"Possibly the most transparent amplifier on Earth"

[adeptusmajor]

http://www.ebay.com/itm/Battery-Tube-Only-Headphones-Amplifier-for-Sennheiser-HD-580-600-650-Beyer-DT880-/331142257370?pt=US_Pro_Audio_Amplifiers&hash=item4d199ddada

Not sure how we're meant to interpret "transparent", as a description of sound quality or more literally as in "open chassis". But we probably wouldn't want to risk letting the chassis "limit the magic of the music" the way all those pesky components that other guys use do. Or maybe side panels just cost extra.

 

[rock soderstrom]

;D ;D ;D

 

[hymentoptera]

"For the schematic Only" 

and then... "No resistors"... "only 2 electron tubes in class A"

how do you do this with no resistors?? Don't you at least need a voltage divider for biasing?

 

[zamproject]

i saw this time ago...

For the schematic Only please visit my other items

which is 47$  ???

hope this listing is just to show the finished "product" and if an idiot buy it, the seller stop it....

  :-\

 

[emrr]

We may have a winner for "batshit crazy"

 

[Script]

Ingenious -- and a true bargain

 

[gemini86]

I wish I had the money to buy this JUST for the opportunity to sue the pants off him when it does nothing it claims to.

 

[bruce0]

I am thinking that this particular greek fellow cannot afford pants.  Plus they interfere with the magic of the music.

 

[Harpo]

Heating the tubes seems to be the only thing this 'design' will do, if at all and relies on the drive ability of the sending device ...
My improved class 'A'udiophool design would additionally come with LEDs in order to make the tubes shine in a colour of choice instead of only heating up your room. For only 17,378 $ more this would be a steal.

 

[pucho812]

starved plate designs equal low headroom equal distortion happening much sooner when listening to it which now days people translate to "analog warmth"

 

[joaquins]

Heating the tubes seems to be the only thing this 'design' will do, if at all and relies on the drive ability of the sending device ...
My improved class 'A'udiophool design would additionally come with LEDs in order to make the tubes shine in a colour of choice instead of only heating up your room. For only 17,378 $ more this would be a steal.

It really looks like that, I don't think it would do >>MHz because the cable inductance and the ground only goes by the chasis. If you enlarge the pic from the top of the tubes the wire from the RCA goes behind the tubes to where the output miniplug is. The tube has most of the pins unsoldered and only two wires from it and two pins together, 4 and 5? one is from the PS... Sorry, battery, and the other to ground I guess... sorry, chasis. I guess only pins 4,5 and 9 are used. Oh, heater of 12ax7 and some more. But 12V on both heaters in parallel! oh, both tubes are in series! they are only heating your room, yes.

JS

 

[hymentoptera]

Here's the updated model, now with one resistor and one pot.
http://www.ebay.com/itm/Tube-600-Ohm-Headphone-Amplifier-for-Sennheiser-HD-580-650-AKG-K240-Beyer-DT-990/331168875897

Apparently, according to the photos, this one is for use with mp3 players 

 

[iampoor1]

"Q: Is that a price mistake?
A: In a way yes. It sounds much better than 47K would sugest. You can buy the schematic for 47usd and make one. Best regards, Aetoulis "

;D