High Frequency noise in the D8b

[Y-my-R]

As everyone (including yourself) already said in their suggestions for things to try: "Process of elimination" is the way to figure out where the issue is coming from.

So, if the noise happened when using your "typical" signal path, minimize the signal path and see if it still happens. If not, add stuff back into the signal path that you are normally using, and test when/if the issue comes back.

Time (e.g. for thermal issues) is also an important factor, of course. Just for the sake of not having to deal with a variable that is difficult to control (e.g. how long exactly until heat might introduce the issue), I'd do my first set of tests with a "warm" console that's been running for a few hours. If I can't reproduce the issue then, I'd try again with a cold system, and try to repeat the tests quickly while it hasn't reached full operating temperature, yet.

And I agree with the various ways that were suggested to eliminate portions of the signal chain, to see if the issue is still there, without that component or path. Such as, trying a different channel, "bypassing" the D8B by recording directly to the HDR from a different ADAT source... or bypassing the HDR, by recording from the D8B to a different recording medium (e.g. a DAW or just a DAT recorder, for example).

If you had any other analog gear in the chain (e.g. I almost always add a touch of compression to vocals on the way in, before hitting the converter... so, IF I were to use the D8B pres, I'd almost certainly have a comp inserted... and with that unbalanced connection, that could introduce interference like that noise... but if your signal chain is fully digital, then this should mean that you do NOT have anything on the insert, right?).

Another issue that I had a number of times with DAW computers in the 90's with different soundcards, was that they would pick up interference from inside the computer case. This could be a high pitch wining that changes either with CPU or graphics activity, such as mouse movement.
Clearly, the D8B doesn't suffer from that sort of issue if everything is working right... but I wonder if anything could either have gone bad that could cause that... or maybe it it could be something like not having re-installed some sort of shield or metal cover/barrier back into the D8B or the rack unit when having them apart, and now interference is impacting a component, that was previously better shielded?

Or sometimes (I think), hardware devices with an issue can introduce interference via ground. So, IMO for the sake of troubleshooting, it would also be worthwhile to disconnect all outboard gear that is usually "permanently" connected, and check if the noise still happens.

Anyway... just trying to throw out some thoughts.

Part of the reason why I have more than one D8B, and why I keep more than one in working order, is so I can replace the whole unit, and check if a problem I'm observing, is also present with another unit. So, if that is an option (and IMO it is, since these desks sometimes pop up pretty cheap on craigslist, etc.), I'd keep a spare around, just for troubleshooting and eventually, for parts.
Not to sound like a hillbilly, but also used to have 3 cars of the same model, for the exact same reason why I keep 3 D8Bs around, hahaha. It can help take some guesswork out, if you have an option to compare between units

[Old School]

Hey Y-my-R,
I actually do (or did) have a spare D8B, but I've been robbing parts off it for a while now, so it was not close to a functional state. So, today I spent most of the day scrounging to see if I could make it operable, it had the old motherboard, which was shot, so I installed a used one ( the newer model) and it was hard to know which way some of the connectors should be oriented as there are no markings on the board or connectors (com 1 and com 2 are the confusing ones). Well, I finally got it to start booting, I reset the cmos and when the Mackie 5.1 screen came up I thought I was home free, but it stuck on that and then the image of the faders finally came up but there was a message block Error: surface control card not ready; last known state: reset. What to do now? I don't have anything to feed a digital signal into the other d8b, but I know the problem is in the d8b cause I can boot it and set the clock to internal and go in the studio and I hear it in the headphone system, no HDR connected. Also, unlike the older sessions I checked where it seemed to come in and get worse as the session went on, it is now present right from the start. I have checked out all the consoles that are in my price range and the only one that comes close to the D8B is the behringer X32, for which there is an ADAT card available. But it has some issues which would be problematic for me, and the other consoles that record via USB are too slow for overdubs.

Have a blessed day,
Mike

[Phil.c]

It looks like you need another d8b to test off, there are some good buys out there and probably a lot cheaper than a more modern desk and you know what you're doing with a d8b, I have two good spares.

