To stand-by, or to not stand-by?

[ThermionicScott]

Sorry, I have a naive tendency to assume the amp was designed properly in the first place. I question the wisdom of using a 5Y3 to feed four hungry EL84's along with preamp tubes -- that's twice the amount of current a real 5Y3 is rated to deliver, let alone some rebranded Russian tube.

Standby switches cause the spike of inrush current that blows rectifier tubes -- that is one of many reasons I argue against their use. If Jared's amp were biased properly with a capable rectifier tube and he left the standby "on" at all times, he'd be fine.

- Scott

[Jared Purdy]

...I have the strangest feeling I may have said this before...

But then, you know all this already Jared, if you don't believe any of the responses you get why ask a question? Or, do you just want to hear answers that fit your perception? People who contribute to this forum do so because they like to help people, so they freely contribute their time to field queries, often when they have better things to do, like paying work...like I do now. Goodbye.

That is completey out of line! Why the hell do you think I asked the question in the first place? Did you not read that I just got into electric guitars last year, and therefore know very little about tube amps, and in particular, standby switchs, such as the Mesa LSS. It is the first amp that I have had with a standby switch, and I have had it all but 5 weeks. And to top it off, it developed a series of tube related problems, as you will know doubt know by now as you read the other, very different thread.

I appreciate all of the comments that the majority of you have offered to me to help me better understand this issue. However, the "old timers" false accusations doen't sit well with me at all.

[Jared Purdy]

Thanks and I will check diyaudio later. The Peavey article is the first one I have read on tubes. So, what is the best advice for teh this Mesa? Turn power on, wait 30 secs or so, turn standby on, jam a while, if I ahve to go do something for 20 minutes, leave amp on, turn amp off??? How long shoudl standby be used for and often over the course of a day, say it I'm home all day, and I'm pickin a little, then doing something else, etc???? I posted the same question over at tdpri, and one guy weighed in saying that he turns his amp on in the morning,and turns it off at night! That seems like a long time, and a waste of electricity if it is not even being played.

[MWJB]

You think I'm out of line? You already had many of these answers dealt with in a previous thread. Taking information offered in good faith & either not reading it/not querying it if you don't understand it, then starting a new thread querying the info that you have been supplied with already on another thread does not sit well with me. I don't mean to play the martyr, but I & everyone else who gives you insights into your issue, do it out of kindness & often when it is eating into time that could be more productively spent...to then be cross examined doesn't feel good, or make me want to continue to contribute to your thread (but, nevertheless, I have).

Sure, you will often get differences of opinion...but if your not happy with the answers you get then it's time for you too look deeper in to what makes amps tick in the first place so you can make a more informed opinion.

[MWJB]

If you need to go away for 20 mins or so, assuming the amp doesn't hum & you don't leave the guitar in a fashon that will cause feedback, you may as well leave it in play mode (not bother with standby). I would use the standby when initialy powering up (that's what it is for) & not leave the amp in standby for extended periods.

[ThermionicScott]

Here's what I'd do about the standby switch:

1) find the position where the amp is allowed to make noise, then
2) never ever touch the switch again.



Seriously, the filter caps and rectifier tube will be much happier, and the power tubes will just get "irked" for a couple seconds whenever you turn the amp on. No big deal. Turn the amp's volume knob down when you don't want it to make sound.

- Scott

[GregS]

How long shoudl standby be used for and often over the course of a day, say it I'm home all day, and I'm pickin a little, then doing something else, etc???? I posted the same question over at tdpri, and one guy weighed in saying that he turns his amp on in the morning,and turns it off at night! That seems like a long time, and a waste of electricity if it is not even being played.

I'd say that's also a waste of tube life. I wouldn't turn the amp off if you're going to be playing it again in 5 minutes or so but if it'll be 30 minutes or more I would.

More wear and tear will occur on the tubes during the power up time than will when in the on-state over the same time interval. However, after a certain amount of time elapsed while idling the amount of wear from idling will exceed that from powering up. Like with a car the most engine wear occurs when you start it so it doesn't make sense to shut the engine off at stop lights or for very short periods of time - but if you're not going to drive it again for an hour it doesn't make sense to leave it idling all that time.

