Maybe a question for Jim, as I remember him mentioning speccing them for
Armstrong.

100 watt per channel amp. Space not a problem.

Single pole preferred. (it's a triple amp, not stereo - and three pole
might be more of a problem sourcing at an economic price)

Best relay with low power consumption coil?

Easy enough to just pick one from a supplier's stock, but hoped someone
could advise on the ideal.

--
*Where do forest rangers go to "get away from it all?"

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

Dave Plowman (Rabit Nutter) wrote:
=======================================
>
> Maybe a question for Jim, as I remember him mentioning speccing them for
> Armstrong.

** Errr - wot would that fool know ?

>
> 100 watt per channel amp. Space not a problem.
>

** Operation here on Earth is essential.

> Best relay with low power consumption coil?

** What DC voltage?
But most importantly WHAT exactly do you expect the damn relay to do ??

Be forewarned, you have picked on one my hottest topics.
One most amp designers get WRONG !

....... Phil

In article <6a36030f-b14f-4076-aeed-28425dffeaeen@googlegroups.com>,
Phil Allison <pallison49@gmail.com> wrote:
> Dave Plowman (Rabit Nutter) wrote:
> =======================================
> >
> > Maybe a question for Jim, as I remember him mentioning speccing them for
> > Armstrong.

> ** Errr - wot would that fool know ?

> >
> > 100 watt per channel amp. Space not a problem.
> >

> ** Operation here on Earth is essential.

> > Best relay with low power consumption coil?

> ** What DC voltage?
> But most importantly WHAT exactly do you expect the damn relay to do ??

> Be forewarned, you have picked on one my hottest topics.
> One most amp designers get WRONG !

Go on, then. Give me the benefit of your wisdom. Operating voltage doesn't
matter as I'll likely use a dedicated supply. But I'd guess 12v gives the
biggest choice.

--
*You are validating my inherent mistrust of strangers

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

In article <597930b111dave@davenoise.co.uk>,
Dave Plowman (News) <dave@davenoise.co.uk> wrote:

> Maybe a question for Jim, as I remember him mentioning speccing them for
> Armstrong.

> 100 watt per channel amp. Space not a problem.

> Single pole preferred. (it's a triple amp, not stereo - and three
> pole might be more of a problem sourcing at an economic price)

> Best relay with low power consumption coil?

> Easy enough to just pick one from a supplier's stock, but hoped
> someone could advise on the ideal.

Best? I don't know. I can tell you that the Arcam P7 uses these...
https://uk.farnell.com/omron/g2r-1-e-24dc/relay-spdt-250vac-30vdc-16a/dp/9949429?ost=994-9429

https://uk.rs-online.com/web/p/non-latching-relays/0366300/

24Volt though and good for around 10+ years before you get some
distortion due to poor contact connection.

Changed all 7 of mine last year but the amp was from 2004.

Bob.

On Sun, 10 Oct 2021 14:51:56 +0100, "Dave Plowman (News)"
<dave@davenoise.co.uk> wrote:

>In article <6a36030f-b14f-4076-aeed-28425dffeaeen@googlegroups.com>,
> Phil Allison <pallison49@gmail.com> wrote:
>> Dave Plowman (Rabit Nutter) wrote:
>> =======================================
>> >
>> > Maybe a question for Jim, as I remember him mentioning speccing them for
>> > Armstrong.
>
>> ** Errr - wot would that fool know ?
>
>> >
>> > 100 watt per channel amp. Space not a problem.
>> >
>
>> ** Operation here on Earth is essential.
>
>> > Best relay with low power consumption coil?
>
>> ** What DC voltage?
>> But most importantly WHAT exactly do you expect the damn relay to do ??
>
>> Be forewarned, you have picked on one my hottest topics.
>> One most amp designers get WRONG !
>
>Go on, then. Give me the benefit of your wisdom. Operating voltage doesn't
>matter as I'll likely use a dedicated supply. But I'd guess 12v gives the
>biggest choice.

If you want a relay that will handle real power with very little loss,
go to a car spares place and get the ones they use for car headlights.

d

--
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https://www.avast.com/antivirus

On Sun 10/10/2021 12:13, Dave Plowman (News) wrote:
> Maybe a question for Jim, as I remember him mentioning speccing them for
> Armstrong.
>
> 100 watt per channel amp. Space not a problem.
>
> Single pole preferred. (it's a triple amp, not stereo - and three pole
> might be more of a problem sourcing at an economic price)
>
> Best relay with low power consumption coil?
>
> Easy enough to just pick one from a supplier's stock, but hoped someone
> could advise on the ideal.
>

cpc.farnell.com

3PCO 12VDC 10A contact rating 11-pin Octal SW02499 + socket SW02501
2PNO 12VDC 30A contact rating chassis mount by lugs SW04023

On Sun, 10 Oct 2021 16:17:38 +0100, Woody <harrogate3@ntlworld.com>
wrote:

