View Single Post
  #6   Report Post  
Posted to sci.electronics.repair
Phil Allison[_3_] Phil Allison[_3_] is offline
external usenet poster
 
Posts: 1,249
Default Valve amps and microcontrollers

Arfa Daily wrote:

"Phil Allison" wrote in message
...
Arfa Daily wrote:


Now this amp has a PIC onboard that (as well as controlling the
footswitch
functions, also) senses the inserted jack in the input socket.
But, in addition, it also disables the Bias control circuitry, so as
well
as muting the signal to the Power Amp, it also puts -100v bias onto the
output valves, thus cutting them off completely, unless a plug is in
the
input socket.

But what I didn't know was that the PIC also gets a signal from the
Speaker jack sockets, and will again not take off the -100v bias unless
THIS also has a plug in it.


Whilst it's all very clever sticking a micro in there, realistically,
what
is the point ?



** None so blind as those who will not see.



When has a shorted input, as is the case with most amps with
a switched input socket, ever caused any kind of problem ?


** It does not mute nor put the amp in standby.



I never said it did put it in standby, did I ?


** You are making a false comparison by inventing straw man.


And whilst it doesn't 'mute'
the amp, it keeps it quiet enough for all practical stage-use purposes.


** Bull****.

FX loops are not muted, reverb is not muted and any noise/hum from the input st valve onwards is not stopped.


And if you really want
to shut the output stage off along with the rest of the amp, what was
wrong
with a standby switch ?


** Requires an intelligent human operator.



Oh puleese ...



** My god you are a ****ing tedious ****wit.


When I see some of this stuff, I can't help but
think that it is design for the sake of the designer's ego.


** Lucky your mad ideas are not anybody's concern.


Lucky I'm not just mad,


** Right, you are an arsehole and a pommy pig too.


What the uP does in this examples is useful, clever and makes great
selling points too - the number ONE thing a guitar amp has to do is sell
well in an extremely oversupplied market.


The number one thing it has to do is ..



** Sell well - you ****wit pommy knob.



..... Phil