[kartik]

Quote:

Originally Posted by mikeg Your suggestion, for me to use the SDS as a power preamp, ahead of the E/90, yielded magical results. The character of the sound (i.e., sound signature) that the E/90 now produced through the ESP/950 headphone, changed completely. The sound was much more refined, and the sound stage increased greatly. The performance of this Koss headphone, when connected to the E/90, which was in turn connected to, and powered by, the SDS, was similar to the performance obtained by driving this headphone with the McAlister amp. Your advice to connect the E/90 in this manner saved me approx. $600. I was planning to buy an AKG 701, and to drive it with my Corda Aria. But, now I can dispense with this purchase, and I can sell the Corda Aria. In addition, I can now use the entire Koss ESP/950 system, rather than retaining it solely for occasional display at meets. As a consequence of your advice, here is how I've now connected this Koss system for my every day use. In my headphone setup that is located next to my computer, I use an ASL AQ-1005DT 300B tube amp. to drive a K1000 headphone. I now connected an ASL UHC-Signature speaker/headphone converter/transformer to this amp., and then connected the headphone outputs of this UHC-Signature device to the inputs of the E/90. While the sound stage that results from this setup is not as wide as that obtained when I connected the E/90 to the SDS, the quality and richness of the sound are wonderful. It's the kind of sound that I'm used to hearing from 300B tubes. BTW, in all of my preceding tests, I powered the E/90 with an Elenco Precision 0-30 volt variable power supply (costing approx. $75), and not with the wall wart that was provided by Koss with the headphone.

Cheers! How does the ESP-950 compare to the K1000 from the same source?

 

[mikeg]

Just compared them for the first time. The presentation of the K1000 is superior to that of the ESP/950; i.e., much larger sound stage, better instrument separation, more detail, etc., etc. But, I think that I'll still enjoy the more intimate and less resolved sound of the Koss. It could also be that the Koss may satisfy me more than the K1000 for some kinds of music, but this remains to be seen. So far I've enjoyed listening to the Koss in this setup. And, my comparison of these two headphones was done with only one recording; i.e., Brahms and Mozart clarinet quintets.

Quote:

Originally Posted by kartik Cheers! How does the ESP-950 compare to the K1000 from the same source?

 

[kartik]

Quote:

Originally Posted by mikeg Just compared them for the first time. The presentation of the K1000 is superior to that of the ESP/950; i.e., much larger sound stage, better instrument separation, more detail, etc., etc. But, I think that I'll still enjoy the more intimate and less resolved sound of the Koss. It could also be that the Koss may satisfy me more than the K1000 for some kinds of music, but this remains to be seen. So far I've enjoyed listening to the Koss in this setup. And, my comparison of these two headphones was done with only one recording; i.e., Brahms and Mozart clarinet quintets.

Wind instruments probably are better suited to the more rich presentation of the Koss as opposed to the slightly drier presentation of the k1000. There are very few cans that can match the soundstage of the K1000. Ths R10s have a huge soundstage, but I think the K1000s sound more real. Referring to edstrelow's initial observations,the Koss,although less accurate are more musical and rich than the staxen. I think this observation may extend in a way to the comparison with the K10000.

 

[mikeg]

In this setup, the Koss is very pleasant to listen to. But, as shown by listening to the K1000, lots of detail (e.g., background strings) is almost inaudible in the Koss. Primary instruments (e.g., the clarinet in this chamber music) are very prominent. But, the accompanying instruments (i.e., background strings) almost completely fade into the background. The K1000 brings out all of this detail, however.

Quote:

Originally Posted by kartik Wind instruments probably are better suited to the more rich presentation of the Koss as opposed to the slightly drier presentation of the k1000. There are very few cans that can match the soundstage of the K1000. Ths R10s have a huge soundstage, but I think the K1000s sound more real. Referring to edstrelow's initial observations,the Koss,although less accurate are more musical and rich than the staxen. I think this observation may extend in a way to the comparison with the K10000.

 

[mikeg]

As a final test, I compared the sound of the ESP/950 in the preceding setup (i.e., E/90 connected the an ASL AQ-1005DT amp., through an ASL UHC-Signature device) to that produced by an HD600 driven by a Corda Aria amp. The sound signatures and performance quality of the two systems were very similar.

 

[kartik]

Although given Jan Meier's preferences, the Aria is probably voiced for the HD600 while the ASL rig is a mongrelized fit for the ESP/950. Nonetheless, I find myself agreeing with your observation about the main instrument vs. backing instruments. In any case, chasing perfection, while certainly desirable is economically adverse. For now I'm adequately stoked by my present arrangement with the Koss.

