[kelly]

(This was intentionally posted for public consumption.)

Kevin

In the wake of people building and conversing about the amplifiers you've desined a problem has arisen. The internet quickly adopts abbreviation for words regardless of their origins and correctness. Already we have had confusion when discussing your various designs because of this. If you'd be so kind, please provide us the correct names and acronyms for your headphone amps, both dynamic and electrostatic.

From your profile, I noticed:
Quote:

Headphone Amp Inventory kg mark 1, kg mark 2, kg mark 3, sselectro mark 1, ssdynamic mark 1

...but could not tie them mentally to the correct amplifiers.

 

[kevin gilmore]

Lets see, i don't remember either

Some stuff is unpublished, or sort of unpublished.

There is a portable/home unit with ssm2131 and ha5002
output drivers. The oldest of the bunch i think.

There is the AC coupled electrostatic tube amp. (published)

There is the DC coupled servo electrostatic tube amp with
apex high voltage op amps. (published)

There is the solid state electrostatic amp. (published)

There is the solid state dynamic amp in both balanced
and unbalanced form. (published)

Then there is the fet/tube hybrid electrostatic monster
amp, to be published next week or so. (soon)
I've decided to name this one "Blue Hawaii"

Then there is the portable with burr brown opamps and
ha5002 drivers with the cosel switching supply.
(pictures published, schematics obvious) This and a pair
of ety-4s is what i have been traveling around the world
with over the last week.

Then there was the solid state electrostatic amp using
apex high voltage opamps. (not really published) and
expensive to boot.

Is that it, i think so...

I'm willing to adopt any reasonable naming convention...

 

[kelly]

Thanks Kevin, but you need to name them too.

I say you call the electrostatic hybrid Bob, but that's my only suggestion.

 

[Budgie]

I like "Really Expensive Electrostatic Headphone Solid State Apex Microelectronics Opamp Headphone Amp" for that last one.

 

[zzz]

Quote:

Originally posted by kelly Thanks Kevin, but you need to name them too. I say you call the electrostatic hybrid Bob, but that's my only suggestion.

Hm, Bob. I like Bob

.

 

[kevin gilmore]

I forgot one. Actually i probably forgot more than one if
i open up my closet and go looking for old stuff.

The all tube, gas tube as voltage level shifter version.
Sounded pretty nice, but the gas tubes were noisey..


Hmm Bob.... Didn't microsoft have a product named bob???

 

[zzz]

Quote:

Originally posted by kevin gilmore Hmm Bob.... Didn't microsoft have a product named bob???

It was canned. Now after that many years it's pretty much dead of course.

 

[eric343]

LOL, Bob, the ultimate insult-the-user-by-assuming-they're-a-drooling-moron interface. Although a friend of mine is looking for a copy...

 

[Budgie]

Every time I hear the name Bob I laugh. A female friend of mine once made the comment that since she found out about Bob, she hasn't really needed a man. I asked who Bob is and she said "Battery Operated Boyfriend."

 

[eric343]

LOL!

Of course, Bob is also the diety of the Church of the Subgenius...

 

[ppl]

Hi Kevin Would You Elaborate upon any difficulties you have had ar shall i say Fears regarding the HA- 5002's lack of short Circuit Protection? I also use this buffer in one version exactly the same as my EL-2001 Amp But replacing the Output stage Buffers with this fine part. So far i haven't had a problem and that includes my real world test of inserting and removing the Headphone Plug at up to 3/4 Volume. This was quite loud on my MDR-7506's. However i am taking opinion's about this. From users of this part like yourself.

I am also most interested in all fourm members of the need for current liminting.

 

[kevin gilmore]

Actually until recently i did not know that there was a short
circuit problem. So i did not care whether the unit was on
or not when i plugged the headphones in. But in all cases
the volume was always at zero so there probably would never
have been a problem. For portable use, i first plug the
headphones in and then plug in the power. To turn it off
i remove power then remove the headphone jack. So far
no problem.

I have an old preamp that uses these as buffers. Probably
shorted it numerous times, never ever did it blow up.

Soon i will have an ultra micro version of my class a unit
for portable use, and that will happily drive a dead short
forever.

 

[andrzejpw]

Quote:

I like "Really Expensive Electrostatic Headphone Solid State Apex Microelectronics Opamp Headphone Amp" for that last one.

Hmmm, REEHSSAMOHA. Ree Hsaa Moha? Sounds sort of like a new Starbuck's coffee.

 

[Discovery]

Kelly,

Bob is an amusing choice. Reminds me of a friend of mine who was also an engineer. When he couldn't think of an appropriate variable name in C (or signal name in VHDL), he would just name it bob. It eventually became our catch-all name for anything that where an appropriate name wasn't immediately obvious.