Standby Switches are they necessary

[kagliostro]

One of the ipotesis about the presence on Fender's amps of the standby advanced by Merlin Blencowe is

The other possibility is that the 5E6 was rhe first amp where Fender used a DC-coupled cathode follower. This stage will sometimes arc between grid and cathode at switch-on if the cathode has not yet warmed up. (These days you should put a diode or neon-lamp between grid and cathode to prevent this, not rely on the user).

Franco

[jjasilli]

I'm not sure why there's a focus on Fender's use of Standby SW's.  Other makers used them too: Magnatone, Ampeg, etc.

[kagliostro]

May be it is a wrong news, but many say Fender was the first to apply that solution


Franco

[pompeiisneaks]

I'm not sure why there's a focus on Fender's use of Standby SW's.  Other makers used them too: Magnatone, Ampeg, etc.

Because those amps came out after leo's first amps, as far as I recall the history.  He was one of the, if not the very first tube guitar amplifier builders. 

Wikipedia shows Leo's first amps were with K&F and were in 1946.  Magnatone did start making some amps in the 30's but I can't see much documentation on them other than a few photo's that are really hard to see for sure, but I don't see any standby switches, the dickerson were the first generation: http://www.magnatoneamps.com/dickerson.html

Ampeg started in 1946 as well, but I can't find any data showing any of the earlier generation amps or their potential use of standby, all of the amps I find in pictures are the 60's to 70's style amps that do definitely have standby.  I'd definitely love if you can find data supporting that one.  As was shown earlier, I've read the blencowe books and part of my idea of this came from there, but I may be remembering a lot of it 'wrong' but the facts of the cathode stripping and the need for a stanby on those higher voltage amps is real, and does still indicate clearly that it's at least highly probable that people assumed (Leo included) that all tube amps needed one. 

They don't.  That's the bigger fact that is true and more pertinent to the thread imo.

~Phil

[sluckey]

Standby switches were introduced as a convenience feature for the player. It was also a good money maker for the manufacturer. Use a $1 part and charge the players $10 to $20 for that convenience. And the players wanted it. Any player whose amp did not have a standby switch wanted one. Soon they were on almost every quality amp that was powerful enough to play live venues.

[jjasilli]

It's not clear that Magnatone, Ampeg etc. should be suspected of copying Fender's use of a Standby SW.


As to cathode stripping: my position is that it is a rude and reprehensible practice which has no place in our modern, enlightened society.  All cathodes of every kind & description  -- be they heated directly or indirectly; whatever their chemical composition; and whatever their voltage to the grid -- should be treated with the utmost respect that they deserve.


And what about the good, hard-working people who make & sell Standby SW's?  What will happen to them if we abandon them to their fate just to look more technically prescient to the next guy?


Furthermore, we should consider the devoted beliefs of our fellow Forum members.  For example, Ritchie200 declares himself to be a Cathode Follower.  How would he feel if we went about stripping cathodes left & right?


'Nuff said! 

[VMS]

Dave Friedman and John Suhr talk little about standby switches on 2 hour mark:


https://www.youtube.com/watch?v=9U5gX5J0pNQ

[PRR]

> those amps came out after leo's ... He was one of the, if not the very first tube guitar amplifier builders.

Gibson, Vega, Electro String, Rickenbacker, Dobro, National, Audio-Vox and others were in the racket before WWII; Leo may have fixed some of those, but as you say his building started after WWII.

OTOH, the pre-war amps were often more Hawaiian-style small-gain amps, and maybe (maybe!) less raucous when left on between hulas than the higher-gain jobs like in Bob Wills' band.

[jubal81]

D-Lab Terry did a fun video on standby switches showing the current spikes on a scope. Bottom line was that they always give tubes a current spike, whereas an amp with rectifier tube never does without the switch - concluding that if you want a mute switch, there are better ways to do it.

