Ever seen one of these?

I haven't tried them yet. Stupid huh?

I haven't been able to do anything with them with other priorities, and first thing was to have a close look and make sure everything looked alright. Next I need to make up some cabling to get them connected to the patchbay. I've got all the bits gathered up to make that harness, and once that's done I'll do some A/B testing using playback of some raw material or something to demonstrate what they do...they need to be calibrated and stuff first but I'm getting there.
 
wire harness done...

Made up a 4-channel TRS to spade terminal harness for the two SEP400's:

IMG_6543_1_1.JPG



I'm getting really close to testing these things out...The next issue is to figure out how to calibrate the input and output levels on these things...the instructions are a bit dubious because they were written assuming they units were installed in a broadcast application and/or interfacing with other CRL units...rather than providing instructions to get the same output level as what is being input, the instructions indicate to set the source level to 0dBm nominal and then adjust the SEP400 input control so the CAL peak light just lights 10~20% of the time during input of program material. Not as straighforward as using tone.

Can anybody give me any insight into this? The calibration instructions are in section 2.3.3 (page 13 of the pdf) in the manual, which is available here.
 
So I've tested them out.

Its a start. I am not at all disappointed with them that's for sure. As I menton in the linked thread above the input sensitivity is off. The input knobs are fully counter-clockwise and the input signal is borderline too hot. There are dip switches inside for setting the input sensitivity range into one of three ranges, so I can adjust that. I'm figuring now that the input strength really effects how the unit responds because the detented "PROCESS" knobs on the front set how the circuitry handles the source signal and I figure its effect will be most, er, effective if that signal isn't too hot or too weak. So I'll keep getting a feel for it. I think I'll start with trying to set the dip switches to a setting that allows the INPUT knobs to be set around 12:00 with no distortion and then I can see at what level a 1kHz tone makes the CAL lights just start to light and that way I'll be able to get both channels the same, and then I can get the OUTPUT knobs set so the same level that goes in comes out...then live with it for a bit and see if it is in a good all-around range for different material...tweak as needed.

I'll have to take a short video of what they look like in action...those big red yellow and green pilot lights flickering away...its...vintage.
 
Wow you made those cables? Where did you get that cabling? Did you just use shrink tubing? You did a a really nice job.


sweetbeats said:
Made up a 4-channel TRS to spade terminal harness for the two SEP400's:

IMG_6543_1_1.JPG



I'm getting really close to testing these things out...The next issue is to figure out how to calibrate the input and output levels on these things...the instructions are a bit dubious because they were written assuming they units were installed in a broadcast application and/or interfacing with other CRL units...rather than providing instructions to get the same output level as what is being input, the instructions indicate to set the source level to 0dBm nominal and then adjust the SEP400 input control so the CAL peak light just lights 10~20% of the time during input of program material. Not as straighforward as using tone.

Can anybody give me any insight into this? The calibration instructions are in section 2.3.3 (page 13 of the pdf) in the manual, which is available here.
Click to expand...
 
Thanks, guys! I appreciate that!

Yes, the snake cable is just 4-channel Gepco cable I got from Redco.

The terminals are just 18~22AWG solderless crimp connectors. I trimmed off the plastic cover that was over the crimping lug and cut up a bunch of pieces of heat shrink of appropriate sizes. I keep a number of sizes of heat shrink on hand both 2:1 and 3:1 with the adhesive wall inside. The electronics shop I go to locally has 4' sticks for about $8 to $12 as small as 1/8" on up to 1.5".

I have an automatic stripping tool too that saves time and avoids damaging the wire strands when stripping insulation.
 
Yah.

They've ended becoming my favority site for bulk cable and connectors...best overall prices on ELCO stuff...really great wiiiide selectiion on bits and pieces for audio/video/data, and they have some really nice Redco-branded XLR connectors for a very reasonable price. I got a few of them and next time I need XLR connectors I'll probably get them over Neutrik.

Another place to check every now and then is Parts Express. Current deals on bulk snake cable here: http://www.parts-express.com/wizards/searchResults.cfm?srchExt=PROMO&srchPromo=21&CFID=27451203&CFTOKEN=80533291

12-channel Belden snake cable for $1.75/ft. That's a good deal.

