[dra1]

Good afternoon,

Need some help with a learning questions on my OLD stax headphones I found.

I am a long term audiophile and have started to enjoy headphones including the Sennheiser 650's (smooth abd wondrerful) and AKG701's ( a little less smooth but better PRaT). I have found my old Stax SR80's. They have a five pin din like connector. but I cannot find the amp box. Pardon the nievity but here are my questions:

1) Can I connect them to my stereo with a fancy adapter cable? My stereo has an AR CDIII Mk2, Rowland Coherence 1 original and Berning ZOTL headphone amp. If so where can I get the cable?

2) Can I buy a new stax amplifier (nto too expensive) for these headphones? Do these stax amps still connect directly to speakers or do they connect to RCA preamp inputs?

Thanks for your patience and help in advance.

Al

 

[grandenigma1]

Quote:

Originally Posted by dra1 1) Can I connect them to my stereo with a fancy adapter cable? My stereo has an AR CDIII Mk2, Rowland Coherence 1 original and Berning ZOTL headphone amp. If so where can I get the cable?

No you can't you will need an electrostatic amp or energizer.
Quote:

Originally Posted by dra1 2) Can I buy a new stax amplifier (nto too expensive) for these headphones? Do these stax amps still connect directly to speakers or do they connect to RCA preamp inputs?

Yes, you can buy a new amplifier. Something like the srm-313 should be just fine. The new amps have RCA and some have XLR as well for inputs.

 

[catscratch]

The SR-80's are electrets if I'm not mistaken, but they're not self-biasing. You need an energizer unit like the one that came with them originally to bias the stators, or you need a Stax amp. The fact that they're 5-pin means that they're pro-bias, and pro-bias energizers are very hard to come by. These energizers connect to the speaker terminals of your power amp, and can give you very good performance if the power amp is up to spec.

The least expensive Stax amp is the SRM-212, and Stax has a newer version of it out, though I don't know if it's for sale separately. But, I'm not sure if the SR-80's are good enough to warrant the expense.

I'd suggest scouring ebay for used Stax pro-bias amps. The SRM-1 Mk II is obviously one of the best choices, but it will be pricey. The SRM-212 and equivalent is the minimum you'll need.

 

[studeb]

SR-80 are indeed electrets, but are not pro-bias. All the electrets had 5 pin plugs. They would have been run from a SRD-4 energizer box, which is really just a step transformer, they show up on eBay every now and then. In theory you could run them from a Stax amp, the bias pin is a dummy pin so would not carry any voltage, and an electrostaic energiser (SRD-3 -5 -6 -7)could also work. Never tried running electrets off an electrostatic amp.

 

[catscratch]

Oops. Well, if they're not pro-bias, then plugging them into a pro-bias amp is one scorchingly bad idea. Good thing you pointed that out.

 

[grandenigma1]

Quote:

Originally Posted by catscratch Oops. Well, if they're not pro-bias, then plugging them into a pro-bias amp is one scorchingly bad idea. Good thing you pointed that out.

Only one way to find out just how fun that would be thoug

 

[Carl]

Quote:

Originally Posted by catscratch Oops. Well, if they're not pro-bias, then plugging them into a pro-bias amp is one scorchingly bad idea. Good thing you pointed that out.

With electrets the bias of the amp doesn't matter (as the polarisation voltage isn't connected to the headphones), so if it can run off a 230v bias amp, then it can also run off a 580v one.

To use an electrostatic amp, you should only need to turn the volume right down, and slowly turn it up until you reach listening volume.

 

[wualta]

It may be too late now, but the simplest and by far cheapest way to get your SR-80s connected back up to your stereo would be to buy a used SRD-4 adaptor box (it's not an amp, just a box), which is what your SR-80s came with originally. They're plentiful and cheap on eBay and you may have some luck with CraigsList and other online selling vehicles.

What's in the box? Transformers. They'll take the moderate voltage from the back of your power amp and crank it up to the high voltage all electrostatics need. And if you feed the box with a high quality signal, the SR-80s will sound surprisingly good, especially if you goose them a bit on the extreme high and low end. Got EQ?

The SR-80s use electret diaphragms. We wouldn't call them self-biasing because electrets are internally, inherently biased; they hold a permanent electrostatic charge. So the SRD-4 box contains no bias circuitry. Which means if you ever want to upgrade to the "big" Stax electrostats, say an SR-X Mk 3, or a Lambda, you'll have to get another adaptor box. But we can cross that bridge when we get there.