Looking for a power switch...green led push type ....for *extremely* vintage GP11 Pre.....????

[tonewheelkev]

It's been a long time!!

Think it's time I dealt with this one....before dropping off the perch (as we all do eventually!) in an untimely manner.

 

As it says....Looking for a power switch...green led push type ....for *extremely* vintage GP11 Pre.....????

 

Any thought please??

 

Kev/Leeds

[BassmanPaul]

I looked at a GP11 on line but I couldn't see the power switch! Where is it hiding?

 

 

[sandy_r]

7 hours ago, tonewheelkev said:

..Looking for a power switch...green led push type ....for *extremely* vintage GP11 Pre.....????

 

Any thought please??

 

are you hoping to repair the existing switch - or just replace with a new one, which contains a green led?

 

is the work going to be carried out by a suitable tech (whether you or someone else)?

 

Edited November 2, 2023 by sandy_r

[DGBass]

If you mean something like this then a suitable replacement shouldn't be too hard to find. Just getting the right diameter to fit the exisiting hole can be tricky but not impossible on these old MKII GP11 pre-amps. The obligatory safety warning is needed because it means re-wiring the mains supply. UK mains voltage can be very hazardous for your general health. If the original is dud, disconnecting the mains and measuring the old one will give you an idea of the right fit for the hole. You could then source one and get a tech to professionally fit the part for you. Coloured ones are nice, but plain ones with a black cap will do the same thing and usually be cheaper. Would likely need to be a latching type switch and not a momentary one but without a schematic I couldn't be sure. If it pushes in, clicks and stays in and needs to be pushed again to pop out its likely latching. 

 

 

 

Edited November 2, 2023 by DGBass

[tonewheelkev]

Thanks for the replies!!

I've attached a pic...showing 12mm hole for the switch.

Original switch has already had a rebuild....and has now past the point of no return when it comes to another

Hoping to stick closely to the 12mm aperture with the replacement....and there are some switches that I've found!

Would this do the job??....I'd be selecting the latching option

https://www.ebay.co.uk/itm/324785111506?hash=item4b9eb381d2:g:XbgAAOSw2adhOyBx

.There's a link to a .pdf showing the switch spec too....here >>>>>LA12 spec.pdf

 

Edited November 3, 2023 by tonewheelkev

[sandy_r]

49 minutes ago, tonewheelkev said:

Thanks for the replies!!

I've attached a pic...showing 12mm hole for the switch.

Original switch has already had a rebuild....and has now past the point of no return when it comes to another

Hoping to stick closely to the 12mm aperture with the replacement....and there are some switches that I've found!

Would this do the job??

https://www.ebay.co.uk/itm/324785111506?hash=item4b9eb381d2:g:XbgAAOSw2adhOyBx

 

 

hi

yes, that switch meets the service spec (3A 240V AC) - hopefully it won't be supplied with the switch manufacturer's name emblazoned on it !

 

if you've previously serviced the switch yourself (and avoidied injury!), replacing a latched version like this (5 tags) should be fine. You'll need to find suitable supply points for the internal LED (9-24V AC or DC - i'd choose DC, if poss - the voltage range shown implies that the LED is already fitted with a current-limiting resistor - check polarity required, using eg. PP3 battery and a 2k7 (ono) resistor, in series)

 

Take all necessary precautions to make safe and secure connections between the switch tags and preamp cabling - insulated boots on push-fit spade terminals, or heatshrink wrap over soldered joints.  I see your solder-sucker in the photo - i'm sure you know the score!

 

As always, if you intend to open the equipment and work on the wiring, you do so entirely at your own risk!

 

Good luck with the repair!

 

Edited November 3, 2023 by sandy_r

[tonewheelkev]

14 minutes ago, sandy_r said:

hi

yes, that switch meets the service spec (3A 240V) - hopefully it won't be supplied with the switch manufacturer's name emblazoned on it !

 

if you've previously serviced the switch yourself (and avoidied injury!), replacing a latched version like this should be fine. You'll need to find suitable supply points for the internal LED (9-24V AC or DC - i'd choose DC, if poss - the voltage range shown implies that the LED is already fitted with a current-limiting resistor - check polarity required, using eg. PP3 battery and a 2k7 (ono) resistor, in series)

 

Take all necessary precautions to make safe and secure connections between the switch tags and preamp cabling - insulated boots on push-fit spade terminals, or heatshrink wrap over soldered joint.  I see your solder-sucker in the photo - i'm sure you know the score!

 

As always, if you intend to open the equipment and work on the wiring, you do so entirely at your own risk!

 

Good luck with the repair!

 

Excellent...and thanks for the swift reply!!

The original led part of the switch has what looks like (and measures as ) 1.2K in series with the led.

Would that need to be changed to suit the new switch??

[sandy_r]

9 minutes ago, tonewheelkev said:

Excellent...and thanks for the swift reply!!

The original led part of the switch has what looks like (and measures as ) 1.2K in series with the led.

Would that need to be changed to suit the new switch??