[doktor1360]

Hey Mike...

I don't know what your actual budget is in regards to obtaining another desk, but this unit is on eBay - owner appears to be negotiable on price and the shipping, too. They're a music store with a good bit of gear listed, and they've had an eBay store for about 10 years.

https://www.ebay.com/itm/254880542806?hash=item3b58107056:g:~WwAAOSwqKZgOB4h

They've got a few listed on Reverb, too. This one in particular is killing me - if you can afford trip up to the north side of DC, you'd gain a windfall of gear and/or potential profits on top of it all. Somebody has to take this guy up before he moves it to an electronic recycling center (as indicated). I'd do it, but it would be like a 3-5 day excursion there n back here from GA and I'd need to rent a van, hotel accommodations, etc...

https://reverb.com/item/52950384-a-lot- ... bus-mixers

I'm seriously f'n tempted, but it seems like the cost involved would negate any profits...

Apologies for the waste of anyone's bandwidth...

[Phil.c]

Good info there, to be honest, I love the d8b and wouldn’t want anything else hence me having two spares!

[Old School]

Hi Phil and Dok,
Good info there Dok, I did see that listing on reverb and would love to take all that stuff off his hands, but its just not feasible for me to rent a big truck (not fond of pulling a trailer to Maryland) and hiring someone to drive it for me right now (although in the back of my mind, I'm still trying to think of a way to sell it to my wife). Phil, I guess you're right about being fond of the D8b, way ahead of it's time and so under-appreciated. I'm not giving up on getting the spare going, as I feel its So close to booting up. Really wish I was more of an electrical diagram guy. I have been reluctant to take parts from the noisy one, but may have to start swapping out cards, trial and error, until either the noise goes away on the first board or the second one boots. I pray that one or the other will happen soon!

Thanks for all your help, this is truly a great forum!
Have a blessed day,
Mike

[Phil.c]

Good luck Mike

[Y-my-R]

Mike, how is your "daily driver" D8B authorized?

Are you using an original serial code, or are you running a crack?

The reason why I'm asking is, because the more likely cause of that high pitch noise, would come from the console, IMO. If you run your "daily driver" D8B via the crack, then you can simply connect the other console to your "daily" rack unit, and it should boot just fine, as long as the console generally works.

That is... in theory, there's of course always a small risk that the spare console could have a serious electrical defect that could cause damage to the rack unit, you need to keep working. But if you know that the spare console worked before and you know what "good parts" you may have replaced with "potentially bad/intermittent" parts, and there were no "everything I connect this to gets fried" issues, then I'd think it'd be worthwhile to just hook up the spare console to your MAIN rack unit.

This only works, when running the crack, though. Otherwise, you'll get some error about having to authorize, since the serial code in the DSP board won't match the "real" code for your daily unit, when hooking up the spare console.

Basically, i'd hook up the spare console to the "main" rack unit, and then move some of the digital connections from the main unit to the spare as well... then try if the noise still happens.

If not, then it's something in your "main" console. If the spare makes the same noise, then it must be something in the rack unit, or something that is now connected to the spare again as well.

Dumb question, though: You didn't add any new gear to your studio, or maybe even just new lights or something? I'm just wondering if there might be a new source of interference - if so, try with the new thing unplugged, too

As for used D8Bs... I'm in Los Angeles and since there are (or were) lots of mid-level studios around here, they pop up on Craigslist often enough. I paid $200 for 2 otherwise complete D8Bs that had an Error 43 (those were my first D8Bs). My third unit, I paid $125 for - also complete and had Error 43. And I paid $45 for a used rack unit, that ended up booting right up (and giving an auth error).
In the end, there weren't any "true" hardware issues with any of them. New battery, configuring the BIOS the way it should be, and reseating/cleaning the ribbon cables was all that was really necessary for each of them.
(Well, one has a weird thing with clocking that seems to depend on temperature and doesn't always recognize all the I/O cards... so that one became a spare. But generally they all "work". So, I think there's a good chance that other such "spares" might just fire right up, as well. From my experience, it's mostly BIOS and OS-Install/Auth issues that cause people to give up on their D8Bs).

