JimL

The difficulty in performing that piece is that it sounds different every time.

Well, that didn't work! Strawhat blew up his regulator by connecting the input and output ground terminals. Sorry about that, I was going by my original point-to-point wired PS rather than KG's PCB rendering.

Or maybe they'll sound louder if you turn them inside out...

Well, as mypasswordis has pointed out, the concept of consonance and dissonance has been a moving target, from before Bach to now. It is certainly interesting to read contemporary critics complaining about harsh dissonances to them on hearing pieces of music which we now consider standard parts of the "classical" repertoire and some of the most beautiful music ever written. Anyone interested in this should get a copy of Slonimsky's Lexicon of Musical Invective, where you can read comemporary critic's slagging of Beethoven's Ninth Symphony "an incomprehensible union of strange harmonies", Tchaikovsky's Violin Concerto, whose finale "transfers us to a brutal and wretched jollity of a Russian holiday. We see plainly the savage vulgar faces, we hear curses, we smell vodka." or this, "in search of ear-rending dissonances, torturous transitions, sharp modulations, repugnant contortions of melody and rhythm, Chopin is altogether indefatigable." One of the funniest putdowns I've read was Mark Twain about Wagner, " His music is better than it sounds."

Wow, great build, Geoff!

I believe it is. Here is a quote from the Headcase thread: kevin gilmore 4/22/15 .... I have also added the cascode to the carbon

One additional comment, although this may be getting deep into the weeds for some. It's not just the raw standing current that matters, but also how well it's used. The current generation of Gilmore amps, along with the SRX Plus, uses a cascode constant current load which significantly increases the efficiency with which the signal current goes to the headphone rather than heating up the load. Few, if any, other designs do as well. For example the original SRX design with 50k resistors uses the bulk of its signal current to drive the resistors.

Absolutely agree as a technical matter that being able to swing full voltage at 20 kHz is better than not being able to. The SRX Plus, for example, is not able to do so, and in fact, as I posted in that thread, actually measurably rolls off at lower frequencies as the output voltage increases (it's flat at 100 VRMS to over 20 kHz which is pretty loud, though). BTW, KG's calculation is actually a minimum estimate of the current required, because a stat headphone is not a capacitor - it makes NOISE, e.g. music, which means it has to consume ADDITIONAL current over what a capacitor requires. However, as Dr. Gilmore points out, the question is, how loudly do you listen and how much actual audio content is there at 20 kHz. There is actually some data on the latter point. A number of years ago, Peter Baxandall and Nelson Pass both measured slew rates in recorded music and both came to similar conclusions, namely that an amplifier capable of reproducing a 6 kHz sine wave (yes, 6 kHz, that is not a misprint) with low distortion is adequate for music signal, because of the natural roll-off of musical instruments. Note that this was equivalent to the fastest music signal they found, and that everything else they measured was SLOWER than that. More recently, Baxandall published that he had found a recorded music signal that required an amp to be capable of reproducing a 15 kHz sine wave with low distortion. That is significantly faster, and in fact is within striking distance of the 20 kHz signal at full output voltage requirement - however, it must be noted that this is a unique event, and for almost all music the lower requirement is adequate. Is it appropriate for a state of the art amplifier to aim for the more stringent requirement? Absolutely! Will the lower requirement suit the needs of most? Probably. Of course, extra headroom is always nice - but there is a cost. For Stereophile Class A, the cost is always worth it, almost by definition. For Stereophile Class B, the question is, how much can you cut back for as little sonic cost as possible. Finally, if you listen at lower levels, the requirements decrease accordingly. This is why spritzer suggested to Tyll that he listen to electrostatic headphone amps at high levels to differentiate between them - because this stresses the amp the most.

If you're into DIY you should be able to build a good amp for less than $1k.

ROTFLMAO!

Ah, good point. Silly me, thinking that quality was involved.

Not so sure about a $1000 amp, from the reports it sounds like it's a LOT less efficient than the SR007s - IIRC a couple said that at "reasonable" listening levels on a BHSE the SR007s and 009s were "screaming loud". Doubt even China could build a $1000 Circlotron clone.

Yup, that's fine.

Oh,oh. If I hear that a black hole has formed in Illinois, I'll know what happened.

At least it's a super cheap single power

Ha, sounds like I guessed right on the topology being an Egmont, but 6C5 outputs - really? They're more feeble than half a 6CG7/6FQ7.

MOSFETs work great! As current sources.

Maybe he's got the EL509 triode strapped? I think I saw somewhere that the rp for that is around 300 ohms. BTW sorry for the late comment, I just saw this.

Actually, there is a lot of carbon in poo.

Kinda what I was thinking.

Must have been a best seller! Wonder how this makes the people who bought it at list price feel?

For some reason which I can't explain, I wandered over to the Cavilli website today and saw that the Liquid Lightning 2T was selling for $2499.50. Original price was $4250. Wonder what's going on?

Cool, and that would be a PURTY plug!

Doh! (slaps forehead) Thanks for the reminder.

Um, depends on whether you are using cap input or choke input filter. I was referring to the filtered voltage out, not the AC voltage out. If you are using cap filter then something around +/-270 volts AC RMS should work, if you use a choke filter then yeah, you need 400 volts AC RMS. I believe the KGBH PS has the rectifiers on the board and it is a cap filter board so something around +/-270 volts AC RMS should do it. My design uses a choke filter (although KG's board design has the rectifiers on board) so if you wanted to have choke filter input you should use around +/-400 V RMS.