I primarily joined this forum just to ask this question, sorry if that's frowned upon. Anyway... I'm trying to repair a little practice amp which has a broken input jack, but I'm having trouble finding a replacement. It's a 1/4" mono switching jack with a SPST push to break switch that's operated by the jack being inserted. The switch is completely electrically separate from the jack contacts and this is the problem. All of the switching jacks I can find connect the tip and sleeve to other contacts when the jack is removed.
I made a bad diagram in MS paint showing how this socket is:
(http://dl.dropbox.com/u/992948/80758bh43kb3/4358hbbk/switch.png)
Can someone help me find another one of these (preferably more robust though ;)) or even just point me in the right direction with something to google? I've tried lots of different searches and only found things like the 'mono switched' in this diagram: http://www.neutrik.com/content/technicalsupport/faq.aspx?faqId=205_747846926.
What does the SPST switch do on this jack? I've not heard of a jack like you're asking for, but you could always use a regular switched jack and have the switched portion operate a SPST relay.
Quote from: joecool85 on December 29, 2010, 12:57:32 PM
What does the SPST switch do on this jack? I've not heard of a jack like you're asking for, but you could always use a regular switched jack and have the switched portion operate a SPST relay.
I'm not actually sure what it's doing, I don't really understand the whole circuit but I'd guess it's earthing the input. What would be a regular switched jack by the way? The kind in the diagram on the Neutrik website?
Quote from: eyeball226 on December 29, 2010, 01:03:08 PM
I'm not actually sure what it's doing, I don't really understand the whole circuit but I'd guess it's earthing the input. What would be a regular switched jack by the way? The kind in the diagram on the Neutrik website?
Yes, I was referring to a jack like the mono switched neutrik you had the link for.
What type of amplifier is this? Maybe you (or someone here) can find a schematic and we can tell you if you even need the switched portion of that jack/what it is for.
Quote from: joecool85 on December 29, 2010, 01:27:29 PM
Quote from: eyeball226 on December 29, 2010, 01:03:08 PM
I'm not actually sure what it's doing, I don't really understand the whole circuit but I'd guess it's earthing the input. What would be a regular switched jack by the way? The kind in the diagram on the Neutrik website?
Yes, I was referring to a jack like the mono switched neutrik you had the link for.
What type of amplifier is this? Maybe you (or someone here) can find a schematic and we can tell you if you even need the switched portion of that jack/what it is for.
I've just had a look at the circuit and actually it's ridiculously simple: One of half of the switch is connected to ground and the other half is connected to the input. I'm a moron! I'm pretty sure the neutrik one would do the job fine, all I'd have to do is connect TN and SN together.
EDIT: To answer your question, it's just a little Squier transistor amp. Thanks for your help!
Quote from: eyeball226 on December 29, 2010, 01:35:14 PM
I've just had a look at the circuit and actually it's ridiculously simple: One of half of the switch is connected to ground and the other half is connected to the input. I'm a moron! I'm pretty sure the neutrik one would do the job fine, all I'd have to do is connect TN and SN together.
EDIT: To answer your question, it's just a little Squier transistor amp. Thanks for your help!
That makes a little more sense, although I'm not sure why it needs to put input to ground when you are unplugged. What model amplifier is it?
It's an SP-10, one of these:
(http://www.dv247.com/assets/products/41586_l.jpg)
I'm guessing the input is grounded when there's no plug in it so it doesn't hum.
Quote from: eyeball226 on December 29, 2010, 03:27:11 PM
It's an SP-10, one of these:
I'm guessing the input is grounded when there's no plug in it so it doesn't hum.
If that's the case you could just use a regular jack and have a normal amp like everyone else lol.
Yes, that's the solution "everybody else" uses.
Unfortunately, Fender (and its siblings as Squier) *loves* a jack model which nobody else uses, with extra switches and contacts. Oh well.
You may order it from them, maybe you'll need to go through an authorized shop or something, or maybe Mouser or some of the other "big" shops has an equivalent one.
Worst case, put a regular switching jack type (I guess the hole is small for a Cliff("Marshall")) type but enlarging holes in aluminum panels is easy.
Put it with legs away from the PCB (it won't match anyway) and wire them to the corresponding holes with short pieces of wire.
Good luck.
PS: get and link to the schematic of *any* small Fender amp, so we all see the same image, the jack wiring will be the same or very close.
TBH, I'll probably just buy a normal mono switching jack. Now I know that it's just earthing the input and nothing special I know what to do.
antique radio supply (tubesandmore.com) has the fender jacks.
I've gotten them from Mouser too...but they of course list them by the manufacturer.
Can't find the old invoice...but think it's one of the Kobiconn ones at mouser...you might need to check a couple of data sheets
Quote from: bry melvin on December 29, 2010, 05:52:47 PM
antique radio supply (tubesandmore.com) has the fender jacks.
I've gotten them from Mouser too...but they of course list them by the manufacturer.
Can't find the old invoice...but think it's one of the Kobiconn ones at mouser...you might need to check a couple of data sheets
I probably won't seek out the exact jack now I know what the functionality is and how easy it is to replicate, thanks though!
Quote from: eyeball226 on December 30, 2010, 10:59:16 AM
I probably won't seek out the exact jack now I know what the functionality is and how easy it is to replicate, thanks though!
Good luck and let us know how it comes out.
Quote from: joecool85 on December 30, 2010, 11:55:33 AM
Quote from: eyeball226 on December 30, 2010, 10:59:16 AM
I probably won't seek out the exact jack now I know what the functionality is and how easy it is to replicate, thanks though!
Good luck and let us know how it comes out.
It was so long before I got round to fixing the amp that I forgot about this. I attached it by wires rather than trying to mount it directly on the board (which is a stupid design really) and it's been working fine for a few months now. Thanks for all the help!
Quote from: eyeball226 on June 19, 2011, 09:27:36 PM
It was so long before I got round to fixing the amp that I forgot about this. I attached it by wires rather than trying to mount it directly on the board (which is a stupid design really) and it's been working fine for a few months now. Thanks for all the help!
That's great, and thanks for getting back to us.