Headamp Blue Hawaii Special Edition

Discussion in 'High-end Audio Forum' started by audiosceptic, Aug 13, 2009.
  1. bombay317
    I have some tube rolling questions.

    1. If you are tube rolling but are only replacing one pair of tubes, is it the two on the left for the left headphone jack?
    2. When you use the bias adjustment, is there a separate way to do it if you only change two of the four tubes?
    3. what plate voltage and plate current to you get on the tubes when you perform the bias adjustments?

    I'm still looking around the different threads but I have not yet found an answer to those ones.
  2. soren_brix
    1) why in heavens name would you "roll" only one pair???
    2) each channel is adjusted separately, and it is usually not needed unless the tubes are seriously out of spec, and in that case shouldn't be used anyways
    3) you cannot adjust the plate voltage, and probably won't want to adjust the current; you adjust for ~ ABS(10V) DC offset, and balance
    Whitigir likes this.
  3. SeaWo|f
    Someone did just as you described on their DIY bhse and gg. The reason why they did it was to play with the emissions labs dht 20b. At 500 a pair it was probably because the guy didn't want to spend 1k for the quad.

    Also don't buy these tubes and put them in your bhse.. while the electrical properties for the driver application is compatible further modifications are needed. And not just a socket adapter btw.
  4. Whitigir
    Let’s not go there, if those people know how to DIY and mess with Emission Labs, they don’t belong here. You don’t want to see any BHSE owners burn down their amp, or have some magic fire crackers go off
  5. bombay317
    OK, so I'll aim for a matched quad.

    I'm not intending to adjust plate voltage or current, but the person who I contacted to get me some tubes was asking me some questions I could answer and some I couldnt. He asked directly:

    1. What is the plate voltage? I didnt know the answer to this.
    2. What type of bias system is it, to which I answered "fixed" because we have the adjustment system.
    3. When the system is adjusted to correct offset and balance, what is the no-load plate current? I dont know the answer to this.
  6. soren_brix
    ...not sure which guy you are refering to here, but if its Mr. Surströmming I'm pretty sure he knows what he is doing, and don't need to ask how to balance the amp and knows EMS needs 5V for filament rather ...
    Rossliew and Whitigir like this.
  7. Whitigir
    I would advise you to tell the person that you do not know the answers to any of this. All you want and know is that you want a matched Quad of El34 or 6CA7, and the amplifier unit is BHSE. If the seller is interested in specifications, contact headamps. If he doesn’t want to sell you the tubes, go to other places that do
  8. bombay317
    Thank you for the reply and I will do this.
  9. soren_brix
    1) 0V ...the output is taken from the plates, cathode is around - 400V - -425V'ish (having +400V - +425V across the constant current source)
    2+3) constant current ~18mA-24mA (The original was 24mA, but I seem to remember Justin lowered the current to ~18mA)

    I don't know the exact BHSE values, but it is in that neighborhood
  10. JimL11
    1. The plate voltage, as Soren says, is 0 volts with respect to ground, however, the cathode sits at close to -400volts, so the cathode to plate voltage, which is probably what is being asked, is about 400 volts.

    2. The bias system is fixed.

    3. The standing plate current is around 20 mA - close enough, anyway.
  11. SeaWo|f
    Yea I guess I did not make it clear enough that bad things can / will happen unless you really know what you are doing. It was actually JoaMat, and it does look like he eventually sprang for the quad.
  12. bearFNF Contributor
    At a minium I would think matched pairs should be used with the matched pair on the same channel. Both pairs should be the same tubes, also.

    Matched quad would be nice and probably best, but is it really needed? I have only used matched quads and haver been wondering about the matched pair options out there.
    Last edited: Nov 18, 2017
  13. soren_brix
    ... if you don't have a tracer it's is probably best to ask for matched quads, and ask the seller for his interpretation of "matched", ... and hope for the best
    bearFNF likes this.
  14. wrathofkhan
    Is there anyone out there that has or heard the Sennheiser HE 1 and compared it to the BHSE + SR 009.
    At $50,000 + I am just wondering how good they really are?.
  15. stersa
    I have heard HE1 for 2 hrs aprox and i have a BHSE with 009-
    For me,is better HE1 2-5% more.
    First,because HE-1 has Included DAC and is all in one Gear.
    HE1 has better sound with rock-metal.electronic and similar or a bit better with classical-vocal-jazz-acoustic music then BHSE/009

    For me,is similar ..HE-1 against BSHE/009/007 mk1/Dave..:)..my combo

    Personal opinion.


    Last edited: Dec 20, 2017

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