>On Sun 10/10/2021 12:13, Dave Plowman (News) wrote:
>> Maybe a question for Jim, as I remember him mentioning speccing them for
>> Armstrong.
>>
>> 100 watt per channel amp. Space not a problem.
>>
>> Single pole preferred. (it's a triple amp, not stereo - and three pole
>> might be more of a problem sourcing at an economic price)
>>
>> Best relay with low power consumption coil?
>>
>> Easy enough to just pick one from a supplier's stock, but hoped someone
>> could advise on the ideal.
>>
>
>cpc.farnell.com
>
>3PCO 12VDC 10A contact rating 11-pin Octal SW02499 + socket SW02501
>2PNO 12VDC 30A contact rating chassis mount by lugs SW04023

Halfords

https://www.halfords.com/tools/fuses-electricals-and-fixings/electricals/halfords-hef554-relay-12v-30amp-4-pin-184013.html

d

--
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On 11/10/2021 12:51 am, Dave Plowman (News) wrote:
> In article <6a36030f-b14f-4076-aeed-28425dffeaeen@googlegroups.com>,
> Phil Allison <pallison49@gmail.com> wrote:
>> Dave Plowman (Rabit Nutter) wrote:
>> =======================================
>>>
>>> Maybe a question for Jim, as I remember him mentioning speccing them for
>>> Armstrong.
>
>> ** Errr - wot would that fool know ?
>
>>>
>>> 100 watt per channel amp. Space not a problem.
>>>
>
>> ** Operation here on Earth is essential.
>
>>> Best relay with low power consumption coil?
>
>> ** What DC voltage?
>> But most importantly WHAT exactly do you expect the damn relay to do ??
>
>> Be forewarned, you have picked on one my hottest topics.
>> One most amp designers get WRONG !
>
> Go on, then. Give me the benefit of your wisdom. Operating voltage doesn't
> matter as I'll likely use a dedicated supply. But I'd guess 12v gives the
> biggest choice.
>

**I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
the output stage fail, there is a good chance that 45 Volts will applied
to the relay contacts. Since all commonly available relays are rated to
break no more than 27 Volts DC, an arc will be set-up, which will,
eventually, weld contacts together, allowing the full rail Volts to be
applied to the speaker. I've seen this occur many, many times. Using a
changeover relay, where the unused contacts are earthed may be helpful.
Or not. If the relay is only required for muting during power-up, then
anything from Farnell will do. There are fancy high(er) DC Voltage rated
relays available, but they are hideously expensive. The best option is
use the relay to shut off the AC and hope that there is insufficient
energy in the filter caps to damage the speaker/s.

Trevor Wilson wrote:
================
>
> >
> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
> the output stage fail, there is a good chance that 45 Volts will applied
> to the relay contacts. Since all commonly available relays are rated to
> break no more than 27 Volts DC, an arc will be set-up, which will,
> eventually, weld contacts together, allowing the full rail Volts to be
> applied to the speaker. I've seen this occur many, many times. Using a
> changeover relay, where the unused contacts are earthed may be helpful.
> Or not. If the relay is only required for muting during power-up, then
> anything from Farnell will do. There are fancy high(er) DC Voltage rated
> relays available, but they are hideously expensive. The best option is
> use the relay to shut off the AC and hope that there is insufficient
> energy in the filter caps to damage the speaker/s.
>

** Only seen one amp that does that - the Crown PAS2 "Self Analysing" amp.

The AC supply relay was independently powered and reacted to any of the following.

1. DC voltage of either polarity at the output of greater than 20V.
2. Continuous high frequency output of 20V rms at or above 20kHz.
3. Large sub-sonic output below 20 Hz.

This amp was strictly for pro audio use, where very high powered speakers would be the only loads.
Many hi-fi speakers are relatively fragile.

....... Phil

On 11/10/2021 9:47 am, Phil Allison wrote:
> Trevor Wilson wrote:
> ================
>>
>>>
>> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
>> amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
>> the output stage fail, there is a good chance that 45 Volts will applied
>> to the relay contacts. Since all commonly available relays are rated to
>> break no more than 27 Volts DC, an arc will be set-up, which will,
>> eventually, weld contacts together, allowing the full rail Volts to be
>> applied to the speaker. I've seen this occur many, many times. Using a
>> changeover relay, where the unused contacts are earthed may be helpful.
>> Or not. If the relay is only required for muting during power-up, then
>> anything from Farnell will do. There are fancy high(er) DC Voltage rated
>> relays available, but they are hideously expensive. The best option is
>> use the relay to shut off the AC and hope that there is insufficient
>> energy in the filter caps to damage the speaker/s.
>>
>
> ** Only seen one amp that does that - the Crown PAS2 "Self Analysing" amp.
>
> The AC supply relay was independently powered and reacted to any of the following.
>
> 1. DC voltage of either polarity at the output of greater than 20V.
> 2. Continuous high frequency output of 20V rms at or above 20kHz.
> 3. Large sub-sonic output below 20 Hz.
>
> This amp was strictly for pro audio use, where very high powered speakers would be the only loads.
> Many hi-fi speakers are relatively fragile.
>

**Every ME power amp ever made has the following:

* A relay driven TRIAC to switch mains supply on and off.
* Two (or three) thermal sensors to shut mains power off, if temps
exceed a preset level.
* Mains AC is also disconnected if any of the following conditions are met:
* A DC Voltage of more than 2 Volts on either output stage.
* Excessive LF signal present (around 10 VRMS @ 10Hz, 1VRMS at 1Hz)
* Excessive HF signal present (around 5VRMS @ 10kHz, 2VMS @ 20kHz)
* Mains leakage. I am uncertain of what level, but not much.

