Hi all.
Forgive me if this is the wrong sub-forum...
I have a NAD 1240 preamp with a broken headphone jack. It is a solderable PCB-type, I believe the part # from the service manual is
L451Y017H01 PCB TYPE 9 PIN JACK HEADPHONE
This is the actual part that is broken (I stepped on something, lost balance and steadied myself on the first thing I found--the 1/4" heaphone plug sticking out of the preamp). Unfortunately, signal to power amplifier goes through this jack and the accompanying PC-board (# L241A066H12), so not good!
I doubt NAD stocks these, as I purchased the preamp new in 1987...
Does anyobody know where I can get a hold of such a phone jack? I can look for a similar vintage dead amp/preamp, but these are scarce here... Let me know. Cheers!
--Christian
Forgive me if this is the wrong sub-forum...
I have a NAD 1240 preamp with a broken headphone jack. It is a solderable PCB-type, I believe the part # from the service manual is
L451Y017H01 PCB TYPE 9 PIN JACK HEADPHONE
This is the actual part that is broken (I stepped on something, lost balance and steadied myself on the first thing I found--the 1/4" heaphone plug sticking out of the preamp). Unfortunately, signal to power amplifier goes through this jack and the accompanying PC-board (# L241A066H12), so not good!
I doubt NAD stocks these, as I purchased the preamp new in 1987...
Does anyobody know where I can get a hold of such a phone jack? I can look for a similar vintage dead amp/preamp, but these are scarce here... Let me know. Cheers!
--Christian
That's probably unavailable today. If you don't use the headphone jack, it's possible to wire across
the switches in the jack so it does not cut off the signal at the RCA jacks. This can be done either
right on the jacks's switch contacts, or between the preamp circuit's output and the RCA jack.
NAD 1240 Stereo Pre Amplifier Manual | HiFi Engine
If you do use the headphone jack, after shorting the switches you'll have to turn off the power amplifier
when using the headphones.
the switches in the jack so it does not cut off the signal at the RCA jacks. This can be done either
right on the jacks's switch contacts, or between the preamp circuit's output and the RCA jack.
NAD 1240 Stereo Pre Amplifier Manual | HiFi Engine
If you do use the headphone jack, after shorting the switches you'll have to turn off the power amplifier
when using the headphones.
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> If you don't use the headphone jack,
That's what I was hoping too; but Christian steadied himself "on the first thing I found--the 1/4" heaphone plug sticking out of the preamp", which suggests it is in use.
In Switchcraft lingo this would be open tip ring plus *two* isolated transfers, which is not on their 2-page list of codes.
There is enough info on the HiFiEngine manual to permanently juice the RCA outs, losing the feature of silencing them when a HP plug is inserted.
That's what I was hoping too; but Christian steadied himself "on the first thing I found--the 1/4" heaphone plug sticking out of the preamp", which suggests it is in use.
In Switchcraft lingo this would be open tip ring plus *two* isolated transfers, which is not on their 2-page list of codes.
There is enough info on the HiFiEngine manual to permanently juice the RCA outs, losing the feature of silencing them when a HP plug is inserted.
Yes, I can't imagine that an interchangeable replacement would be available, or even ever was.
Also the pcb could easily have been damaged from this accident, so check that out carefully.
If extremely lucky, maybe only the plastic top of the jack was detached, but doubtful.
Anyway, 34 years isn't too bad. Post some inside photos. Can you do soldering work?
Also the pcb could easily have been damaged from this accident, so check that out carefully.
If extremely lucky, maybe only the plastic top of the jack was detached, but doubtful.
Anyway, 34 years isn't too bad. Post some inside photos. Can you do soldering work?
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As I cant find the original part ( obsolete ) The UK at Farnell has a whole range of PCB phone jacks so the USA version should have them too --just checked they do.
Mouser has a better display and you can pick your contacts .
I never found it much of a deal changing them if you are not worried about cosmetics .
Mouser has a better display and you can pick your contacts .
I never found it much of a deal changing them if you are not worried about cosmetics .
Maybe this one will work if you solder some wire to PCB.
9-Pin 1/4" Stereo Jack for Guitar & Bass w/ DPDT Switch - GuitarElectronics.com
9-Pin 1/4" Stereo Jack for Guitar & Bass w/ DPDT Switch - GuitarElectronics.com
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Hi all.
Thanks for your replies. I've had the service manual for it since the 1990s, I've done surgery on the preamp before... I managed to glue the jack back together (cyanoacrylate). It all works as before, but it's a weak point.
I can certainly rewire it, or replace it with a generic switching or non-switching jack. The preamp is already modified anyway: there is an easy way (via convenient jumpers) to insert a re-purposed tape monitor switch to bypass the opamp tone control/preamp, turning it into a passive unit. I found no degradation in sound when fed from my CD player, and the phono preamp is ahead of the inserted bypass.
I am not super attached to the preamp, but if I could get a headphone jack from a dead NAD vintage unit... I'll just wait til one comes my way. Anyway, I still have the Korg B1 and ACA to build! Cheers.
--Christian
Thanks for your replies. I've had the service manual for it since the 1990s, I've done surgery on the preamp before... I managed to glue the jack back together (cyanoacrylate). It all works as before, but it's a weak point.
I can certainly rewire it, or replace it with a generic switching or non-switching jack. The preamp is already modified anyway: there is an easy way (via convenient jumpers) to insert a re-purposed tape monitor switch to bypass the opamp tone control/preamp, turning it into a passive unit. I found no degradation in sound when fed from my CD player, and the phono preamp is ahead of the inserted bypass.
I am not super attached to the preamp, but if I could get a headphone jack from a dead NAD vintage unit... I'll just wait til one comes my way. Anyway, I still have the Korg B1 and ACA to build! Cheers.
--Christian
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