"Dave Plowman (Nutcase ****head )

Can anyone explain the Quad 405 internal grounding?

** Not to a raving pommy **** like you.


On all, the 'power' ground is via the heatsink to chassis.

** Basic electrical safety required by law in most countries for non class
II electrical items with user accessible metalwork.


On the DIN input ones, the 'signal' is grounded to chassis at the DIN
socket.

** Safety ground for the Quad 33 pre amp and FM3 tuner which have none of
their own.


With the board removed, there is 10 ohms between signal to power ground -
as expected due to R2.

** Ground loop breaker.


On late 405-2 with phono connectors, the phonos are isolated from the
chassis.

** Most pre amps and tuners with phono output are either safety grounded or
class II.


On the early amp with nothing connected, DC at the output is about 2 mV.
On the phono version, 25 or so.

** DC to chassis or DC to speaker ground ?

I'm guessing it's to do with early amps not having a mains ground ....

** You just posted that they ALL did.

**** off - you stinking, pommy, autistic retard.



..... Phil

In article ,
Phil Allison wrote:

"Dave Plowman (Nutcase ****head )

Can anyone explain the Quad 405 internal grounding?

** Not to a raving pommy **** like you.

Still off the meds?


On all, the 'power' ground is via the heatsink to chassis.

** Basic electrical safety required by law in most countries for non class
II electrical items with user accessible metalwork.

You're a fool That is a mains ground. By using 'power' I thought most
would understand I'm talking about the PS ground.


On the DIN input ones, the 'signal' is grounded to chassis at the DIN
socket.

** Safety ground for the Quad 33 pre amp and FM3 tuner which have none of
their own.

More Phil********. On the 33, the mains input ground pin is connected to
chassis. I'd guess the same on the FM tuner. The mains *outputs* on the 33
are two pin. So if you connect a 405 to a 33 using the supplied mains lead
there is no ground connection. The signal DIN cable provides that.


With the board removed, there is 10 ohms between signal to power
ground - as expected due to R2.

** Ground loop breaker.


On late 405-2 with phono connectors, the phonos are isolated from the
chassis.

** Most pre amps and tuners with phono output are either safety grounded
or class II.


On the early amp with nothing connected, DC at the output is about 2
mV. On the phono version, 25 or so.

** DC to chassis or DC to speaker ground ?

Are you really that thick? On the 405, they are the same. The speaker
grounds go to the same place as the PS ground, bolted to the chassis. The
mains ground is also bolted to the chassis a few inches away.

I'm guessing it's to do with early amps not having a mains ground ....

** You just posted that they ALL did.

Make that 'when used as part of a Quad installation' then.

**** off - you stinking, pommy, autistic retard.

Why do you bother replying when it's obvious you know nothing about it?
And you claim to be a Quad expert. Gawd save us.





--
*The older you get, the better you realize you were.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (Nutcase ****head )

Can anyone explain the Quad 405 internal grounding?

** Not to a raving pommy **** like you.


On all, the 'power' ground is via the heatsink to chassis.

** Basic electrical safety required by law in most countries for non
class
II electrical items with user accessible metalwork.

That is a mains ground.


** Yes - and YOU made no distinction

By using 'power' I thought ...


** You are an autistic retard with NO ability to think.



On the DIN input ones, the 'signal' is grounded to chassis at the DIN
socket.

** Safety ground for the Quad 33 pre amp and FM3 tuner which have none of
their own.

More Phil********. On the 33, the mains input ground pin is connected to
chassis.

** The supplied AC leads are only 2 wire here in Aussieland.

I do not own a 405, 33 or FM3 and do not live in the UK.


With the board removed, there is 10 ohms between signal to power
ground - as expected due to R2.

** Ground loop breaker.


On late 405-2 with phono connectors, the phonos are isolated from the
chassis.

** Most pre amps and tuners with phono output are either safety grounded
or class II.


On the early amp with nothing connected, DC at the output is about 2
mV. On the phono version, 25 or so.

** DC to chassis or DC to speaker ground ?

Are you really that thick? On the 405, they are the same.


** I do not own a 405, 33 or FM3 and do not live in the UK.

Last time a saw any of them on the bench was over 10 years ago.


