What do you do if your amp has no standby switch?

[GuitarStv]

Just wondering what the deal is if your amp is really old and doesn't have a standby switch. I usually turn it on and leave it at minimum volume for a couple of minutes before playing . . . but I've realized that the amp doesn't seem to produce any volume for the first 20-30 seconds anyway . . . is that like a build in forced standby switch?

 

[greendy123]

Re: What do you do if your amp has no standby switch?

Turning all volumes and preamp knobs to zero works, I think turning your guitar to zero to might be good too. Maybe you just need to wait a bit longer for the amp to warm up. Try waiting like 10mins next time you use the amp.

 

[kmcguitars]

Re: What do you do if your amp has no standby switch?

My Princeton has no standby. Just start it up,And let it idle for a minute or so.

 

[Scott_F]

Re: What do you do if your amp has no standby switch?

5AR4 rectifier tubes take a few seconds to "come up to speed". If you had a solid state rectifier plug, you will kill off your power tubes prematurely if you don't have a standby switch.

Westlabs sells a nice 3 way power switch that goes from off (down) standby (middle) to on (up). I use one of these in my Franklin since matchless didn't include a standby in their original lightning. They cost a lot (like 10-12 bucks I think) but it can make you feel better.

 

[GuitarStv]

Re: What do you do if your amp has no standby switch?

See the thing is, this amp doesn't even have a true ON switch . . . it turns on with the tone knob set all the way to high . . . it does have a ground reverse switch, but all that seems to do is electrocute me when I flip it

 

[Bludave]

Re: What do you do if your amp has no standby switch?

Just wondering what the deal is if your amp is really old and doesn't have a standby switch. I usually turn it on and leave it at minimum volume for a couple of minutes before playing . . . but I've realized that the amp doesn't seem to produce any volume for the first 20-30 seconds anyway . . . is that like a build in forced standby switch?

Many of the old Fenders did not have standby switchs. A good friend of mine has a 1962 Fender Tremolux.... 35 watts 2 6L6 powere tubes.... no standby. If you have an amp that does have a standby and if you turn power on and stanby on at the same time it will take about 20 seconds or so before you get sound. The tubes have to warm up a little to produce sound. The purpose of the standby is when you take a break you can leave the amp on and keep the tubes warmed up. This will minimize wear and tear on the tubes. Most newer amps are equipped with standby if they are tube powered amps that are SS do not have standby.

 

[Bludave]

Re: What do you do if your amp has no standby switch?

See the thing is, this amp doesn't even have a true ON switch . . . it turns on with the tone knob set all the way to high . . . it does have a ground reverse switch, but all that seems to do is electrocute me when I flip it

What kind of amp is it?

 

[MDS]

Re: What do you do if your amp has no standby switch?

So is that why my Classic 30 doesn't have a standby? Because it's so "classic" I always thought it was because Peavey was CHEAP! Fortunately it was easy to add one...

 

[GuitarStv]

Re: What do you do if your amp has no standby switch?

Cool . . . it's an old handmade Thorcraft Mustang amp. I havn't been able to find any information on it other than that it was made in Canada in the 60s, class A, point to point hand wired.

 

[Scott_F]

Re: What do you do if your amp has no standby switch?

With the reference to getting shocked via the ground switch, that tells me that it still has the old 2 prong power cord on it. You really need to ground that puppy properly. If you're not up for it, take it to a tech before you hurt yourself. That will free up that little old ground switch to be used as a standby!

 

[Bludave]

Re: What do you do if your amp has no standby switch?

This might give you a little more insight as to what you have. But regarding standby switchs. A lot of the loder Fenders did not have them either. Nothing to be concerned about. My understanding is the standby was added when the wattages started getting pretty high. I don't know if thats fact or not, but I do remember reading it somewhere. I found this info on Harmony central. I don't know how crediable it is but it may give you more info than you have now. Sounds loke a cool old amp though!

http://www.harmony-central.com/Guitar/Data/Thorcraft/Mustang_G40_110_Combo-01.html

 

[Bludave]

Re: What do you do if your amp has no standby switch?

