Does turning tube amp and preamp on at exactly the same time hurt them?

Discussion in 'Audio Hardware' started by Funky54, Oct 9, 2019.

  1. Funky54

    Funky54 Coat Hangers do not sound good Thread Starter

    I have always turned on my pre-amplifier and turntable first, then my amplifier last. I did this in the reverse order to turn them off. Starting with the amp than the preamp.

    What I am asking is, is there any ill effects to turning them on and off at exactly the same moment?

    In addition to loving two channel, by profession, I am a smart home low-voltage Integrator. I have some very well-built nicely designed controlled receptacles. I am considering using one to turn on or off a nice power conditioner that has all my gear plugged into it and Left on all the time. That way I’m controlling the switch providing the conditioner with power.
  2. Agitater

    Agitater Forum Resident

    It depends on the design of the preamp. Some
    preamps stage nicely and once their internal self-test is done (capacitors charged, etc., etc.) cycle on without spiking into the amp.

    Some preamps, external turntable controllers and even DACs don’t play nice and cause loud spikes. The solution to that is to always ensure that the preamp volume control is either turned all the way off or muted when switching things on and off.
    billnunan and The FRiNgE like this.
  3. Rolltide

    Rolltide Forum Resident

    Vallejo, CA
    It seems from about 1950-1977 this was definitely necessary and from there graduated to YMMV. My guess is few modern solid state preamps still do this, but I'm sure we could find some.
  4. SandAndGlass

    SandAndGlass Twilight Forum Resident

    In pro audio, the rule is to turn the gear on in order starting with the source, moving to the preamp and then finally to the power amp.

    Pro audio gear is generally turned off in reverse order, starting with the power amp.

    I leave my tube preamp on mostly 24/7 so it does not really apply here.

    But, as a general rule, I the power amp will be piece of gear that I will turn on.
    waaguirr and The FRiNgE like this.
  5. Ontheone

    Ontheone Forum Resident

    You should let a tube preamp warm up for a minute or so before turning on the amp to avoid the risk of sending a possible transient through the amp which could damage your speakers. At a minimum I'd keep the preamp in standby mode or mute mode for a minute or so. My VAC preamp manual even states to do so for this very reason.
  6. pscreed

    pscreed Upstanding Member

    If you turn them both on at the exact same nanosecond this false shadow world we all suffer in will be instantaneously dissolved and the truth will be revealed to us all...

    ... so keep trying brother. Keep trying.
    bever70 likes this.
  7. 5-String

    5-String Forum Resident

    Sunshine State
    Preamp first, wait a few minutes, then the amp. When turning off, do the opposite, amp first, then preamp.
    The best would also be to start from the source progressively to the speakers.
    The reasons are what @Ontheone mentioned above.
  8. mkane

    mkane Musics a Passion

    I always have the volume on zero when not using. Class D amps powered up 24/7. Tube line stages off until use.
  9. The FRiNgE

    The FRiNgE Forum Resident

    No. Tube amps are less likely to be bothered by simultaneous power up. I know in all cases, guitar tube amps power up simultaneously, being that the pre-amp stages and amp stages are always entirely integrated. Never has a guitar amp been damaged by powerup. (that I have seen) I would say the same applies to tube hifi gear.

    As you have indicated and likewise other members here, the correct powerup procedure is sources first, the power amp last.. reverse for power down. However pro gear involves many, many, many connected devices, and multi-channel mixing consoles.. mostly solid state, when powered up simultaneously could send a giga-normous spike through the power amp... and the poor, poor unfortunate speakers.
    Last edited: Oct 10, 2019
    SandAndGlass likes this.

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