Extending the BFC cable

[Y-my-R]

Alright… I have a setup that works with the long BFC cable, so I’m solved, happy and can start installing the cable tunnels over the door, etc. great!

For the curious, what I’m NOT sure about, is what specific component it is, that you need to have in your D8B rack unit, to make it work with a long BFC cable.

Here’s what I did, today:
I figured I’ll just have to try with my “daily” system, that I had kinda vowed to myself, NOT to use for experiments anymore! You know… never touch a running system and all…but anyway.
Since the intention is, to eventually have the 50 foot BFC rack unit BECOME the center of my “main” D8B system, I “touched my running system," after all, and attached the 50’ long BFC cable to my “daily driver" D8B rack unit.
I connected the other end to a spare test console (that I recently thought I fried something in, but it kept working normally since then, as long as I used it with the stock-length BFC cable).

So, now with a whole set of 50 foot long cables (BFC, DB25/RSS-Data, VGA, and PS/2 for mouse and keyboard, that go to my KVM switch), everything just booted up like nothing happened. Ready to use. Rainbows and smiles, everywhere

For the record…I didn’t try MIDI yet, but that should just work (or not), based on standard cable length limits… I don’t need to reach as far for that, for my specific setup. So, I won’t need as long a cable run and am not really worried about MIDI that much.

Now, what’s different in my “daily driver” unit (that WORKS with a 50 foot BFC cable):

- “New” Motherboard(!) (John, you called it!)
- Hand-written revision marks on Linear Power Supply - I’m not sure how to read this: (RC11? R41?)
(But I’m not sure if this is the set of power supply components, that originally came with this D8B rack unit… if so, I always changed as a complete set, though. I never changed motherboards between them, though)

LinearPSU_REV_what_s.JPG (Array KiB) Viewed 2995 times

In comparison to that, here’s what’s in the my “Spare/Test/Experiment” D8B rack unit, that works fine with a stock (comparably short) BFC cable, but does NOT work with the 50 foot long BFC cable (stuck or flashing LEDs from channels 13 and up):

- “Old” Motherboard
- Revision marks not present on Linear Power Supply. No pen marks… just the blank "055-123-00 REV.:___”

However, the power supply in the “bad” unit above, definitely is not the original one. The power supply I had previously installed in this rack unit, also FAILED to work to power a console with the long BFC cable… (but it could still simply be that it’s the “old motherboard” that is the problem).

Unfortunately, I’m no longer sure, if the “previous” power supply in that unit, was even the original one or not. And I have 2 “loose” sets of D8B power supply components right now, and don’t remember which I tried last, and which I was worried I might have fried in an earlier experiment. I’m also no longer sure, if the PS components in my “daily driver” unit were ever transplanted or not… In short, it’s an overpowering mess (please excuse the pun).

I could take/share pics of the hard-to-read REV number on the board that didn’t work, if anyone cares enough to want to know. But again, this set might have a different problem, so what’s the point, right?

So, I think the only thing that is really possible to clearly deduct from what I did is, that rack units that “should” work with a 50 foot long BFC cable, should have this stuff in them to be on the (probably) safe side, before custom-making such a cable (or paying a premium, if you’re good at finding unicorns):

- New Motherboard
- Revision Marks on the linear power supply, that look like the same or a higher number than the picture I shared further above.

That is... unless RHJ_Music or Captain America run their long BFC cables with old-board based rack units? If you guys could share your "known-good" configurations, that would be interesting, I think!

Oh, otherwise, the components in the working and failing power supplies looked similar enough to my eye. Both, the working (w/ 50' cable) power supply set AND the power supply set that only works with the short BFC cable, both used Astech PSUs and the same transformers (the more common one, that I have in 3 of 4 rack units).

Anyway, I hope what I shared here is useful, and I’m just happy that I can start moving all my noisy cr*p into my new machine closet, soon! (the computers, my PA amp that has a fan, etc.)

Wish me luck, that I won’t run into ground loop issues with the power outlet in my to-be machine closet… I never really used that one in conjunction with my recording setup, other than for trying the D8B just now… and so far, it sounded clean when alone on that outlet. Anyway, I’ll find out very soon!

Thanks again for everyone’s help!

[Y-my-R]

I celebrated too soon. When running on external word clock, I get everything from drop-outs, over 0dB noise drones to audio completely shutting down on the ADAT inputs... seems to get better/worse, depending on how I route the BFC cable, and what other stuff that may interfere, gets close to it... unplugging the VGA cable (probably poorly shielded) at the rack unit end, also helped... but still not good enough.

Internal clock works fine. But using that is out of the question for me (it doesn't fit into the concept of how this whole setup works).

I already tried with a "short" DB25/Data cable, and that doesn't change anything, and tried booting with nothing but the BFC and the short DB25 connected. So, the interference happens in the BFC, for sure.

