When to Poweroff amps and preamps

The real SS engineers with good ears put in an effective standby circuit, including hybrids with tubes ( see for example Ayre or Vandersteen M7 HPA )

and of course super engineers like Jim White of Aesthetix also know how to engineer a great sounding FPGA DAC With tubes that also has a standby mode. Of course those who are living in 1985 and incapable of forming new impressions will protest. Again glad to be one of “the eighteen “.

heavy - is your MC240 stock ? Mine is 1961 and super modified.... sweet amp for sure

And no amount of “ on “ is going to save ya from SMPS hash, so get those isolated from delicate analog devices and on the ugly side of your electrical panel. Both.

Unless they run a very high-biased Class A, I'd never turn them off but to change a power cord, etc. My gear is rarely turned off.

If tubes, then yes, turn on to use and then turn off when done due to heat and the lifespan of the tubes.

Most preamps ought to stay on 24/7. Mine have no power switch (solid state). Eve tubes, if they run moderatlely cool to warm are best just left one. There is some sonic benefit and the power drain/heat is minimal in many preamps.

Power amps are anther story. I’ll steer clear of tubes where the tube itself and state of bias is critical to how much it may be left on and if you can even get replacements!


For solid state power amps, it depends on the design. Without getting techie some have standby modes that allow them to warm up in a claimed 15-60 minutes. There is no danger to leaving them on - just heat, and wasted electricity -- which is both a cost and an enviro factor.

The real answer on how much warm up can be best determined by your ears. If you cannot hear the difference reliably between 30 and 120 minutes, then who cares? turn them off. Yes, as noted, there is a surge at turn on but all most stuff is 30 year old prototypes and has been turned on and off thousands of times. QED. For me, 30-60 minutes n the power amp (from **standby**) is sufficient. From truly off, several hours. That’s why i designed standby!

I have had owners and dealers claim a subtle improvement over days. Maybe its true, but it is also very much at the margin and likely only audible by those with excellent hearing, great systems and/or terrific imagination.

I really don’t believe that there is a single answer, given the many variables. And the difference between waking from standby and truly powering up, and stabilizing is just huge. In my case you can hear the image expand, the bass extend, and the top recede. Its very dramatic ( and kinda cool).

G

I turn both my SS Pre & Amp off. If that is what you decide to do then this is what I found out here. Laughing Our Faces Off. This refers to the Amp, L & O = Last ON
F & O = First Off
This made sense to me as my last system, Infinity Kappa 8's with an Adcom 555II amp. This set up for 15 years did the same thing every time when turning off in this way with the volume turned down all the way down. For 15 or so seconds the speakers had a popping noise, then I turned the Pre off.