All ME amps have used such systems since 1977. Speaker damage is an
extremely rare event.

On Monday, October 11, 2021 at 3:19:43 PM UTC+11, Trevor Wilson wrote:
> On 11/10/2021 9:47 am, Phil Allison wrote:
> > Trevor Wilson wrote:
> > ================
> >>
> >>>
> >> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> >> amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
> >> the output stage fail, there is a good chance that 45 Volts will applied
> >> to the relay contacts. Since all commonly available relays are rated to
> >> break no more than 27 Volts DC, an arc will be set-up, which will,
> >> eventually, weld contacts together, allowing the full rail Volts to be
> >> applied to the speaker. I've seen this occur many, many times. Using a
> >> changeover relay, where the unused contacts are earthed may be helpful.
> >> Or not. If the relay is only required for muting during power-up, then
> >> anything from Farnell will do. There are fancy high(er) DC Voltage rated
> >> relays available, but they are hideously expensive. The best option is
> >> use the relay to shut off the AC and hope that there is insufficient
> >> energy in the filter caps to damage the speaker/s.
> >>
> >
> > ** Only seen one amp that does that - the Crown PSA2 "Self Analysing" amp.
> >
> > The AC supply relay was independently powered and reacted to any of the following.
> >
> > 1. DC voltage of either polarity at the output of greater than 20V.
> > 2. Continuous high frequency output of 20V rms at or above 20kHz.
> > 3. Large sub-sonic output below 20 Hz.
> >
> > This amp was strictly for pro audio use, where very high powered speakers would be the only loads.
> > Many hi-fi speakers are relatively fragile.
> >
> **Every ME power amp ever made has the following:
>
-------------------------------------------------------------------------

** FYI to all:

ME brand amps are *secret* devices, TW is or was an agent for them for decades.
No schems are published.
Owners are warned to refer all service to ME.

So no surprise I have never seen one cos nobody has.
And TW can say anything he likes about them.

But I know they use a very large cap banks in the PSU,
which must dump fully into the attached woofer VC in case of DC offset faults.
A feature is they have no VI current limiting - so the unprotected BJT output
stage is vulnerable to user accidents and driver burn outs.

But TW thinks they are " magic" .

....... Phil

On 11/10/2021 3:37 pm, Phil Allison wrote:
> On Monday, October 11, 2021 at 3:19:43 PM UTC+11, Trevor Wilson wrote:
>> On 11/10/2021 9:47 am, Phil Allison wrote:
>>> Trevor Wilson wrote:
>>> ================
>>>>
>>>>>
>>>> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
>>>> amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
>>>> the output stage fail, there is a good chance that 45 Volts will applied
>>>> to the relay contacts. Since all commonly available relays are rated to
>>>> break no more than 27 Volts DC, an arc will be set-up, which will,
>>>> eventually, weld contacts together, allowing the full rail Volts to be
>>>> applied to the speaker. I've seen this occur many, many times. Using a
>>>> changeover relay, where the unused contacts are earthed may be helpful.
>>>> Or not. If the relay is only required for muting during power-up, then
>>>> anything from Farnell will do. There are fancy high(er) DC Voltage rated
>>>> relays available, but they are hideously expensive. The best option is
>>>> use the relay to shut off the AC and hope that there is insufficient
>>>> energy in the filter caps to damage the speaker/s.
>>>>
>>>
>>> ** Only seen one amp that does that - the Crown PSA2 "Self Analysing" amp.
>>>
>>> The AC supply relay was independently powered and reacted to any of the following.
>>>
>>> 1. DC voltage of either polarity at the output of greater than 20V.
>>> 2. Continuous high frequency output of 20V rms at or above 20kHz.
>>> 3. Large sub-sonic output below 20 Hz.
>>>
>>> This amp was strictly for pro audio use, where very high powered speakers would be the only loads.
>>> Many hi-fi speakers are relatively fragile.
>>>
>> **Every ME power amp ever made has the following:
>>
> -------------------------------------------------------------------------
>
> ** FYI to all:
>
> ME brand amps are *secret* devices, TW is or was an agent for them for decades.
> No schems are published.

**Incorrect.

> Owners are warned to refer all service to ME.

**Indeed they are. ALL outputs, drivers, pre-drivers and front end
transistors are matched to within 1% for hFE and Vbe. It is impossible
for a regular service person to match sufficient devices to properly
repair an output stage. Use of unmatched devices compromises performance
and reliability.

>
> So no surprise I have never seen one cos nobody has.

**Nonsense.

> And TW can say anything he likes about them.

**Sure. Would you like to hear one? I can send one over for you to
audition. I fully expect that this action will not result in a sale. I
can get Tony to deliver one anytime.