I still have a few more troubleshooting ideas before that, but am thinking that I might have to run the BFC inside a shielded cable tunnel to get "truly" clean audio on external clock (...maybe just run it through pipes/tubes... I still got some unused strainless steel drum rack tubes that I'm thinking might work for that and as my new "stylish" door frame, haha)... BUT I'm not sure if I want to put in THAT much effort.

Anyway, the saga continues. Now I'm not surprised that Mackie never started offering the long cable as an accessory. I think there might be some caveats "attached" to that... or maybe I still have power supply issues. It's an endless rabbit hole...

This makes me wonder, though... RJH_Music and Captain America... how do you clock your D8B with the long BFC cable? Internal or external? If external, did you have to do anything special to make that work (e.g. route away from power lines, etc.), or did it "just work" and sounds clean while running on external clock?

Thanks again!

[RJH_MUSIC]

Not sure if you saw my thread on new Power Supply Build, but I uploaded a document that contains the entire instructions and pin outs for building a new CPU. Also listed all of the power supplies i successfully used and extended the BFC to 40 feet. I know others have extended to over 50 feet. Had some challenges with the Mouse and USB keyboard at hose lengths but solved those problems.

Check out the thread

[Y-my-R]

RJH_Music, so do you run your D8B on external clock or internal? Internal works for me. External works for a moment, then the clock degrades quickly and artifacts get worse until it’s 0 dB noise on the digital inputs on the Tape returns, and sometimes I even get the “question mark” in the console’s display.

So, the EXTERNAL clock signal that appears to be passing from the console through the long BFC cable to the rack unit, probably loses signal strength and then drowns in interference until I just get only noise or lose the clock completely.

On internal clock, no such problem exists and everything is happy.

In case you’re always only using the INTERNAL clock, then the build could still be failing on external clock and you might not know…? I mean, some people only use the analog inputs on the D8B and don’t care about digital sync and always leave it on “Internal”. From some threads I read here, some rare “specialists” even have “resample” turned on on the input (GASP!!!!!)… but I don’t want to sink that low into amateur land.

That’s why I need to be REALLY sure, that EXTERNAL clock actually works with extended cable lengths, since every minute I’d be troubleshooting this, would be for nothing, if it doesn’t work for anyone else. Since your (RJH_Music) cable is a home-brew and not as long, it would be MUCH more interesting for me to hear, if Captain America’s 50’ BFC cable actually works with EXTERNAL clock without problems. @Captain America - do you have clean audio on external clock with the long BFC cable?

Also, I think before I go back to trying to troubleshoot on a component level (where the pin-outs and BOM would be useful), I’ll first try to identify the “best” of the 4 power supply sets I have, to see if the setup works with that, on external clock.

To that end… I looked closely at all the components in the different power supplies I have, but the revision markings are really inconsistent (or often not present), and dates that are printed on some components, are rather “mixed up” than clearly showing which is the newest one (…and I’m not sure if the newest one would even be the best one… there could have been a “cost down” version, after Mackie gave up on the longer BFC cable for mass production, where the BOM may have been “reduced’ to use cheaper components that wouldn’t be enough for use with a long BFC cable, but still work fine with the short one - does anybody know?).

Here’s the markings I found on the PSU components in my 4 power supply sets. As long as I owned these 4 units, no PSU components other than the AT/computer supply, was ever taken out of context of the other components. I did move PSU-sets between different rack units, though... so the new/old board & PSU combinations are a mess at this point):

Unit 1 (Main/Machine closet/"New" Motherboard):
Transformer: 600-036-00 E/I 0599 (<— 1999?)
Linear PS: “R41” (or similar) pen markings. Orange “Adiboard Brasil” name on board
Distribution board: No pen markings. Adiboard Brasil.
Astech (same on all): No pen markings. Board says "W1 R18” below “ASTEC”.



Unit 2 (Backup/Under Argosy/"Old" Motherboard)
Transformer: 600-036-00 E/I 3100 (<— 2000?)
Linear PS: No/unreadable Rev markings.
Distribution board: No pen markings. Adiboard Brasil.
Astech (same on all): No pen markings. Board says "W1 R18” below “ASTEC”.

Unit 3 (Windows 98/"New" Motherboard))
Transformer: 600-011-00 E/I 4198 (Pen: 110) (<—1998?)
Linear PS: “R14” (or similar) and "220 10/98” pen markings (partial stamp: 2X1).
Distribution board: "464c 10/98” pen markings.
Astech (same on all): No pen markings. Board says "W1 R18” below “ASTEC”.


Unit 4 (Parts/"Old" Motherboard)
Transformer: 600-011-00 E/I 3298 (<—1998?)
Linear PS: "136 9/98” pen markings (Stamp: 898-2X1)
Distribution board: "87c 9/98 NS” pen markings.
Astech (same on all): No pen markings. Board says "W1 R18” below “ASTEC”.

