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phixphi

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Posts posted by phixphi

  1. Thanks for the reply guys. I'm quite happy with my Sigma/404 but in the future might try.

    bwck2000, how do you get a dust free environment? You have an access to a clean room or simply a thorough

    cleaning of the working area is enough?

  2. On 2/15/2020 at 8:01 AM, bwck2000 said:

    Left to right: 404, L700 and 507 Sigma 

    The one with 404 driver is more laid back and has more colouring while the 507 one has the best transparancy . But the L700 sigma is the best with a very full bodied mid bass and excellent 3D- imaging and soundstage I have never heard of in any other headphones.

    Love all three of them 

    AFB4CFF3-6009-4BDB-BF57-D6C846664119.jpeg

    A-ha! So it is possible to fit newer drivers than 404 into Sigmas? I was recently redoing my Sigmas and was told 404 is the last driver that fits.

  3. On 12/13/2019 at 1:00 PM, zolkis said:

    Terrible match IMHO. Also the Ether Voce pads.

    The best pads I came across for the 007 were the 009 pads.

    Actually they proved to be the best for all my headphones. I love those pads - especially after I removed the white reinforcing layer from the internal foam. Same mod works great for the 007 pads as well. Best generally usable ear pads in the industry IMHO (not counting special ones like Focal or Sony or Phenomenon). I have dozens of obsolete pads from other makers that I collected over time, but the 007 and 009 pads stand out. So if anything, I'd move *for* them, not away from them :).

    I second Zolkis findings. Have followed his instructions, first modded original 007 pads then 009 pads and no way back. In  2 words - increased immediacy.

  4. I played a bit with my BHSE. The amp is a-m-a-z-i-n-g with my O2mkI after 717! Explosive dynamics, detail, realistic complicated rendering. I must say my listening education is missing in some areas to fully understand and digest what this amp is doing.

    Did some small changes:

    1) Changed the Furutech Alpha power cord it originally came with to a DIY solid core

    Found the right polarity

    Lifted the amp ground (I know I know, I put myself at risk but the amp is grounded via the preamp and I want to avoid gnd loops)

    All above in one go, I'm not particularly keen on doing all those small listening steps, that annoys me. This change was quite prominent. The sound became even more direct and intense, more dynamical (had to lower the volume by 2 points) almost like sharply etched. Freaking intense experience, at some moments a bit too much.

    2) Changed the original Head-amp russkie Mullard copies (with about 10h on them only) to new GT EL-34M, grade 7. At first listen after biasing the change was in somewhat opposite direction to the above. More relaxed sound, less intense, a bit lower in volume, but with a beautiful bass. Harpsichord started to sound a bit "electronic" though and less freaking detailed. Burned them in for 12h with pink noise (burning the O2's also). This opened up the sound and gave it more edge and detail but not as much as it was in 1). Changing dynamic balance of my FR64 arm to a static one also restored some of the crazy dynamics from 1). Hard to decide which sound I prefer. Keep listening and experimenting.

    The source: EMT930 +FR64S+modded FR7f + AQ Leopard 144V + DIY EAR834 with a red tip Tlf 12AX7 at the input. All pneumatically suspended.

    Cheers

     

     

     

     

     

     

     

    • Like 1
  5. Yes, Russian Mullards. I followed Justins video: 

    1) Set balance and gain 5mins after power up

    2) Corrected after 1h to below 1V 

    3) Monitored for the next 3h, all was stable

    4) Powering after few days I find again -27V + to gnd after 45 mins of warmup. So I corrected again to below 1V but after 10-15mins it drifted to -11V

     

    Perhaps the tubes are still setting?

  6. Hi guys,

    Sorry if this has been asked already: I rebiased a set of new tubes as per Justins instructions in a 4h session. Then after powering the amp again after few days the gain drifted away again to -27V and stays there unless I rebias again. Is that normal? I guess I dont need to rebias everytime I power it up?

    Another Q: Are the 2A and 0,2A fuses fast or slow blow? I wanted to try some nice silver ones.

     

    Thanks in advance!

  7. Looks like problem solved: "No this isn´t possible the new driver frame don´t fit in the Sigma housing. Last drivers they work was from the Lambda SR-202/303/404 series."

    Soeren from Inexxon.de

    Looks like transplantation is the only way. Anyone has a spare Lambda Signature to sell :) ?

    Cheers

     

  8. Hahaha :D

    It's their way of quantifying when the tube starts to distort.

    This is what Brent Jessee says: "The hardness is actually the plate current draw of the tube when under full operating voltages for the plate, screen grid, and with negative grid bias applied at the proper voltage"

    What plate current correspond to their "hardness" they however do not disclose as its their commercial secret. Only the higher the "hardness" the higher the plate current. The Shuguangs I inherited my BHSE with were rated 30mA but unfortunately gave up the ghost.

    PS Impressively made amp, Justin! Great job!

     

  9. Hi all,

    Just joined the BHSE club acquiring a nice early specimen with the serial number #34 :)

    After some research here and on head-fi started to look for a set of good tubes.

    Here comes a question: There is a big variation in plate current in the EL34 kingdom from specimen to specimen. Since the output tubes are current sourced and sinked, is there a risk of burning the source/sink with a tube with a high plate current?

    For example Groove Tubes labels their EL34M according to their hardness parameter from 1 to 10 with the highest numbers being the most linear but as far as I understand drawing the most plate current. I'm looking for them (was advised the 7-9 range) but started wondering if too strong a tube can possibly burn its current source/sink?

    Thank you in advance for any input!

     

     

     

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