Or better yet how about the 28-channel cable for $1.95/ft.??? :eek:

Anyway, I've been happy with both those vendors.
 
sweetbeats said:
Yah.

They've ended becoming my favority site for bulk cable and connectors...best overall prices on ELCO stuff...really great wiiiide selectiion on bits and pieces for audio/video/data, and they have some really nice Redco-branded XLR connectors for a very reasonable price. I got a few of them and next time I need XLR connectors I'll probably get them over Neutrik.

Another place to check every now and then is Parts Express. Current deals on bulk snake cable here: http://www.parts-express.com/wizards/searchResults.cfm?srchExt=PROMO&srchPromo=21&CFID=27451203&CFTOKEN=80533291

12-channel Belden snake cable for $1.75/ft. That's a good deal.

Or better yet how about the 28-channel cable for $1.95/ft.??? :eek:

Anyway, I've been happy with both those vendors.
Click to expand...

Yes, I've bought a few things from Parts Express. I forget what they were now it was a while back.
 
I've had one of thse opened up for awhile pecking away at recapping, swapping out some of the opamps and some other light modding.

Replaced all the caps, PSU caps with Nichicon PW's and increased the main filter caps from 1000uF to 2200uF, and increased the voltage on the secondaries...swapped out the input coupling caps (which were two 10uF polar caps back-to-back for a 5uF non-polar array for each input leg) for Nichicon ES MUSE 10uF non-polar caps (one for each leg), and all the rest of the caps are Nichicon KT's. All the audio path opamps (which were 4558's) were replaced with OPA2134's.

I've only done one so far so I can compare with a stock unit. If the difference is very noticeable then I can work backwards swapping back in the old opamps in some logical progression (reminder...they are socketed so this is an easy experiment) to learn what, if anything, had the greatest impact.

No stable and/or appropriate listening environment to test this out out yet but eventually...just nice to have this one "done" and at-the-ready to calibrate and then compare to the other one.

IMG_0638_6_1.JPG


IMG_0639_7_1.JPG



Plug for CRL/Orban: three times now I have had interactions with them regarding these old CRL units...they are ancient history when you look at the business progression of CRL's morph into Orban but nevertheless I have had some of the most helpful and rapid friendly response from those folks. Truly benchmark setting AFAIC for customer service. They take pride in their creations and their customers based on my experience. If I'm needing something in the future for which Orban has a product offering I will take a serious look even just by virtue of their service. On top of that I continue to be impressed with the design, materials and build-quality of my old SEP400A's. Nicely done overall, and it is my understanding that it is at least as good or better with Orban.
 
I can't believe it- two whole pages or replies and not one person admits that he's seen these things... in Ghostbusters!

Who you gonna call?:)
 
Perfect example of why it's not always proper or prudent to do wholesale opamp "upgrades"...

Awhile ago I mentioned I'd replaced all but one opamp in these units with OPA2134...9 of them...replaced one TL072 and eight 4558s. Well I'm getting ready to do some mods to a dbx 119. Both the dbx and these CRL units have proprietary VCAs in them and there are opamps that are in the feedback loops of those VCAs. The circuits are calibrated to the components in those loops. Change the opamps and you for sure upset the calibration and possibly put parts in place that are incompatible with the proprietary amps specification-wise. I was dumb. I thought "Oh gee look! Crappy 4558s...a veritable GOLDMINE of make-it-better!" Never underestimate your ability to be a complete ignoramus. So I put the 4558s back in. I left the OPA2134s in place for the input and output drivers, as well as the two mid-stage drivers.

Think before you "improve" things. Know what you are getting into...ask yourself why. Assume you don't know the whole picture.

I'm happy to have friends that explain this stuff to me. I already knew not to do it to the dbx unit, but it triggered my memory: "Oh wow...wait...I replaced opamps in the SEP400A that have got to be in the feedback loops of those VCAs...ARG!" Out comes the schematic.

You can see little round stickers on the black boxes inside the units. Those stickers have stuff written on them by the tech that setup the units at the factory...and there is a blob of glue on the associated trimmers that sez "don't mess!"

image.jpg
 
Im interested in what you're planning on doing to the dbx 119. I have had on for a while now and I actually use it for acoustic guitar tracks sometimes. I always though it would be nice to be able to put a make up gain control on it somehow.
 
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