I'm guessing it's to do with early amps not having a mains ground ....

** You just posted that they ALL did.

Make that 'when used as part of a Quad installation' then.


** All 405s have a 3 pin IEC mains inlet, so are safety grounded.

I have never come across anyone so ****ing stupid as to interfere with this
here in Australia.

Only pommy ****S like you do **** like that.

**** off and DIE - you stinking, pommy, autistic retard.

In article ,
Phil Allison wrote:
"Dave Plowman (Nutcase ****head )

Can anyone explain the Quad 405 internal grounding?

** Not to a raving pommy **** like you.


On all, the 'power' ground is via the heatsink to chassis.

** Basic electrical safety required by law in most countries for non
class
II electrical items with user accessible metalwork.

That is a mains ground.


** Yes - and YOU made no distinction

By using 'power' I thought ...

You didn't think before jumping in with your usual insults. In the UK one
talks about mains rather than power. And besides, it should have been
obvious if you had a brain cell still working.


** You are an autistic retard with NO ability to think.



On the DIN input ones, the 'signal' is grounded to chassis at the
DIN socket.

** Safety ground for the Quad 33 pre amp and FM3 tuner which have
none of their own.

More Phil********. On the 33, the mains input ground pin is connected
to chassis.

** The supplied AC leads are only 2 wire here in Aussieland.

I do not own a 405, 33 or FM3 and do not live in the UK.

If I wanted to know about OZ mains I'd ask in an Oz group. ;-)

But I'll bet your wrong. With the 33/303 or 33/405. the preamp was earthed
via the mains lead. The mains to the amp came from the 2 pin switched
outlet on the 33. It *only* got its mains earth via the signal cable. Same
with the FM tuner. But they all have a three pin mains inlet, so can be
used 'stand alone' with a three pin mains lead, and still be earthed.

My guess is using a DIN connector to provide a safety earth would not pass
regs these days.


With the board removed, there is 10 ohms between signal to power
ground - as expected due to R2.

** Ground loop breaker.


On late 405-2 with phono connectors, the phonos are isolated from
the chassis.

** Most pre amps and tuners with phono output are either safety
grounded or class II.


On the early amp with nothing connected, DC at the output is about
2 mV. On the phono version, 25 or so.

** DC to chassis or DC to speaker ground ?

Are you really that thick? On the 405, they are the same.


** I do not own a 405, 33 or FM3 and do not live in the UK.

Last time a saw any of them on the bench was over 10 years ago.

And you didn't look closely at it even then...

I'm guessing it's to do with early amps not having a mains ground
....

** You just posted that they ALL did.

Make that 'when used as part of a Quad installation' then.


** All 405s have a 3 pin IEC mains inlet, so are safety grounded.

The earlier 303 also had a three pin mains inlet. But like the 405 was fed
with a two pin lead on a Quad setup to prevent a ground loop.

I have never come across anyone so ****ing stupid as to interfere with
this here in Australia.

Not surprising if they're all as thick as you.

--
*Plagiarism saves time *

Dave Plowman London SW
To e-mail, change noise into sound.

IIRC the shield on a DIN connector was always intended to be the chassis
connection, with pin 2 optionally being an isolated signal ground. Quad
were rather naughty when they connected pin 2 to chassis in the 303.
Keeping it separate would have allowed more flexible connection without
introducing hum loops. Linking the shield to pin 2 is fine for low level
inputs, but it shouldn't be done when linking to other equipment.

Modern electrical safety earthing might allow the 303 to be powered from
the 33 as the mains transformer appears to include an earthed shield
which would isolate the secondary from the primary. That would make it a
Class II (double-insulated) appliance. Of course, the shield would have
to be capable of carrying any fault current from the mains until the fuse
blows. Also, all mains leads (& probably internal mains wiring) would
need an outer sheath to provide double insulation.

"mick"

Modern electrical safety earthing might allow the 303 to be powered from
the 33 as the mains transformer appears to include an earthed shield
which would isolate the secondary from the primary.

** That is an electrostatic shield - it helps to eliminate mains noise.

That would make it a Class II (double-insulated) appliance.

** Absurd crap !!!

The basic principle of class II is *NOT* to rely on the mains earth for
user safety.

