[iFi audio]

Using the iFi iESL, I initially tried one AHB2 amps to power the Stax X9000's, but it wasn't loud enough. I then tried two AHB2 amps and was really pleased with the headroom (very seldom do I see the Benchmark lights clip anymore unless I have things uncomfortably loud).

Now, I finally have another way to power my electrostatic headphones, as I now own some original Stax SR-009's and a BHSE. To my ears, the BHSE is really transparent too.

However, the iFi iESL + two Benchmark AHB2 amps + DAC3 + HPA4 combo is so good, it may even surpass or at the very least be as good as the famous BHSE (or any electrostatic amp for that matter)!?! I wasn't expecting this, but with the Stax X9000, I can drive the BHSE into clipping while the iFi iESL combo pictured below still has around 3dB of headroom left.

With the Stax SR-009 headphones, both electrostatic setups have way more headroom than needed. No way would I turn up either until they clip.

I'm honestly not sure where to go from the iFi iESL + two Benchmark AHB2 amps + DAC3 + HPA4 combo. I doubt anything available is going to be as transparent and powerful. Hopefully one day we see someone with an Audio Precision analyzer setup a test circuit that can measure a setup like this, and compare it to some of the top electrostatic amps.

Excellent stuff, thank you very much

 

[aokman]

Using the iFi iESL, I initially tried one AHB2 amps to power the Stax X9000's, but it wasn't loud enough. I then tried two AHB2 amps and was really pleased with the headroom (very seldom do I see the Benchmark lights clip anymore unless I have things uncomfortably loud).

Now, I finally have another way to power my electrostatic headphones, as I now own some original Stax SR-009's and a BHSE. To my ears, the BHSE is really transparent too.

However, the iFi iESL + two Benchmark AHB2 amps + DAC3 + HPA4 combo is so good, it may even surpass or at the very least be as good as the famous BHSE (or any electrostatic amp for that matter)!?! I wasn't expecting this, but with the Stax X9000, I can drive the BHSE into clipping while the iFi iESL combo pictured below still has around 3dB of headroom left.

With the Stax SR-009 headphones, both electrostatic setups have way more headroom than needed. No way would I turn up either until they clip.

I'm honestly not sure where to go from the iFi iESL + two Benchmark AHB2 amps + DAC3 + HPA4 combo. I doubt anything available is going to be as transparent and powerful. Hopefully one day we see someone with an Audio Precision analyzer setup a test circuit that can measure a setup like this, and compare it to some of the top electrostatic amps.

About the only step ups are high end direct drive amps (debatable if they’re actually superior). Or if you’re into DIY tinkering, using larger Lundahl audio transformers which will be superior to the iESL transformers.

The iESL is excellent though, shame they didn’t keep producing it but I love my Lundahl transformers anyway now…

 

[iFi audio]

shame they didn’t keep producing it

Pro iESL turned out a late bloomer and partially because how popular e-stats got in recent years. We did a small batch recently and some distributors may still have a unit or two, so if someone wants a brand new iESL, they still can be found. Thanks!

 

[etc6849]

About the only step ups are high end direct drive amps (debatable if they’re actually superior). Or if you’re into DIY tinkering, using larger Lundahl audio transformers which will be superior to the iESL transformers.

The iESL is excellent though, shame they didn’t keep producing it but I love my Lundahl transformers anyway now…

Do you have any build pics and bill of materials? Sounds like a decent project. Feel free to PM if you have some links to share.

I thought the Blue Hawaii was one of the top direct drive electrostatic amps, but I've only had electrostatics for a year or so. It definitely sounds very clean to me, and has tons of headroom with the SR-009's I also bought from the former BHSE owner. The X9000's shouldn't be that much harder to drive (only 1dB difference in sensitivity), but for whatever reason are compared to the SR-009's.

 

[Jacksatin]

My last setup with ifi pro IESL with ferrum Hyspos at 9 volts. However the output power is showing only 2.0 watts and 0.2 A. K, is that alright or should I go down to 7.5 volts to get more power ?
IMO, the ferrum Hyspos is better than ifi ipower stock (in term of sound)

My setup is using Chord Ultima5 and pre3 to connect IESP via loundspeaker input.

