Standby REALLY necessary???

[Leee]

Despite the fact that the Blues Jr and Pro Jr do not have the switch?

I dunno.

Are the Blues Jr. and Pro Jr. tube rectified?

Seriously, I dunno.

 

[CB91710]

Makes you wonder if using standby on that amp is not recommended, what OTHER solid state rectified amps would qualify for an exception? This is why this subject is like who’s on first sometimes

I’m with you, I’ll keep using mine since the amp manufacturer saw fit to put it there. I don’t have an ac30 btw.

It could have to do with the location, values, or even the quality of the filter caps.

 

[CB91710]

I dunno.

Are the Blues Jr. and Pro Jr. tube rectified?

Seriously, I dunno.

Nope.
Just 3 12AX7s and a couple of EL84s.
Pro Junior may only have two 12AX7s

Likewise for the later silverface Fenders... as mentioned, only the amps over 20w had the switch, but they all went to solid state rectifiers at some point in the 70s.

 

[Leee]

Is the low power the trick?
Tubes don’t take as big of a hit?

 

[CB91710]

Is the low power the trick?
Tubes don’t take as big of a hit?

Theoretically, they are all driven to a particular percentage of their rated capacity, so the only difference between a 20w and 100w amp is the total current draw on the power transformer, and the heat load on the chassis.
The main difference between the amps above 20w is they would typically use the 6L6 or EL34, while the smaller amps use the 6V6 or EL84 (yes, I'm ignoring the KT line)

But that's current flow through the tubes. At idle, it's just a static voltage on the plate until the grid starts to conduct.
Either a solid state or tube rectifier are going to "slam" the plate when the standby is released.

With a solid state rectifier, the plate sees full voltage immediately... and on a cold tube, nothing happens. The plate holds the voltage until the cathode is hot enough to conduct and until the grid sees a signal (ignoring the bias for simplicity).
Some claim that this causes "cathode stripping" or "poisoning".... but if it's too cold to conduct, it's too cold to conduct, and nothing happens unless something goes wrong and it arcs.

How many TVs, stereo systems, and other consumer electronics have a standby switch? I think high-power HAM radio amplifiers have them.... but I've also had solid state CB radios with one.

It really is something unique to guitar amplifiers, and I honestly believe it was a response to requests from customers who didn't want to have to "warm up" their amp just before every set.

 

[SoK66]

Sticky question for you tube amp guys -

Is it really necessary to use the standby switch on your tube amp?

REALLY?

I’ve heard the debate on this for 30 years, heard a lot of bullshit in the meantime, and seen some pretty knowledgeable people shrug their shoulders and say “I don’t really know.”

A lot of tube amps don’t even have them.

The general consensus I gather is that Leo Fender did it way back when due to tech manuals from RCA.
Leo used lots of RCA tubes, which were also used in radio transmitters that operated at much higher voltages.
Standby switch was the norm on this very expensive gear, and it trickled down into Leo’s guitar amplifiers.

Fender was building amps in great numbers, so everyone watched what they were doing. Hey, if Fender is doing it …

Surfing the web and reading several different sources, it’s become more apparent that the standby switch is still used just because everyone expects it to be there.

Is this really the case?

No

 

[thorens]

Sticky question for you tube amp guys -

Is it really necessary to use the standby switch on your tube amp?

REALLY?

I’ve heard the debate on this for 30 years, heard a lot of bullshit in the meantime, and seen some pretty knowledgeable people shrug their shoulders and say “I don’t really know.”

A lot of tube amps don’t even have them.

The general consensus I gather is that Leo Fender did it way back when due to tech manuals from RCA.
Leo used lots of RCA tubes, which were also used in radio transmitters that operated at much higher voltages.
Standby switch was the norm on this very expensive gear, and it trickled down into Leo’s guitar amplifiers.

Fender was building amps in great numbers, so everyone watched what they were doing. Hey, if Fender is doing it …

Surfing the web and reading several different sources, it’s become more apparent that the standby switch is still used just because everyone expects it to be there.

Is this really the case?

Really neceassary not. During stand by only the tube heaters are working. Your tubes will lasting longer if warmed up before getting the full voltage for doing the work. (Same if you got tube recifierers in your amp).

 

[solidwalnut]

Kinda nice to have during a gig when you have to keep all quiet when you switch out or troubleshoot any cables going in/out of the amp. Keeps the tubes at the ready.

 

[Six6String6]

Marshall tech department said no, when I inquired.
My DSL20 has one, my Origin 20 does not even have one.
In tube powered audio amps none of them have them.
So I’m going with a no.

