DIY Orthodynamic Headphones by dBel84 Page 2

Leak 3000 Isodynamic

dBel84 - Next up is a pretty standard vintage ortho except that it is rare as hens teeth – probably the only Leak isodynamic I know that exists. It is a near twin of the Wharfedale ID2 (the successor of HP1). A very different design, the driver is fashioned after the mighty Fostex T50. Stock it sounds a little thin in the lower end – I modded it as much as I could without killing the tone. It has a little more weight but still not as powerful as it could be. The tops are pretty sparkly; mids are a little forward; but overall a good listen if you can stand the pressure on the ears for long enough.

Tyll - Wow! These are right out of Austin Powers bedroom. Big, black, and mod, bay-bee.

I hear these pretty much exactly as described above, but I'd not call the highs "sparkly." My perception is that they're a bit inarticulate and withdrawn relative to the mid-range; a bit boring and constricted sounding. Measurements were decent. Poor 30Hz square wave performance on one side is likely fit issues. The drivers are out of polarity.

Wikiphonia pages for the Leak 3000, and Wharfedale ID2 from which comes.

Yamaha HP50

dBel84 - I got rid of (gave away to enthusiastic orthobloomers) most of my Yamaha Orthos. This was one of my first Orthos – it came from Germany and smelled bad. It is the HP50 – a mono (originally) headphone that was supplied free with Yamaha organs. I cleaned it up, and settled on a “differentially” damped scheme in the end. The driver is damped by a donut of Smeggy felt, followed by light felt. The back of the cup is damped with Moorbrook. I re-cabled to stereo with OFC plated silver (actually some sort of high end guitar cable).

Tyll - Again, fit issues show up in erratic bass response with poor seal. Highs seemed a bit inarticulate; mids are nicely rendered but a bit forward. I continue to be impressed by the low notes with these old Ortho cans; though not quite loud enough in these cans it's still quite good --- especially for a freebee with your Yamaha organ. I'd say these are the best measurements of the group.

They didn't smell bad to me.

Wikiphonia Yamaha HP50 page.

Fostex T10

dBel84 - Sticking with small drivers, we next have the fostex T10 . Early series fostex, same era as the T20v1 which put fostex on the recording studio map. Round driver but not center pinned. One of my favorites. This one is damped with dense Auzzie wool felt up against the driver, a porous donut followed by a disk of Moorbrook. Sound is (to my ears) beautifully balanced. I use these quite frequently but the supraaural pressure does get to me after a while.

Tyll - Though not having quite the bass authority of some of the other cans, and sounding a bit "ch" when it should sound "sh," I found these headphones remarkably natural and transparent.

Measurements of this headphone are surprisingly good; they could easily pass for a current production headphone. Drivers are out of polarity.

Wikiphonia Fostex T10 page.

Telefunken TH 700

dBel84 - One of the largest circular drivers – this is another rare headphone from Telefunken. The driver was probably made by PMB as it looks like a PMB driver and it is well known that PMB oem’d for several other manufacturers. There is still some debate as some of the drivers have quite unique features --- not expected if a company was merely flogging off drivers. I think this headphone sounds great, pinna pain is supreme after a few minutes so although this sounds good , I hardly use them. When I started messing with the zebra cups – this was one of the drivers I had in mind to transplant. The Wharfies just sounded so good to me that I never moved on. They are damped pretty much like I damp most orthos (in other words – I can’t friggin remember ;-) ) but generally I start off without any damping and then muck about until I push them over the edge and back off a little from there.

Tyll - Wow, realy a cool headphone from a bygone era. The bails remind me of Beyer headphones.

It strikes me that there is a similarity between all these cans but for the Wharfdales. Somewhat recessed highs and never piercing, good bass (though sometimes a bit uneven, due to the pads mostly, I think), and a really natural sounding mid-range. I can see why people like to play with planar-magnetic headphones.

I think the measurements in the bass and the shape of the 30Hz square waves on the Telefunkins are a bit poorer than they otherwise might be but for the poor seal of these cans. And yeah, the clamping pressure coupled with the thin pads is a bit much to take for long. If they weren't such cool and rare headphones, I might suggest modifying the pads.

Wikiphonia Telefunken TH 700 page.


dBel84's picture

Thanks Tyll , just blown away at how seriously terribly the wharfedales measure. An old curmudgen once said, "Give a listener flat response between 100 and 10000 Hz (with nothing to compare it to) and he'll be perfectly happy. For awhile, at least" Hopefully my while will keep on going as I seriously love those cans. To fill in a few voids re the origin of the zebrawood - they came from a now unobtanium online headphone that sounded like it should for the money and the Telefunken pads were in poor shape , the stax srx were as close as I could match and that is what was on the sample you had. Very intrigued by the HP50 findings as at most small meets this is the ortho loved by most. I had a lot of fun , glad you did too ..dB

svyr's picture

>Zebrawood Wharfedale

those look pretty sweet (like Stax 4070 woodies :D )

UtzY's picture

Talking about Stax, I really want to see how well they measure. I've seen many but I not so detailed like Tyll's. :)

PS: Please Tyll, I know that they aren't your priority, but make this site a one-stop destination for this kind of things :)

svyr's picture

mm, I'd love to see the graphs for SR 202,404, 407,507 and some omegas.

Unfortunately it doesn't seem likely many people will send those in :D...Maybe if Tyll attends meet.

Same goes for high end IEMs btw.

Tyll Hertsens's picture

Bringing the measurement gear to meets would be a bit of an ordeal, and the noise level might mess up the THD measurements. I've done it before, but I think it's unlikely again ... but we'll see.

I will get to electrostatics measurements eventually, I promise. It will just be a while.

sgrossklass's picture

I'm quite impressed by the results on some of these. The T-10s could almost pass for an early HD595 (albeit a much less sensitive one), or a DT880-32. Save for the lowest octaves, I'd say these are definitely better than the Thunderpants (which are likely to be limited by their drivers).

Those HP-50s look like they could even use a wee bit MORE damping still, in spite of already being quite insensitive as-is. Not bad at all for a freebie!

Now some of the others clearly measure like yesteryear's technology, but still gems like these show the potential of orthos. Without the whole ortho DIY scene, we certainly wouldn't be seeing new commercial models nowadays.