[Duggeh]

Earwicker7: Same mechanical principles, different drive system, the AMT as the acronym refers to is like a pleated ribbon driver and is driven with the same sort of electricity that moving coil and ribbon drivers like which is comparitivly high current and low voltage.

The piezo driver in the H2 is folded or pleated like the AMT so it does fire against itself, but rather than a folded ribbon its a folded piezoelectric film and that likes the same sort of electricity which electrostatic transducers like, a comparitively high voltage, low current type.

You'd probably get some sound of them from the AMP 2 with an adapter but the volume would be very limited and you'd get maximum power handling distortion out of them if you tried to feed them more than the few watts they'll be happy with in that scenario.

The K1000 would I think be a better second headphone to try with the AMP 2.

On the AMT front, I'm trying the drivers in a crappy DIY put together using Stax Lambda pads to create a fixed earcup volume for the driver to push against and moving the driver a little closer to the ear in the process. Planar headphones like to push against a fixed volume of air. Very interesting listening.

 

[earwicker7]

Makes sense. I wasn't aware that the drivers were that different. Does this result in a substantial difference in the sound?

 

[Duggeh]

Vast. And yet not.

The H2 have got gobloads of low end, I haven't heard the AMT from the AMP2 but until today I'd never been satisfied with its cerebral, coughing mouse low end. Both are very very fast though. I rate both below the Omega 2 ultimately.

Heres the sealed earcup frankenphone with the Precide drivers.

 

[spritzer]

Now we need to get you a decent amp to use them with, young squire. So which is it, B22 or a DynaFet?

 

[bjarnetv]

wow, those look almost as good as the HEaudio jades, is that the same kind of tape nasa uses in their spaceships?

how do they sound compared to stock: better, strange, worse?

i´ve been thinking of transplanting the jecklin ps2 drivers into a ghetto DIY wooden housing, to see how they sound with a sealed baffle and real earpads, not to mention an adjustable headband.
still not sure what pads to use though.

 

[Duggeh]

It's most irritating that the Pass Labs has the hum issue in one channel with the AMT drivers, the NAD does a nice job though and at this time the housing solution (which I've spent the last hour tidying up) is of primary importance.

To answer your question though, I'd go with the B22 I think

@bjarnetv

I prefer the sound. These aren't going back in the Ergo housing. You lose some air, "air" which anyone familiar with a K1000 would be able to nod in recognition of, but the gains in the low end are absolutely worth the sacrifice.

As for the Jecklin closed solution, the best idea I came up with in my mind for that was to fill a square hole with a round peg and mount them on a baffle with an SR-Omega pad. I can't think of any larger circumference pads which would actually provide any real closure.

 

[spritzer]

Getting the housing right is paramount. Even upgrading to some ducktape would be a major upgrade.

The SR-Omega pads on the Jecklin are a very good idea although they would look strange. Not that that is a new thing to Float owners...

 

[bjarnetv]

Quote:

Originally Posted by Duggeh /img/forum/go_quote.gif It's most irritating that the Pass Labs has the hum issue in one channel with the AMT drivers

background hum is seriously driving me insane as none of my amps are silent enough for the jecklins.
what kind of amp did you use when you had the jecklins? did you have any issues with background noise?

the omega pads seems like a good choice, but how do stat drivers react if the baffle-opening is smaller than the drivers themselves: more bass?

 

[WindowsX]

I'm still looking.....for commercial amp that can properly drive H2 without TR2...

 

[spritzer]

I used my Audio Analogue Puccini with the Jecklins and there was no hum. Very silent amp though...

Many stats have a smaller baffle opening such as the Stax SR-1,2,3 and 5 and the effect is a bit like horn loading a dynamic driver. That's an extreme case and you would be ok with the size of opening which the SR-Omega earpads will give you.

 

[Duggeh]

double post

 

[Duggeh]

Quote:

Originally Posted by bjarnetv /img/forum/go_quote.gif background hum is seriously driving me insane as none of my amps are silent enough for the jecklins. what kind of amp did you use when you had the jecklins? did you have any issues with background noise? the omega pads seems like a good choice, but how do stat drivers react if the baffle-opening is smaller than the drivers themselves: more bass?

I used my NAD C352. I also have had both versions of the PS2 transformer box and two seperate sets of headphones, no hum with either of them, ****lots of hum when I ran them out of my dads Quad 405-2, but thats been in need of an overhaul to replace caps and stuff for at least 5 years.

I couldn't guess what the effect would be with the pads. Normally (ortho DIY and such) its sticking big pads like the O2 pads onto headphones built using little drivers like the SFI tweeters, I can't think of an example of someone going the other way off the top of my head. There might be reflection issues or lensing but unless you're going to Sigma-fy the Jecklin drivers, whch would be impractical at best, I can't think of a better solution.


Quote:

Originally Posted by WindowsX /img/forum/go_quote.gif I'm still looking.....for commercial amp that can properly drive H2 without TR2...

Alio

Theres the Alio from Byon, but I've read no reports at all of the combination. It's one of two possibilities confirmed by TakeT, the other involves modificaiton of a tube amplifier. See Untitled Page

Aside from those two, you're goign to have to look at solutions not confirmed by TakeT as 100% workable or safe and by that I mean electrostatic amps. The H2 amp design that Dr Gilmore came up with was a modification of one of his electrostatic amps. A KGSS or Blue Hawaii would do the job but the problem is the voltage output of the amp being too much for the parts that are inside the H2 headphone which raises the danger of damaging the headphone if too much power is fed.

 

[WindowsX]

I wish I could get SS amps for TakeT since tube amps aren't hard to make with 4.8k output impedance and some matching. Also, Alio has 100v swing which isn't good enough for mere $2k amp and that DIY amp can be done in hands when I want in my country.

Anyway, I found Burson HA amplifier can drive TakeT H2 at barely listenable level too with 300ohm output gain jack.

 

[spritzer]

Quote:

Originally Posted by WindowsX /img/forum/go_quote.gif ...Also, Alio has 100v swing which isn't good enough for mere $2k amp...

Based on what exactly? This isn't an electrostatic amp and you will overload the phones at roughly 200v. What these phones require is low voltage swing compared to ESP's but a lot of current and amp capable of maintaining the power output over a large impedance range.

 

[b0dhi]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif Based on what exactly? This isn't an electrostatic amp and you will overload the phones at roughly 200v. What these phones require is low voltage swing compared to ESP's but a lot of current and amp capable of maintaining the power output over a large impedance range.

That amp would result in relatively low volume. It would be listenable but you wouldn't be able to "turn it up" when you wanted to. I have routinely put 400v across mine and they continue to work fine.


These phones can be driven fairly well by some simple mods to the internal circuit to reduce the impedance. Doing so, I've run them directly from my Juli@ soundcard (putting out 20vpp in balanced mode), into the 150ohm+ load of the modified H2. This achieves a decent volume. However this has a downside which is that the frequency response is altered, and the bass becomes quite anemic (although it still achieves deeper bass than with the TR2, which says something...).

Ideally these should be driven with a very high (100kohm-1megaohm) series resistance and kilovolts across them. They need no more than 20ma for a good volume.