[kagliostro]

Nowaday we can use this item to solve that kind of problem (spikes)



http://www.kemet.com/Lists/ProductCatalog/Attachments/146/F9000_GenInfo_RCUnits.pdf

https://www.terapeak.com/worth/rifa-film-capacitor-pmz-2035-rc-unit-0-1uf-330ohm-380vac-800vdc-x1-nos-m-paper/261437970833/

https://www.rapidonline.com/kemet-pmr209mc6220m100r30-0-22-f-20-250vac-metallized-paper-rc-unit-capacitor-51-6823

http://www.xcomfort.co.uk/shop/accessories/113-cmmz-00-07-rc-unit.html

Franco

[Platefire]

Wow! This debate is still going on? Hey if a standby switch makes you feel good and happy about your amp's operation---like me!----use it, if it don't--forget it. I don't think it's going to makes a nat's hair worth of difference either way. A healthy amp will turn on and off no problem regardless. Platefire

[jjasilli]

This debate is just getting "warmed up"!      Standing-by. . . for inrush of HT comments.

[pompeiisneaks]

Wow! This debate is still going on? Hey if a standby switch makes you feel good and happy about your amp's operation---like me!----use it, if it don't--forget it. I don't think it's going to makes a nat's hair worth of difference either way. A healthy amp will turn on and off no problem regardless. Platefire

The debate is more about 'what can damage the amp' not 'if it's setup right'  Or at least that's what it seems to me. 

They're never 'needed' on tube guitar amplifiers.   The 'function' that people want them for is 'mute' not 'standby' so anyone building amps can and should make a 'mute' switch that grounds out some part of the signal path or lifts the cathode somewhere in the path so a tube can't conduct.  That's the safest/most correct way to implement 'mute'  If you MUST do standby (not sure why you ever would need to) you need to be careful of design considerations to ensure you're not damaging the amp with it.  The section in Merlin's book covers this as well.  He basically says don't do it unless you can't stop yourself, and if you must do some specific things to avoid making a standby that can cause damage to the amp.

That's all, nothing to see here, move along.

(I've also never gotten the need to 'mute' but then I've got a volume pedal on my board and just roll it off before swapping guitars (when I'm not using my A/B switch).

~Phil

[PRR]

> ... or lifts the cathode somewhere in the path so a tube can't conduct.  That's the safest/most correct way to implement 'mute'

That will POP bad.

The grounding of a zero-DC signal point is usually fine and quiet.

[SnickSound]

Wow! This debate is still going on? Hey if a standby switch makes you feel good and happy about your amp's operation---like me!----use it, if it don't--forget it. I don't think it's going to makes a nat's hair worth of difference either way. A healthy amp will turn on and off no problem regardless. Platefire

The debate is more about 'what can damage the amp' not 'if it's setup right'  Or at least that's what it seems to me. 

They're never 'needed' on tube guitar amplifiers.   The 'function' that people want them for is 'mute' not 'standby' so anyone building amps can and should make a 'mute' switch that grounds out some part of the signal path or lifts the cathode somewhere in the path so a tube can't conduct.  That's the safest/most correct way to implement 'mute'  If you MUST do standby (not sure why you ever would need to) you need to be careful of design considerations to ensure you're not damaging the amp with it.  The section in Merlin's book covers this as well.  He basically says don't do it unless you can't stop yourself, and if you must do some specific things to avoid making a standby that can cause damage to the amp.

That's all, nothing to see here, move along.

(I've also never gotten the need to 'mute' but then I've got a volume pedal on my board and just roll it off before swapping guitars (when I'm not using my A/B switch).

~Phil

I have a tuner pedal on my board, that'll mute the amp

If I must, I can just pull the input lead halfway and that will ground the input grid.

Turning 420VDC+ off with a switch rated for 240V just seems like a ridiculously complex and risky way of muting an amplifier

[pompeiisneaks]

Hey snick, looking forward to more on the video about the reactive load you're doing! ;)

~Phil

[Platefire]

OK, I see! Concerns about damage/Extra Wear-Tear on amplifier due to standby usage compared to just muting in however manner you chose to mute.

Regarding under rated standby switches. In my 55 years of guitar playing, I've never had one standby switch fail!?

So I won't argue my points for Yea! Standby Switches--any further because they are rather UN-technical and more about what I like and what I'm use to.

I keep thinking the new generation pickers and SS amps may gradually overtake us somewhere down the line but tube amps are still holding their own very good so far even with all the new technology. We'll see I reckon! Platefire

[SnickSound]

Fun fact, look at Marshall's new Origin line:


Notice something? No Standby switch, instead it's a power level switch.
I would bet money there is a time delay built-in instead.

