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SupOrSalad t1_j2cahfk wrote

The funny thing is a lot of these old headphones that are between 1000-4000ohms are meant to be run on crystal radios. No external power, just the energy in the radio waves themselves are what supplies power to the radio and headphones


pongpaktecha t1_j2ckxwe wrote

They can also be hooked up in parallel with out too much issues since the paralleled impedance will still be plenty high


HedgehogRoutine2695 t1_j2d75hq wrote

now how tf does that work


florinandrei t1_j2ff0l2 wrote

It only works when the signal is very strong, and it's an AM thing.

I've done this as a kid. There was a powerful AM station nearby, enough signal for listening in headphones. Using a huge wire antenna, good ground connection, and an output transformer, I was actually able to feed just barely enough signal in a small speaker. Placing the speaker in a small transistor radio box (like a DIY speaker box) made it audible in my room at a soft, but decent level.

There were no batteries in the schematic. All the energy came from the radio station. Since only one strong station was in the area, I didn't even need an LC frequency filter - a germanium diode was the only real component besides the headphones (or speaker + transformer). One side of a germanium transistor also works instead of a diode. Silicon diodes / transistors don't work.

The signal was plenty for comfortable listening in headphones. I was able to even use metallic rain gutters as an antenna, and my hand as a "ground connection" and it still worked okay. I could impress my friends by touching one wire to the rain gutters, and AM radio would play in the headphones.

High impedance headphones worked better. For the speaker, the transformer basically was just an impedance adapter - speakers have low impedance, but the schematic required high impedance for best results.

Here's the schematic for headphones:

Replace the headphones with transformer + speaker if you wish, but don't expect a lot of volume even in the best case.

If there is no strong AM station nearby, then it will not work at all.

General info and more complex schematics:


SuperTinkerer t1_j2e59oo wrote

Like son goku's spirit bomb...extracting tons of energy from the air..haha,does not work like that...


audiochef68 t1_j2ck4vx wrote

Are these from an electric chair ?


Suspicious_Life_6846 t1_j2cv3i9 wrote

Crinacle: ๐ŸŽ Dongle ๐Ÿ‘


sverek t1_j2c9xdh wrote

Dongle will drive it just fine.


ZevireTees OP t1_j2ca3y7 wrote

I won't buy these. They need too much work to look good. The would be cool to play with.


f3llyn t1_j2cnbux wrote


moonra_zk t1_j2f1hl2 wrote

Knew what it was before I clicked, simply the best restoration channel on YouTube.


f3llyn t1_j2f2lys wrote

Yes, his work is impressive.


Ticonderogue t1_j2d7zux wrote

All beat up makes a statement. If these headphones could talk. I'd buy them for the right price.


YourMother0HP t1_j2d0yz1 wrote

Even your topping a30 will drive it just fine


sverek t1_j2d6obi wrote

Topping will burn these headphones with hatred for the free world.


ZevireTees OP t1_j2c9p8w wrote

I found these headphones online, and I don't understand how you would be able to run 1500 ohm headphones. I wanted to find some headphones that looked kind of like these but I want to see of someone can mod the with new drivers. I came across these and was stunned because I had not seen over 600 ohms.


blargh4 t1_j2cbpxm wrote

> I don't understand how you would be able to run 1500 ohm headphones

depends entirely on their sensitivity... possibly very easily.


Half-White-Mexican t1_j2ccb16 wrote

I converted a kilo-ohm military aviation/tank headset and it got more than enough power from my TA-30. You can drive them with any amp that provides enough power.


Berny-Aver95 t1_j2chqx3 wrote

And how do they sound?


Half-White-Mexican t1_j2cnsm9 wrote

All mids. Great for radioing your comrades, awful for everything else.

I was able to EQ them and they sound half decent, but still don't have all that much technical ability.


oratory1990 t1_j2d8942 wrote

> You can drive them with any amp that provides enough power.

With a load impedance that high you'll mostly be concerned about providing sufficient voltage. Current draw (and hence power) won't be high due to the high load impedance.


Cartella t1_j2cxua6 wrote

Assuming the same efficiency, the difference in sensitivity of a 1500 ohm headphone and a 600 ohm one is 4 dB, which is probably less than you think. Or almost 8 dB from a 250 ohm one.


audiophile_lurker t1_j2dxsb9 wrote

Electrostatic headphones have impedances to the tune of 100,000 ohms. 1500 ohm is not that big a deal as long as long as they are either fairly sensitive (which is probably the case for crystal radio headphones), or you got a high voltage amplifier (do not need much current at this point).


Shlushii t1_j2eh4xc wrote

Hotwire it right into the back of a serious speaker amp


Xypton t1_j2csz6e wrote

Fun fact: BA drivers can be of arbitrary impedance, even something like 20Kฮฉ is possible, as this saves power for application in hearing aids


sandtymanty t1_j2cyoxg wrote

I love these 16th century headphones.


iAyushRaj t1_j2cp4iq wrote

Apple Dongle with an iPhone ๐Ÿ‘


Pr3ssF2PayR3sp3c7 t1_j2ddj9n wrote

My Sennheiser HD 414 has 2000 Ohms. But they are surprisingly easy to drive. I even get them to a listenable level with my phone


Overall_Falcon_8526 t1_j2er2o8 wrote

Ask not what your headphones can do for you - Ask what you can do for your headphones.


excellent_alt6969 t1_j2dy902 wrote

i dont know about these headphones but they better sound MAJESTICALL for me to run out and buy another fucking amp to drive these fuckers


dangit1590 t1_j2erg1t wrote

Damn these the jfk edition


emceejc88 t1_j2f4262 wrote

I thought it was some kind of virginity lock at firstโ€ฆ


PrimitiveMeat t1_j2fg2ub wrote

Probably still better than the Gen4 A50 Astros


Doc-85 t1_j2em9kr wrote

Holy shit, you need a whole electric substation to power these or a small scale nuclear reactor!