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Posted (edited)

Anyone have a minijack (3.5mm stereo, panel mountable) that they like? I am having problems with a flaky Switchcraft 35RAP whatever they are, and need to replace. I have some Kobicon that I have used with no problems so far, but looking for any other suggestions.

Edited by Pars
Posted (edited)

For me the kobicons have been reliable. If you still want to use the kobicons I have some left over from earlier projects. Foc.

Edited by Victor Chew
Posted (edited)

Marshall,

 

I've used the Kobiconns that you showed before and still have a few. The panel holes would need to be enlarged for those. I think I am going to use these from Digikey (CUI, on the left):

 

SJ1-3545_sml.jpg         35RAPC2BH3.jpg

Since this is for a Pimeta with its active ground, these would be going on a metal (anodized) Hammond panel. Will this be a problem? The Switchcrafts also have a metal barrel, tied to jack ground, and have not been a problem from that perspective. Thought I still had some of the CUI jacks (left) but don't seem to be finding them. I know I've used them before but can't remember what in :eek:

Edited by Pars
Posted

Yeah, you are probably right. I'll insulate the output jack, or use the Kobiconns I have. I built this about 5 years ago or so, and don't recall if I insulated the output jack or not ???

 

Not a fan of the active ground/rali splitter stuff.

Posted

Got the amp back today. This one has the 20 pin DIP socket for the feedback/gain resistors. One of the 10 ohm resistors had fallen out, so that accounted for his problems with one channel not working. He said he could get both to work by fiddling with the jack, but I suspect he was just getting both the L and R across one contact, i.e. mono.

 

I had not insulated the jacks; the grounds on both jacks were connected together thru the front panel. When I tested the V+/V- split to input ground, they were perfect. I replaced the jacks with the insulated Kobiconns, and now the resistance from IG to OG is around 4M ohms. I haven't tested the power and rail splitting yet since replacing the jacks, but I have some TLEs so will replace that if necessary. Any other tests I should do? It has been probably 5 years since I built this, and it is one of the few active ground amps I have built.

 

Thanks for the help!

Posted (edited)

After replacing the jacks with the Mouser # 161-7300-EX I had, I retested the amp, The rail splitter seemed fine, IG -> OG offset was less than 1mV, DC offset on either channel < 1mV, so everything seems good. Jack grounds insulated from one another now. I would guess that the OG being shorted to the IG only disabled the ground opamp/buffer loop, but apparently did not damage them. Can't believe I missed that when I was building the amp, but I guess I was focused on the trickle charger stuff, etc. :palm:

Edited by Pars

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