 

[edstrelow]

I have just been moving amps around my systems and sat a Stax SRM-3 and Stax 404 down to compare with the Koss 950, using the Elenco power supply. I fed them both from a Sherwood Newcastle cd player, a good performing bargain unit. I had not made any direct comparisons in a few years and had always assumed that the Stax system would outperfom the Koss, but in this set-up it was by no means clear that the Stax was better. The Koss had much better dynamics, and had a sense of drive, openness and air. The Stax by comparison seemed rather constricted. The Stax did have a somewhat cleaner sound, for example there was a roughness to the voice of Maria Callas in an older recording that I tried. ( Of course no-one ever accused her of having a pretty voice).

I had owned the Koss set-up before I owned any Stax lambdas or the current 404. I had always felt that it was a step or two down from the Stax pro systems. However, with the substitution of the $60.00 Elenco regulated power supply for the transformer supplied by Koss, it is by no means clear that the Stax is better. I would expect many listeners to prefer the Koss, especially with rock/pop. And the Koss set-up at about $600.00 is considerably cheaper, probably even compared to Japanese Stax prices for phones and amp. Since you may also be able to get a reconditioned Koss system for a lot less than $600.00, it is worth looking in to to check out electrostatic sound without dropping a bundle.

I should add however that the Stax SRM-3 is not a currently made amp and I did not have an upgarded power cord for it or even sorbethane feet which can make an improvement (but at a cost). Also, you may get better sound with the Stax 313, 717 or various newer tube amps that Stax has. Still the cost would be much higher than the Koss 650.

Nor is there anything special about the Elenco power supply. It is just a big regulated bench supply and there may be others that work as well. It was the second non-Koss design I had tried and was somewhat better than the first and not too expensive.

 

[kartik]

Quote:

Originally Posted by edstrelow I have just been moving amps around my systems and sat a Stax SRM-3 and Stax 404 down to compare with the Koss 950, using the Elenco power supply. I fed them both from a Sherwood Newcastle cd player, a good performing bargain unit. I had not made any direct comparisons in a few years amd had always assumed that the Stax system would outperfom the Koss, but in this set-up it was by no means clear that the Stax that this was so. The Koss had so much better dynamics, that it had a sense of drive, openness and air. The Stax by comparison seemed rather constricted. the Stax did have a somewaht cleaner sound, for example there was a roughness to the voise of Maria Callas in an older recording that I tried. ( Of course no-one vere accused her of having a pretty voice). I had owned the Koss set-up before I owned any Stax lambdas or the current 404. I had always felt that it was a step or 2 down from the Stax pro systems. However, with the substitution of the $60.00 Elenco regulated power supply for supplied transformer it is by no menas clear that the Stax is better. I would expect many listeners to prefer the Koss especially with rock/pop.

Important to note that at ~$700, your Koss setup is much cheaper than the 404 and the koss has a warranty to die for.

 

[catscratch]

Time to raise the dead.

The recent Koss hype raised by the excellent A250 has re-awakened my interest in the ESP-950. This thread has been a very valuable source of information. Since I have an EA-1 to drive the ESP-950, I can definitely relate to MikeG's impressions (thanks Mike!).

But, I'm also interested in the K340. The one thing that I didn't find here was a comparison between the K340 and the ESP-950 when the latter is driven by the McAlister amp. Can someone clue me in?

 

[Carl]

*Patiently waits for own ESP-950s to arrive*

 

[edstrelow]

When I get some free time I will make a Koss 950 - Stax adapter, using the ends of old headphone cables to try the 950 on the Stax 717 amplifier.

 

[Carl]

Quote:

Originally Posted by edstrelow When I get some free time I will make a Koss 950 - Stax adapter, using the ends of old headphone cables to try the 950 on the Stax 717 amplifier.

I'm opting for a full recable, myself.

 

[catscratch]

Does anybody know what the bias voltage of the ESP-950 is?

 

[mikeg]

Peter McAlister must know, because he installed an ESP/950 output connecter in the McAlister amp. that he assembled for me. Give him a call at is 705-737-9269.

Quote:

Originally Posted by catscratch Does anybody know what the bias voltage of the ESP-950 is?

 

[Carl]

Quote:

Originally Posted by catscratch Does anybody know what the bias voltage of the ESP-950 is?

600 volts, but they can be run at 580v without any issues.