[wink]

The number is really 41 as the rats made a mistake when diesigning the earth as the ultimate computer to solve the problem of "What is the meaning of life, the universe........... and everything".
 
As far as the headphone impedances go, I'd pick the:-
Mode1 Red for the LCD, and
Mode 2 Yellow for the HD800.
My reasoning is that to have the headphone impedance in the middle of the amplifier's impedance range should be the best compromise.
 
For the Stax SR009, the Mode2 Blue sounds best.
 
Remember, high fidelity is about reproducing the sound closest to the signal being provided to the system.
e.g. Bad should sound bad, good should sound good, and, great should sound great.
 
If you have a bad recording being played, and one amplifier or headphone makes the recording more tolerable because it is not reproducing all the bad parts then it is not really a piece of high fidelity equipment.
 
Of course, this is different to the amplifier or headphone producing it's own spurious signals or colouration which make the recording being played sound worse or even better than it should.
 
One of the problems is to find which of the above situations is occuring.

 

[eric65]

   
As far as the headphone impedances go, I'd pick the:-
Mode1 Red for the LCD, and
Mode 2 Yellow for the HD800.
My reasoning is that to have the headphone impedance in the middle of the amplifier's impedance range should be the best compromise.
 
For the Stax SR009, the Mode2 Blue sounds best.
 
Remember, high fidelity is about reproducing the sound closest to the signal being provided to the system.
e.g. Bad should sound bad, good should sound good, and, great should sound great.
 

 
OK !
 
It is also my feeling given by the Stax SR-009 headphone with my audio system.
 
bad recording  --> bad listening
good recording --> good listening
great recording --> great listening
 
(NB: the limiting factor of the sound quality in my audio system (with a big L for the word "limiting")  is that of the recording quality. The role of the sound engineer is fundamental; without him, no fidelity; no high fidelity system if it is to reproduce with fidelity the mediocrity of recording a bad sound engineer

).
 
Otherwise
 
Choices (above) really interesting.
 
If I summarizes your choices:
 
Audeze LCD-3F (110 Ohms): best in mode1 (red) (Impedancer 32 Ohms)
 
Sennheiser HD-800 (360 Ohms): best in mode2 (blue) OTL (or in mode3 (yellow) : Impedancer 128 Ohms ?) (not clear)
 
Stax SR-009 (145 000 Ohms): best in mode2 (blue) OTL (if this mode is possible for a Stax headphones, which is not certain) (without step-up output transformer, so with a unbalanced connection and with a sound level limited below 100 dB SPL)
 
 
My choices :
 
Audeze LCD-3F (110 Ohms): best in mode2 (blue) OTL (better clarity) or eventually in mode3 (Yellow) (Impedancer 128 Ohms) (it will try)
 
Sennheiser HD-800 (360 Ohms): best in mode2 (blue) OTL (better clarity, definition and spatialization) or eventually in mode3 (Yellow) (Impedancer 128 Ohms) (for a more opulent and euphonious sound)
 
Stax SR-009 (145 000 Ohms): best in mode1 (red) (with galvanic couplet sym. balanced step-up 1:2 transformer) (better clarity, definition and spatialization but with a sound level limited below 107 dB SPL) or in mode3 (yellow) (with galvanic coupled sym. balanced step-up 1:6 transformer) (better euphonious sound (with the SR-009) ; better sound amplitude ; sound level higher, limited below 117 dB SPL)
 

 
Happy new year

 

[eric65]

Hello, for those who are interested, here is an estimate of the maximum voltages, max powers, and max amperage of the headphone amplifier Luminare in OTL Mode: 
 
Mode2 (blue) (OTL) (without transformer) (gain = 32 dB) (gain = x40)
Load 46 Ohm: P max = 690 mW ; V max = 5.6 V : I max = 122 mA
​Load 50 Ohm: P max = 750 mW ; V max = 6 V : I max = 122 mA
​Load 55 Ohm: P max = 825 mW ; V max = 6.8 V : I max = 122 mA
​Load 60 Ohm: P max = 900 mW ; V max = 7.4 V : I max = 122 mA
​Load 110 Ohm: P max = 1.65 W ; V max = 13.5 V : I max = 122 mA
​Load 220 Ohm: P max = 3.3 W ; V max = 27 V : I max = 122 mA
​Load 360 Ohm: P max = 5.4 W ; V max = 44 V : I max = 122 mA
Load 1200 Ohm: P max = 5.5 W ; V max = 81 V : I max = 68 mA
 
 
(EDIT - Note: do not hesitate to correct me on error in this data)

 

[kevin gilmore]

so I spent new years eve trying to make sense of this...
6 shots of vodka later, still did not make sense.
 
