Am I just imagining this or does my Monique M700 sound better when it's hot?
Used to switch it
off between sets, but
I've been letting it
run continuously for 4.5 hrs at gigs (turn down volume for set breaks) and it breaks up nicely with heavy string attack on my passive P bass w/ Roto SS rounds. Very nice!!
Top of amp is rather warm to touch and took a while to cool down (until I pointed a portable fan on it). The internal fan is on but takes ages to completely cool down at end of night.
Fdeck
@50hz & Tuner on top.
This is one of those areas (better over time) that is often rabidly discussed. Some say there can be no difference. Some swear by improvements in tone and playing characteristics that show up only after long "ON" times. I stay out of rabid discussions as a rule, but I have learned some things I will share.
I do understand that having tubes on long enough so that they run hot is going to give us improved characteristics. It is real. One of the good people I worked with in the past designed his tube gear purposely confining the tubes so that they ran physically hot. My 100 watt guitar amplifier, The Praxis, will char the inside of the wooden enclosure. All in the quest of tone.
The tubes themselves, the inner bits, being steel and precious metals in a vacuum, change shape over time. This is primarily a result of the heat generated by the filament in the vacuum (or near vacuum). That red glow (the filament) runs at about 1200 degrees centigrade. That's over 2000 degrees Fahrenheit. Just think about metal and 2000 degrees for a minute and it gets pretty interesting. The only reason the internal bits do not melt is the vacuum. This heat related change of shape is part of the explanation of the grumbles and strangeness we sometimes hear in the first few minutes with most tube gear. The other part is manufacturing techniques.
If you can give the Monique side of your Monique 700 Rack Mount some time to warm up, that is a good thing. As for how long, it only depends on how long you have available. Often we are not given the opportunity to warm things up, the performance is all that matters, but if time is available it is a good idea.
The other side of your Monique 700, the Class D Amplifier does not benefit from extended warm-up time. The amplifier part of your Rack Mount Monique 700 is going to sound exactly the same cold as it does warm. I recommend turning the amplifier OFF and leaving the Monique side ON between sets. That is why I put separate power switches on your Monique side and your Amplifier side.
As for the heat you feel in the top of the chassis, that is a good thing. The standalone M700 gets pretty toasty on top too. That is heat that has been removed from your 700 watt amplifier. There is a pretty gnarly aluminum heat sink added to your amplifier in addition to the fan to keep your amp cool. For the M2500, the heat sink is 6 inches wide. This is significantly more cooling than Hypex (the amplifier manufacturer) requires.
"Cool" means under the boiling point of water, 100C or 212F. If the vents are blocked and the fan is off, your amp can generate enough heat by itself to get too hot. If it does so, it quietly turns off and waits until it is cool enough to operate again. No damage done, unless we are in the middle of a performance.
In summary:
More warmup time for Monique is a good thing.
More warmup time for the amplifier adds nothing to the performance, except a slightly warmer stage.