So, when looking at the above, the numbers that looks like a date code on the transformers, makes me think that “Unit 2” should be the newest one.

However, looking at the “Adiboard” brand name that appears on one of the boards in Unit 2, but on TWO of the boards in Unit 1, makes me wonder if Mackie switched to a new supplier (Adiboard) at some point, and that the transformer in Unit 1, might just have come from a pile/bin, that had older manufacturing dates? But those two transformers have the same model numbers printed on them and newer numbers that look like dates, compared to the other ones. So, I’d think that the newest set of components, should either be from Unit 1 or from Unit 2.

Now, Unit one is what gives me the issues with external clock right now.

Unit 2, is where the console doesn’t power up and flashes (or lights” the meters on channels 13 and up. HOWEVER, I have not yet (consciously) tested the power supply components from that unit, with a “new motherboard” unit. So, this may still be an improvement over the PSU components in “Unit 1”…

…and now that I’ve typed ALL of this out, with the intention to ask the forum for input, I realize that there’s really only a single test to run here: Move PSU components from Unit 2 to Unit 1 and test. So, that’s what I’ll do.

For me, the BIG lingering question aside from my own experiments is still, if others have EXTERNAL CLOCK running successfully on a D8B system with a long BFC cable… Captain America? RJH_Music?

Thanks very much again in advance - I’ll do the PSU swap test, and will post an update, once I know more.

(And just to mention; I'm not sharing all this here so I don't feel so alone on my little journey or something... I'm sharing this, in case certain things/hardware-versions are required to use a longer BFC cable with a D8B... and so far, it looks as if you can't just extend the cable for ANY version of the rack unit (and I don't think everyone who wants to use a longer cable, will build their own power supply from scratch - people will want to know if a longer cable would work with THEIR rack unit). So, the "oversharing" I'm doing, isn't about me... just saying, in case it looks like I'm filling the forum with my personal chatter).

[RJH_MUSIC]

I do not think it is a cable length issue. I have both d8b's set to internal clock. If you use the midi interface you should be able to send MMC and Midi Clock to the d8b from your DAW with no issues. Someone once told me from either this forum or from Mackie directly is that the quote - " The d8b clock does not play well with others and it likes to be the set to internal". As a matter of fact, I have to turn things on in my studio in the following order in order to get the d8b to even boot up correctly;

Turn on both d8b's. Once fully booted and project loaded,
Turn on Audio Interface
Turn on computer

[RJH_MUSIC]

I set it once years ago to external and all hell broke loose. never tried it again.

[Y-my-R]

The issue only comes in on EXTERNAL clock and with the LONG BFC cable attached (this is with Unit 1 listed above).

I tested Unit 1 with a short BFC cable, and that works fine on EXTERNAL clock. No clock degradation.

Also, that same console works fine on external clock with "Unit 2" (which uses the "stock" BFC cable) and without even changing any clock cables on the console, or changing settings (I move the same CF card between consoles when testing, since it's easily accessible from the outside) - I made sure the clock is set to external and that the sample rate is right, of course... besides, it DOES lock with the long BFC cable... the clock signal just appears really weak/unstable... but if it was the wrong settings, it wouldn't work at all).

As for the D8B liking internal or external clock... I don't know what it is, but some CONSOLES seem to behave better than others, from my experience.
One of my spares used to work fine with INTERNAL or EXTERNAL clock, but was a little finicky with accepting external clock, and I sometimes had to boot a few times unit it would work normally. That same unit, meanwhile REFUSES to work with external clock (I have 3 different Apogee clock cards, and it's the same with all 3).

My "main" Console never fuzzed around much with external clock. I do NOT follow a boot order, but usually just turn the external clock on, switch my audio interface to external (I often have it set to internal while working ITB), and then press the power buttons on other gear that uses the external clock randomly. I never even see the question mark on the D8B... it just locks.

So, from my experience, it depends on the console, but what you're describing wasn't an issue with my main console at all... and isn't an issue when I use it with the stock BFC cable. So, I'm pretty sure it isn't that.

So, did you ever TRY to run your D8Bs on External clock (or do you use Apogee clock cards and have a clock cable go to the cards, at all?)

But to respond to "not a cable-length issue" comment... the issue does NOT happen, unless the long BFC cable is added to the equasion (and only on external clock). So, it's either a cable length issue, a cable defect, or an insufficient component (or components (plural)) in the power supply to support such a long cable length and the resulting drop in signal strength (in this case, of the clock signal... but if that doesn't get boosted anywhere, then EVERYONE should have problems with running the D8B on external clock, with a long BFC cable... and that's why I'm asking for your experience with running on external clock).
I can't really think of any other possible cause.

Thanks again!

