You need a differential probe like the MDP3000 which is pretty affordable: https://www.micsig.com/MDP/ Plus you need an oscilloscope... There's a lot of cheap Chinese made options now like this 12 bit scope: https://int.rigol.com/products/detail/DHO800 I don't see this being a $1000...

If they do come out with a Stax X9000 successor, used prices will go down a bunch. This will be great for anyone looking to try the X9000. I'll never sell my X9000 that I bought new, because if I did, I'd lose too much on them :) Plus, no way am I buying another new flagship when the X9000's...

https://www.avmentor.net/reviews/2016/benchmark_dac2hgc_ahb2_2.shtml It looks like it is 16V/uS, but probably in stereo mode so should be double in bridged mode. All I did was solder a 120pF 2kV cap across L+ and L- at the output of one the transformers with no resistors and no headphones...

I measured them both ~1000V at 1kHz with a 120pF load to simulate the headphones. Did you measure the Sansui in your transformer setup? I also probably had the AHB2 in stereo mode when I did the measurements, but have them in bridged mode now. I bet that improves the slew rate even more. No...

Could be, but I need to have someone in South Carolina bring one by for me to try out. There needs to be a measurable improvement too, plus I need to get one at a fair used price. No way would I shell out $6900 plus shipping for one without seeing published measurements like Benchmark does in...

This is what I had a picture of from before when I was comparing the two; while feeding each from a signal generator. Note the small amount of ringing on the transformer setup is negligible in my opinion as both setups ring when my DAC is used. BHSE (800V/15us) = 53.3V/us Transformer setup...

You're welcome to your opinion, but it's not objectively true. I have a used BHSE I bought which is superb, but was curious about transformer mods after seeing old posts on them and videos like this: I've measured square waves and sine waves, etc... comparing the two setups below. BHSE's...

A few measurements of what the AHB2's are doing in the transformer setup... I posted more measurements in the ifi pro iesl thread. I stopped testing at 2kVpp, so I don't know what the max is. At 10Hz, I was getting ~1450Vpp before you'd see small misshaping of the sine wave. Above 13Hz...

Benchmark all the way, even when driving electrostatic headphones like the Stax X9000's.

The BHSE is very low noise, as is the AHB2's connected to the transformers. They both sound identical to me, except the transformer setup I modded has more headroom and the AHB2 amps can also drive my bookshelf speakers too if I add a speaker selector or use the one built in the iFi Pro iESL...

Running several Stax headphones with it: L700mkII, SR 009 and X9000. The X9000 likes the extra headroom; this was my motivation for attempting the project to get over 2kV with no clipping. Note the high voltage warning sign: safety first :)

I'm planning to use this talented gent's design once he finalizes it: What he did is the inspiration for what I've done thus far; he even answered several questions to get me started. It's a pretty innovative approach, although the DC to DC converter he uses is a little costly. He has...

Just in case someone else wants to try it, at their own risk of course and only if they are comfortable doing it... This is where I grabbed the positive and negative bias voltage from... white is the negative, and blue is the positive.

@BassicScience Supercharged ifi Pro iESL... Had to 3D print the headphone jack. Going to eventually case mount this and try making my own board to produce the bias voltage. Using the iFi iESL to provide the bias voltage for now though. I'm not sure where this tops out at as I only tested it...

I am definitely NOT overloading the input. If I was, it would show up in my measurements as I could never display a sine wave at full voltage output like I am in the measurements below. You will never get more than ~1500V peak to peak out of the BHSE. Sadly, sending it a consumer voltage...

This is not really needed as the BHSE handles a pro level signal just fine. The clipping I see is exactly at the limits of the BHSE per its specs and has nothing to do with the higher pro level signal from the DAC3. The one reason I would want to make that change is if I heard hiss or knew...

Are you sure it's not clipping? I drive mine with a Benchmark DAC3 B with pro level XLR outputs, and send the DAC3 an AES 0dBFS signal from my PC. If I move my BHSE volume up to the 2 o'clock position, I definitely get clipping. I verified this using a HV differential probe and my...

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...

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...

I'm very unlikely to damage things and have used a lot of test equipment. I agree a casual user with no technical background or equipment could easily damage things :)

Right you are, the manual is there. Thanks! https://cdn.shopify.com/s/files/1/0024/1788/5248/files/headamp-blue-hawaii-special-edition-manual.pdf?v=1681485399 It is pretty lacking from a technical perspective though. No mention of the mysterious red LEDs seen from the top of the amp... I...

I can definitely see a pot next to each tube through the holes in the top of the BHSE? Each pot has a blue colored body and brass screw.

I am a new owner of a BHSE, but the biasing video shows "this video is private" for me? Anyone have instructions? The amp I bought used seem to have all the packaging, but no manual. Also, I'm curious what readily available tubes are best as far as sound quality? It seems some use PSVANE...

Pics or it didn't happen lol. By pic I mean write out your screen name on paper and put the headphones on top. That's the only way I trust someone who thread craps constantly about a product they've never owned. Surprised you aren't pushing Audeze in this thread like before.

I'm pretty sure the Benchmark is this though :):