The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Tubes4hifi VTA tube amp and preamp kits and all products

    Shutdown of preamp - then Thump (not Trump)


    Posts : 2265
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Shutdown of preamp - then Thump (not Trump) - Page 2 Empty Re: Shutdown of preamp - then Thump (not Trump)

    Post by deepee99 on Mon Oct 09, 2017 10:20 pm

    jfine wrote:
    tubes4hifi wrote:To answer the specific question jfine has rather than confirm the sequencing of turn on/ off which everyone seems to know, the answer is a muting relay could be added which would short the output of the preamp to ground, pretty simple

    hmmm...muting relay....mute....mute button....well yea my SP14 Khozmos has a mute button, so mute the linestage, shut off amp, then shut off linestage *without waiting* and no more thump, at least the last few times I tried it anyways, huh

    That's the beauty of the Khozmos. It also zeroes to mute when shut down. So if you had everything cranked up when you went to bed, you re-start harmless.

    Posts : 372
    Join date : 2014-06-23

    Shutdown of preamp - then Thump (not Trump) - Page 2 Empty Re: Shutdown of preamp - then Thump (not Trump)

    Post by Dogstar on Mon Oct 09, 2017 11:24 pm

    deepee99 wrote:
    Dogstar wrote:When did I say I had a problem?

    I volunteered the sequence I followed for the three years I've had this setup. The only thing I said was that if I powered off the amp first while the source was still playing and the preamp was still on that the source became distorted until the amp was completed off. I didn't say it was bad or even a concern. It just is.

    The only other thing I will say is that the distorted sound during power down if I turn the amp off first is perceived by others that are listening as something bad.

    I prefer to not hear that distorted sound ...that's why I turn the volume down and power off the source and the preamp before shutting off the amp.
    Dogstar, just avoid the problem. Main amps' output will always decay unless they're shut down first. Tube or s/s/, doesn't matter. You might save your speaks from some nasty transients that way.

    Powering-up works in reverse, esp. with tube gear. Fire up all the peripherals and line pre-amp first, let them get over their warm-up belching, and after a couple of minutes, light the mains with the volume control muted or selector switch set to an un-used position.

    My speakers are the single-largest investment I have in my system and I try all I can to prevent nasty transients from getting at them, which usually originate at the source level.

    I guess the reason I've always thought the sequence I followed was good because I've never heard a thump.

      Current date/time is Sat Feb 22, 2020 3:24 pm