Two reasons:

1. If the mains earth connection is missing anywhere, the equipment still
operates ( with no warning to the user) and you have no safety.

2. If the AC outlet or equipment plug is miswired, active can appear on the
earth conductor and you have a lethal situation.

A very nasty example of scenario "2" occurs when the equipment plug has
earth and neutral wires reversed - which goes unnoticed until the day it is
plugged into an outlet that has active and neutral reversed.



..... Phil

In article ,
Phil Allison wrote:
A very nasty example of scenario "2" occurs when the equipment plug has
earth and neutral wires reversed - which goes unnoticed until the day it is
plugged into an outlet that has active and neutral reversed.


Crikey. Have you never heard of RCDs in OZ? I sort of guessed it was third
world - but not that bad.

--
*Aim Low, Reach Your Goals, Avoid Disappointment *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 02 Aug 2014 11:24:57 +1000, Phil Allison wrote:

"mick"

That would make it a Class II (double-insulated) appliance.

** Absurd crap !!!



Ah... yes... That screen couldn't make it Class II could it? It would
need to be earthed. lol I missed that one!

I take that back, the Quad 303 definitely requires a mains earth to the
metalwork in order to comply with current UK regs. It can't rely on the
input connector as that can be unplugged while leaving the mains supply
connected. That makes it even more sensible not to connect signal earth
directly to chassis in the 303.


The basic principle of Class II is *NOT* to rely on the mains earth for
user safety.

Two reasons:

1. If the mains earth connection is missing anywhere, the equipment
still operates ( with no warning to the user) and you have no safety.

2. If the AC outlet or equipment plug is miswired, active can appear on
the earth conductor and you have a lethal situation.



The principle of Class II is that there is NO REQUIREMENT to rely on
earthing for user protection at all, as all mains-carrying wiring is
double-insulated away from the user side. Note that phone chargers etc
are virtually all Class II. In the UK these have a dummy plastic earth
pin which is only used to open the live & neutral shutters on the socket.

The mains output sockets on the 33 almost certainly wouldn't be legal now
anyway. Getting live and neutral right way round is a 50/50 guess.


A very nasty example of scenario "2" occurs when the equipment plug has
earth and neutral wires reversed - which goes unnoticed until the day it
is plugged into an outlet that has active and neutral reversed.


Agreed. It's only relatively recently that domestic wiring in the UK has
been using earth-leakage protection. Older installations (including my
own!) don't have it - in fact, I'm still on rewirable fuses here!
Consequently we tend to be careful about wiring plugs & sockets up
correctly. Even when properties are being refurbished over here, there
is no legal requirement to change any existing distribution boards etc.
unless they are damaged. Consequently there are a lot of houses in the
same condition as mine.

I have a Rogers Cadet here, and the mains through connectors are lethal. I
don't know how they got away with them at the time.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"mick" wrote in message
eb.com...
IIRC the shield on a DIN connector was always intended to be the chassis
connection, with pin 2 optionally being an isolated signal ground. Quad
were rather naughty when they connected pin 2 to chassis in the 303.
Keeping it separate would have allowed more flexible connection without
introducing hum loops. Linking the shield to pin 2 is fine for low level
inputs, but it shouldn't be done when linking to other equipment.

Modern electrical safety earthing might allow the 303 to be powered from
the 33 as the mains transformer appears to include an earthed shield
which would isolate the secondary from the primary. That would make it a
Class II (double-insulated) appliance. Of course, the shield would have
to be capable of carrying any fault current from the mains until the fuse
blows. Also, all mains leads (& probably internal mains wiring) would
need an outer sheath to provide double insulation.

In article , Brian Gaff
wrote:
I have a Rogers Cadet here, and the mains through connectors are lethal.
I don't know how they got away with them at the time. Brian

Back then there was a tendency to assume people buying serious hifi kit
would have a clue about such matters. Particularly when many units could be
bought without any case, thus exposing high voltages (in safety terms). The
makers assumed the buyer was an adult who would take responsibility to
deploying and using safely.

It was also common for either the pre or power amp to be mains powered
from the other via an 'umbilical' of some kind. Also why then it was common
to include circuit diagrams, etc.

Different world.

Jim

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