PCB edge connectors... what will they do to my sound?

MadDave12 · 30th July 2009, 08:15 PM

For a special purpose project (I've said too much already), I'm sorely tempted to utilize traditional PCB edge connectors for some sub-assemblies, including all wires running to my preamp tubes.

Any thoughts on the problems I'll see with this approach? I'll watch the distance between bare traces to avoid arcing, of course.

ChrisA · 30th July 2009, 10:37 PM

Quote:

Originally posted by MadDave12
For a special purpose project (I've said too much already), I'm sorely tempted to utilize traditional PCB edge connectors for some sub-assemblies, including all wires running to my preamp tubes.

Any thoughts on the problems I'll see with this approach? I'll watch the distance between bare traces to avoid arcing, of course.

There are several designs. The best ones use pin and socket connectors and not just "pins" printed directly on the PCB. Old Apple Macs (power PC) used these for expansion cards and today parallel IDE disks that mate with wide (34 pin?) IDC connector (pins are 0.1 inch OC) also use these. They are pretty good. It is typical to tie every other pin to ground There are specs for the resistance on each pin. You will likely need to gang multiple pins for high current lines, certainly the 6.3V heaters and likely B+ and half the pins for grounds.

Think about accidents where a card is half-way inserted and at an angle. The printed pins can short two contacts. The pin and socket design can't do that

If you want to stay with plugable moduals and at the same time retain an "old time" look. Use tube sockets and plugs as your interconnects. These are actually rated for high voltage. Today's do not say "500V" anyplace on the package.

I've been wanting to design a "21st Century" tube amp for a long time. It would be controlled by a microconroller. The uP could automatically sequence the power up and then check voltages and bias levels. Computers are now so cheap the whole uP system would cost less then one good power tube. To be tuely "21st Century" I'd need something better than turrent boards but just as easy to modify. Little 3" square PCBs might be good

nigelwright7557 · 30th July 2009, 10:57 PM

The main problem could be crosstalk.

Conrad Hoffman · 31st July 2009, 12:04 AM

I don't suscribe to big changes in sound resulting from wire, connectors etc, unless they've begun to oxidize. That said, if you're going with traditional PCB fingers, I'd only consider gold plated fingers against gold plated high quality connectors. As suggested above, there are better solutions. I'd check the Samtec catalog for their various edge connection and stacking solutions.