

They all seem to behave differently (the 5ohm, 25ohm, and 200 ohm)

Do you have another pair to compare to the stock? Or do you use another reference headphone to tune them?

Thanks

Hi SHAMuuu,

The pads, I bought them a time ago but for sure from Wang Yi Fei on Ebay and for almost sure it are the extra thick earpads for the Audio Technica ATM-50.
Sorry, no pics from the inside but from this forum you might just remember the pic of the guy standing in front of a window wearing a dt simply opened up, mine look the same (they all do).

One line I didn't understand; Only kmann, me, and I guess you now.

I have three DT-48's, this (former) A, and two ''S'' type's both 25 Ohm, they all sound different....

As a very interesting first test I put my hands over the drivers and then slowly of and on while the music was playing, it gives an idea of the ''tonal range'' your playing in.
I use a ''homemade'' reference recording to tune them, human voices are perfect so it's a recording of friends of mine talking ''around my head'' while I wear miniature measurement microphones (Panasonic mce-2000) IN my ears. When the reproduction gets ''scary'' I'm on the right track... .

If I do use a reference headphone it's the Beyer DT-990 , midrangewise spot on, or the Philips Fidelio X2, one of the few HP's that can convincingly reproduce piano's....

Hope this helps and... thanks fot the respons....

 

[SHAMuuu]

Hi SHAMuuu,

The pads, I bought them a time ago but for sure from Wang Yi Fei on Ebay and for almost sure it are the extra thick earpads for the Audio Technica ATM-50.
Sorry, no pics from the inside but from this forum you might just remember the pic of the guy standing in front of a window wearing a dt simply opened up, mine look the same (they all do).

One line I didn't understand; Only kmann, me, and I guess you now.

I have three DT-48's, this (former) A, and two ''S'' type's both 25 Ohm, they all sound different....

As a very interesting first test I put my hands over the drivers and then slowly of and on while the music was playing, it gives an idea of the ''tonal range'' your playing in.
I use a ''homemade'' reference recording to tune them, human voices are perfect so it's a recording of friends of mine talking ''around my head'' while I wear miniature measurement microphones (Panasonic mce-2000) IN my ears. When the reproduction gets ''scary'' I'm on the right track... .

If I do use a reference headphone it's the Beyer DT-990 , midrangewise spot on, or the Philips Fidelio X2, one of the few HP's that can convincingly reproduce piano's....

Hope this helps and... thanks fot the respons....

Thats quite a collection to have 3. Nice to see you appreciate them.

Earlier, I meant only like 3 users are "modding" dt48 /480. As time goes by, and prices go up, don't see much talk about them anymore. @kman1211 is a big fan of the dt480, and told me about them.

The guy with the open dt48 you mention... the dt480 is like that... it's open but it's inside an enclosure like the dt150.

I've put them in wood enclosure before as well as dt770 shell

Still trying to perfect them in wood cup setup. But it's been fun playing with the various drivers as they all have their own unique characteristics.

Always cool to see mention of the dt48s!

 

[DesertSnake]

New audiometric ones have arrived. What is unusual is that the wire screen is mounted on magnets. Someone tried to pull out the plug and tore the blue wire out of the solder joint inside the connector. I will figure out how to connect them so that the sound is in phase and install a standard plug