 

 

I would start with the existing 1.2k resistor in place, as before (if you find that the switch LED is too dim, however, then you could re-connect the switch LED to the other end of that 1.2k resistor)

 

[tonewheelkev]

2 minutes ago, sandy_r said:

 

I would start with the existing 1.2k resistor in place, as before (if you find that the switch LED is too dim, however, then you could re-connect the switch LED to the other end of that 1.2k resistor)

 

Sounds like a plan...you're a Gentleman!

Thanks again

[Chienmortbb]

Those switches have mains voltage lamps, not LEDs. If they are OK, then the internal lamp (mains) may work without connection to the resistor.

[sandy_r]

1 hour ago, Chienmortbb said:

Those switches have mains voltage lamps, not LEDs. If they are OK, then the internal lamp (mains) may work without connection to the resistor.

 

...i believe that those particular switches do in fact contain LEDs (operating from 9-24V, AC or DC).  The latched version has 3 connectors for the 240V mains switch and an additional 2 (smaller?) tags for isolated connection to the internal LED and current-limiting resistor)

 

the link which Kev provides above contains the relevant details

 

[tonewheelkev]

1 hour ago, Chienmortbb said:

Those switches have mains voltage lamps, not LEDs. If they are OK, then the internal lamp (mains) may work without connection to the resistor.

Page one of the spec does describe it as "Two-way LED lamp"......

LA12 spec.pdf

[BassmanPaul]

Personally I'd just put a toggle switch in there and be done with it. LOL

 

[agedhorse]

Note that the switch is only rated for 2A (inductive, which is what the power supply presents to the switch). The device should be fused at 2A or less.

[sandy_r]

2 hours ago, agedhorse said:

Note that the switch is only rated for 2A (inductive, which is what the power supply presents to the switch). The device should be fused at 2A or less.

 

The TE Service spec for the GP11 Preamp with 240V input, specifies a 100mA rated fuse in series with this switch

 

The  switch example shown in Kev's  link earlier (thermal  current rating, Ith, of 3A) meets and exceeds the indicated requirement

 

[agedhorse]

17 hours ago, sandy_r said:

 

The TE Service spec for the GP11 Preamp with 240V input, specifies a 100mA rated fuse in series with this switch

 

The  switch example shown in Kev's  link earlier (thermal  current rating, Ith, of 3A) meets and exceeds the indicated requirement

 

Correct, I was addressing this in general since the GP-11 preamp is used in many of the amps also, and it would be easy for somebody later on looking at this thread to misinterpret the information being presented. Some of those amps for the 230/240V market are fused at 3.15A or higher which is why I mentioned it. For other markets, the 125V rating (inductive) is what's important, and these amps can be fused at 6A or higher depending on  the model. 

 

For example, the GP-11 AH500 is fused at 5A for the 240V market and 10A for the 120V market.

 

The switch that was posted is rated at 2 amps inductive because that's how it's being used. The resistive or thermal current rating does NOT apply in this application since the load is inductive.

 

I used to work as an engineer for one of the previous owners of Trace Elliot so I am very familiar with the technical details of the line (during that era anyway, the current owner's versions are entirely different).

[sandy_r]

23 hours ago, sandy_r said:

 

The TE Service spec for the GP11 Preamp with 240V input, specifies a 100mA rated fuse in series with this switch

 

The  switch example shown in Kev's  link earlier (thermal  current rating, Ith, of 3A) meets and exceeds the indicated requirement

 

 

5 hours ago, agedhorse said:

Correct ...

 

Your concern, for possible misapplication of this question & answers about the GP11 preamp to other TE systems which contain power supplies operating at greater then 20x the OP equipment here, is very worthy

 

Now - let's be clear for this actual question:

 - The OP equipment 240V mains fuse (in series with the power switch) is rated at 100mA (ie. 0.1A) by TE;

 - The OP suggested switch is a suitable replacement for the OP power switch

 

ATTN.  Everybody else possibly thinking of replacing a power switch in some different setup: YMMV

 

Keep Calm and Carry On, Kev

 

[tonewheelkev]

4 hours ago, sandy_r said:

...............Keep Calm and Carry On, Kev

 

......Phew!!!!!!🤒 .....well I think!!!!!😉

[agedhorse]

13 hours ago, sandy_r said:

 

 

Your concern, for possible misapplication of this question & answers about the GP11 preamp to other TE systems which contain power supplies operating at greater then 20x the OP equipment here, is very worthy

 

Now - let's be clear for this actual question:

 - The OP equipment 240V mains fuse (in series with the power switch) is rated at 100mA (ie. 0.1A) by TE;

 - The OP suggested switch is a suitable replacement for the OP power switch

 

ATTN.  Everybody else possibly thinking of replacing a power switch in some different setup: YMMV

 

Keep Calm and Carry On, Kev

 

Yes, of course in this case it’s fine but the GP-11 pre was used in in many other amp models too, and that wasn’t clear from the original post. This was a common mistake made when customers were asking for manufacturer support… the first question was always “stand alone preamp or one of the amp models with the GP-11 preamp”?

Edited November 5, 2023 by agedhorse