KGSS vs BHSE

[Dreadhead]

Hello everyone,

I'm thinking about buying an electrostatic amp and I'm leaning towards the KGSS because of my general dislike of tubes and the fact that when you change the tubes you can change the sound etc. I prefer to have such things under control (barring damage, SS is the same now as it is in a year).

That said if the BHSE is only uses the tubes for the high voltage swing capabilities and is entirely transparent then maybe that's a better bet. On paper it has a lot more voltage swing etc.

At least initially I will be using the Koss ESP950s but I figure I'll end up with O2s as well. They'll all have to go though my correction process and then I'll see if electrostatic is worth it to me. If not I'll stick to dynamics and sell off the electrostatic. I'll be honest and say I don't expect the electrostatics to improve much on the corrected dynamics or even on the ER-4s/AE-2 combo that I listen to as my portable. The latter probably the most accurate and transparent combo with no correction that I have heard, though even Ety states that Electrostatic is supposed to be even more accurate.

I heard the KGSS powering 02s and I'll be honest and say I preferred it to an ES-1 and HE90s (but then the owner switched the tubes sense and that combo improved).

What says the peanut gallery? I'm buying this as a "I'm done" amp so I'm not so concerned about the price difference.

[Dusty Chalk]

The BHSE is easily some of the best sound I've ever heard.

[pabbi1]

I have extensive time with all you are curious about, except BHSE.

Beats me what you would like better.

[crappyjones123]

bh + jades fed by an exemplar 2900 was about the best combo i have heard with headphones so far. o2's might sound better, i cant say it because i never got them to fit me properly so i dont know if anything im missing. say what you want about 650s and r10s being amazing, they are when amped and sourced properly but i dont think the 650s come even close to having the same kind of sound stage as the jades. r10s, i heard a long time ago so i cant say that conclusively.

now im not saying that bh + jades are the best combo period, just that its the best ive heard so far.

i used to think that you could spend a few more thousand dollars chasing those last few % but with the bh and jades, that increase in sound quality and soundstage was anything but a few %. given the cost of the whole setup i think that i would just stop there. if you can tell the difference between a bh and a bhse and a kgss then pick the one your ears tell you sounds the best.

[spritzer]

Now if you wanted nothing but voltage swing then the Koss E/90 would be the ultimate amp but that clearly isn't the case which goes to show that voltage swing isn't the end all yardstick to measure ESP amps. The KGSS will always be limited by the transistors in use i.e. how much voltage they can take but you can increase their bias and use an even more robust PSU to have moar powah on tap. This was never an option from Justin and I doubt it's something he'll even consider for the new model since extra heat is always bad news so consider this a DIY only option.

The BH is fully DC coupled so it's very linear and while the tubes used do change the sound it's best just to stick with the best, Mullard XF1 and XF2, as they will last for years and sound great. While the BH does have more voltage swing it's not the ample voltage that makes a difference but the amount of current on tap. Difficult phones like the SR-Sigma are transformed from a midrange-centric mess to a fullrange transducer just because there is enough power for the phones to do their thing.

[luvdunhill]

Hello everyone,

I'm thinking about buying an electrostatic amp and I'm leaning towards the KGSS because of my general dislike of tubes and the fact that when you change the tubes you can change the sound etc. I prefer to have such things under control (barring damage, SS is the same now as it is in a year).

you're one strange cat. so, you'd rather have a designer tune your amp to his tastes, rather than have control over this yourself?

[Dreadhead]

you're one strange cat. so, you'd rather have a designer tune your amp to his tastes, rather than have control over this yourself?

Yup I guess so I find at least with Justin he doesn't tune anything, the amp is the input plus gain and current delivery and that's it. If I want to color the sound I can do so with my DEQ2496 and I have extremely fine control though I generally do not move anything from measured dead flat + 5 to 7 dB roll off for proximity effects due to the fact that mastering studios have roll off at the speakers.

I'll be the first to admit that I'm strange though. Though I don't know anyone who's normal .

[Dreadhead]

Now if you wanted nothing but voltage swing then the Koss E/90 would be the ultimate amp <snip>

Spritzer I entirely get your point re the voltage swing because at least out of the E/90 the Koss are horribly inaccurate in the high frequency range (at least to my measurements).

