Remote Power Supply Connection

I've built an out board power supply that (to me) looks kinda nifty, so I'd
like to use handsome and modern connectors. Eons ago I was familiar with old
and large but reliable Cinch Jones types of plugs and receptacles. But what
is a better and craftier type plug, harness, and receptacle for today's
audio equipment? The connections are: 12.6, 6.3, +/-5 &15, B+, Bias, and 2
grounds. I might also make 1 or 2 control lines remote if I change my mind.
A name and part number may be asking too much, but what the heck, I'll ask.
All ideas and comments most welcomed. Thank you.

Cordially,
west

"West" <west@verizon.net> wrote in message
news:JruWj.23633$5b3.10306@trnddc05...
> I've built an out board power supply that (to me) looks kinda nifty, so
> I'd
> like to use handsome and modern connectors. Eons ago I was familiar with
> old
> and large but reliable Cinch Jones types of plugs and receptacles. But
> what
> is a better and craftier type plug, harness, and receptacle for today's
> audio equipment? The connections are: 12.6, 6.3, +/-5 &15, B+, Bias, and 2
> grounds. I might also make 1 or 2 control lines remote if I change my
> mind.
> A name and part number may be asking too much, but what the heck, I'll
> ask.
> All ideas and comments most welcomed. Thank you.
>


Hi West. The situation might be different in the US,
but here in the EU you would run up against considerable
difficulties with the safety regs, and also with meeting
domestic insurance requirements.

When I started to build such an amp as you describe,
my M50 with a separate psu, I was surprised to find
that connectors rated for high DC voltage in industrial
or professional use were only rated at 70VDC for
domestic applications.

I came across a range of military grade NATO
screw connectors, by various manufacturers. They
were mainly painted "grey drab" or "military khaki"
However, I did find one firm, German, that could
supply nickel plated connectors, (maybe for the
Colonel's RT:-) . The company is part of the
Lapp Group, and the round connector is in their
Epic range.

A Google search will find their website. There is
little point me giving you the part number I have as
it comes from the EU dealer (Farnell) catalogue.

I have used these for a several years on various projects
that require a separate psu.

http://www.kolumbus.fi/iain.churches/Pics/DCPowerConnector.jpg

I use the 9 pin connector, though 12, 18 and 24 pin types are
available, IIRC. You *must* use the centre pin for ground as it
is longer and more substantial than the other pins. It connects
first and is the last connection to be broken when the cable
connector is removed. I try to follow some sort of a standard,
and use 1+2 and 3+4 for heaters. 5 for bias, 6 for B+ and 7+8
for the safety trip circuit. 9 as I say is ground.

EN 60065 very much dictates what we may or may not do in the
EU, but I could find nothing, or no-one that could tell me precisely
what the requirements or possibilities were for high voltage DC on
tube amps.

But I do know from conversation with professional tube builders
that solutions like the octal plug and socket are strictly forbidden
these days, in the EU (I don't know about the US or Australia)

None of the builders I talked to would even consider an amp
with a separate high voltage DC supply.

So I tried another source of information, and spoke with
an industrial insurance inspector whom I had met at local
broadcast. I underlined the point that I was interested not
in industrial (broadcast) but domestic applications. He could
give me nothing firm, but made some recommendations
which would affect the safety evaluation decision made by
a company like his. (Once again this info refers to
Scandinavia and may not be applicable to the US)

First he stresses that the DC cable needs to be as short
at possible and armoured, with a strong woven steel braid
connected to ground (So that your neighbour's prize winning
Doberman cannot chew its way through to your 450VDC,
electrocute itself, and leave you open to a huge compensation
settlement!)

Secondly, he stressed that the PSU must have a female connector
(pretty obvious really) with the male chassis connector at the amp
end.

Thirdly, there must be some method of shutting down the DC
instantaneously, if *either* end of the cable is disconnected.

Fourthly, the male connector, with the pins exposed must have
a diode on the B+ pin so that DC cannot get back from the
amp reservoir cap to the pins.