>
> But I know they use a very large cap banks in the PSU,
> which must dump fully into the attached woofer VC in case of DC offset faults.

**Yep. Fortunately, such damage is extremely rare.

> A feature is they have no VI current limiting - so the unprotected BJT output
> stage is vulnerable to user accidents and driver burn outs.

**Untrue. Very early model ME amps used no VI limiters. When a couple
failed, Peter Stein began installing VI limiting in all models
(including retro-fitting to previously released amps). A feature that
exists in all ME amps.

>
> But TW thinks they are " magic" .

**Absolutely not. Absolutely stable, regardless of load. No output
inductor, so a resistive output impedance, prodigious current ability,
etc, etc. Demand sensitive fan cooling. Cool air is drawn through the
main filter capacitor banks. Electros last a very long time (decades).
They are simply logically designed. Not only do they do exactly what is
promised by the manufacturer, but can be 'field serviced' quickly and
easily. Something that was designed in from day one. One or both output
stages can be removed and replaced in around 45 minutes (for the largest
model). Less for smaller amps. No de-soldering required. Contrast that
with an equivalent Mark Levinson I did last year: 14 hours to remove
both output stages. Same again to replacement. LOTS of de-soldering
required.

No magic. Just logical design.

And, don't forget the protection systems. Very well thought out.

Trevor Wilson wrote:

===================

> >>>>
> >>>>>
> >>>> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> >>>> amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
> >>>> the output stage fail, there is a good chance that 45 Volts will applied
> >>>> to the relay contacts. Since all commonly available relays are rated to
> >>>> break no more than 27 Volts DC, an arc will be set-up, which will,
> >>>> eventually, weld contacts together, allowing the full rail Volts to be
> >>>> applied to the speaker. I've seen this occur many, many times. Using a
> >>>> changeover relay, where the unused contacts are earthed may be helpful.
> >>>> Or not. If the relay is only required for muting during power-up, then
> >>>> anything from Farnell will do. There are fancy high(er) DC Voltage rated
> >>>> relays available, but they are hideously expensive. The best option is
> >>>> use the relay to shut off the AC and hope that there is insufficient
> >>>> energy in the filter caps to damage the speaker/s.
> >>>>
> >>>
> >>> ** Only seen one amp that does that - the Crown PSA2 "Self Analysing" amp.
> >>>
> >>> The AC supply relay was independently powered and reacted to any of the following.
> >>>
> >>> 1. DC voltage of either polarity at the output of greater than 20V.
> >>> 2. Continuous high frequency output of 20V rms at or above 20kHz.
> >>> 3. Large sub-sonic output below 20 Hz.
> >>>
> >>> This amp was strictly for pro audio use, where very high powered speakers would be the only loads.
> >>> Many hi-fi speakers are relatively fragile.
> >>>
> >> **Every ME power amp ever made has the following:
> >>
> > -------------------------------------------------------------------------
> >
> > ** FYI to all:
> >
> > ME brand amps are *secret* devices, TW is or was an agent for them for decades.
> > No schems are published.

> **Incorrect.

** Links ?

> > Owners are warned to refer all service to ME.
> **Indeed they are.

** Service monopoly is soon gonna be illegal.

>
> > So no surprise I have never seen one cos nobody has.
> **Nonsense.

** Its a figure of speech Trev - not literal.

> > And TW can say anything he likes about them.

> **Sure.

** So it is not common knowledge among techs.

Would you like to hear one?

** ROTFL !!

> > But I know they use a very large cap banks in the PSU,
> > which must dump fully into the attached woofer VC in case of DC offset faults.

> **Yep.

** Bad idea.

> > A feature is they have no VI current limiting - so the unprotected BJT output
> > stage is vulnerable to user accidents and driver burn outs.

> **Untrue. Very early model ME amps used no VI limiters. When a couple
> failed, Peter Stein began installing VI limiting in all models
> (including retro-fitting to previously released amps). A feature that
> exists in all ME amps.

** TW can say anything he likes .....

> >
> > But TW thinks they are " magic" .

> **Absolutely not.

** So they are crap then ?

> They are simply logically designed. Not only do they do exactly what is
> promised by the manufacturer,

** Same all all other hi-fi amps.

> but can be 'field serviced' quickly and easily.

** But only by the anointed ones, at giant cost.,

TW goes on to say that other "snake oil" amps are worse.
Maybe true.

