to standby switch.. or not to standby switch

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Bieworm
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to standby switch.. or not to standby switch

Post by Bieworm »

that's the question..

Is there any plausible reason to use your standby switch? I read a lot that it's completely not necessary.

The problem would be 'cathode stripping' by stressing the cold tube with high voltage. I also read that one can even begin to think about this phenomenon at a 1000V+, which never occurs in a guitar amplifier.

Any other thoughts? I do not always use it to be honest...
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Re: to standby switch.. or not to standby switch

Post by Daviedawg »

This thread is like Hailey's Comet. It appears at predictable times and creates fear in the unwary then brings unending argument about what it is.

My view:
You are probably correct that stripping is a myth in guitar amps. For me a standby switch on a valve amp is a convenience as you can head off and make a cup of tea, pour a beer, or whatever and come back and play straight away. The test is whether you need one on a ss amp. The answer is no for convenience at least. Since stripping is a myth you can leave it on standby for long periods with no harm done. Just in case I have a large value resistor across the standby switch allowing a low level voltage to run while on standby. Just in case the myth is fact. Call me superstitious if you like. But then there is magic in those valves my son.

So.. I like a standby switch. But I do not have one on my Champ. I cannot explain that.

Dd
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Re: to standby switch.. or not to standby switch

Post by JMPGuitars »

I assume you've read Merlin's website regarding this. He points out plenty of interesting theory, including workarounds like the one Dd mentioned. I'm relatively indifferent about standby switches, but they're generally expected, and I like switches, so I keep them.

If this were more of a concern, I think we'd hear a lot more about tube rectifier failure, but that's not fantastically common. Eventually they die like any other tube, but I can't think of a single time in 30 years of playing where a rectifier tube actually needed to be replaced. I'd be more likely to consider the resistor on the switch for an amp whose rectifier tube costs more than $10. Or if I wasted money on NOS stuff.
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Re: to standby switch.. or not to standby switch

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JMPGuitars wrote:
Wed 04/15/20 10:04 am
I assume you've read Merlin's website regarding this. He points out plenty of interesting theory, including workarounds like the one Dd mentioned. I'm relatively indifferent about standby switches, but they're generally expected, and I like switches, so I keep them.

If this were more of a concern, I think we'd hear a lot more about tube rectifier failure, but that's not fantastically common. Eventually they die like any other tube, but I can't think of a single time in 30 years of playing where a rectifier tube actually needed to be replaced. I'd be more likely to consider the resistor on the switch for an amp whose rectifier tube costs more than $10. Or if I wasted money on NOS stuff.
My thoughts exactly.
BTW I hear just as often people complain about noisy NOS tubes than I hear people rave on about them.
It's cool to have an oldskool American tube , but there is something kinky sexy about them russian tubes too. But mostly I buy JJ preamp tubes, and the EL84 my preferation is on mil spec sovteks. They just don't crap out...
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Re: to standby switch.. or not to standby switch

Post by JMPGuitars »

Bieworm wrote:
Wed 04/15/20 12:12 pm
My thoughts exactly.
BTW I hear just as often people complain about noisy NOS tubes than I hear people rave on about them.
It's cool to have an oldskool American tube , but there is something kinky sexy about them russian tubes too. But mostly I buy JJ preamp tubes, and the EL84 my preferation is on mil spec sovteks. They just don't crap out...
The only time I bother with NOS is for things like tube mics, but then I still only get inexpensive ones...and usually when I get NOS it's because they're not in production anymore.

JJ preamp tubes are good, but never use their EL84 power tubes (they're trash). For EL84s I've had good luck with new production Mullard, and Tung Sol. TAD is okay too, but I think usually overpriced and selling too much mojo. I'm not personally into EH or Sovtek. Neither sound great to me, though I have nothing against them really.
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Re: to standby switch.. or not to standby switch

Post by Bieworm »

JMPGuitars wrote:
Wed 04/15/20 12:19 pm
Bieworm wrote:
Wed 04/15/20 12:12 pm
My thoughts exactly.
BTW I hear just as often people complain about noisy NOS tubes than I hear people rave on about them.
It's cool to have an oldskool American tube , but there is something kinky sexy about them russian tubes too. But mostly I buy JJ preamp tubes, and the EL84 my preferation is on mil spec sovteks. They just don't crap out...
The only time I bother with NOS is for things like tube mics, but then I still only get inexpensive ones...and usually when I get NOS it's because they're not in production anymore.