Last of all, he said that he would not be happy to see
>265VDC carried between the PSU and the amp,
unless they were mechanically joined together, and
the cabling was internal between the two units.


Hope this helps.

Cordially,
Iain

Fuck 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.

I'd use common 8 or 11 (yes there is) pin octal connectors.

--
Message posted using http://www.talkaboutaudio.com/group/rec.audio.tubes/
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"BretLudwig" <bratzirules@gmx.us> wrote in message
news:6889949c0f7376f69fcc9ea26ef19be9@localhost.talkaboutaudio.com...
> Fuck Brussels.

I tend to agree with you, but.....

>
> Do it yourself and who will know?

If the house is damaged by fire, even if it is nothing to
do with the amp, it's a stone cold certainty, as least
in this part of the world that the insurance company
will deem the cover invalid.

And what happens when you start your next DIY
amp? You sell the existing one to that pal of yours
who has been pestering you to let him have it since
day one. If something happens, friendship will count
for nought, he (or his wife) will come after you with
everything they can muster. It doesnät even have to
be anything as serious as a fire, one of the children
may burn him/herself on an exposed power tube.

Safety is not a thing to be taken lightly, Bret.

> Put simply the use of an outboard power supply chassis is the OPTIMUM way
> to achieve the BEST possible performance.

Agreed. My 50 watt stereo amp is built that way.
The psu weighs 40kgs. The noise floor is -106dB

>
> I'd use common 8 or 11 (yes there is) pin octal connectors.

Yes. The 11 pin is a relay base, but the use of octal or 11 pin
plugs and sockets for high voltage DC is strictly forbidden here.
with no exceptions made for modifications. Things may be
different in the US, I don't know.
>

Regards to all
Iain

In article <p6GWj.942$_03.344@reader1.news.saunalahti.fi>,
"Iain Churches" <IainNG@kolumbus.fi> wrote:

> > Put simply the use of an outboard power supply chassis is the OPTIMUM way
> > to achieve the BEST possible performance.
>
> Agreed. My 50 watt stereo amp is built that way.
> The psu weighs 40kgs. The noise floor is -106dB

What is the reference level for that -106 dB noise floor?


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

"John Byrns" <byrnsj@sbcglobal.net> wrote in message
news:byrnsj-BEF3EF.14095914052008@newsclstr03.news.prodigy.net...
> In article <p6GWj.942$_03.344@reader1.news.saunalahti.fi>,
> "Iain Churches" <IainNG@kolumbus.fi> wrote:
>
>> > Put simply the use of an outboard power supply chassis is the OPTIMUM
>> > way
>> > to achieve the BEST possible performance.
>>
>> Agreed. My 50 watt stereo amp is built that way.
>> The psu weighs 40kgs. The noise floor is -106dB
>
> What is the reference level for that -106 dB noise floor?

Full power 50W "A" weighted.
I think that quoting SNR as a ratio is a bit misleading.
I should have written 100µV.

Many people seem to measure SNR ref 1W these days,
which gives a better perspective. An amp with a noise
floor of 1mV has what looks like a fairly respectable
SNR of 86dB ref 50W. But, according to my shirt-cuff
calculations, that's only 69dB ref 1W


Regards
Iain

>> "> Fuck Brussels.

I tend to agree with you, but.....

>
> Do it yourself and who will know?

If the house is damaged by fire, even if it is nothing to
do with the amp, it's a stone cold certainty, as least
in this part of the world that the insurance company
will deem the cover invalid.

And what happens when you start your next DIY
amp? You sell the existing one to that pal of yours
who has been pestering you to let him have it since
day one. If something happens, friendship will count
for nought, he (or his wife) will come after you with
everything they can muster. It doesn�t even have to
be anything as serious as a fire, one of the children
may burn him/herself on an exposed power tube.

Safety is not a thing to be taken lightly, Bret.

> Put simply the use of an outboard power supply chassis is the OPTIMUM
way
> to achieve the BEST possible performance.

Agreed. My 50 watt stereo amp is built that way.
The psu weighs 40kgs. The noise floor is -106dB

>
> I'd use common 8 or 11 (yes there is) pin octal connectors.

