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Cabling a TR806 rack - screw terminals wtf? Sorted!

PostPosted: Tue Apr 01, 2014 2:00 pm
by Drumstruck
Hi my good fellows and lady,

I have this luverly old piece of kit and request some assistance on connecting the screw terminals for the QLZ quad pres ....

fyi it's a Valley People TR806 rack - fully populated with their 800 series modules. So far I've worked out the Maxi-Qs (4) and Gain Brains (2) and Kepex gates (2) - they have dedicated balanced input terminals and dedicated unbalanced output terminals.

But I am stumped with the QLZ Quad pre..... it's a Quad pre but there are only 2 banks of screw terminals for the 4 pres.....

Here are some photos:

TR806 front trock.jpg

TR806 rear trock.jpg

this one is sideways.....
TR806 terminals trock.jpg



thanks

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Tue Apr 01, 2014 2:07 pm
by Chinagraf
Maybe there are no in's on the back for the QLZ as they are on the front, so the back connector instead of 2 in and 2 out is 4 out?

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Tue Apr 01, 2014 2:20 pm
by Paul Maybury
Nice rack! Those Maxi Q's are wild.
I'd say Chinagraph is right about the terminals for the QLZ's.
Cheers,
Paul

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Tue Apr 01, 2014 2:27 pm
by Drumstruck
Thanks Gents - I think there must be a way to do this as I received enough pigtailed XLRs for 12 ins / 12 outs when I purchased the unit.

8 of each (XLR M and XLR F) are used for the EQs/GBs/Kepex so that leaves 4 of each for the QLZs for rear I/O.......

I suspect that the Key terminals have something to do with it.....


??????????

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Tue Apr 01, 2014 2:49 pm
by Chinagraf
Anything is possible, time to get the multimeter out?

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Tue Apr 01, 2014 4:28 pm
by Drumstruck
I think you may be right Andy.....

I saw that Rob had racked a pair of those QLZ pres for Angus so I would guess that he knows them outside in...

So, I removed the QLZ module from the rack and did some eyeballing:
- it has 2 circuit boards
- the LHS card has the 4 XLR inputs and looks like it links to 8+4 connections in the PCI-style slots for terminal bank 1
- it bridges to the RHS card via a multi-pin connector
- the RHS card has the input gain / phase switches and also has similar 8+4 connections in the slot for terminal bank 2

So.... I'm guessing that screw terminal bank 1 will be inputs and screw terminal bank 2 will be outputs.....


Searching the web I've found .pdf operating manuals for the Gain Brain II / Kepex II and some other VP modules if anyone wants a copy .... the Key terminals appear to be what we'd call sidechain nowadays for the Kepex - though you guys probably knew that.

Nothing to be found for the QLZ and the TR806 rack....


Interesting fiddling and thinking B-)

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Tue Apr 01, 2014 6:15 pm
by Chinagraf
Doesn't that leave you one i/p and o/p short? There's 9 connectors per barrier strip yeah? Unless they all share one ground on each strip. Have you tried the geekslutz sub forum on gearslutz? Someone there might know. I had a rack of 8 qlz's but they came in there own rack. I think I swapped them for some magic beans or somethin.

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Wed Apr 02, 2014 7:50 am
by Drumstruck
Thanks Andy,

There are 8 screw terminals per strip but I'm fairly sure that the -ive shares ground. See pic 3 for the layout (3 in / 3 key / 2 out) showing balanced ins / key and unbalanced outs.

I've done the search on GS - there are quite a few short threads and one more useful one where a guy got his TR806 sorted out but he didn't have the QLZ modules....

I'll be doing some multi- testing today and will update :-)

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Wed Apr 02, 2014 10:26 am
by Drumstruck
Update.... the multi-meter tells me that:

Barrier strip 1 connects to the front panel XLR inputs 1-4 from top to bottom (unbalanced)
XLR input pin 2 = +ive
XLR input pin 3 = -ive
XLR input pin 1 = grnd and (4 of them) connect to the ground terminals on all other barrier strips and to the chassis

So that explains the inputs - available from both the front panel XLRs and the rear barrier strip - goodness so far.


Next I'll be checking the outputs :-B

Re: Cabling a TR806 rack - screw terminals wtf? help.....

PostPosted: Thu Apr 03, 2014 3:17 pm
by Drumstruck
another day on.......

The Maxi-Qs are outta sight - nice sound and range from surgical to broadbrush

The Gain Brain IIs have a few intermittents and require someone with more nouse than me to remedy....

The Kepex IIs - one shows me how drastic these can be / the other has an intermittent in/out switch... actually, it's an out/out switch atm....

Buggered if I can get the QLZ connections worked out yet - some weird things happening with the +/- phase switch - more testing...... (-|

Re: Cabling a TR806 rack - screw terminals wtf? Sorted!

PostPosted: Fri Apr 04, 2014 3:23 pm
by Drumstruck
Yes!Yes!Yes!Yes!Yes!Yes!Yes!Yes!!!!! The QLZ outputs have been nutted out!

For future reference, in the old days hot was cold and cold was hot, so instead of connecting XLR pin 2 to +ive one needs to connect XLR pin 1 to +ive, and XLR pin 1 to ground ....

- Barrier strip 2 is the outputs as I suspected:
- Terminal 1 is output 1
- Terminal 2 is output 2
- Terminal 3 is ground
- Terminal 4 is output 3
- Terminal 5 is output 4
- Terminal 6 is ground
- Terminal 7 I haven't a clue and it doesn't matter....
- Terminal 8 is ground

Barrier strip 1 is the inputs (and these ins + the front XLR ins work):
- Terminal 1 is input 1
- Terminal 2 is ground + balance
- Terminal 3 is input 2
- Terminal 4 is ground + balance
- Terminal 5 is output 3
- Terminal 6 is ground + balance
- Terminal 7 is input 4
- Terminal 8 is ground + balance

whew

Next back to the Gain Brains and Kepex to see if my luck holds on a bit longer ;)

Re: Cabling a TR806 rack - screw terminals wtf? Sorted!

PostPosted: Fri Apr 04, 2014 3:35 pm
by Chinagraf
Good news Ian. I should have mentioned that the Valley stuff was pin 3 hot. I was aware of that. Same as the ADR stuff. I once got given a stereo F760 because it didn't work anymore, but it turns out once I rewired it to pin 2 hot it worked fine.

Re: Cabling a TR806 rack - screw terminals wtf? Sorted!

PostPosted: Fri Apr 04, 2014 4:25 pm
by Drumstruck
Thanks again Andy - I tried the cold for hot as a last resort and luckily it worked :-).

For the Gain Brains, Maxi-Qs and Kepex it doesn't matter - they run either way. Hopefully this will help any other t'rockers who get some of this gear.

Re: Cabling a TR806 rack - screw terminals wtf? Sorted!

PostPosted: Mon Apr 07, 2014 12:33 pm
by Drumstruck
Perhaps the penultimate post in this thread:

A bit of terminal cleaning / card seating and wiring integrity checking has every module working now.

All -ives are connected to +ive terminals
All +ives are connected to -ive terminals (except on the QLZ outs where the +ives aren't connected to anything)
All grounds are grounded

The intermittents have reduced to negligible and it's looking like a bit of pot and switch lube may solve those issues.

my goodness :-)