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Amplifiers shootout for Stax 009 (Eddie Current Electra, AudioValve RKV + WooAudio Wee, Stax... - Page 5

post #61 of 72
Thread Starter 
Cat6man: congrats, color me envious wink.gif
post #62 of 72
Originally Posted by cat6man View Post




I'm listening right now to 009 + BHSE + D1 Dual and if anything can get better than this, I think my head would explode.


My big issue now, evaluating the TotalDAC, is the the digital volume control has to be set at -30dB or lower feeding my VTL amps to Nola speakers.

The digital attenuation kills the magic.  I tried comparing 0dB attenuation in DAC + BHSE vs. -28dB attenuation in DAC and more gain in BHSE and it was no contest.  The BHSE attenuator is much superior to digital volume control at those levels.


I'm trying to find a way to keep Vincent's DAC but I don't use a pre-amp (or want one) and the digital volume control is a roadblock for me.




p.s. If the T2-like is really noticeably better than the BHSE, I don't want to hear it!  These *&! head-fi meets have already cost me much more than I ever anticipated :) 




Congratulations on your very good audio system (Japanese estat, American amp, French dac).

What wonderful production of High-end Hi-Fi material !


Listening, yesterday evening,  the 009 + RKV amp (without Wee 1:50 voltage  transformers) + Dac Audiomat Maestro Reference (*) + Audiomat D1 Drive is not bad either and if anything can get better than this, I might lose a very good bottle of Bordeaux...​ :)



(*) French dac (Audiomat), also : http://www.mutine.com/Fiches/Mutine_Fiche_Audiomat_Maestro_Reference_En.pdf

as Totaldac D1 Dual : http://www.totaldac.com/REFERENCE-D1-eng.htm


Edited by eric65 - 2/24/14 at 6:26am
post #63 of 72



rkv father (AudioValve germany) we may be preparing a very nice surprise; to follow on HCFR on Stax thread ...

post #64 of 72
Interesting read =)
I know I was switching between 3 stax amps in a not so scientific pattern (SRM1MK2, 727 and 424 was it?)
I could barely hear a difference in general between amps that ranged $500 from each other.
Then I tried my friend's custom amp and it improved tenfold compared to the tiny bit of little improvement the 727 was able to bring over the others.
post #65 of 72
Originally Posted by eric65 View Post



rkv father (AudioValve germany) we may be preparing a very nice surprise; to follow on HCFR on Stax thread ...



post #66 of 72

Reflections on an Innovation (continued)



post #67 of 72

New Energizer for Stax Headphone by AudioValve (for RKV-mkII) : prototype.




post #68 of 72

New Energizer AudioValve for Stax Headphone (Prototype)


Link constructor for specification http://www.audiovalve.info/rkv/audiovalve%20rkv%20mark2.php


and some comments on HCFR : http://www.homecinema-fr.com/forum/post178189300.html#p178189300



Edited by eric65 - 7/19/14 at 12:23am
post #69 of 72

New Energizer AudioValve for Stax Headphone (Prototype) 


Discussion (other comments and synthese)



post #70 of 72



Here is the latest information (with specifications in English) produced by Mr. BECKER (rkv father) of AudioValve Germany on its box adapter VERTO (necessary to operate Stax Headphone with the RKV (OTL) amp, but also with orthodynamic and electrodynamic low impedance headphone, with the highest quality of sound reproduction that is).


" Description (VERTO)

The passive box can be used together with AudioValve RKV II and RKV III tube based headphone amplifiers. There was a simple idea behind the VERTO. Why not use the transformer in step up mode to produce the high voltage for the STAX electrostatic headphones? The RKV models use one transformer per channel (impedancer) to drive low impedance headphones (< 100 Ohm). In the RKV III the transformers are mounted inside the case, for the RKV II the impedancer can be bought as a separate box. RKV II and III are regarded to belong to the best sounding headphone amps regardless of price, see many reviews all over the world.

For a game changing product a simple idea is not enough, you have to find also a proper implementation. There are already promising approaches in the market combining transformers with headphone amps to drive STAX headphones. But RKV and VERTO are now exploiting the full potential of that approach. Inductance and capacitance of the transformer can harm the sound. The Pikatron output transformers we use have only very little stray inductances and capacitances. To avoid distortion we use only a low step up ratio of 1 to 5. But key is the fact that the output impedances of RKV II and III are extremely low, too low to cause any negative effect on the sound.

The VERTO supports the current STAX PRO plug with 580 V DC bias as well as the former bias of 300 V used by older STAX headphones. The higher PRO bias uses a 5 Pin connector, the 300 V DC bias can be identified by a 6 Pin headphone plug at the end of the headphone cable. So the VERTO is suitable for all STAX models.

The VERTO has is connected to the headphone amp with a phone cable and standard plug coming with the VERTO. There is nothing to buy for you in addition to the VERTO. Also the VERTO does not require a separate supply voltage. This ensures that there is no interference and hum caused by main connection. The RKV III has to be switched to the OTL mode when driving the VERTO.
To increase the versatility we implemented a switch for 8 ohm as well as 32 ohm. So you can connect high efficient loudspeakers as well as headphones with low impedance. Feel free to drive mobile headphones designed for Apple devices as well as low impedance high end planars like Audeze or Abyss. Check to drive your high efficient loudspeaker with your tube and transformer based RKV and VERTO chain!
Since the connection of the VERTO to the headphone amp is implemented via a standard phone plug you can use it also with other headphone amps instead of the RKV II and III. You will achieve very good results in the case you use a headphone amp with low output impedance and a high output voltage. We doubt that you will get to the same ultimate sonic quality as with the RKV models. The RKV II and III are able to deliver 100 volts peak-peak drive.

We use only high quality components in the box. The Picatron transformers are built based on our specifications. For wiring the main audio connections to the sockets of the headphones and the STAX female socket cable we use a well-known German high end audio cable manufacturer by the name of HB cable design from Cologne. The core of the cable is made of silver-plated oxygen-free copper conductors stranded several times.
- Compatible with all STAX electrostatic headphones (580 V DC PRO bias 5 Pin connector as well as 6 Pin 300 V DC bias)
- Suitable for low and middle impedance dynamic or planar headphones as well as ultra high efficient loudspeakers
- 3 switchable modes for STAX electrostatic mode, 8 ohm and 32 ohm
- One Teflon female jacket for STAX PRO bias 5 Pin and 6 Pin headphones
- Two Combi jackets phone plug and XLR for dynamic and planar headphones
- Loudspeaker terminals to connect spades or bananas
- 60 cm cable with phone plug fixed to the case for connection to the headphone amp (like Audio Valve RKV II and III as well as other headphone amps with low output impedance and high output voltage)
- No separate supply voltage needed, static high voltage is generated by the signal
- One high quality Pikatron output galvanic coupled transformer for each channel
- Internal bias voltage for STAX 300 + 580 VDC (LED controlled)
- Internal HB cable design with a cross section of 0.72 sq. mm, embedded in a PTFE Teflon insulation air. The conclusion is a 5 mm diameter strong silicon of insulation, the high-voltage signal line outwards reliable and well insulated
- The device provides both the required for the operation of the headphone-static voltage of 300 / 580 VDC, and up to 550 Vrms signal voltage
- Bandwidth up to nearly 100 KHz - ( 470 pf load )
- Dimensions: w * h * d ( cm ) - 110 * 105 * 165
- weight: 2 kg

- Silver case (black on request)
- Chrome mode switch (golden on request)
- Cable with phone plug 60cm length (different length on request)
- Price: 690,- EUR including VAT "


Edited by eric65 - 7/20/14 at 11:00pm
post #71 of 72
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