As far as your power argument goes I am more than a little confused. I'm not saying your wrong but as I understand it the electrostatics are acting as large (moving) capacitors so what you need to drive them is high voltage with a low output impedance and hence more current. If the transducer is the same you can't deliver more current with the same voltage unless the transmission loss (internal resistance) is reduced (P=IV=V^2/R). Electrons flow because of voltage not because of current. Are you talking about the rate of change of voltage to the grids (slew rate)? That would be current limited I guess but that's all I can think of which can make sense I guess.

I'm sorry if the above is entirely wrong but please explain to me why it is.

[Dreadhead]

Yup I guess so I find at least with Justin he doesn't tune anything, the amp is the input plus gain and current delivery and that's it. If I want to color the sound I can do so with my DEQ2496 and I have extremely fine control though I generally do not move anything from measured dead flat + 5 to 7 dB roll off for proximity effects due to the fact that mastering studios have roll off at the speakers.

I'll be the first to admit that I'm strange though. Though I don't know anyone who's normal .

I meant roll off at the listening location. Sorry

[spritzer]

They are indeed capacitors so their impedance varies with frequency. It can dip very low in the bass and treble while the midrange is pretty benign but the amp must overcome this above all else. High slew rate and a low output impedance are vital as well but if the amp can't maintain a stable output voltage into any load then you have bigger problems.

As for the sound comparison, the BH is even more pure then the KGSS let alone something like the 717 I'm using now. I'm eagerly awaiting the BHSE and I have no doubts that it will be superb but I have a new DIY BH lined up just in case I like the older one better. One thing is clear, the synergy with the old BH and the SR-Omega is something that has to be experienced.

[Dreadhead]

They are indeed capacitors so their impedance varies with frequency. It can dip very low in the bass and treble while the midrange is pretty benign but the amp must overcome this above all else. High slew rate and a low output impedance are vital as well but if the amp can't maintain a stable output voltage into any load then you have bigger problems.

As for the sound comparison, the BH is even more pure then the KGSS let alone something like the 717 I'm using now. I'm eagerly awaiting the BHSE and I have no doubts that it will be superb but I have a new DIY BH lined up just in case I like the older one better. One thing is clear, the synergy with the old BH and the SR-Omega is something that has to be experienced.

I look forward to hearing the BHSE sometime. I am going to move forward with the KGSS I think. Maybe Justin will let me drive out to him to hear stuff.

By the way because a capacitor's impedance goes to infinity as frequency goes to zero so again I don't see the bass improving with more power, the highs on the other hand will likely benefit from more power. After my experience with the measured response out of the AE-2 vs the GS-X and the very different power abilities I'm not so sure that I need the power. We'll see of course.

[spritzer]

While a ES driver behaves like a cap they aren't the same since you have to deal with damping and the load impedance presented on the diaphragm. Due to this and other factors the basic shape of an ES impedance curve is like a bell causing them to draw a lot of power at the treble and bass. If this wasn't the case then why did Stax and KG design amps with that massive current source on the output stage instead of a simple plate resistor?

[The Monkey]

What is Justin's build time on a KGSS these days?

[spritzer]

He's working on a new version so two years...?? Just kidding but I'm not sure if he will make any of the older ones as parts like the K389's are near unobtainium.

[luvdunhill]

After my experience with the measured response out of the AE-2 vs the GS-X and the very different power abilities I'm not so sure that I need the power. We'll see of course.

I think a comparison of he SRM-001 and BHSE with your correction methods would be quite interesting............................. not

[spritzer]

I think a comparison of he SRM-001 and BHSE with your correction methods would be quite interesting............................. not

You know that power is over rated anyway... We are clearly both wasting out time with all those huge caps, transformers etc.

[wavoman]

...If I want to color the sound I can do so with my DEQ2496 and I have extremely fine control though I generally do not move anything from measured dead flat + 5 to 7 dB roll off for proximity effects due to the fact that mastering studios have roll off at the speakers

Could you elaborate on the EQ settings you use (to compensate for the mastering)? I have a pro dbx EQ box but I hadn't considered injecting it into the balanced chain between my CDP and my KGSS (which I use with O2 007a's/Spritzer mod).

Interesting idea.

[Dreadhead]

You know that power is over rated anyway... We are clearly both wasting out time with all those huge caps, transformers etc.

lol you guys are funny. I'm just an engineer and refuse to buy anything from ANYONE without some proof. Telling me that it's true because a designer makes the amps more powerful (what else is there to do to amps) is not a good enough story for me.