 

[searswashere]

I wonder if they were also installed as a quick-n-easy mute per the "warm up just before the set". I'm sure enough people forgot their volume was on 0 pre standby switch haha.

 

[Spooky88]

I'm not an amp tech. I thought of becoming one. I've built an amp, and I've attended an amp schematic analysis class. The class was with Bruce Egnater. This subject came up. I wish I had videos him discussing it, so I could provide the details. He explained that the switch is very useful. Tubes need to warm up, capacitors need to fill. Something along those lines. I don't recall the exact details anymore. He explained that some components that prevent excess amounts of current to pass through them can, in fact, allow too much current get past them if not warmed up. Either damaging, or at the very least, shortening the life of components downstream. He suggested, if you have a tube amp with a Standby switch, use it. Wait 15 to 20 seconds after powering the amp to turn it off Standby.

I forgot all the details, but I'll listen to the creator of a successful amp company. So I use my Standby switch every time I turn on a tube amp.

I quickly grabbed a description of the class from his FB page.

View attachment 872399

I am taking Bruce’s class in September. And inside my standby switches. Cuz they’re there.

 

[TLmix]

Short answer is No. It doesn’t pre warm the tubes, just lights up the filaments and can be worse for the amp. It’s meant to be used between sets. I think it disconnects all but the first filter cap in Fenders.

Check out The Truth About Vintage Amps podcast. Skip answers this in detail many times.

The Truth About Vintage Amps Podcast: Big Index Page - Fretboard Journal

By popular demand (well, at least one of you asked for it), a growing index of topics found on the Truth About Vintage Amps... Note: This information is now compiled in an amazing Tableau page created by Ray Laliberte. Episode 1 -Restoring a Gibson "Charlie Christian" amp from the '30s/'40s...

www.fretboardjournal.com

 

[hbucker]

I know nothing about the electronics of it.

But functionally, I like being able to go on standby between sets or if I know I'll be back to play some more in a few minutes. Kind of an instant on and off (like solid state) for my amps - no warmup period re-needed.

But I agree with an above post. If you turn it on, play for a while and then turn it off once a day, the standby doesn't seem functionally necessary.

 

[efstop]

If I was gigging or if I wanted to take a short break I can turn the volume to 0.

 

[Playergjn]

Sticky question for you tube amp guys -

Is it really necessary to use the standby switch on your tube amp?

REALLY?

I’ve heard the debate on this for 30 years, heard a lot of bullshit in the meantime, and seen some pretty knowledgeable people shrug their shoulders and say “I don’t really know.”

A lot of tube amps don’t even have them.

The general consensus I gather is that Leo Fender did it way back when due to tech manuals from RCA.
Leo used lots of RCA tubes, which were also used in radio transmitters that operated at much higher voltages.
Standby switch was the norm on this very expensive gear, and it trickled down into Leo’s guitar amplifiers.

Fender was building amps in great numbers, so everyone watched what they were doing. Hey, if Fender is doing it …

Surfing the web and reading several different sources, it’s become more apparent that the standby switch is still used just because everyone expects it to be there.

Is this really the case?

I experimented with not using Standby on my 100 watt Plexi (solid state rectifier). This shortened power tube life.

 

[redcoats1976]

Interesting thread! I'm all ears.

im energized...

 

[MyGuitar]

There are two switching on moments:
1. Switching on heaters is dangerous because cool heaters have lowered resistance. So it is good idea to provide "soft" switching on. Partly NTC thermistors in AC circuit can help to do it. But it would be good idea to switch on with lowered AC voltage. In some amps you can use power transformer's higher voltage regimes (if there are such), and then go to nominal voltage (some old Fender export amps have switchable very different AC voltages).
2. Switching on plate voltage is not healthy for cool tubes, so Stand-By switch is right solution. NTC thermistors can additionally soften this switching.

 

[mdubya]

I (used to) like to power up my amp and leave it on all day.

The stand by lets it stay on but muted between playing sessions/sets.

That is all I ever cared about.

I think stuff lasts longer if you turn it on and leave it on vs. on/off on/off, multiple times a day.

2204 has a stand by and I use it.

The Champ and Champion 600 do not.

I power up my studio monitors and AX8, first thing, almost every day. I shut them down at bed time. No stand by.

I don't spend much time thinking about it, though.

 

[fry]

If I was gigging or if I wanted to take a short break I can turn the volume to 0.

This is the simple solution I heard a guy explain one time.

 

[Jaguarguy]

Here's Dr. Z's response to the question in his Ask Me Anything session a couple years ago.