Connectors for modular tube preamps/line amps, etc.

yeah, i am really into dave's little projects. i'm sortof halfway through the various incarnations of his preamp and lineamp. the idea occurred to me too that modularity would be neat, a shared psu. is there a place where these ideas have been fleshed out more, or if not, can we do that here? i guess i am interested in knowing what kind of filtering, if any, is needed at each module to ensure isolation between modules. should one duplicate the last RC filter of the power supply at the input of each module, rather than do it once just in the power supply box? this is a bit of a new area for me. a nudge in the right direction would be much appreciated.
jrd

If you are going to build more than one mic pre, or eq, or compressor, it sure makes sense to go modular. Low noise, less work, and cheaper than building ten power supplies. 100 ma of B+ will power a lot of racks, if you add on a beefy filimaent supply.

On the down side, if you want to take a micpre over to a friends house and have a shootout, you have to haul the whole enchillada over there, unracking both supply and micpre, disconnecting cables, but on the plus side, if someone breaks into you house and steals your LA2, they will be disappointed when they find out that it is worthless without out the supply, and will be knocking on your door to bring it back.

Well, maybe.

Dave, how about DIN connectors? The roland gtr synths use a 13 pin config, which was still availible last time I checked. I bought a couple of 13 pin jacks for a 24pin->13 pin synth converter I built.

[quote author="Emperor-TK"]Dave, how about DIN connectors? The roland gtr synths use a 13 pin config, which was still availible last time I checked. I bought a couple of 13 pin jacks for a 24pin->13 pin synth converter I built.[/quote]
:shock: This must be another kind of 'DIN' as we know DIN, right ?
I realize DIN stands for a lot much more than just those 3/5-pin MIDI- & older audio-gear plugs, but if they go further on that same route I guess they're not suited because of the high-voltage-requirement (less sturdy contacts & small distances)

I'll go along with Clint in suggewsting separate connectors for power & signal. 8-pin plugs/sockets for power, 5-pin XLR for signal I/O. It'll still be modular, just two plugs per module. Heck, even a hard drive uses two.

What I use on tubed projects, with an 8-pin (octal) setup:

Pin 1: Plate Ground
Pin 2: Plate B+
Pin 3: N.C. (left optional)
Pin 4: Filament - (grounded)
Pin 5: Filament +
Pin 6: Filament - (boosted to 100V or so, for cathode followers)
Pin 7: Filament + (the other half of the pin 6 circuit)
Pin 8: Chassis ground

Peace,
Paul

realize that if you run two sets of wires, and one set has a ground, and the other set has a ground, and that if they get spread out, you might have one gigantic - Ø?B on your hands.

[quote author="clintrubber"]
:shock: This must be another kind of 'DIN' as we know DIN, right ?
I realize DIN stands for a lot much more than just those 3/5-pin MIDI- & older audio-gear plugs, but if they go further on that same route I guess they're not suited because of the high-voltage-requirement (less sturdy contacts & small distances)[/quote]

I haven't checked the voltage/current specs on the DIN stuff yet. Steve Bench has noted that he uses them for his external power supplies though. I thought it might be worth looking into.

2-7 pin DIN connectors mentioned on here

Hmmmmm...what about using some of the DIN "Eurocard" connectors and just ignoring several rows of pins to isolate B+ rails from low voltage stuff?

One "issue" with octals, Jones, and similar is the required insertion force to mate them as a module.

Bri