[headinclouds]

pham I love the classic style and quality of your work. Nice to see something different.

 

[nepherte]

I own the KGSSHV but keep tossing about a tube amplifier that could get the most out of my 009 as well as dynamic headphones like the Utopia and other electrostatic headphones with different bias voltages. And after months of prototyping... here we have reached the final version, called DT-HWT.

It features a dynamic bias voltage power supply unit which allows you to set different bias voltages for electrostatic ear speakers from 100-volt bias up to 620-volt bias.

• Tube complement for the amp unit is: two EF86/E80F/6D8 & two 12AU7/5814A/E80CC/E82CC & four EL95/6AQ5
• Tube complement for the power supply unit is: two KT66/KT77/KT88/6550/6L6/EL34/350B/350A & one 6080/5998/6AS7/6H13C/2399

This baby is neutral and unstressed for long listening sessions and linear and damn quiet, it has a very wide bandwidth/soundstage, high resolution and very high definition in spades. Happy tubes rolling...

Thumbs up!

 

[pham]

Thank you all for your kind words.

I very much enjoyed building DIY stuff. And here we go...

DT-HWT Amplifier schematic:

DT-HWT Power Supply schematic:

Look forward to receiving your comments about this little baby.

 

[pham]

Good thing to have, i found that 400v bias makes phones less sharp, but lowers sensitivity also. Ok for lambdas
For 007 it had negative effect, sound was not ok. I´d like to see schemas, +1.

Yes, I found the same effect with my 009. Setting a bit higher voltage bias like ~600 VDC while listening to complex classical pieces does make the phone sharper, faster which I feel more enjoyable.

 

[chinsettawong]

Beautiful work!

 

[JimL11]

Thank you all for your kind words.

I very much enjoyed building DIY stuff. And here we go...

DT-HWT Amplifier schematic:

DT-HWT Power Supply schematic:

Look forward to receiving your comments about this little baby.

So, the front end of the amp looks similar to the old Mullard ten and twenty watt Hi-fi amps but with ECC82 for the phase splitter. But the EL95 output tubes are connected as cathode followers with feedback so the output sits at ground potential. And, there's only one cap between input and output. The potential issue here is the need for the phase splitter to swing high voltages. Did I miss anything?

 

[kevin gilmore]

Vcc L == Vcc R == 275 volts
Vcc C == 450V

So max electrostatic output is something like 1000 Vppss, thd is 1 to 2%

hybrid tube/solid state shunt regulated power supply is definitely nice although quite complicated.

 

[hpeter]

Look forward to receiving your comments about this little baby.

I would be litttle afraid doing power CF with such high amplitudes. I meant the cathode-heater isolation, is like 100V max or so.

 

[kevin gilmore]

You can float the filaments on the output tubes, same as megatron, works fine

Need one filament winding per output tube, 4 windings total

 

[karlgerman]

What a happy day. They had the HE1, the MSB Stax-amp and the new STAX Flagship amp for testing at the Munich HighEnd show.
Very subtile first impressions:
the STAX Amp sounded flat on 009 and 007mkII, but that may result on music choice and quality they offered from the music server.
MSB was nice, warm sounding remind me on my BHSE,
Sennheiser HE1 -- best presentation, quiet listening room, very enjoyable and powerful sounding system-wow!
to bad that these toys are so expensive
KARL

 

[Whitigir]

I will take that Bugatti, is it your

 

[karlgerman]

As a Chiron driver it is allowed to park inside the show!

joking,---- that was the Car HiFi BURMESTER sound presentation object.

In fact, this is my car. Not to far away from the entrance too.

 

[Ali-Pacha]

Geil !

Ali

 

[Pokemonn]

karl german, is last picture you? you looks like my father... Lol

 

[behwatch]

Lol SR009 is not in the Lambda series. Should be High End series...