The other issue is all the other components being subjected to the heat of the tubes for a much greater length of time - particularly with a combo amp with the tubes upside down. Again, more damage is done from the re-heating and re-cooling of the parts/circuit boards when turned off and on but if the amp is left on and hot all day this factor could become a lot more significant.

[Jared Purdy]

Since when did I ever not express my thanks and gratitude for the comments by the various contributors? The question that was asked on the other thread about blown tubes and fuses is entirely different than the post here about standby switiches, and when to use, not to use. I think that you need to go back and reread the original threads, and the posts by other members, including the thank you's by me to get a clear and accurate picture for yourself. You think that you are the only person in the world who is not busy, you talk about wasting time, such as the courtesy that I have now taken to send you this post? Your arrogance is pathetic. Do me, and the rest of the posters to this thread a favour, and do not reply to ANYTHING that I post in ther future. You obviously have other things to do, so don't waste your time here.

[Jared Purdy]

Thank's Greg, I think that seems to be the general consensus, though there are some guys who leave their amps on all day, which is also a waste of electricity.

[JoeM]

My tube amps all seem to sound a bit better once they get a little hot. Except for initial turn on, I dont put any amp in standby. There's times I've thought to come back and play some more after some practicing, but have forgotten to turn the thing off overnight! My Princeton doesnt have the standby switch, still works fine after 40 years or so.

[Tom Phillips]

IMHO this amp is a lemon or, if other people are having the same problem with this model, the design is bad. Unless you are flipping the power and/or standby switch switches quickly On and Off, you should be able to operate them in any order at any time without blowing tubes or fuses. If it were mine I would return it to the store before too much time goes by. The idea about giving them one more chance to fix it would be fair but you need a clear path to a fix or a refund from the seller.

IMO,
Tom

[Jared Purdy]

Did you bother to read the post, from beginning to end? Whenever I see a post, or a response that begins with: "In my opinion" when in fact the person making the opinion has only stated the obvious, that it is their totally uninformed opinion) I retreat. Best of luck. As a newbie, I actually think that I might be further along than you!

[Tom Phillips]

Yes. I did read the post. And the complete other thread about this amp.

[Prairie Dawg]

As I understand it, the standby switch was there to prevent so called 'cathode stripping' that is, damage to the elements by applying B+ to a cold tube, which would happen if and only if you were using solid state rectification. Since cathode stripping may or may not exist at the kind of voltages we're accustomed to. At least, that's what I'm told.

If the idea of applying hard B+ to a cold tube bothers you, put in a thermistor. A number of amps have them as soft start devices, Mouser has buckets of them for about $1.36 each, and they can often act as a fuse of last resort. A typical example is in the Hot Rod Deville, and some Vox AC50s which used a Brimistor-a rod shaped thermistor. Workman Manufacturing made a lot of dough peddling what they called Globars to the teevee repair trade.

But if you're using tube rectification none of this is necessary as in the time it takes a rectifier tube to come on line your power tubes are heated up pretty well.

Having said that, if you do have a standby switch you can get a surge when you throw it, and some folks have reported rectifier tube damage, blown fuses and the like in reissue AC30s because of this.

I leave the standby "on" all the time and just turn the guitar down for breaks. Simple.

Now I gotta check the Traynor YCV80 that I picked up over the weekend and see how that's built. maybe it has a thermistor already.

[Steve Conner]

Did you bother to read the post, from beginning to end? Whenever I see a post, or a response that begins with: "In my opinion" when in fact the person making the opinion has only stated the obvious, that it is their totally uninformed opinion) I retreat. Best of luck. As a newbie, I actually think that I might be further along than you!

Jared, with all due respect, MWJB is a professional amp builder and long-term member (5 years? 10? As long as I can remember.) of the forum. You are... a guy who asks a LOT of annoying questions.

As you can see there is no real consensus amongst us on what the standby switch actually does, or is supposed to do. For all we know it may actually be a kind of self-destruct button whose sole purpose is to help Mesa sell more rectifier tubes. Why don't you call Mesa tech support and ask them.