Re: Remote Power Supply Connection

"Patrick Turner" <info@[EMAIL PROTECTED]
> wrote in message 
news:482D77C2.B65FAD8D@[EMAIL PROTECTED]
>
>
> Trevor Wilson wrote:
>>
>> "Iain Churches" <IainNG@[EMAIL PROTECTED]
> wrote in message
>> news:yy9Xj.1624$_03.705@[EMAIL PROTECTED]
>> >
>> >
>> > "Trevor Wilson" <trevor@[EMAIL PROTECTED]
> wrote in message
>> > news:694fk9F30lh2sU1@[EMAIL PROTECTED]
>> >>
>> >> "BretLudwig" <bratzirules@[EMAIL PROTECTED]
> wrote in message
>> >>
news:7a2f6434985dd93af0ad7ca24683b83c@[EMAIL PROTECTED]
>> >>> "BretLudwig" <bratzirules@[EMAIL PROTECTED]
> wrote in message
>> >>>
news:6889949c0f7376f69fcc9ea26ef19be9@[EMAIL PROTECTED]
>> >>>> **** Brussels.
>> >>>>
>> >>>> Do it yourself and who will know?
>> >>>>
>> >>>> Put simply the use of an outboard power supply chassis is the 
>> >>>> OPTIMUM
>> >>> way
>> >>>> to achieve the BEST possible performance.
>> >>>
>> >>> **Nonsense. Whilst an external power supply *may* have some 
>> >>> advantages,
>> >>> transferring large amounts of DC is a dumb thing to do. Using AC is

>> >>> far
>> >>> more
>> >>> sensible. Capacitors need to be placed close to output devices, not

>> >>> many
>> >>> cm away"
>> >>>
>> >>> That defeats the purpose of having the PS outboard. You want the AC

>> >>> OFF
>> >>> the signal chassis!
>> >>
>> >> ******elding is cheap and simple. By all means, keep the power 
>> >> transformer
>> >> off the signal chassis, but rectifying and smoothing, THEN trying to
>> >> couple the result to the signal chassis is a recipe for disaster.
>> >
>> > Please elaborate. What kind of "disaster" ?
>>
>> **Google: 'Welder'. Welders operate on DC current. It is for this
reason
>> that commonly available relays have a maximum working Voltage of 27
VDC.
>> Much higher and the arc created can be self-sustaining. Damage can be
>> considerable.
>>
>> > My own 50W amp now five years old, has been running
>> > several hours per day without any problems.  It meets my
>> > objective for a very low level of hum and noise.  To build
>> > the same amplifier in a single chassis with the required
>> > physical separation between critical components
>> > would have required a footprint the size of a desktop.
>> >>
>> >>>
>> >>> You want the primary filter caps on the PS chassis and some more on

>> >>> the
>> >>> signal chassis, with a choke before them that sees only the ripple 
>> >>> for
>> >>> AC.
>> >>
>> >> **Nope. You *only* want to transfer AC between chassis. Not DC.
Unless
>> >> you are a fool, of course.
>> >
>> > The idea, Trevor, is to build an audio chassis in which the
>> > only AC is the signal.  It is a very good solution if it can be
>> > implemented in a safe way.
>>
>> **Trying to use connectors for DC (with appreciable current and
Voltage) 
>> is
>> dumb design. Much smarter to use AC.
>
> Well now, you'd really know wouldn't you, after you've
> designed and built so many amplifiers.

**I know a little about DC arcs. Here's some information for you:

http://www.arcadvisor.com/faq/dc_direct_current_arc.html



>
> An octal socket has no trouble with DC, and its DC that
> is conducted effortlessly from circuit to vacuum tubes
> via the pins.
>
> As long as the direct current is low as it usually always is with
> B+ and B- supplies, the octal is fine for up to 1,000V.
> the typical current rating for a single octal pin and its gripper
> is 5 amps, about right because a KT88 needs 1.8A of heater current.
> But with an anode supply, say with +500V, even with 12 x KT88
> used with each drawing 60mA, there is only 720mA total.
> Where I have above 500Vdc on a pin, I leave the two pins each side
> disconnected to anything, or use the adjacent pins for
> other B+ voltages so a huge potential difference doesn't exist.
>
> In my 845 amps, there is 14Vac transfered to the amp chassis where there
> is a rectifier
> and choke input. Peak charge currents are low, and the 3.4A of 845
> heating current
> does not over stress the octal pins.
>
> In one amp I have 3 octal sockets for the umbilical cables
> with 4 and 5 way mobile crane cabling.
> Pins are tied together to get extra rating for heater current to 12
> output tubes tubes
> used in two channels.
>
> There are very few plugs and sockets other than octals if any that are
> as cheap, simple,
> require no special crimp tools, have good voltage insulation ratings,
> good current ratings for
> tube amps, and which can be easily be beefed up abd ruggedized and
> fitted with screw clamps
> and pressure switches if need be.
>
> If you are so darn wise and experienced,
> please tell us EXACTLY how YOU would do the umbilical and amp design.

**Asked and answered. Use AC. Do not use DC.

>
> But I think you have not the slightest idea that's any good.

**Of course you don't. I suggest you study up on DC arcs sometime.

Trevor Wilson