....... Phil

On 11/10/2021 4:12 pm, Phil Allison wrote:
> Trevor Wilson wrote:
>
> ===================
>
>>>>>>
>>>>>>>
>>>>>> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
>>>>>> amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
>>>>>> the output stage fail, there is a good chance that 45 Volts will applied
>>>>>> to the relay contacts. Since all commonly available relays are rated to
>>>>>> break no more than 27 Volts DC, an arc will be set-up, which will,
>>>>>> eventually, weld contacts together, allowing the full rail Volts to be
>>>>>> applied to the speaker. I've seen this occur many, many times. Using a
>>>>>> changeover relay, where the unused contacts are earthed may be helpful.
>>>>>> Or not. If the relay is only required for muting during power-up, then
>>>>>> anything from Farnell will do. There are fancy high(er) DC Voltage rated
>>>>>> relays available, but they are hideously expensive. The best option is
>>>>>> use the relay to shut off the AC and hope that there is insufficient
>>>>>> energy in the filter caps to damage the speaker/s.
>>>>>>
>>>>>
>>>>> ** Only seen one amp that does that - the Crown PSA2 "Self Analysing" amp.
>>>>>
>>>>> The AC supply relay was independently powered and reacted to any of the following.
>>>>>
>>>>> 1. DC voltage of either polarity at the output of greater than 20V.
>>>>> 2. Continuous high frequency output of 20V rms at or above 20kHz.
>>>>> 3. Large sub-sonic output below 20 Hz.
>>>>>
>>>>> This amp was strictly for pro audio use, where very high powered speakers would be the only loads.
>>>>> Many hi-fi speakers are relatively fragile.
>>>>>
>>>> **Every ME power amp ever made has the following:
>>>>
>>> -------------------------------------------------------------------------
>>>
>>> ** FYI to all:
>>>
>>> ME brand amps are *secret* devices, TW is or was an agent for them for decades.
>>> No schems are published.
>
>> **Incorrect.
>
> ** Links ?
>
>
>>> Owners are warned to refer all service to ME.
>> **Indeed they are.
>
> ** Service monopoly is soon gonna be illegal.

**Sure. Need I remind you that Peter Stein has not manufactured a new
amp since 2007?

>
>>
>>> So no surprise I have never seen one cos nobody has.
>> **Nonsense.
>
> ** Its a figure of speech Trev - not literal.
>
>
>>> And TW can say anything he likes about them.
>
>> **Sure.
>
> ** So it is not common knowledge among techs.
>
> Would you like to hear one?
>
> ** ROTFL !!

**Is that a yes? Let me know when it's convenient and I will have Tony
drop one in. You can keep it for a week or two.

>
>
>>> But I know they use a very large cap banks in the PSU,
>>> which must dump fully into the attached woofer VC in case of DC offset faults.
>
>> **Yep.
>
> ** Bad idea.

**So are relays in series with speaker lines.

>
>>> A feature is they have no VI current limiting - so the unprotected BJT output
>>> stage is vulnerable to user accidents and driver burn outs.
>
>> **Untrue. Very early model ME amps used no VI limiters. When a couple
>> failed, Peter Stein began installing VI limiting in all models
>> (including retro-fitting to previously released amps). A feature that
>> exists in all ME amps.
>
> ** TW can say anything he likes .....

**And yet, it is a fact.

>
>
>
>>>
>>> But TW thinks they are " magic" .
>
>> **Absolutely not.
>
> ** So they are crap then ?

**Nope. They're not magic. They are very good performing amplifiers.
Sound good too.

>
>
>> They are simply logically designed. Not only do they do exactly what is
>> promised by the manufacturer,
>
> ** Same all all other hi-fi amps.

**No. They ACTUALLY do what they're advertised to do. Most manufacturers
tell lies about what their products can do. ME does not.

>
>> but can be 'field serviced' quickly and easily.
>
> ** But only by the anointed ones, at giant cost.,

**No. Let's look at the claim I made about 'field service' capability:

* A service company has stocks of ME output stages on the shelf.
Amplifier comes in for service. A new module is bolted in. Re-biasing is
performed and the amplifier is ready to go within a couple of hours
(proper biasing can take an hour of so).

>
> TW goes on to say that other "snake oil" amps are worse.

**Most are. Few are designed for quick or easy service. Most are
designed to look pretty, without regard for the poor bastard who has to
fix them. I'm pretty certain you've had your fair share of those. I did
a Rowland amp a few years back, which was well designed for easy
service. Early (fan cooled) Krells were excellent to service. Later
model ones, not so much. More like Hell in aircraft grade aluminium
alloy cases.

> Maybe true.

**Definitely.

Trevor Wilson wrote:
=================
>
> >>> But I know they use a very large cap banks in the PSU,
> >>> which must dump fully into the attached woofer VC in case of DC offset faults.
> >
> >> **Yep.
> >
> > ** Bad idea.

> ** So are relays in series with speaker lines.

** Stupid straw man fallacy.

>
> >>> But TW thinks they are " magic" .
> >
> >> **Absolutely not.
> >
> > ** So they are crap then ?
> **Nope. They're not magic.

** Your OTT words say otherwise.

> **No. They ACTUALLY do what they're advertised to do. Most manufacturers
> tell lies about what their products can do. ME does not.

** Now that is a blatant LIE !!

> >> but can be 'field serviced' quickly and easily.
> >
> > ** But only by the anointed ones, at giant cost,

> **No.

** Yes.
> * A service company has stocks of ME output stages on the shelf.

** An irrelevant, massive red herring.

> > TW goes on to say that other "snake oil" amps are worse.

> ** Most are.

** ROTFL !!!!!!

TW only ever compares ME with other audiophool amps.

" Hitler ain't such bad guy compared to Stalin or Mao."