 

[elwappo99]

My last setup with ifi pro IESL with ferrum Hyspos at 9 volts. However the output power is showing only 2.0 watts and 0.2 A. K, is that alright or should I go down to 7.5 volts to get more power ?
IMO, the ferrum Hyspos is better than ifi ipower stock (in term of sound)

My setup is using Chord Ultima5 and pre3 to connect IESP via loundspeaker input.

Did you connect a Ferrum Hypsos to the iESL for the 5v power in?

 

[BassicScience]

Did you connect a Ferrum Hypsos to the iESL for the 5v power in?

That would be silly in the extreme. The power supply's only functions for the iESL are to illuminate the LEDs and keep the capacitor bank fully charged. In the latter capacity, they're literally only connected for a period of milliseconds every 30 seconds! Transformers are passive devices, and are also not connected to the power supply.

 

[elwappo99]

That would be silly in the extreme. The power supply's only functions for the iESL are to illuminate the LEDs and keep the capacitor bank fully charged. In the latter capacity, they're literally only connected for a period of milliseconds every 30 seconds! Transformers are passive devices, and are also not connected to the power supply.

Well I'm kind of confused. I agree, there's no real point to connecting it since it powers the LED and relays so it's not really in the signal path.

But then the Hypsos is pulling 2w which would kind of imply that's what they did.

 

[BassicScience]

Well I'm kind of confused. I agree, there's no real point to connecting it since it powers the LED and relays so it's not really in the signal path.

But then the Hypsos is pulling 2w which would kind of imply that's what they did.

Apologies, I responded in the abstract vs. in the context of @Jacksatin 's query. A 2W draw sounds about right for some LEDs and relays (I forgot about these). Adjusting the power supply voltage is highly unlikely to affect the power draw significantly.

On another note, I wouldn't drive a non-estat with the iESL personally. Unless your amp can't handle a higher impedance headphone, there's no reason to put transformers in the signal path. OTOH, it can be a bit more convenient in a situation where you're using the same amp to drive conventional headphones and estats (via the iESL), and the sound quality degradation is fairly minimal (but definitely audible) in my experience.

 

[Jacksatin]

Apologies, I responded in the abstract vs. in the context of @Jacksatin 's query. A 2W draw sounds about right for some LEDs and relays (I forgot about these). Adjusting the power supply voltage is highly unlikely to affect the power draw significantly.

On another note, I wouldn't drive a non-estat with the iESL personally. Unless your amp can't handle a higher impedance headphone, there's no reason to put transformers in the signal path. OTOH, it can be a bit more convenient in a situation where you're using the same amp to drive conventional headphones and estats (via the iESL), and the sound quality degradation is fairly minimal (but definitely audible) in my experience.

Thanks for your kind sharing this infomation. it means that to change the PSU (such as Hypsos instead of the stock ifi ipower) will not effect to any sound then. Because it is only supply to LEDs and Relays.
Then I will use the Ferrum Hypsos to supply to another devices to get definitely audioble upgrade.

 

[elwappo99]

Thanks for your kind sharing this infomation. it means that to change the PSU (such as Hypsos instead of the stock ifi ipower) will not effect to any sound then. Because it is only supply to LEDs and Relays.
Then I will use the Ferrum Hypsos to supply to another devices to get definitely audioble upgrade.

The Hypsos is quite expensive, but very impressive. I'm sure you'll find something to plug it into!

 

[draytonklammer]

Does using the output binding posts on the back of the iFi iESL bypass the iESL's transformers and other hardware?

 

[basisunus]

Does using the output binding posts on the back of the iFi iESL bypass the iESL's transformers and other hardware?

Never used it that way. But it should be the case, at least the transformers and capacitors are bypassed, which are pretty much the main stuff inside.

 

[draytonklammer]

Never used it that way. But it should be the case, at least the transformers and capacitors are bypassed, which are pretty much the main stuff inside.

This is my assumption, but I was very curious.
Just wanted to test the 4-pin XLR output on the front versus the bypassed speaker taps with an adapter I have.

 

[iFi audio]

This is my assumption, but I was very curious.
Just wanted to test the 4-pin XLR output on the front versus the bypassed speaker taps with an adapter I have.

I don't have a definitive answer for you, but if you feel you need "direct" confirmation, please drop our support a note using submit a ticket here...

https://support.ifi-audio.com/

just to be sure,

I have inquired as well, will post when I get an answer unless I am beaten to it!

Cheers!!