Multi-pin voltages plug

[Guitarist]

I am going to tap the B+ and heater voltage from a poweramp to go to an external tube preamp pedal. What might be a good, small plug-in connector for this?

[Enzo]

Don't know what size limits you have.

I like these a lot for any multipin connection - the CPC - Circular plastic connector - series from AMP. You order the plug, receptable and male and Female pins separately The shells come in a variety of pin counts, you don;t have to use all the pins, just mount as many as you need. The shell will be stable with any number.

Here is a four pin.
http://www.alliedelec.com/Images/Pro...l/512-1100.jpg

Allied and others sell them.

XLRs would work, they come in higher pin counts than just 3.

I would not be a fan of DIN connectors for this.

Manage your pin count. You might want two for heaters, one for B+, one for ground. DO you consider any possibility to expand the use later, 5v or 12v for LEDs or relays, make room on the connector. Possibke more than one ground return wire?

[Don Moose]

Possible more than one ground return wire?

DEFINITELY more than one GND - one per DC rail pin/voltage, one per AC (heater) pair (for the center reference) and at least one per signal pin.

It's _vital_ that the signal and power not share a ground run ... in my stupid opinion, anyway.

[Guitarist]

Quick ?:

Does the signal require a ground back into this "power supply"? Convention would suggest it. I probably wont have any more filter caps inside this "remote" preamp. But, in this case, it is for a tube buffer on my pedal board and there'll be other ground returns. I guess I'm just being lazy

If one were to use 12 Volts for the heaters (pin 9 nc) that would use a separate ground for sure even though it goes back to the same place and thanks for the heads up with the center reference.
?: With 12V we don't need to float the heaters, -'ve goes right to ground. I always have to do this with 6 Volts DC with 33 to 100 Ohm resistors.

I just had a failed attempt to tap off the power rails in an EH 12AY7 preamp. There was a hum of the B+ despite the mic preamp working perfectly.