Too funny.

....... Phil

Also does this relay need to isolate the speakers completely, including the
Earth, ie in case you wanted to use them on something else, ie break before
make changeover of all connections?
Is it going to be energised to remain on for the default amp config, or
does it work in reverse?
Brian

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Note this Signature is meaningless.!
"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:59793f2893dave@davenoise.co.uk...
> In article <6a36030f-b14f-4076-aeed-28425dffeaeen@googlegroups.com>,
> Phil Allison <pallison49@gmail.com> wrote:
>> Dave Plowman (Rabit Nutter) wrote:
>> =======================================
>> >
>> > Maybe a question for Jim, as I remember him mentioning speccing them
>> > for
>> > Armstrong.
>
>> ** Errr - wot would that fool know ?
>
>> >
>> > 100 watt per channel amp. Space not a problem.
>> >
>
>> ** Operation here on Earth is essential.
>
>> > Best relay with low power consumption coil?
>
>> ** What DC voltage?
>> But most importantly WHAT exactly do you expect the damn relay to do
>> ??
>
>> Be forewarned, you have picked on one my hottest topics.
>> One most amp designers get WRONG !
>
> Go on, then. Give me the benefit of your wisdom. Operating voltage doesn't
> matter as I'll likely use a dedicated supply. But I'd guess 12v gives the
> biggest choice.
>
> --
> *You are validating my inherent mistrust of strangers
>
> Dave Plowman dave@davenoise.co.uk London SW
> To e-mail, change noise into sound.

I was thinking the same, but then again one particular rather over
engineered American amp of the lat 70s used an actual solenoid that moved a
switch. Bit of overkill I'd say. Having said that I permanently removed the
cover of the Denons speaker relay so I could slide a piece of paper between
the contacts to clean them after about five years. And no it was not that
the psu was not able to drive the relay due to the voltage being a bit low
with age either.
Brian

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"Don Pearce" <spam@spam.com> wrote in message
news:6162ff8f.19267625@news.eternal-september.org...
> On Sun, 10 Oct 2021 14:51:56 +0100, "Dave Plowman (News)"
> <dave@davenoise.co.uk> wrote:
>
>>In article <6a36030f-b14f-4076-aeed-28425dffeaeen@googlegroups.com>,
>> Phil Allison <pallison49@gmail.com> wrote:
>>> Dave Plowman (Rabit Nutter) wrote:
>>> =======================================
>>> >
>>> > Maybe a question for Jim, as I remember him mentioning speccing them
>>> > for
>>> > Armstrong.
>>
>>> ** Errr - wot would that fool know ?
>>
>>> >
>>> > 100 watt per channel amp. Space not a problem.
>>> >
>>
>>> ** Operation here on Earth is essential.
>>
>>> > Best relay with low power consumption coil?
>>
>>> ** What DC voltage?
>>> But most importantly WHAT exactly do you expect the damn relay to do
>>> ??
>>
>>> Be forewarned, you have picked on one my hottest topics.
>>> One most amp designers get WRONG !
>>
>>Go on, then. Give me the benefit of your wisdom. Operating voltage doesn't
>>matter as I'll likely use a dedicated supply. But I'd guess 12v gives the
>>biggest choice.
>
> If you want a relay that will handle real power with very little loss,
> go to a car spares place and get the ones they use for car headlights.
>
> d
>
> --
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
>

Yes I lost a speaker on an amp where the relay got stuck once, it more or
less melted the coil. It was badged Memorex, but looked well made inside,
but the power amps were modules from the far east and the relay was quite
small. The power module lost one transistor apparently. It was Din based but
no clue who actually built it. Shame as it worked well for a while.
I guess, once again, not enough stress testing of the components and or
bean counters buying the cheapest crap that works.

Brian

--

This newsgroup posting comes to you directly from...
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Blind user, so no pictures please
Note this Signature is meaningless.!
"Trevor Wilson" <trevor@rageaudio.com.au> wrote in message
news:isgu48Ffav7U1@mid.individual.net...
> On 11/10/2021 12:51 am, Dave Plowman (News) wrote:
>> In article <6a36030f-b14f-4076-aeed-28425dffeaeen@googlegroups.com>,
>> Phil Allison <pallison49@gmail.com> wrote:
>>> Dave Plowman (Rabit Nutter) wrote:
>>> =======================================
>>>>
>>>> Maybe a question for Jim, as I remember him mentioning speccing them
>>>> for
>>>> Armstrong.
>>
>>> ** Errr - wot would that fool know ?
>>
>>>>
>>>> 100 watt per channel amp. Space not a problem.
>>>>
>>
>>> ** Operation here on Earth is essential.
>>
>>>> Best relay with low power consumption coil?
>>
>>> ** What DC voltage?
>>> But most importantly WHAT exactly do you expect the damn relay to do
>>> ??
>>
>>> Be forewarned, you have picked on one my hottest topics.
>>> One most amp designers get WRONG !
>>
>> Go on, then. Give me the benefit of your wisdom. Operating voltage
>> doesn't
>> matter as I'll likely use a dedicated supply. But I'd guess 12v gives the
>> biggest choice.
>>
>
> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm amplifier
> will use rail Voltages of approximately +/-45 Volts DC. Should the output
> stage fail, there is a good chance that 45 Volts will applied to the relay
> contacts. Since all commonly available relays are rated to break no more
> than 27 Volts DC, an arc will be set-up, which will, eventually, weld
> contacts together, allowing the full rail Volts to be applied to the
> speaker. I've seen this occur many, many times. Using a changeover relay,
> where the unused contacts are earthed may be helpful. Or not. If the relay
> is only required for muting during power-up, then anything from Farnell
> will do. There are fancy high(er) DC Voltage rated relays available, but
> they are hideously expensive. The best option is use the relay to shut off
> the AC and hope that there is insufficient energy in the filter caps to
> damage the speaker/s.

