+ Reply to Thread
Page 1 of 3 123 LastLast
Results 1 to 10 of 27

Thread: Valve amp question

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date: Jun 2015

    Location: London/Durham

    Posts: 3,663
    I'm Lawrence.

    Default Valve amp question

    I've bought a brand new integrated by Mistral. It has 4xEL34, 2xECC83 and 2xECC82. I noticed that when switching on one of the small valves glows very bright for a fraction of a second initially then goes back to normal. The other three are always normal. I thought this might be a function of the cheap Chinese valve but when I switched to NOS valves (all except the power valves) the new one does the same.

    Does anyone know what the most likely cause is? If it was both of one type I would presume it's just part of the design but as it's only one of them (presumably in one channel) then it doesn't seem right. Should I be worried, at least about valve life if nothing more?

    Thanks in advance for any advice.

    Sent from my POT-LX1 using Tapatalk
    Last edited by Lawrence001; 19-11-2019 at 08:07.

  2. #2
    Join Date: Apr 2016

    Location: Bishops Stortford

    Posts: 863
    I'm Chris.

    Default

    I've found that many valve amps are a bit quirky in this way. I think its about the circuits coming to equilibrium when first switched on. Sometimes a valve will glow a bit momentarily and sometimes there will be an audible hum in the speakers for about a second. I think this is pretty normal and even occurs in some AudioNote kit.
    Apparently there are ways to ameliorate these effects, but it involves additional circuitry that almost always has an inverse effect on sound quality.
    Cheers Chris
    SW1X Universal Music Server UMS I Signature with Power Supply Unit PSU I Signature
    SW1X USB II
    SW1X DAC III Special
    SW1X Open Baffle Speakers containing both vintage and modern alnico drivers and paper cones. All silver wired and crossover-less where possible - 4" vintage Siemens Klangfilm tweeters, 8" SEAS exotic W8 midrange drivers and vintage 15" Altec VOTT 416 bass drivers
    DRD 45 single ended, 45 triode, monoblocks,
    Silver mains cables, interconnects and speaker cables by SW1X

  3. #3
    Join Date: Dec 2008

    Location: East Riding of Yorkshire

    Posts: 4,506
    I'm Shaun.

    Default

    My amps have a switch on delay so that the valves only reach full capacity a minute or so after power up. Just a thought.

  4. #4
    Join Date: Mar 2008

    Location: Galashiels

    Posts: 12,969
    I'm inthescottishmafia.

    Default

    This is quite normal and is nothing to worry about.
    “Music has always been a matter of energy to me, a question of fuel. Sentimental people call it inspiration, but what they really mean is fuel. I have always needed fuel. I am a serious consumer. On some nights I still believe that a car with the gas needle on empty can run about fifty more miles if you have the right music very loud on the radio”

    Hunter S Thompson

  5. #5
    Join Date: Jun 2015

    Location: London/Durham

    Posts: 3,663
    I'm Lawrence.

    Default

    Thanks all I'm less worried than I was, but still a little perturbed that only one of the two ECC83s does it, it makes me wonder if there is some imbalance between the pair in the circuit, although there is no audible channel imbalance.

    Sent from my POT-LX1 using Tapatalk

  6. #6
    Join Date: Mar 2016

    Location: Brighton, UK.

    Posts: 1,300
    I'm Mike.

    Default

    Once you've had a listen let us know what its like. I'm after an EL34 valve amp meself.
    Current system. NAS Interspace, Jelco 750, /Nagaoka MP 200/Graham Slee Era V. CDP - Mission PCM 7000. Amps - Quad 909/Croft micro 25. Chario Syntar 100 Tower. QED XT40 speaker cable/Straight wire interconnects.

  7. #7
    Join Date: Jun 2015

    Location: London/Durham

    Posts: 3,663
    I'm Lawrence.

    Default

    I've been listening for a week now it's bloody lovely! I need to decide which one of my EL34 amps to sell as I want to keep them both!!

    Sent from my POT-LX1 using Tapatalk

  8. #8
    Join Date: Oct 2012

    Location: West London

    Posts: 143
    I'm Steve.

    Default

    My VTL pre does that on one of the ecc82's. None of the others do that and it has no effect on sound or running.
    Thorens TD550, Ortofon 12", Ortofon Jubilee or Koetsu Black; Rothwell MCL SUT, VTL 2.5 pre, XTC POW 1 power; Naim CD5x; KEF Reference 3.2's; Van den Hul interconnects and speaker cables.

  9. #9
    Join Date: Jun 2015

    Location: London/Durham

    Posts: 3,663
    I'm Lawrence.

    Default

    Quote Originally Posted by Slawts View Post
    My VTL pre does that on one of the ecc82's. None of the others do that and it has no effect on sound or running.
    That's good to know. I wonder if a slight difference in resistance or whatever in one channel means the switch on surge all flows through the path of least resistance.

    Sent from my POT-LX1 using Tapatalk

  10. #10
    Join Date: Jan 2009

    Location: Essex

    Posts: 21,887
    I'm openingabottleofwine.

    Default

    The heaters of the EF86s in my Radford STA15 III intially glow brightly on switch-on, then immediately 'die down' to a normal glow. So nothing to worry about!
    Barry

+ Reply to Thread
Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •