Black Pearl --electronic pop switching between pentode/triode switch

Discussion in 'Amps and Cabs' started by cawirth, Jan 22, 2008.


  1. cawirth

    cawirth Member

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    Just bought a Genz Benz Black Pearl "sight unseen" based on the fabulous comments noted on this board and I couldn't be happier. Looks like the rest of my amp arsenal will soon be on e-bay. Did have a question for all the veteran BP owners though...does your amp make a load electronic pop sound when switching between the pentode/triode mode? The rest of the time the amp is scary quiet; even when switching between 15/30 watt mode or alternating between standby and power.

    I'm hoping there isn't an issue with the amp and everything is ops normal.

    Thanks in advance,

    Chris
     
  2. stump

    stump Member

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    It's normal as far as I can tell. I typically go to stand by when I change either switch. You could email G Benz and ask just to get it direct from the man.
     
  3. HEAVENandHELL

    HEAVENandHELL Member

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    I switch both the Pentode/Triode switch and the 15/30 watt switch on my BP30 with the amp on and not in standby and there is no loud popping. Maybe a small pop but nothing worth worrying about.
     
  4. Steve Dallas

    Steve Dallas Supporting Member

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    I typically recommend putting the amp on standby before using that switch. It is kinda hard on the power toobs when you do it hot.
     
  5. MisterAgreeable

    MisterAgreeable Member

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    Mine pops - not terribly loud, but it's noticeable. I don't see why switching those while the amp is one might hurt anything. If I understand what it does correctly you're just turning voltage to the suppressor and screen grids, which doesn't strike me as all far off from taking the amplifier out of standby.

    I'm not sure how switching to low power was actually implemented, but I can envision a few ways of accomplishing that that wouldn't hurt anything.

    Either way the owner's manual says pretty explicitly that switching those while the amplifier is in use is fine.
     
  6. HEAVENandHELL

    HEAVENandHELL Member

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    Although turning off the amp may never be a bad idea, the owner's manual specifically states "It is not necessary to turn the amp off to use this switch."

    Gregg
     
  7. Miles

    Miles Member

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    Mine pops. If mismatching ohms, the pop is louder than with a safe ohm match.

    The manual says it's fine to switch between 2 and 4 tubes, or pentode/triode without turning the amp off, but it's not a bad idea to turn off.

    My Lonestar Classic that I sold when friggin' nuts if I EVER changed power or wattage settings while the power was on. Sometimes, it would go silent, but the Black Pearl doesn't seem to be sensitive to this.
     
  8. sf audio

    sf audio Member

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    seems pretty normal to pop - I just turn down the volume when I do it...

    gotta a question on the speaker outs on my 2X12 BP - the cabinet speakers are 16 ohms - does this mean that both speaker outputs are 16 ohms, or when using both it's 8 ohms a piece? I always forget this stuff.....
     
  9. cawirth

    cawirth Member

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    Hey thanks for all the quick replies to my question on the popping noise. Looks like nothing to worry about. You guys are terrific!

    Chris
     
  10. drbob1

    drbob1 Silver Supporting Member

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    Every amp I've owned that had a pentode/triode switch pops when switched.
     
  11. HEAVENandHELL

    HEAVENandHELL Member

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    I just watched the video on Blackheart's website for the BH5H. It popped a little when they changed from 5W to 3W.
     
  12. Miles

    Miles Member

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    8 ohms a piece, they are not the same ohm load for each speaker jack. So, 2 16ohm cabs, and you would bring your impedance down to 8ohms. I use the internal cabinet (16ohms) and an 8ohm cab (occasionally) and that brings it to about 5.33ohms.

    So, I can run my BP on 8 or 4 ohms interchangeably, though there is a slight difference in tone. However, I generally just run the amp through it's internal cabinet cause I hate to mismatch too often. Extreme mismatches on the Black Pearl (example, 16ohm cab into 4ohm tap), will not fry the transformer, but it does wear it down after time.

    You just have to be careful with impedance.
     
  13. Simon

    Simon Supporting Member

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    Mine pops as well. I just use stand by.
     
  14. jbert58

    jbert58 Silver Supporting Member

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  15. es125luv

    es125luv Member

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    mine does it as well... BUT I WOULD NEVER BE SWITCHING THIS ON THE FLY...


    I always use the "standby" mode for this... I know the manual says it's okay, but why chance it.
     
  16. Dave Stout

    Dave Stout Member

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    Without seeing the schematic I can't be sure however this could be coming from 2 things. First off the pop could be coming from discharging the choke. When a large voltage is removed from a large choke (inductor) there is a large collapsing magnetic field or transient. Since this is tied to your output transformer you will hear that in the speakers. The second explanation could be the fact that you are changing potential on the screen grid which internally could cause the tube to become unstable. Not to sure about the second exxplanation but the first is pretty good. Have a good one!
     

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