Yes. The 11 pin is a relay base, but the use of octal or 11 pin
plugs and sockets for high voltage DC is strictly forbidden here.
with no exceptions made for modifications. Things may be
different in the US, I don't know."<<

You are in-and don't take this personally-a very fucked up country. Mind
you, mine's headed that same goddamned way. The essentially female
mentality, as Dr. Pierce correctly pointed out, which is a healthy thing
inside the home, when allowed to _legislate_ makes the country unlivable
for any self respecting male.

That said...First, I KNOW for a fact that in Australia and New Zealand
both as well as the UK, there are people running vintage Mc and Altec hi
fi with separate factory power supplies as well as numbers of ham radio
operators using Collins, Drake, Yaesu and Heathkit gear with separate
power supplies. If THEY are allowed to get away with it why are YOU not?
Geese and ganders and all that.

There is NOTHING unsafe about high voltage power cords as long as they
are correctly specified and terminated. Long experience has proven that
electrocutions with using and servicing high voltage equipment are almost
invariably from the AC mains and not internal HV. That's even true of
microwave ovens and the old tube oscilloscopes and avionics.

And....NEVER sell working homemade mains powered DIY equipment ever.
Ever. ALWAYS disable it and sell it as parts with no connected AC cord.
If nothing else remove the power transformer and cut the wires off the IEC
connector or fixed cord and terminate the cord with wire nuts or cut it
off. That way the buyer "repairs" it and is now the builder. Why do you
think 80% of new piston aircraft registrations worldwide are Experimental
Amateur Built?

--
Message posted using http://www.talkaboutaudio.com/group/rec.audio.tubes/
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"BretLudwig" <bratzirules@gmx.us> wrote in message
news:00e22eedd5d8dcd17ee932fa1e451f86@localhost.talkaboutaudio.com...
>
>>> "> Fuck Brussels.
>
> You are in-and don't take this personally-a very fucked up country.

Well, actually it's just one country of 25 EU member states, all having
common regulations. As far as electrical safety is concerned, they
make a lot of sense. We still cannot agree however upon a common
mains voltage, or mains connector. The voltage from country to
country ranges from 220V to 230V (most of Western Europe and
Scandinavia) to 240V in the UK. The problem has been resolved
by specifying the mains voltage at 230V -6/+10%

As regards the mains connector, most European countries use thre
Schuko plug type F, or variants thereof. Many of these can be inserted
either way round.

http://en.wikipedia.org/wiki/Schuko

The UK and Ireland have the best plug of all, with a substantial
brass ground pin at the top. This can only be inserted one way,
and has an internal fuse.

http://www.russandrews.com/product-UK-Reference-13A-Mains-plug-1861.htm

>Mind
> you, mine's headed that same goddamned way.

We get the impression that yours is *far* worse:-)

> That said...First, I KNOW for a fact that in Australia and New Zealand
> both as well as the UK, there are people running vintage Mc and Altec hi
> fi with separate factory power supplies as well as numbers of ham radio
> operators using Collins, Drake, Yaesu and Heathkit gear with separate
> power supplies. If THEY are allowed to get away with it why are YOU not?
> Geese and ganders and all that.

Perhaps you misunderstand. The regulations apply to
new equipment, and do not differentiate betweeen
commercial built or DIY. As you say there are a great
number of people still using original amps with octal DC
connectors. One also sees American guitar amps with a
two wire AC feed and "death cap" on a switch, remarkably
often. You may not build and sell such a product any more.
People use old and unsafe equipment at their own risk.

>
> There is NOTHING unsafe about high voltage power cords as long as they
> are correctly specified and terminated. Long experience has proven that
> electrocutions with using and servicing high voltage equipment are almost
> invariably from the AC mains and not internal HV. That's even true of
> microwave ovens and the old tube oscilloscopes and avionics.

You may well be right. But where were you when the
legislation was being drafted? :-) Now we have to
comply with what we have.


