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Half power switch
Posted: Sun Jun 01, 2014 6:31 pm
by PhilUK
Seen this mentioned a few times, do we know if it was a factory mod or available to order?
I've seen a hole pre-cut in an early 74 chassis (presumably for the switch) which was then covered by the serial plate.
Any body else seen this?
- PASwitchHole.jpg (323.68 KiB) Viewed 1261 times
Re: Half power switch
Posted: Sun Jun 01, 2014 6:34 pm
by PhilUK
Sorry forgot to ask exactly how the half power was achieved. What did the switch do?
Re: Half power switch
Posted: Mon Jun 02, 2014 11:58 am
by Dr.HI-TONE
the hole was present till the mid 1970's
when activated the switch lowered via a large resistor, the voltage on the plates
Re: Half power switch
Posted: Tue Jun 03, 2014 8:04 am
by PhilUK
Thanks for that, was this an option available when ordered or was it a special or even a later factory mod do we know?
Re: Half power switch
Posted: Tue Jun 03, 2014 11:56 am
by Dr.HI-TONE
It was an option for new products early on. I think it was phased out as it is very hard on the tubes unless you place the amp on standby before switching.
I would have to guess that it simply wasn't worth the trouble that came with users flipping the switch repeatedly without using the standby switch.
But that is just my theory.