Hey snick, looking forward to more on the video about the reactive load you're doing! ;)

~Phil

So do I hehehe
So many projects, so little time to work on them!
Hoping to do some tweaking to it this week. I got to try the "proof of concept" build at a gig last friday and ended up taking it out of the chain, it made things a bit too rubbery. I'm thinking the 1mF coil might be too much, so I have to source a smaller one to compare.

[dennyg]

So with only 6 builds under my belt you can discount my commentary accordingly - but for better or worse, I'm a cult follower of The Valve Wizard and he's not steered me wrong yet.  He's proven to me time and again that much of what has ended up in modern amp designs has been perpetuated without question from 50+ year old designs.  No standby switches for my amps.  I just played my 50th gig with my first DIY amp and not failed me yet, still using original tubes. But now that I just jinxed myself with that amp, I'll be playing the next show with my most recent build - a modified 20W version of Sluckey's  plexi/jcm800.  Which also has no standby switch :|

[ernie_jr]

my 2 cents worth. Although I use a stand by in all my builds, I still have my dad's fischer stereo tube amp that came with SS rectifier and no stand by and it new seem to hurt the power tubes. In fact, they still test strong and he got it in the 60"s

[jjasilli]

Yes, My son's Stromberg Carlson hi-fi amp of that period has no standby function (though I installed one when I rebuilt it). 


But my Stromberg Carlson PA amps do have a standby function, operated off an octal plug-in relay, which can be remotely operated.  It disconnects the power tube's cathodes from ground.  There's no popping.  It does this at the bottom of 10 Ohm bias sense resistors (which I think also serve as HT "fuses" ).

[Ed_Chambley]

I am not convinced it hurts anything at all to do it either way.  That is unless Power Tubes and Caps should last more than 50 years.




I have seen too many old fender amps that I know the players used standby switches religiously that have tubes in them that are original.  I have a 62 Bassman and a 64 Super Reverb with original tubes or at least the date code on the Bassman confirms the 5881 were older.  The Super Reverb only began not using a standby about 7 years ago when My father gave it to me.  He was always taught to turn on AC power for at least 30 seconds before turning on the DC.




Bassman is SS rectified and I did replace the Standby switch last night.  The switch you could tell was used often as it had a loose feel to it.  Partial from usage and part from switching DC.  So from early 1962 until last night a fender bassman never needed a single part and even then the switch was still working, so it did not really need this.  Would soon tho.




Before you consider the slow warmup for the Super Reverb, it does not use a GZ34, but a 5U4GB.






Also, after rereading this thread last night, I checked a few tubes which were original to amps I bought as collectable.  This one is a 66 JTM45 and actually came with GEC KT66, which I replaced when I bought it.  I have owned it for 12 years now so it only saw use by a dumb player who doesn't know standby switches kill tubes.  He played the amp loud through the late 70's until I bought it 2005.  I checked the tubes and they are still stunning.




What am I missing?  If we were to slow the inrush and let the tubes take time to warm up and caps to not get hit, would they last forever?  And even if they could last forever none of us could stand it anyway.  All my friends who play use standby switches do the ritual startup and shut down.  Most all of them play old fenders which according to standby is probably the worst design from what I read.




I have no doubt and am not arguing points of modern knowledge as it seem conclusive additional stress is caused by standby switches.  It seems to me if you really like to turn off your DC and are willing to only use your tubes for 50 years, I say standy.  If you have had problems with flipping a standby switch and blowing up tubes and caps, well by golly you just did not build them like they used to.




Anyone?  Have you ever had a problem with an amp you know was caused by the standby switch, other than the switch itself?  I am telling you, if the amp has one the vast majority of players are tearing up their amps daily.  So next time you see someone playing a Blackface 65 Deluxe and they flip to standby for a break, simply remind them that their tubes, even though they may be original to the amp, would last longer if they understood the correct modern switching.


One more thing and I will stop.  Is it best to let you car idle so the oil pressure is up when you first start it for a minute before putting it in gear, or is it 30 seconds?  I cannot remember.  I do know oil pressure almost immediately ramps up, but how much oil should be on the rocker arms before I start to drive.