With the reference to getting shocked via the ground switch, that tells me that it still has the old 2 prong power cord on it. You really need to ground that puppy properly. If you're not up for it, take it to a tech before you hurt yourself. That will free up that little old ground switch to be used as a standby!

Well there ya go!:notworthy

 

[GuitarStv]

Re: What do you do if your amp has no standby switch?

With the reference to getting shocked via the ground switch, that tells me that it still has the old 2 prong power cord on it. You really need to ground that puppy properly. If you're not up for it, take it to a tech before you hurt yourself. That will free up that little old ground switch to be used as a standby!

Yeah, I probably should get a proper ground for it . . . it's fine when the ground rev. switch is set properly, but every time that I move it I have to plug it in, turn it on, touch somthing metal on it, and if I get zapped, get a long wooden stick to flip the ground rev. switch . . . I don't know though, how will I warm up for guitar playing without that 110 volts limbering up my arm?

 

[Rich_S]

Re: What do you do if your amp has no standby switch?

Get that ground switch and its related "death cap" removed and get a proper 3-conductor grounded cord installed immediately. Stop screwing around with something that couple easily kill you. We went through this recently with
chopstherocker's Bandmaster head.

About the standby switch: Scott hinted at this, but here's the reason to have one (or not). Tubes need to be warmed up before the high voltage (called B+ by the amp geeks) is applied. If the filaments (heaters) are not hot, it's rough on the tubes to hit them with the B+. In amps with a tube rectifier (small amps, tweed Fenders, JTM Marshalls) the high voltage can't get to the audio tubes before they are warmed up, because the tube rectifier has to warm up, too. By the time the recto is hot, and letting the DC flow, the other tubes are ready.

By contrast, solid-state rectifiers don't need to warm up. They can supply B+ as soon as the power is turned on. Manufacturers installed standby switches to keep B+ off the tubes until they have warmed up. So, you mostly see standby switches on amps with SS rectifiers: post-tweed Fenders, JMP and later Marshalls, most 50-watt or bigger amps.

Some amps with tube rectifiers have standby switches, but it's just for convenience, it doesn't hurt the amp by not having one.

Did I mention you should get that power cord replaced?

Also, what kind of tubes are in that amp? Some small, old amps have a special tube set that lets them operate off 120 VAC with no power transformer. You thought the ground switch/death cap setup was bad? These little monstes are even worse. Post your tube types, and we can tell from that what kind of amp it is.

 

[wixedmords]

Re: What do you do if your amp has no standby switch?

5AR4 rectifier tubes take a few seconds to "come up to speed". If you had a solid state rectifier plug, you will kill off your power tubes prematurely if you don't have a standby switch.

Westlabs sells a nice 3 way power switch that goes from off (down) standby (middle) to on (up). I use one of these in my Franklin since matchless didn't include a standby in their original lightning. They cost a lot (like 10-12 bucks I think) but it can make you feel better.

Great info Scott.

Thanks

 

[GuitarStv]

Re: What do you do if your amp has no standby switch?

I posted in another message, but there's one 12ax7, two 6av6, and one 6bq5 . . . I think that one of the 6av6s is tied up with the tremolo circuit . . .

 

[Rich_S]

Re: What do you do if your amp has no standby switch?

I posted in another message, but there's one 12ax7, two 6av6, and one 6bq5 . . . I think that one of the 6av6s is tied up with the tremolo circuit . . .

6BQ5 is just another name for an EL84 - so the amp's probably about 5-7 watts. Those 6AV6's are weird - a high gain triode (similar to 1/2 a 12AX7) and a pair of diodes!? Yeah, those are probably the tremolo circuit.

Anyway, none those are the types used in PT-less death machines.

 

[GuitarStv]

Re: What do you do if your amp has no standby switch?

PT-less death machines? Sounds like a great band name . . . I figured that they couldn't be that bad, cause like I said . . . been zapped several times with no problems. . .