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Power supply setting at back of tube amp

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Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 12:22 pm
by TheLegit
Hello!

I've got a Peavey Invective and I noticed that the power supply setting at the back (red slidey thing) is set to 220-230V, however we are in the UK should I pop this over to 240V to be safe.

Thanks

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 12:45 pm
by Wonks
If you've got a multimeter, then if you feel competent to, then you can always measure the mains voltage where you are. You should be able to stick the prongs of the multimeter into the ends of an IEC lead (the two outer sockets, not the one on the top of the triangular pin arrangement). If it's nearer 240v than 230v, then the 240v setting will be slightly better for the amp. However this is obviously potentially very dangerous if you are not competent with electricity and electrics/electronics, so if in any doubt, don't do it.

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 1:57 pm
by ef37a
I would always put an amp on the 240V tap.
Almost everyone gets 240V ish* and some quite a bit over that at times. Assuming you are the exception and you do get 230V you will never notice the tiny loss of clean headroom.

All the specifications I checked were with a monitored 230V input from a Variac so the amps would actually be a little "punchier" out in the Big Bad World but reliability tests were done at mains + 10% = 253V but I am not sure every manufacturer was as fussy? I do know many older Fender inports went through OP valves in short order unless tapped up to 240V, even smoked the odd mains traff I understand?

*Now, you see, I shall be deluged with peeps claiming "I only get 225V!! "

Dave.

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 2:10 pm
by MOF
Is there a 240v setting? The other setting could be 110v for the USA but I’d be surprised if there’s a 230 and 240.

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 3:06 pm
by Hugh Robjohns
[quote="ef37a"]Almost everyone gets 240V ish* and some quite a bit over that at times. /quote]

Clearly, a 240V setting would be safest on valve equipment like this, but I think it's an over-generalisation so say 'almost everyone gets 240V or more' !

I've never seen more than 235VAC where I am. It's currently sat at 232V, and often drops to 228-229 at times of peak demand... but the long term average is definitely 230V, not 240.

And I think the trend is definitely for the electicity suppliers to recalibrate the local distribution transformers for a nominal 230V as and when they can, and all new developments are as close to 230V as practical (although the exact voltage received obviously depends on how close you are to the transformer and the tine of day).

H

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 4:06 pm
by ef37a
Hugh Robjohns wrote:
ef37a wrote:Almost everyone gets 240V ish* and some quite a bit over that at times. /quote]

Clearly, a 240V setting would be safest on valve equipment like this, but I think it's an over-generalisation so say 'almost everyone gets 240V or more' !

I've never seen more than 235VAC where I am. It's currently sat at 232V, and often drops to 228-229 at times of peak demand... but the long term average is definitely 230V, not 240.

And I think the trend is definitely for the electicity suppliers to recalibrate the local distribution transformers for a nominal 230V as and when they can, and all new developments are as close to 230V as practical (although the exact voltage received obviously depends on how close you are to the transformer and the tine of day).

H

See! Yes Hugh point taken but, running a valve guitar amp on its 240V tap will do no harm at all and even if the user got the absolute minimum allowed they would rarely notice, might even like the "crunch" if giving the amp the beans!
On the other hand, running valves, especially if fixed biased, over design limits reduces their life drastically and guitar amp designers tend to run them to their limit anyway, at nominal mains input!
This is especially the case with modern valves.

Dave. BTW, did not get notification of your reply Hugh.

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 5:04 pm
by TheLegit
Thanks everyone I'll switch over to 240V in that case

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 7:35 pm
by MOF
I'll switch over to 240V in that case
Was there a 230v and a 240 v setting? Just curious, I tried to get a clear picture of the amp but couldn't see the selector switch.

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 8:33 pm
by wireman
I'm currently at 246,244,247,248V depending which device I believe, have seen it at 249V.

At least the kettle boils fast...

The UK standard is 230V nominal with a tolerance that means it can rise to 253V. It is in the interest of the distribution companies to keep the voltage high.

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 8:55 pm
by Hugh Robjohns
PW as a substation at the bottom of his garden, and he had very high mains volts until he complained and the electricity board reset the transformer. Light bulbs last much longer now, apparently! :-)

Re: Power supply setting at back of tube amp

PostPosted: Thu Apr 18, 2019 8:56 pm
by wireman
Wonks wrote:If you've got a multimeter, then if you feel competent to, then you can always measure the mains voltage where you are. You should be able to stick the prongs of the multimeter into the ends of an IEC lead (the two outer sockets, not the one on the top of the triangular pin arrangement). If it's nearer 240v than 230v, then the 240v setting will be slightly better for the amp. However this is obviously potentially very dangerous if you are not competent with electricity and electrics/electronics, so if in any doubt, don't do it.

You could also use a plug in power/energy meter that measures voltage.

I use a special plug like one of these

Image

with a Class III meter on an appropriate AC Voltage range (double check that) and I don't leave the plug where it is accessible.

A power meter is the safest option.

Re: Power supply setting at back of tube amp

PostPosted: Fri Apr 19, 2019 12:04 am
by TheLegit
MOF wrote:
I'll switch over to 240V in that case
Was there a 230v and a 240 v setting? Just curious, I tried to get a clear picture of the amp but couldn't see the selector switch.

There's a setting which says 220-230V and one for 240V only

Re: Power supply setting at back of tube amp

PostPosted: Fri Apr 19, 2019 6:55 pm
by MOF
Thanks, unusual!!

Re: Power supply setting at back of tube amp

PostPosted: Thu Jun 06, 2019 9:16 pm
by TheLegit
I switched over to 240 and it still sounds great but is running noticeable cooler - thanks all!