[ericj]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Not too surprising they mention electrets needed care to last a long time. Sony famously had problems with their earliest electret mics, many of which are now dead. Didn't make their electrets right or didn't know how. Fixed the problem by the mid '70s.

I think it was cute how they included a graph that shows how their sensitivity-conservation scheme works. Reminds me of seeing the CFO of a former employer tell us about the future.

Quote:

Have you found anything about the pentagonal shape of the diaphragm?

Nope. Maybe i can find some more sony electrostatic patents . . . .

 

[spritzer]

Quote:

Originally Posted by wualta /img/forum/go_quote.gif Have you found anything about the pentagonal shape of the diaphragm?

My guess is that they were trying to break up the standing waves without using bass to do so. Beyer use a large brass ring that the diaphragm was mounted to, to do the same thing.

 

[khbaur330162]

Did some snooping and found this picture:

Original Link

The overall headband assembly and design is very similar apart from some aesthetic differences and the energizer box looks virtually exactly the same. I know there was discussion a while ago about Sony possibly having the ECR-500's OEM'ed from another company or something. Dunno if it's a missing link, but it's definitely curious.


Anyway, I was able to snag a pair of Sony ECR-500's off eBay a little while back and they sound very promising out of the Beta22 even though they aren't being driven to normal listening volumes. Purchased a vintage Kenwood KA-3700 speaker amp to drive the energizer and am hopefully getting a matching pair of K340 velour pads because they are far more comfortable and set your ears a little bit further from the driver which, from what I can tell, benefits these drivers quite well.

Might have pics with the velour pads on my pair or something if you guys are interested and I'll also try to post my impressions of these nice vintage cans.

 

[wualta]

Hope you have fun with the ECR once you get it hooked up to a decent speaker amp (I'm not familiar with the Kenwood KA-3700; the only Kenwood amp I have is a late-'70s KA-7100), and yes, we'll be very interested in your impressions.

The Pioneer does look like a clone, and it's possible the headset and transformer box were both the products of a contractor and then the different big companies tucked their own proprietary drivers inside. The reason I've never been interested in the Pioneer is the back, which is very nearly closed. The cardinal virtue of the ECR is its out-of-head imaging, and you don't get that with a closed back (though AKG tried and partly succeeded). Plus, who knows what sort of driver Pioneer came up with?

If one came up and stayed nice and cheap, it might be interesting to have as an alternative to the Sony. I wonder if the plug/jack is the same?

 

[ericj]

Quote:

Originally Posted by khbaur330162 /img/forum/go_quote.gif I know there was discussion a while ago about Sony possibly having the ECR-500's OEM'ed from another company or something. Dunno if it's a missing link, but it's definitely curious.

Well, I was spreading that idea because i'm an embittered former Sony customer and didn't want to believe that they could get anything right. At least not THAT right.

But if you look up a page or so in this thread you'll see a link to Sony's patent on the uni-electret transducer.


Quote:

hopefully getting a matching pair of K340 velour pads because they are far more comfortable and set your ears a little bit further from the driver which, from what I can tell, benefits these drivers quite well.

I've never found the old vinyl pads to be uncomfortable. Moving the drivers further from your ears might decrease the bass, though, who knows. Tell us how it works out. Worst case scenario you can sell the pads.

Good luck with your Kenwood. Anything that can drive a 4-ohm load to 20 watts or so should get these nice and loud, but sometimes you have to get a bigger amp to get a better amp. I mean, if you wanted a really good 20W amp, you'd have to build an AMB Labs B22 or something.

I Wasn't aware that AKG pads fit these things. I guess that's good to know, if the pads get somehow ruined.

 

[Fitz]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif Well, I was spreading that idea because i'm an embittered former Sony customer and didn't want to believe that they could get anything right. At least not THAT right.

I feel ya there.

They certainly are really nice headphones... I've heard Minh's (aznsensazian) pair and I would love to have one for myself.

 

[spritzer]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif Well, I was spreading that idea because i'm an embittered former Sony customer and didn't want to believe that they could get anything right. At least not THAT right.

check out the Sony R1 and R10 lines... world class components and built so well they put most current products to shame.

 

[khbaur330162]

Got my KA-3700 in the mail yesterday. I have the AUX input hooked up to my Beta22 and my ECR-500's sound pretty darn alright for the $5 they went for on eBay UK. I payed through the nose on shipping, but it was still a pretty decent deal, especially considering their condition (no imbalance that I can tell, and all scratches are abnormally clustered on the metal parts in the headphone's construction).