This is a cool thread.

[shooter]

Anyone?

nothing to do with standby, but, I've found that electronics of ALL types, (under 600vdc)really likes either OFF or ON, doesn't really care which, and really HATES on/off/on/off, that's where I get paid 

[jjasilli]

. . . and Peavey chimes in.  See attachment.


Re car engine warm-up,    I say let's keep the contrarian spirit alive & well, especially if a thread can be clandestinely  (well not anymore) hijacked at the same time:  https://www.accuweather.com/en/weather-news/do-you-need-to-warm-up-your-car-in-cold-weather-experts-explain-engine-oil-life/55447779


Hey, someone had to take the bait!

[pompeiisneaks]

. . . and Peavey chimes in

Except for the fact that the article is full of facts, and then says standby on guitar amps is to stop cathode stripping which it doesn't :D.  (on sub 1k Voltages)  Here the valve wizard explains it:

http://www.valvewizard.co.uk/standby.html

"You may have heard of 'cathode stripping', which is a specious argument wheeled out by standby-switch obsessives. In its purest form, cathode stripping occurs when particles of the oxide coating are physically torn from the surface of the cathode when it is exposed to a powerful electrostatic field from the anode. This would happen if the valve is operated at saturation, without a usual space-charge of electrons to protect it. Fortunately, this effect does not exist in receiving valves, even when operated at saturation, because it requires an electric field strength of at least 4MV/m (yes, 4 million volts per metre!). No guitar amp ever comes close to this. "

~Phil

[jjasilli]

I've already clearly dissembled my beliefs on cathode stripping!  See my Reply #55 hereinbefore.

[Ed_Chambley]

. . . and Peavey chimes in.  See attachment.


Re car engine warm-up,    I say let's keep the contrarian spirit alive & well, especially if a thread can be clandestinely  (well not anymore) hijacked at the same time:  https://www.accuweather.com/en/weather-news/do-you-need-to-warm-up-your-car-in-cold-weather-experts-explain-engine-oil-life/55447779


Hey, someone had to take the bait!

My oh my, Finally someone with s sense of humor.


I tried with the Rectifier, but the car got you.


BTW, when I lived in Germany I got a 150 mark fine ($50 at the time) for warming my car up before I drove it.  Obivously, the polizei do not care to determine what is best for the car, it is what is best for thier country.


With that thought in mind, is it really wrong to have a standby switch.  When flipped on not only do they cause inrush and a need to listen to Rush, the band, they will kill your amp or something in it evenually.  I just have not found out what they kill.  They are a major cause of pollution however.

[pompeiisneaks]

I've already clearly dissembled my beliefs on cathode stripping!  See my Reply #55 hereinbefore.

I get that, I'm complaining about Peavey continuing to 'act smart, yet still be wrong and continuing the bs' :P

[PRR]

> Is it best to let you car idle so the oil pressure is up when you first start it for a minute before putting it in gear, or is it 30 seconds?  I cannot remember.  I do know oil pressure almost immediately ramps up, but how much oil should be on the rocker arms before I start to drive.

What oil pressure?

The pressure at the pump may be rising just on the starter motor. It will typically be high at cold idle because the pump is constant-volume and the bearing leak is slow with thick oil. Old cars often nail 40PSI cold but can't hold 20PSI warm.

So the pump is fine; and the main leak is the crank so that's probably getting oiled within a few seconds.

You ask about rocker arms. (Revealing our age.) My Willys was a forced-oil F-head based on an older splash-oil flathead. The new-fangled rockers had an external oil line. Not very big. Not very clean. It took far over a minute to begin to see oil on the rockers. (But remember that many thousand external-rocker engines got oiled manually, including some reliable aircraft engines.)

The pushrod-oiled V-8s normally get oil fairly quick. They want some pressure in the lifter to keep quiet but not to stay lubrucated; thin no-pressure seepage will do. However the worst rocker wear I ever saw was on such an engine. Ball-stud nearly worn through the rocker. I assume pre-SE oil plugged the pushrod, and the splash from the 13 or so oily rockers was not enough to keep it slick.