Quote:

   
Mode2 (blue) (OTL) (without transformer) (gain = 32 dB) (gain = x40)
Load 46 Ohm: P max = 690 mW ; V max = 5.6 V : I max = 122 mA
​Load 50 Ohm: P max = 750 mW ; V max = 6 V : I max = 122 mA
​Load 55 Ohm: P max = 825 mW ; V max = 6.8 V : I max = 122 mA
​Load 60 Ohm: P max = 900 mW ; V max = 7.4 V : I max = 122 mA
​Load 110 Ohm: P max = 1.65 W ; V max = 13.5 V : I max = 122 mA
​Load 220 Ohm: P max = 3.3 W ; V max = 27 V : I max = 122 mA
​Load 360 Ohm: P max = 5.4 W ; V max = 44 V : I max = 122 mA
Load 1200 Ohm: P max = 5.5 W ; V max = 81 V : I max = 68 mA

 
First has anyone noticed the 32db of gain. In a modern headphone amp?
Some people complain when the gain is 10db. Reason the gain is so high
is that otherwise both the distortion and output impedance would be much
much higher.
 
Damping factor =  (impedance of the load)/(impedance of the source)
 
and noticing that the current is peak, not rms...
 
source impedance calculates to about 663 ohms  but actually tests at  close to 1200 ohms
 
so for 50 ohms, 50/663= .075
for 360 ohms, 360/663= .54
 
product page says damping factor is 600
Really, how and into what load?
 
Most of the really good solid state power amps in this forum have real damping factors
in the range of 100 to 300 into 50 ohms.
 
eddie current Zana Deux 50/30  = 1.6
(biggest OTL headphone amp ever)
 
singlepower extreme with 6080 power tubes  50/75 = .66
 
Happy New Year, same old crap
 
edit: name of eddie current amp

 

[eric65]

 
product page says damping factor is 600
Really, how and into what load?
 

 
What load ? Probably 220 Ohm (Ri = 0.366 Ohm) (in OTL mode)

 

[kevin gilmore]

not possible and you should know this.
 
stop being a parrot, learn psice and calculate for yourself.


edit: ltspice which is free. pspice is not free

 

[eric65]

You might be more kind to your formulations (not really polished) Dr. Gilmore.
 
The problem with you is that you have already told several misleading informations on this thread; So excuse me, but I have more confidence in the manufacturer's specifications that in yourself. Sorry.

 

[John Buchanan]

  You might be more kind to your formulations (not really polished) Dr. Gilmore.
 
The problem with you is that you have already told several misleading informations on this thread; So excuse me, but I have more confidence in the manufacturer's specifications that in yourself. Sorry.

You need to pull your head in Eric65.

 

[kevin gilmore]

the numbers do not lie

81 volts, 122 ma

output impedance extremely easy to calculate

 

[eric65]

  not possible and you should know this.
 

 
A divergence in measurement protocols, no doubt?
 
Nevertheless, it is well known to all that the damping factor is the criterion first to take, before any other consideration, to define the quality of an amplifier. 

(NB: one wonders well why some continue to use tube amplifiers with a very poor damping factor compared to solid state amplifiers, much better (for the damping factor)).

 

[arnaud]

Eric, I wonder how you would react when a patient with no medical background whatsoever would give you a nonsense lecture in your office about how you got it all wrong with your diagnostics.
Got to admire KG's patience here and this is just what you're doing to him...

Arnaud

 

[kevin gilmore]

for those headphones that have wide swings in impedance curves
(just about all of them not including lcd?,he6 and other planars)
(go look at graphs on innerfidelity)
 
the miserable output impedance of the Luminare will make the
frequency response much worse.
 
But there are a whole bunch of tube amps with fairly low output
impedances. And each of these are really great tube headphone amplifiers.
 
Eddie Current Zana Deux, 21 times less output impedance than Luminare
(now with modifications including driving both filaments etc, you can double that number)
 
Singlepower extreme with 6080's, 8 times less output impedance than Luminare
 
Atmasphere M60 more than 133 times less output impedance than luminare
(a real output impedance of less than 4 ohms)
(and the bigger ones approach 1 ohm)
 
Anyone that says that the output tubes in the Luminare have an output impedance
of less than 100 milliohms is flat out lying.

 

[eric65]

I especially admired his rudeness; anything else.

 

[eric65]

 
Anyone that says that the output tubes in the Luminare have an output impedance
of less than 100 milliohms is flat out lying.

 
I never said that (for the Luminare amp) !

 

[kevin gilmore]

but the damping factor of 600 implies those numbers!
 
 
And about the "rude"... you have absolutely no idea.
But not here.