Help me build a XLR switchbox?

[Bill Ferris]

OK, so I spent last evening rewiring the switchbox using twisted pairs. I ran out of wire and still have one source to do but it certainly looks a little more organized inside. Darn if it does not seem to sound better too?

Maybe not Spaghetti but perhaps Fusilli?

Thanks for all the help guys!!!

View attachment 1041353

 

[stoN_Cold]

Nice.

 

[stoutblock]

OK, I installed silver wire on source #1 (TT) and the main outputs. Can't say I hear the difference but at least I know it won't hurt. I am a firm believer that music is an art, and like all art, it is no place for science. If you think it sounds better, it does sound better...

I can now play all my RCA and XLR sources (7) and record on one RCA source and one XLR source without switching any cables. Sweet! and it sounds as good as ever!

 

[bjlefebvre]

I would have twisted the + & - of each balanced wire circuit from the XLR`s to the switch just like is done in all balanced cables of around 3~5 twists or more per inch.

I'm preparing to make a similar RCA switchbox, using a lot of the info found on this great thread (I'll also be incorporating a mono/stereo switch). Is the wire twisting just something beneficial for XLRs? Or would it work for RCA inputs as well? Other than that, I just have to decide whether to use the silicon-coated 24awg copper wire I already have or use the Neotech tefloned stuff.

Oh, and I didn't think "spaghetti" on those innards - looked more like licorice to me.

 

[stoutblock]

I'm preparing to make a similar RCA switchbox, using a lot of the info found on this great thread (I'll also be incorporating a mono/stereo switch). Is the wire twisting just something beneficial for XLRs? Or would it work for RCA inputs as well? Other than that, I just have to decide whether to use the silicon-coated 24awg copper wire I already have or use the Neotech tefloned stuff.

Oh, and I didn't think "spaghetti" on those innards - looked more like licorice to me.

Twisting is a good practice in any case. I’m sure your wire would work just fine.

 

[Bill Ferris]

I'm preparing to make a similar RCA switchbox, using a lot of the info found on this great thread (I'll also be incorporating a mono/stereo switch). Is the wire twisting just something beneficial for XLRs? Or would it work for RCA inputs as well? Other than that, I just have to decide whether to use the silicon-coated 24awg copper wire I already have or use the Neotech tefloned stuff.

Oh, and I didn't think "spaghetti" on those innards - looked more like licorice to me.

I concur.
Every bal./unbalanced switch box that I`ve ever built, I preferred to not only twist the feeds to the jacks/switch, I also physically kept the inputs/outputs separated from each other as far as practically as possible with attention to programing/wiring the selector switches sections/wafers(if rotary) for the best L/R & in/out isolation, especially important for switching low level signals..

When I built a 12 v reed relay based switch box that allowed me to transfer the left and right inputs & outputs from two different preamps/power amps to feed a Velodyne ULD 15 powered sub woofer, not only did I twist my wires to and from my reed/coaxial relays I also placed and grounded(soldered to my internal 14 ga. buss wires) a 1" 3M brand copper tape between the L/R sections & between the in and out sections, as a shield, being concerned about the higher frequency leakage, as well.

Maybe over kill, but I desired the insertion of this switch box to be as sonically transparent as practical as when I switched on my 1960`s Mac C22 preamp which powered via a well filter DC wall wart PS plugged into one of the C22`s switched AC outlets it powered the DPST reed relays to switch over from the default daily driver Mac SS preamp/power amp to route the to and from L/R signal`s and remain sonically neutral, as that was important to me..
Also turning on the C 22 also via another switched AC out energized (4) separate120 volt actuating coil 30 amp rated contact relays to take care of the power amps speaker L/R +/- transfer from the SS to tube amp at the same..

Been in operation since 2000, though I don`t remember the DB isolation figures from that long ago, I did run tests on the switch box at 1 octave frequencies from 20~20kHz. with the in and output jacks loaded with the equivalent line level resistance`s they would probably see in the real world in my application.
Measuring in/out, L/R separation without proper "loading" can result in the performance indicating much less than actually happens when hooked up to real audio equipment..
Don`t ask me how I stumbled upon that little ghost chasing learning curve from many decades ago !!

Sorry about the long winded reply !! =

Regards, OKB

 

[bjlefebvre]

I also physically kept the inputs/outputs separated from each other as far as practically as possible

Thanks for that. Not longwinded at all. That helps my decision to get the larger of the two enclosures I had been looking at. The smaller box would have been a close fit but not too bad for RCA jacks and would have allowed me to stow the box underneath my turntable, which as about two inches of space beneath the plinth. But the larger box will allow more separation.

 

[stoutblock]

I tried to get some cross talk from my box recently but got no indication of any signal bleed. Even using the amplified output signal from my preamp into the boxes inputs there was nothing. I’m sure it is possible if you had poor shielding and/or grounding. I would think an XLR design is probably superior to a SE version in this regard?