Replacement RCA jacks for an HK A250 Epic

[Lucky Pierre]

I have my A250, which I love, especially on Altecs. The amp has been gone through, but the RCA jacks are original and a little dodgy. Has anyone replace said jacks?

FYI, they reside inside the chassis facing up.

Pick pulled from USAM

 

[gadget73]

can probably find those exact jacks somewhere, they were super common. May be the same parts used for a Dyna PAS? Off the top of my head I don't remember the number of jacks per section on those but for some reason I'm thinking one side was 4 and one was 5.

 

[Lucky Pierre]

Thanks, gadget! That is a very good tip.

 

[Mr Boochie]

I have my A250, which I love, especially on Altecs. The amp has been gone through, but the RCA jacks are original and a little dodgy. Has anyone replace said jacks?

On closer inspection, are those RCA jacks sitting on phenolic plastic boards? Like maybe 60-year-old brittle boards? And the jack structures are riveted to them.

If it were me, I'd prolly go the Deoxit D100L route until it stopped working. Maybe gently tease the spring contacts in the back of the jacks. And leave the interconnects in, if at all possible. Don't use heavy ICs.

When it eventually fails, you'll prolly need to DIY a new fiberboard with a metal backing for the new jacks. Drill out the rivets, unsolder the old wires, and resolder the new jacks. I'd take a LOT of photos to keep the wiring correct.

Good luck!

 

[Lucky Pierre]

View attachment 3841870
On closer inspection, are those RCA jacks sitting on phenolic plastic boards? Like maybe 60-year-old brittle boards? And the jack structures are riveted to them.

'Zactly!

 

[gadget73]

yeah you wouldn't replace the individual jacks, if you're doing something with these the entire board gets swapped, which means drilling the rivets out along with desoldering the wires. I'd also try and clean and re-tension them first just to avoid having to deal with that, but if they are too worn or damaged for that to work there isn't much else to be done about it.

 

[Mr Boochie]

yeah you wouldn't replace the individual jacks, if you're doing something with these the entire board gets swapped, which means drilling the rivets out along with desoldering the wires. I'd also try and clean and re-tension them first just to avoid having to deal with that, but if they are too worn or damaged for that to work there isn't much else to be done about it.

On some old units with funky RCA jacks, I'd DIY a strain relief (similar to the one in the photo) near the jack. To take as much interconnect weight off the jacks and help orient them parallel to the connections. I used thin piano wire or paper clips and bent them into a kind of holder shape for the ICs to pass through. Have the weight on the interconnects mostly on the DIY strain relief. Then rig the strain relief to attach to a platform or something behind the amp.

This only works if you don't move the unit with the funky RCA jacks around too much. It never works in guitar amp jacks.

This eventually fails, and you need to replace all the funky connections.

 

[knockbill]

yeah you wouldn't replace the individual jacks, if you're doing something with these the entire board gets swapped, which means drilling the rivets out along with desoldering the wires. I'd also try and clean and re-tension them first just to avoid having to deal with that, but if they are too worn or damaged for that to work there isn't much else to be done about it.

This^^^ I have those jacks on my Scott,,, I finally scrubbed them with a tip cleaning brush (welder supply) and contact cleaner and tighten teh split connectors with a little plier pressure,,, dead quiet and hold tight now, of course teh more ya change plugs or move teh amp around they can get loose again,,,