The sound at first was rather laid back and overall just a bit smothered, however, I suspected the KA-3700 had something to do with it. The volume pot, despite the unit being advertised as 100%, perfect working order, is a bit scratchy when you move it and if I tip it too high on the Kenwood without feeding it a fair amount of juice from the Beta the left channel cuts out completely. So the amp is a little sketch at this point, but if I fiddle with the tone controls and turn the treble up a bit and the bass back a tad these suckers just sing. Very nice extension and clarity with a slight, but obvious leanness to the tone when compared to either my CD3000 or ATH-2 which I've yet to determine good or bad per my tastes. Sound stage is intriguingly odd; more encompassing/spherical than I'm used to with what seems like a bit more definition in it's imaging, while slightly more collapsed than that of my CD3000. For what it's worth, it actually does remind me a lot of the bass light K340 I used to own, I just don't need to crank 'em as much to sound good. (Definitely a positive aspect in my book.)

More on all that to come. I have finals coming up and a few papers due so I won't have much time to listen, but what I hear so far is very promising. So far they've performed particularly well with some of my Clapton so I'll definitely make note to throw the Unplugged album in my heap of stuff to listen to.

Should be fun.

 

[wualta]

Don't wait, get a can of DeoxIT, the miracle contact cleaner, today. Check your local crusty old guy radio-TV parts place, usually in a scummy part of town. If they don't have it, try Parts Express. DeoxIT is your Iffy World Of Analog friend.

The KA-3700 is a good start, but I want to get you into something with defeatable tone controls, preamp outs/amp ins, switchable turnover frequencies for the bass and treble controls, and stuff like that. It can still be had reasonably cheap, too, but we'll worry about that later. Let's see if we can troubleshoot this cut-out problem first.

.

 

[khbaur330162]

Yea it's a nice unit, I think it's like circa 1977 or something. Has an RMS rating of 35wpc I believe and sounds pretty good with how I've configured everything. Quite honestly I wouldn't mind bypassing the volume pot altogether and simply hooking up the rear AUX RCA jacks to the 2 channel, SE output of my Beta. That way I can use a very nice quality stepper as opposed to a standard pot. Do you think it'd be easier to just bypass the volume pot vs. cleaning with DeoxiT? I've been running the KA-3700 full blast for a few hours now and it hasn't even gotten warm...

I got the KA-3700 because it was in my price range which is pretty much anywhere under $100 including shipping.

 

[wualta]

I don't think the pot is causing any sound quality problems that would be audible above the problems you'd find in many old amps-- electrolytic capacitors off value, drifty (and noisy) resistors, bias and offset adjustments off due to age, and so on. So I'd go the DeoxIT route. Besides, if you ever want to sell the 3700, you'll want to keep it stock.

But yes, you could bypass the whole preamp section and go right into the amp. Remember, I didn't say it would be easy to do, nor did I say there wouldn't be shielding problems, etc. Not that I have something against vintage amps (I'm an AudioKarmer, after all), but when you go vintage, it's best to go near- TOTL vintage to get better parts and more features. TOTL amps tend to have more stuff written about them on forums, and that helps when you want to ask a question about parts/schematics/mods.


.

 

[funflyer]

Won a pair of phones only on the 'Bay after reading many passing complimentary comments and becoming more and more interested.  By chance, there was an adapter box separately (but concurrently) on offer from another seller. So I got them both (doubling my chances that the system wouldn't work!)
 
When they both arrived I hooked everything up - and - dead left channel.  Bummer.  So I took the 'phones apart and cleaned up a lot of oxidation at the cord connection points (as well as removed some disintegrated foam damping and replacing it with light felt ).  Voila!  They work and sound delightful.  Not perfectly neutral, but with a very open and realistic mid-range and believable bass for an electret. Highs seem a bit recessed. They reflect what I consider to be some of the best attributes of late 1970s high-end audio - very musical and organic with a smooth, slightly soft and engagingly lush sound.  Very easy to like as they are not too detailed or analytic. Overall, a very enjoyable headphone - despite being 40 years old and perhaps not as accurate as many of today's 'phones.  In regular rotation now with my various planar-magnetics and ESP-950s. 
 
As my bedside system wasn't set up with a "real" amp, I pressed a spare Threshold S/300 into service.  OK, it's a bit of an overkill at 150 WPC, but it is a brilliant amp and can drive almost any load with aplomb. And since I then had a high level output source, I pulled out my ancient Stax SR-3/SRD-5 system as well, and daisy-chained it to the Sony box. The Stax are from about the same period. They were my first high-end headphones (from a time in which the category practically didn't exist!) and still stand up pretty well.  They have great detail and clarity, but an annoying (to me) lower treble prominence and not much low bass. The Sonys are better.  
 
Overall, I see this exercise as vindication of the value of some more vintage equipment.  Old doesn't necessarily mean worthless.  Although restoration and TLC may be needed to make it sing, there is a lot of vintage equipment which easily can compete with all but the best of current gear - and at a much lower price point.