Of course there's also people who try to ask for WAY too much... like one guy trying to sell a Console-only, that looks terrible (missing jog wheel, several missing buttons, etc.) for $500. And I see these ridiculous listings more often than I see appropriately priced ones... you just gotta check often, and be fast when one with a good price pops up.

I found all the 3 units mentioned above (and extra rack unit) via Craigslist... but over the span of about 4 years or so. So, with a little patience (and living close to a metropolitan city), they can be had pretty cheaply, IMO.

[Old School]

Hi All,
Yeah, I know there are D8B's out there to be had for cheap, but aside from the spare I have that is no longer functional, years ago I bought 2 other D8B's online and had to return both of them (after much headache with Ebay and Paypal) one of them was DOA and on the other the faders moved as if you were pulling them through sandpaper. Just don't want to spend money and be no better off when those funds could be applied to something new. Per your advice I have disconnected all outboard equipment and still the noise persists. Also following your suggestions, tonight I'm going to hook the spare console up to my working rack unit and see if will come to life and maybe solve the problem. As for the other CPU, I have now replaced the motherboard and put in a new Astec power supply, and still get "surface control card not ready, last known state: reset". The only thing left would be the smaller power supply, are those still available? Oh, and does anyone think that a bad stick or RAM could cause this error message? I hadn't thought of that until just now. Does anyone have a diagram of what voltage should be on what pin on the BFC so that I can rule this out? Many thanks for all your suggestions, with the help of all you guys, I believe I can fix this.

Have a blessed day,
Mike

[Y-my-R]

The simplest thing that could be wrong to get the DSP card not ready error, is if the DB25 "Console DATA" cable is not connected between the console and the rack (or if it has an issue).

Are you using a known good cable for that? Maybe try swapping that cable out with the one from your main unit, for the test?

If the Com1 and Com2 ports are not hooked up correctly on the new board, THAT would cause this issue, though.

As for how to connect these (i.e. in which orientation) - the red stripe on a ribbon cable always indicates "Pin 1".

On the mainboard, COM ports like that usually have something like a rectangular outline printed around them, where one of the corners is flattened off, and often times red. That corner is where pin 1 needs to go.

Some mainboards don't have that rectangle, but have a small number "1" printed on one corner... that also stands for where pin 1 should go (the red stripe).

Since these don't have a sort of "socket" or retaining walls around the connector on the mainboard, it's really easy to put them on offset, basically leaving two pins on one of the sides sticking out of the connector.

So... I'd take a REALLY close look at the COM connectors on the new board, and make sure that pin 1 is where it needs to be.
The mainboard manual usually also has an image that identifies the connectors and where pin 1 is (sorry... can't look right now).

So, a problem with those, would be my first guess, if you replaced the board, and know that the DB25 cable between console and rack unit is good.

I don't think bad RAM would be the likely cause of that... seems like a communication issue (i.e. (ribbon) cable connections), or actually an issue with the actual DSP board.

Bad RAM would likely fail sooner during startup, or result in random crashes.

...and just for the record: One of my initial 2 D8B's I bought, was "complete" but ASCII input wouldn't work. Likely a bad keyboard controller chip, not sure. That's why I bought that extra rack unit. Sorry, my story earlier sounded as if I never got anything that was actually defective, and that's not the case.
I also really only "fully trust" the one rack/console combination I have. But the other two spares at least boot up (...and now that I think of it, one of them had issues with passing audio, last time I tried, even though it worked when I had decommissioned it).
So, I didn't mean to say that cheap units in perfect shape are readily available. Of course you'll have to be careful, and it's likely that something is NOT right with old boards like that. On average, though, I personally never really got something D8B related that was a lost cause. But that doesn't mean this couldn't happen.

Anyway... I hope it was as simple as those COM1/COM2 connectors (or the BIOS settings for them... if those are set to the wrong IRQ, it will also fail with the same error).

Best of luck, Mike!