Old Music Guy
Active member
Wouldn't it be nice if amp manufacturers would include an AC outlet on the back of practice amps so you could just plug your pedal board there rather that plug it in to a separate outlet?
Sky Blue Lou
Well-known member
My old Musicman 212 HD had one. Great amp for other reasons but that was indeed handy.
Old Music Guy
Active member
Nice amp!
Sky Blue Lou
Well-known member
Yes it was. Not really a "practice amp" at 130 watts but it was my only amp at the time. That was one that got away. Sold it with my 20th Anny Les Paul Custom Black Beauty. Oh the folly of youth.
E
ecc83
Well-known member
Bit of a safety regs nightmare at least in UK? A 13A socket would be rather large and maybe open to abuse...SOME clown will plug in a 3kW fan heater! That leaves the only viable outlet as an IEC power socket which you used to see on old computer towers. The punter would then have to adapt that to 13A to power the pedal board supply.
Then, how do you fuse it and at what value? The amp peeps will have no idea what will be plugged in (see above!). Safety would indicate 3A max to me but that invites nuisance blowing and if you make the fuse "user replaceable" said clown WILL fit a 10Amp or higher, have the fire Xey handy! All this is starting to be a great deal of added cost.
What would be useful and fairly cheap to provide is an amp or so at 9V? Most modern amps use a few op amps and so put 317 reg on the positive rail and feed it to a co-ax socket.
N.B. A lot of amps now have USB ports and you can buy 5V to 12V up converters...I made a 5 to 10V converter many moons ago.
Dave.
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rob aylestone
Moderator
Even worse, how would you keep up with the rules from every different territory? Fitting a 13A socket wouldn't work for sales in Europe, and we'd not want Schuko. IECs with different ends - like Thomann do, works. The gear from them usually has a Schuko and they send a 13A with it in a separate box.
Sky Blue Lou
Well-known member
Difference between mains voltage viz: USA v. UK?
E
ecc83
Well-known member
Well, one assumes it would just parallel (via a fuse!) the mains input. But yes, we are back to Rob's point, connector.
But then we do not have a world standard for voltage or frequency but at least, AFAIK everyone is happy with IEC? I suppose we have to thank Microsoft et al for that?
Dave.
Sky Blue Lou
Well-known member
Umm...okay. Problem is I do not understand electron speak. Didn't understand a word of what you guys said. lol I know I had the amp and the rear outlet worked pretty gooder.
E
ecc83
Well-known member
OK well this https://uk.images.search.yahoo.com/...-cable-black-p9216-7231_zoom.jpg&action=click
is an IEC mains cable as I am sure you know. You can get a complimentary socket that SAFELY delivers mains power. Look up "IEC distribution strips". These cables etc are all rated at 10A max, that's 2.3kW in the UK and about half that in 115V USA. The IEC is the only worldwide standard mains connector that I know of.
Now, the amp's power cable obviously has to carry BOTH the amplifier current AND whatever is plugged in the back. You have to take measures to limit that load otherwise the cable goes on fire!
Of course, not a problem in UK because (polishes nails!) WE put fuses in our plugs!
Dave.
Sky Blue Lou
Well-known member
Threw me at IEC. I said I was ignorant. Well implied it maybe. Thanks for the translation. I get it. Rudimentary. 
TalismanRich
Well-known member
My old Guild Thunderbird amp has a plug on the back, but this is a design from the 60s, so it's a 2 prong socket, and not polarized. I don't think there was a chance that someone would plug a 10 amp space heater into it. It was handy for plugging another amp pulling a couple amps max. That amp also has a polarity switch and a 'hum balance" knob. It's also got the proverbial "death cap", which is another reason I don't fire it up any more. It needs to be converted to a grounded 3 prong plug.
E
ecc83
Well-known member
I was really only thinking UK for the 3kW fan heater! Can't do that on 115V fused at 10A. Yes, that amp needs converting unless it has some massively stupid collector value? Personally I would punch out the two prong socket and fit an IEC. I hate fixed mains cables!
Dave.
TalismanRich
Well-known member
FWIW, I did have my 1953 National amp (Valco build) rebuilt, with new caps and converted to a 3 prong grounded plug. For me, there's no problem with a fixed cable. I don't know if it was that way in the UK, but in the US, most things came that way 50-60 years ago. If I have the Guild rebuilt, I'll keep the fixed cable by convert it to a grounded plug.
E
ecc83
Well-known member
When do as much lugging of kit, gigging or as repair tech as I was, dangly,trippy ffoooking mains leads drive you potty!
Dave.
Old Music Guy
Active member
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Old Music Guy
Active member
I think that's for the cables only. True, at 10A @ 230V. Yet still enough for a 3kW fan.
PorterhouseMusic
Mitakuye Oyasin
Yep, yes. I think it's safe to assume that a design feature like that has legitimate practical and safety considerations. Having worked in a lab at Underwriters Laboratories for many years- I'm pretty sure it would significantly complicate the safety certification process as well.
I agree though - sure would be convenient.
I agree though - sure would be convenient.
PorterhouseMusic
Mitakuye Oyasin
I played hundreds of shows with my beloved 59BMRI and during that period I soft-attached a heavy duty surge protected junction box in the back of that combo amp. It had 4 receptacles iirc.
I had the amp, a pedal board, and a little personal blower/fan (this is Texas) plugged into it most of the time. One cord out to the power supply.
I had the amp, a pedal board, and a little personal blower/fan (this is Texas) plugged into it most of the time. One cord out to the power supply.