In article <isgu48Ffav7U1@mid.individual.net>, Trevor Wilson
<trevor@rageaudio.com.au> wrote:

> **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
> the output stage fail, there is a good chance that 45 Volts will
> applied to the relay contacts. Since all commonly available relays are
> rated to break no more than 27 Volts DC, an arc will be set-up, which
> will, eventually, weld contacts together, allowing the full rail Volts
> to be applied to the speaker. I've seen this occur many, many times.
> Using a changeover relay, where the unused contacts are earthed may be
> helpful. Or not.

I can't comment on any specific currently-available relays or switches for
this. My knowledge of specific relays was decades ago!

... And I wired across the relays in my amps, anyway. :-)

However the unknown is what the typical *actual* voltage, current, and load
inductanc might be in real use. To know that, Dave would need more
observational data. Also is this for protection, or what? Matters if the
amp is going full belt or idling.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
biog http://jcgl.orpheusweb.co.uk/history/ups_and_downs.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article <5979a94a8bnoise@audiomisc.co.uk>,
Jim Lesurf <noise@audiomisc.co.uk> wrote:
> In article <isgu48Ffav7U1@mid.individual.net>, Trevor Wilson
> <trevor@rageaudio.com.au> wrote:

> > **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> > amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
> > the output stage fail, there is a good chance that 45 Volts will
> > applied to the relay contacts. Since all commonly available relays are
> > rated to break no more than 27 Volts DC, an arc will be set-up, which
> > will, eventually, weld contacts together, allowing the full rail Volts
> > to be applied to the speaker. I've seen this occur many, many times.
> > Using a changeover relay, where the unused contacts are earthed may be
> > helpful. Or not.

For some reason, only seen Trevor's reply as part of Jim's one.

Not really worried about a failure mode.

> I can't comment on any specific currently-available relays or switches for
> this. My knowledge of specific relays was decades ago!

> .. And I wired across the relays in my amps, anyway. :-)

What did you do with the other connections between amp and speakers? ;-)

> However the unknown is what the typical *actual* voltage, current, and load
> inductanc might be in real use. To know that, Dave would need more
> observational data. Also is this for protection, or what? Matters if the
> amp is going full belt or idling.

The usual +/- 50v supply. Nominal 8 ohm speakers.

Basically to prevent a switch on/off thump. Very unlikely to have to
handle full output under those conditions.

--
*(on a baby-size shirt) "Party -- my crib -- two a.m

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

Jim Lesurf is Demented like Joe Biden wrote:
==================================
>
> > **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> > amplifier will use rail Voltages of approximately +/-45 Volts DC. Should
> > the output stage fail, there is a good chance that 45 Volts will
> > applied to the relay contacts. Since all commonly available relays are
> > rated to break no more than 27 Volts DC, an arc will be set-up, which
> > will, eventually, weld contacts together, allowing the full rail Volts
> > to be applied to the speaker. I've seen this occur many, many times.
> > Using a changeover relay, where the unused contacts are earthed may be
> > helpful. Or not.
>
> I can't comment on any specific currently-available relays or switches for
> this. My knowledge of specific relays was decades ago!

** How totally irrelevant.

> .. And I wired across the relays in my amps, anyway. :-)

** How silly.

> However the unknown is what the typical *actual* voltage, current, and load
> inductanc might be in real use.

** Hummm: a 6.5 ohm voice coil and 50V of applied DC plus Ohms Law.

> To know that, Dave would need more observational data.

** How utterly fucking stupid.

Drink some warm milk and take nap - Jim.

....... Phil

In article <4ff1bf79-e7f8-457f-8aea-e7ee4f23696bn@googlegroups.com>, Phil
Allison <pallison49@gmail.com> wrote:
> Jim Lesurf is Demented like Joe Biden wrote:
> ==================================
> >
> > > **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> > > amplifier will use rail Voltages of approximately +/-45 Volts DC.
> > > Should the output stage fail, there is a good chance that 45 Volts
> > > will applied to the relay contacts. Since all commonly available
> > > relays are rated to break no more than 27 Volts DC, an arc will be
> > > set-up, which will, eventually, weld contacts together, allowing the
> > > full rail Volts to be applied to the speaker. I've seen this occur
> > > many, many times. Using a changeover relay, where the unused
> > > contacts are earthed may be helpful. Or not.
> >
> > I can't comment on any specific currently-available relays or switches
> > for this. My knowledge of specific relays was decades ago!