[captainamerica]

my clock is always from the d8b - the MASTER clock - and I have no issues with the 50 BFC cable you "sold" me

[Y-my-R]

Thanks very much, Captain America!

Well... I guess nobody other than me tried to run a long BFC cable while running on external clock.

I did a few more experiments today (marked all the power supply components for units 1/2/3/4, then started combining them differently).

I haven't tried all possible combinations, but it appears that being able to power the console enough for it to boot, seems to depend on the "Linear PS".

Here's some variations (all tested in "Unit 1" - which has a "new" motherboard in it):

Unit 1 PSU set w/ long BFC (complete set): Boots, but external clock degrades quickly.
Unit 2 PSU set w/ long BFC (complete set): Unit doesn't boot (interestingly, the meters don't even flash while using this PSU set in the "Unit 1" rack unit. When trying to boot "Unit 2" with the old board and this PSU set, the meters either flash or are stuck from channels 13 and up).
Unit 1 PSU set w/long BFC, but transformer from Unit 2: Boots, but external clock degrades quickly.
Unit 1 PSU set w/long BFC, but Linear PS from Unit 2: Faders repeatedly click, but meters don't light up (insufficient pwr?)
Unit 1 PSU set w/long BFC, but Astec PSU from Unit 2: Boots, but external clock degrades quickly.
Unit 2 PSU set w/long BFC, but Astec PSU from Unit 3: Faders repeatedly click, but meters don't light up (insufficient pwr?)

So, whenever I have the Linear PSU from Unit 2 be part of the PSU for Unit 1, and try to use the long BFC cable, it doesn't power the console (the Rude solo light doesn't even come on... only the faders click).
At least when the "Unit 2" PSU set was still inside of Unit 2, it powered the console just fine, as long as the "stock" BFC cable was used.

I don't want to continue today, but have another few combinations I could try... but start to have the strong suspicion, that the long BFC cable doesn't work while using EXTERNAL clock AT ALL. If that's the case, then it's really no wonder that these weren't made available for purchase.

Does either of you have an Apogee Clock card installed in your console, and have the ability to test of audio is clean if running the D8B to external clock, Captain America and RJH_Music?

I think the "stock" BFC cable might even reach to my machine closet, if I'd cut a trench into the concrete floor, instead of going over the door... but before I do that, I get a different mixer.
...and generally, after having experienced how nice it is to have the D8B dead-quiet (i.e. while running it on "Internal" while in the machine closet), I don't know i I want to put up with the fan noise anymore. I really HATE that sound, even though it's really just the CPU and AT fans (and quieter ones than original).

Anyway... enough testing for today. Thanks again, everyone!

[Y-my-R]

Quick update:

I rolled everything back, in order to have a working setup again (in this case, using the re-assembled "Unit 2" mentioned above with a "stock" BFC cable, and having the rack unit's fans get on my nerves, again).

I also "rolled back" Unit 1, and it is ready to use with the long BFC cable on "Internal" clock... but this doesn't do me any good. I'll pick up the project again when I have some extra time, but needed the studio back in working condition.
There's a good chance that I'll just shorten the cable to the length I actually need, but I'm not sure, yet, since I also don't like the idea of increased interference possibly introducing jitter that I don't notice immediately, but that may still have a negative impact on my over-all sound quality. I'll have to think about it.

While packing it all away, I did two quick measurements of the voltage coming out of the re-assembled units (but WITHOUT having a Console connected), and that was quite interesting, IMO:

Unit 1 (new PSU-set/MB) w/ Long BFC: 15.xx Volts (forgot what it said after the comma)
Unit 2 (old PSU-set/MB) w/ Short BFC: 12.xx Volts (forgot what it said after the comma)

So, to summarize what I wrote out in an earlier post - there seem to be differences between power supply revisions, and an "old" set of power supply components (likely originally paired with "old motherboard" units, but not sure) doesn't power the console with a long BFC cable AT ALL, while a "new" set of power supply components powers/starts it just fine and it works on Internal Clock without issue. However, even with the "new" set of power supply components, switching to external clock will result in degrading word clock, and a shift from clicks/drop-outs to constant disortion and up to lost clock (i.e. questionmark in D8B's display).

Telling from the Voltage emitted by the two different types of power supplies, I'm no longer surprised that the "old" unit wasn't able to power the console at all.

At some point, I'll pop the bottom off of a test-console, and will repeat these measurements under load, to see if that comes out different (and also to see if different consoles might react differently to the different PSU-versions. I only have 2 that I could try with external clock, though... my 3rd console has an issue and doesn't lock to external clock anymore, somehow).

(I didn't have enough time to play with this, but couldn't find a quick and easy way to compare the signal drop on the other wires in the BFC, that are likely responsible for the clock degradation. I think I might still have to go back to my battery/light-bulb idea to test that properly... but for now, this project is on ice for me. Spending 3 weekends in a row on trying to get this to work is enough).