JJ preamp tubes are good, but never use their EL84 power tubes (they're trash). For EL84s I've had good luck with new production Mullard, and Tung Sol. TAD is okay too, but I think usually overpriced and selling too much mojo. I'm not personally into EH or Sovtek. Neither sound great to me, though I have nothing against them really.
In my fenders I use tung sol 5881 reissues. They sound big in those amps. I remember having a bassman with TAD 6l6wgb and remember being very impressed by them.
But for EL84 's I tend to trust only the russian mil spec'd tubes such as the EL84 M
Probably because I used them in vox amps..and certainly the reverb driver of my VK. That one just burns regular EL84 's
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Re: to standby switch.. or not to standby switch

Post by JMPGuitars »

Bieworm wrote:
Wed 04/15/20 3:13 pm
In my fenders I use tung sol 5881 reissues. They sound big in those amps. I remember having a bassman with TAD 6l6wgb and remember being very impressed by them.
But for EL84 's I tend to trust only the russian mil spec'd tubes such as the EL84 M
Probably because I used them in vox amps..and certainly the reverb driver of my VK. That one just burns regular EL84 's
You have an amp with an EL84 reverb driver?? I've never heard that. Sample please. ;)

Supposedly EL84Ms give higher headroom/less gain compared to standard EL84s. I dunno if I believe it.
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Re: to standby switch.. or not to standby switch

Post by Bieworm »

JMPGuitars wrote:
Wed 04/15/20 4:01 pm
Bieworm wrote:
Wed 04/15/20 3:13 pm
In my fenders I use tung sol 5881 reissues. They sound big in those amps. I remember having a bassman with TAD 6l6wgb and remember being very impressed by them.
But for EL84 's I tend to trust only the russian mil spec'd tubes such as the EL84 M
Probably because I used them in vox amps..and certainly the reverb driver of my VK. That one just burns regular EL84 's
You have an amp with an EL84 reverb driver?? I've never heard that. Sample please. ;)

Supposedly EL84Ms give higher headroom/less gain compared to standard EL84s. I dunno if I believe it.
A VK has a 63 reverb tank built in. It's powered by an EL84. Later they went to 6v6, but if you use an EL84 M the problem is over. The el84 M is supposed to handle higher voltages...sturdier
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Re: to standby switch.. or not to standby switch

Post by Riffmonster »

Sorry if I start the topic again, but I was just looking at the Lite IIb stand-by switch after reading Merlin's website. So, why is the stand-by switch before the first reservoir cap and not after?

As well, if I want leave out the stand by switch, I would just connect pin 3 of the EZ81 to the first reservoir cap, right? Is the 220K resistor still needed then?

Thanks, I hope this is not an annoying topic.
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Re: to standby switch.. or not to standby switch

Post by JMPGuitars »

Riffmonster wrote:
Sat 04/18/20 3:38 pm
As well, if I want leave out the stand by switch, I would just connect pin 3 of the EZ81 to the first reservoir cap, right? Is the 220K resistor still needed then?
Yes.

The 220K is still needed. It's a bleeder resistor to drain the filter caps when the amp is shut off.
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Re: to standby switch.. or not to standby switch

Post by Riffmonster »

JMPGuitars wrote:
Sat 04/18/20 4:06 pm
Riffmonster wrote:
Sat 04/18/20 3:38 pm
As well, if I want leave out the stand by switch, I would just connect pin 3 of the EZ81 to the first reservoir cap, right? Is the 220K resistor still needed then?
Yes.

The 220K is still needed. It's a bleeder resistor to drain the filter caps when the amp is shut off.
Thanks, just realized that too!
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Re: to standby switch.. or not to standby switch

Post by crgfrench »

I like to put my standby switch in the rotary SPST in my Pre-PIMV pot. I use these:
https://www.tubedepot.com/products/alph ... ith-switch .
It's nice because you can just turn your MV all the way down and click a little further into standby. No pop. I haven't seen a dual pot with a rotary switch so it wouldn't work for a post-PIMV which a lot of people like.
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