> And....NEVER sell working homemade mains powered DIY equipment ever.
> Ever. ALWAYS disable it and sell it as parts with no connected AC cord.
> If nothing else remove the power transformer and cut the wires off the IEC
> connector or fixed cord and terminate the cord with wire nuts or cut it
> off. That way the buyer "repairs" it and is now the builder. Why do you
> think 80% of new piston aircraft registrations worldwide are Experimental
> Amateur Built?

Once again, I am sure you are right, but there are so
many people eager to take over second hand home-built
equipment. Here, you can make a sales receipt on which
the buyer accepts that the unit may not be fault free,safe to
use, or comply with the current safety regulations. He/she also
agrees to have the unit brought up to compliance before use.
This is done to protect those who restore old radios, etc.

Iain

"BretLudwig" <bratzirules@gmx.us> wrote in message
news:6889949c0f7376f69fcc9ea26ef19be9@localhost.talkaboutaudio.com...
> Fuck 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.

Trevor Wilson

Trevor Wilson wrote:

>>
>> 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.

A remote PS definitely has the advantage of isolating the
amp from the vibration of the power transformer, and
vibration is definitely a bad thing for valve amps. It also
definitely an easy way of decoupling the magnetic fields of
the output and power transformers.

In most cases you would surely need a long cable before the
PS caps became significantly estranged from the demands of
an audio amp? A small cap in the amp itself would make up
for the distance I think.

But perhaps you had another issue in mind?

Also, transferring the filter caps to the amp would mean
that both plug and socket would be live at the time of
parting. I have seen it said that a diode in the amp solves
this problem, but I wouldn't entrust my life to that
solution.

Ian

"Ian Iveson" <IanIveson.home@blueyonder.co.uk> wrote in message
news:crMWj.5272$1q4.981@newsfe23.ams2...
> Trevor Wilson wrote:
>
>>>
>>> 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.
>
> A remote PS definitely has the advantage of isolating the amp from the
> vibration of the power transformer, and vibration is definitely a bad
> thing for valve amps. It also definitely an easy way of decoupling the
> magnetic fields of the output and power transformers.

**You may care to note that I said that transferring *AC* Voltages was
acceptable. It is the transfer of high Voltage DC (at substantial current)
where problems can arise.

>
> In most cases you would surely need a long cable before the PS caps became
> significantly estranged from the demands of an audio amp? A small cap in
> the amp itself would make up for the distance I think.

**Depends what you mean by "small", but yes, capacitance in the amplifier is
essential when using remote power supplies.

>
> But perhaps you had another issue in mind?

**Plugging and unplugging high Voltage DC connectors is a dangerous thing.
AC is not a problem.

>
> Also, transferring the filter caps to the amp would mean that both plug
> and socket would be live at the time of parting. I have seen it said that
> a diode in the amp solves this problem, but I wouldn't entrust my life to
> that solution.

**I would not entrust any easily available connector to high Voltage DC.

Trevor Wilson

"Ian Iveson" <IanIveson.home@blueyonder.co.uk> wrote in message
news:crMWj.5272$1q4.981@newsfe23.ams2...
> Trevor Wilson wrote:
>
>>>

> Also, transferring the filter caps to the amp would mean that both plug
> and socket would be live at the time of parting. I have seen it said that
> a diode in the amp solves this problem, but I wouldn't entrust my life to
> that solution.

You have to use a method (something like a sensing loop
with a relay) to shut of the DC from the connectors if the
cable is disconnected at either end. If a round connector
is chosen, it must be one one with a deep screw collar or
bayonet latch, so there is no access to the pins while the
connector is still making contact. That is why an octal plug
socket cannot be used, although Patrick seems to have
found an innovative way to make that combination safe.

Common sense would dictate the fitting and removal of
the DC umbilical only when the amplifier and PSU have
bveen switched off for some time.

A power diode, as an additional safety measure works
well. These are well-proven techniques from rack-mounted
broadcast equipment in the tube era. But it is also important
to comply with modern safety standards.