And yes, I -still- have rockers. Five assorted yard-engines say "OHV!" on the rocker cover for no good reason. (OK, I have not peeked to see if truth or lie.) And my OHC sedan has a bushel of rockers, I guess 20 for the 16 valves. (Honda VTEC has added bumps and rockers to extend the exhaust opening above 3,600RPM.)

[shooter]

I -still- have rockers

I believe my '08 3.9L Buick still uses old school PR/rocker
my '88 dodge definably does, and oil pressure at start IS 40psi, warm, optimistically 10psi

and Peavey chimes in.

I had to use a fire extinguisher on a Peavey, I quit reading their attachments

[Ed_Chambley]

> Is it best to let you car idle so the oil pressure is up when you first start it for a minute before putting it in gear, or is it 30 seconds?  I cannot remember.  I do know oil pressure almost immediately ramps up, but how much oil should be on the rocker arms before I start to drive.

What oil pressure?

The pressure at the pump may be rising just on the starter motor. It will typically be high at cold idle because the pump is constant-volume and the bearing leak is slow with thick oil. Old cars often nail 40PSI cold but can't hold 20PSI warm.

So the pump is fine; and the main leak is the crank so that's probably getting oiled within a few seconds.

You ask about rocker arms. (Revealing our age.) My Willys was a forced-oil F-head based on an older splash-oil flathead. The new-fangled rockers had an external oil line. Not very big. Not very clean. It took far over a minute to begin to see oil on the rockers. (But remember that many thousand external-rocker engines got oiled manually, including some reliable aircraft engines.)

The pushrod-oiled V-8s normally get oil fairly quick. They want some pressure in the lifter to keep quiet but not to stay lubrucated; thin no-pressure seepage will do. However the worst rocker wear I ever saw was on such an engine. Ball-stud nearly worn through the rocker. I assume pre-SE oil plugged the pushrod, and the splash from the 13 or so oily rockers was not enough to keep it slick.

And yes, I -still- have rockers. Five assorted yard-engines say "OHV!" on the rocker cover for no good reason. (OK, I have not peeked to see if truth or lie.) And my OHC sedan has a bushel of rockers, I guess 20 for the 16 valves. (Honda VTEC has added bumps and rockers to extend the exhaust opening above 3,600RPM.)

What do you call a rocker arm under a camshaft in a overhead cam engine?


I thought the rocker arm was kept and the push rod removed.  Did they change it again.?  I quit working on cars when I started fixing amps.  Musicians may not have money, but most of them can maintain a old car and at least clean and wax one.


So, for a complete detail to my truck you can have your amp worked on.  You still got to pay for parts. 


Also, if you want a Standby switch installed on an amp you bought that doesn't have (Blues Jr.) you can get that too.  I actually installed one on a Champ I built for someone by request.  I figure, it is your amp, you tubes and your money.  Spend it however you wish.

[jjasilli]

I bet you can get a Fine for that in Germany!

[Ed_Chambley]

I bet you can get a Fine for that in Germany!

If I do, it will be my third.


Bogner amps have a Standby switch.  Wonder how big his fine is or even if it is fine at all.


Finally, someone with the nerve to offer up the idea fo fining someone for improper movement and installation of a directional selector switch.  Fine is $175.00 and is a moving violation, but we can change this to inproper use of equipment.  No points on you license, but the fine is a tad more.  Only $295.00.


They do this in North Carolina, so keep it in mind.  Coming south on I-26 from Tennessee into North Carolina is a 7% grade and the speed limit changes from 65 to 55.  Just as you see the sign, you will see a State Trooper.  First he asks if you use Standby Switches.  If you say yes, you get a ticket and leave.  If you say you know better, he will instruct you to call the Solicitors office and they will reduce the fine to no points.


Don't ever say you know better, but will install them if requested.  That is the same as telling a Georgia State Patrol officer when he pulls you over in a brand new red Lincoln Town Car while having a few beers and he asks "whats the hurry son, you heading to a fire"?  You reply "does this look like a GD Firetruck to you"?


They will get pissed and take you to jail even if you have a stack of get out of jail free cards.

[jjasilli]

Probably you can get a Fine in Germany for leaving your amp idling.  No standby SW's on German tours!  And, an idling car is the devils' workshop.