I've done quite a bit of reading on electrostatics and I can't see why there is any more current at low frequencies, because of their limited throw they are trying to move a lot but that's about voltage not current because the electrostatic force is proportional to the voltage on the grid. The larger the voltage swing the better the throw of course with the limit of hitting the grid and shorting. If the ES headphones have built in EQ to bump the lower frequencies to correct for the natural bass loss this will of course require more power because the gain (hence voltage) is increasing. If this is the solution then so be it. The only way you can get something that is essentially a large capacitor to require a lot of current is to change the voltage quickly which is what happens at high frequencies and is most probably why they need a lot of current in the amps (I'd guess that these are pretty high farad capacitors so it's nice to be able to charge them quickly).

The correction as I said before (in another thread) only works if the transducer has decent and correctable response to begin with. From your statements it sounds like the other setup doesn't fall into that category. How about you try using an EQ for a while and see what it does for you.

As far as wasting time with power I do think you are at least for dynamics for bass (without equalization). Being able to deliver current is nothing unless there is a voltage to drive it. If the amp has a set gain it will put out a set voltage and will hence deliver a set current which will not change; unless of course the output resistance is too large and interferes or it can't put out a large current and the delivered voltage drops. Considering most headphones can only handle on the order of fractions of a watt then what are the all the whats that my GS-X has doing? Well partly delivering linearity and lower distortion and that's all I can figure out. I have a separate question as to how audible .0005% distortion is compared to headphones with distortion on the order of a hundred times more (being a physical transducer is a pain).

[Dreadhead]

Could you elaborate on the EQ settings you use (to compensate for the mastering)? I have a pro dbx EQ box but I hadn't considered injecting it into the balanced chain between my CDP and my KGSS (which I use with O2 007a's/Spritzer mod).

Interesting idea.

All I can say is give it a try. What I do is use an ECM8000 measurement mic and a block of foam as a coupler to measure the frequency response of the heaphone and then either invert the impulse response and use a convolver (on the computer) or use the auto EQ function that is a part of my DEQ2496 with some small tweaks where required to get the response as flat as possible (with the roll off).

[GPH]

lol you guys are funny. I'm just an engineer and refuse to buy anything from ANYONE without some proof.

Well, that's one situation where a simple listening test is a damn good proof. Try the Koss ESP-950 out of the E-90 and then out of a KGSS which puts out less voltage than the Koss amp and tell me that you prefer the E-90.

Your scientific exploration is cool and I'm looking forward to more of your tests, but in the end it's all about how it sounds, isn't it?

[Dreadhead]

Well, that's one situation where a simple listening test is a damn good proof. Try the Koss ESP-950 out of the E-90 and then out of a KGSS which puts out less voltage than the Koss amp and tell me that you prefer the E-90.

Your scientific exploration is cool and I'm looking forward to more of your tests, but in the end it's all about how it sounds, isn't it?

It's patently obvious that the E/90 doesn't have enough power for the HIGH FREQUENCIES and that's where the response was horrible. Actually the bass response amplitude (below 50HZ) was high and sort of oscillatory with the E/90 at least according to my measurements.

This PDF is particularly illuminating: http://www.audiocircuit.com/A-PDF/AA-General-GEN/941-GEN-HTW-HAT.pdf

Listening is what it's about in the end. If I find a difference I'll need to find proof though before I'll truly believe it. Now I have this measurement setup it's changed my whole opinion in balanced vs SE but in the end I still listen balanced because hey I paid for the damn thing.

[deepak]

I'm curious about any measurements you saved with the ESP950 and E/90.

[Dreadhead]

I'm curious about any measurements you saved with the ESP950 and E/90.

Well they are in the DEQ2496 I never ran it through Room EQ Wizard because I had it on loan from Dan and knew I'd be sending it back.

I'll take a picture of the PEQ and DEQ settings I ended up with to get close to flat response without the roll off and PM you I guess.

[deepak]

Well they are in the DEQ2496 I never ran it through Room EQ Wizard because I had it on loan from Dan and knew I'd be sending it back.

I'll take a picture of the PEQ and DEQ settings I ended up with to get close to flat response without the roll off and PM you I guess.

Sounds good. I owned the Koss system, so I've already formed a subjective assessment of that pairing

[Dreadhead]

Sounds good. I owned the Koss system, so I've already formed a subjective assessment of that pairing

I did too. It was not good but it showed potential. I'm not against subjective to be honest as long as your headphones aren't whaleskin or something go for it.