Iain

Iain Churches wrote
>
>> Also, transferring the filter caps to the amp would mean
>> that both plug
>> and socket would be live at the time of parting. I have
>> seen it said that
>> a diode in the amp solves this problem, but I wouldn't
>> entrust my life to
>> that solution.
>
> You have to use a method (something like a sensing loop
> with a relay) to shut of the DC from the connectors if the
> cable is disconnected at either end. If a round connector
> is chosen, it must be one one with a deep screw collar or
> bayonet latch, so there is no access to the pins while the
> connector is still making contact. That is why an octal
> plug
> socket cannot be used, although Patrick seems to have
> found an innovative way to make that combination safe.

Not safe enough to be legal here. Innovation and safety
don't mix well, but to his credit I don't think Patrick was
trying to be inventive. He's done the best he can do under
the circumstances, probably. I wasn't keen on the detail
that the HT dies away within 10 secs IIRC. How long do
electrocutions take? When is the most likely time a
connection might be touched?

> Common sense would dictate the fitting and removal of
> the DC umbilical only when the amplifier and PSU have
> bveen switched off for some time.

Empty words, I'm afraid. 600V means very little to common
sense, which anyway these days assumes that all electrical
gizmos are fool-proof.

> A power diode, as an additional safety measure works
> well.

Additional? Works well? How well? How do you know? If the
diode on its own isn't safe enough, and if the device isn't
safe enough without the diode, then how does adding two
unsafe things result in safety? You would need to know the
two probabilities of electrocution, and whether they are
independent, before calculating whether the resulting
smaller probability falls below some threshold.

Except for an inadequate cord clamp at one end, my umbilical
cords have everything everyone has suggested. I won't pass
them on to anyone else, no matter how much common sense they
seem to have.

> These are well-proven techniques from rack-mounted
> broadcast equipment in the tube era.
Ah, those were the days. Remember Les Harvey?

http://en.wikipedia.org/wiki/Leslie_Harvey

> But it is also important
> to comply with modern safety standards.

Which AFAIK mean that an amp with an umbilical cord can
never legally change hands in the UK.

cheers, Ian

"Ian Iveson" bizarrely demands to know:

> How long do electrocutions take?

> cheers, Ian

The official kind is legally regulated. It may be IIRC (1) that the
power is required to be on for five minutes at 5000V and 2A; that's
anyway what I recall for Mississippi -- perhaps these are State laws
rather than Federal. Try Google. (Or ask your pal Ludwig -- he's bound
to relate such details with lipsmacking relish.)

Why have you gone over to the Dark Sida, Ian?

Andre Jute

(1) I only know because I am a novelist --
http://members.lycos.co.uk/fiultra/THE%20WRITER'S%20HOUSE.html -- but
it's a long time since I needed to know. Stephen King once asked the
local doctor, "How do you go about strangling a cat," and was
ostracized in his small town for his curiosity.

On May 16, 2:04 pm, Andre Jute <fiult...@yahoo.com> wrote:
> "Ian Iveson"  bizarrely demands to know:
>
> > How long do electrocutions take?
> > cheers, Ian
>
> The official kind is legally regulated. It may be IIRC (1) that the
> power is required to be on for five minutes at 5000V and 2A; that's
> anyway what I recall for Mississippi -- perhaps these are State laws
> rather than Federal.

Do you just make this stuff up, or do you actually believe yourself?
You certainly opine at whim and without facts.

http://www.angelfire.com/fl3/starke/electricity.html

2640 volts ac should be applied in two (2) jolts of one (1) minute
each, spaced at a ten (10) second interval. On occasion, the subjects
heart will spasm, instead of seizing, during the first application of
current and the application of the second jolt will generally
eliminate this problem. This spasm is due to excessive chemical build-
up (acetylcholine and sympathin) at the nerve junctions and the ten
(10) second wait generally allows for dissipation of the chemicals.

Mississippi has not had electrocution as a legal method in many years
(since 1954). Prior to the present approved method of lethal
injection, they used the gas chamber.

The Feds use lethal injection, but Federal Judges may send condemned
criminals to states with other means. Military tribunals may require a
firing squad - an actual option for several states as well.

Peter Wieck
Melrose Park, PA