> ** How totally irrelevant.

> > .. And I wired across the relays in my amps, anyway. :-)

> ** How silly.

> > However the unknown is what the typical *actual* voltage, current, and
> > load inductanc might be in real use.

> ** Hummm: a 6.5 ohm voice coil and 50V of applied DC plus Ohms Law.

> > To know that, Dave would need more observational data.

> ** How utterly fucking stupid.

> Drink some warm milk and take nap - Jim.

I take it you only do insults on here, rather than a helpful reply?

Do love it when a self called expert can't answer a simple
question.

--
*Cover me. I'm changing lanes.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

Dave Plowman (Total Cunt ) wrote:

==============================
> >
> > > > **I suspect that is not what Phil is asking. A 100 Watt @ 8 Ohm
> > > > amplifier will use rail Voltages of approximately +/-45 Volts DC.
> > > > Should the output stage fail, there is a good chance that 45 Volts
> > > > will applied to the relay contacts. Since all commonly available
> > > > relays are rated to break no more than 27 Volts DC, an arc will be
> > > > set-up, which will, eventually, weld contacts together, allowing the
> > > > full rail Volts to be applied to the speaker. I've seen this occur
> > > > many, many times. Using a changeover relay, where the unused
> > > > contacts are earthed may be helpful. Or not.
> > >
> > > I can't comment on any specific currently-available relays or switches
> > > for this. My knowledge of specific relays was decades ago!
>
> > ** How totally irrelevant.
>
>
> > > .. And I wired across the relays in my amps, anyway. :-)
>
> > ** How silly.
>
> > > However the unknown is what the typical *actual* voltage, current, and
> > > load inductanc might be in real use.
>
> > ** Hummm: a 6.5 ohm voice coil and 50V of applied DC plus Ohms Law.
>
> > > To know that, Dave would need more observational data.
>
> > ** How utterly fucking stupid.
>
> > Drink some warm milk and take nap - Jim.
>>>

> I take it you only do insults on here,

** Its such a target rich environment of know nothing, raving pommy lunatics like you.

> Do love it when a self called expert can't answer a simple> question.

** You meaningless, troll question has been answered already,
you stinking pommy pig.

Here is a simple question:
Why has Covid not killed you yet?

...... Phil

In article <597a33befbdave@davenoise.co.uk>, Dave Plowman (News)
<dave@davenoise.co.uk> wrote:

> > .. And I wired across the relays in my amps, anyway. :-)

> What did you do with the other connections between amp and speakers? ;-)

Not sure what you have in mind. For my 700 amps I never use the headphone
sockets. The 600 has ye olde switch in its socket, but again, I've never
used it.

> > However the unknown is what the typical *actual* voltage, current, and
> > load inductanc might be in real use. To know that, Dave would need
> > more observational data. Also is this for protection, or what? Matters
> > if the amp is going full belt or idling.

> The usual +/- 50v supply. Nominal 8 ohm speakers.

> Basically to prevent a switch on/off thump. Very unlikely to have to
> handle full output under those conditions.

Depends a bit on how big the thump may be and how long the delay you
arrange before the relay closes. However if that's all you need then you
probably don't need a very high current or voltege make/break value. Just
focus on any info on lifetime reliability.

The worry with power amps is that the switch may need to open/close when
large voltages or currents are involved, and a very reactive load. i.e.
when you make or break with a lound signal level into a 'difficult'
speaker.

Also, lifetime. Pretty much any relay will wear out in due time.

TBH I never bothered with worrying about a switch-on thump. If you choose
speakers and amp to work together its not likely to do harm, just make some
listeners worry needlessly. I tend to regard it as confirmation that the
amp came on. 8-]

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
biog http://jcgl.orpheusweb.co.uk/history/ups_and_downs.html
Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf has no fucking brain left wrote:

=================================
>
> > > However the unknown is what the typical *actual* voltage, current, and
> > > load inductanc might be in real use. To know that, Dave would need
> > > more observational data. Also is this for protection, or what? Matters
> > > if the amp is going full belt or idling.
>
> > The usual +/- 50v supply. Nominal 8 ohm speakers.
>
> > Basically to prevent a switch on/off thump. Very unlikely to have to
> > handle full output under those conditions.
>
> Depends a bit on how big the thump may be and how long the delay you
> arrange before the relay closes. However if that's all you need then you
> probably don't need a very high current or voltege make/break value. Just
> focus on any info on lifetime reliability.
>

** Correct.

> The worry with power amps is that the switch may need to open/close when
> large voltages or currents are involved, and a very reactive load. i.e.
> when you make or break with a loud signal level into a 'difficult'
> speaker.

** The simple fact the signal is *AC* mean any tendency to arc upon opening is eliminated.
Same goes for closing.

> TBH I never bothered with worrying about a switch-on thump.

** Or anything else that mattered to owners and you were clueless to fix.

Wot a pommy fraud.

....... Phil