d8b I/O cables and connection

[juanbanzai]

Hi everyone.

I'm really enjoying learning how to use my d8b now that I have it up and running well along with the HDR. However, I'm finding it difficult to comprehend the way the d8b uses its ins and outs. I see the expected 1/4" TRS jacks on the back of the board, but the problem I'm running into is how to connect devices to anything beyond line input 24.

My d8b has three optical I/O cards installed. However, in the manual it shows that there should be three cards with 25-pin D-Sub AIO cards installed. I'm assuming that the analog I/O from 25-48 would be coming from these cards. Is that correct?

Also, I have a single card on the d8b that shows up in the manual as being in the "ALT I/O Card Slot". However the 25-pin D-sub connector on this card is labeled as "AES/EBU PDI-8". I honestly don't have any AES devices in my studio other than a DAT machine I've been archiving old productions from. Is it at all possible to use that input as a regular analog input? I saw in the manual where you select the "Digital I/O" button and look for a menu option to do things with that input, but I haven't been able to figure out anything useful yet.

I found a box in our shop that contained eight 25-pin D-sub to 1/4" TRS" cables in it for use with the d8b. These would be perfect to use for connecting my devices to the d8b... only I don't have the connectors on the board to accept them. Should I take the time to find a set of the 25-pin I/O boards for my d8b (obviously not from Mackie) or is there another solution that I'm just not seeing at the moment? I just have no use for optical connections on the d8b.

Thanks for any info you can provide.

Aaron

[doktor1360]

Hey Aaron... lemme see if I can address some of this for ya at face value...

... I'm finding it difficult to comprehend the way the d8b uses its ins and outs. I see the expected 1/4" TRS jacks on the back of the board, but the problem I'm running into is how to connect devices to anything beyond line input 24...

My thoughts here are to look at the rear of the console, the i/o connections are arranged in a fashion that's defined and highlighted by the white lines delineating the sections involved. There's 12 XLR-F mic inputs with their subsequent insert point 1/4 TS connector inputs, and 24 1/4 TRS line level inputs in this grouping subset. As a blanket statement, when you're tracking any project these are what will be useful in connecting the microphones and line level inputs.

My d8b has three optical I/O cards installed. However, in the manual it shows that there should be three cards with 25-pin D-Sub AIO cards installed. I'm assuming that the analog I/O from 25-48 would be coming from these cards. Is that correct?

Simply put, yes... however the 4 slots in the I/O connector bay could be any combination of DIO-8, AIO-8, OPT-8 or PDI-8 cards (4 card slots tape 1-8, 9-16, 17-24 & ALT-IO). Any digital signal connecting to these fours slots do not engage any of the consoles preamp circuitry or subsequent A/D converters. Internal signal routing is dictated by the card(s) installed here. All this is indicated the block diagram (Figure 1-6 D8B Block Diagram) in Chapter 1 page 14 of the owners manual.

Also, I have a single card on the d8b that shows up in the manual as being in the "ALT I/O Card Slot". However the 25-pin D-sub connector on this card is labeled as "AES/EBU PDI-8". I honestly don't have any AES devices in my studio other than a DAT machine I've been archiving old productions from. Is it at all possible to use that input as a regular analog input? I saw in the manual where you select the "Digital I/O" button and look for a menu option to do things with that input, but I haven't been able to figure out anything useful yet.

Again, I'd suggest pouring over Ch's 1 & 2 of the manual... IMHO, with this console it can be somewhat difficult to apply a vanilla answer for this type of questioning. A lot really depends on what you a) have as far as hardware involved and b) ultimately what you're looking to accomplish...

I found a box in our shop that contained eight 25-pin D-sub to 1/4" TRS" cables in it for use with the d8b. These would be perfect to use for connecting my devices to the d8b... only I don't have the connectors on the board to accept them. Should I take the time to find a set of the 25-pin I/O boards for my d8b (obviously not from Mackie) or is there another solution that I'm just not seeing at the moment? I just have no use for optical connections on the d8b.

Wow... DB25 cabling can be really useful and pricey as well, so I'd hang on to those regardless. To my knowledge, there aren't any i/o boards available from non-Mackie vendors, unless I'm reading this incorrectly. As far as optical connections, that may apply in your specific case... however, there are many users (myself included) that would disagree with their usefulness. Again, it's all about whatcha have and what you're trying to do...

I'm hoping this was somewhat useful, as I'm addressing this kinda shooting from the hip not knowing all the variables involved. I stand corrected if any of this proves to be erroneous...

And of course, based on that you knew this was coming, so here it is:
[Standard Mgmt Disclaimer] - "Your actual mileage may vary..."

[juanbanzai]

Thanks again for the info, Dok.

I spoke to our Chief Engineer this afternoon and he swears the optical cables that connected between the HDR and the d8b are somewhere in the building. This is where it gets weird. Apparently the MDR we had was used as a remote recorder and those 25-pin to 1/4" TRS were used to connect the MDR to a remote mixer we were using. In the STUDIO, the HDR was connected directly the d8b using an optical snake which has not been located yet.

I'm going to spend a lot of the evening trying to compare what I'm reading to what actually is happening on the board. I think I'm making it over complicated. For example, if I have two external EFX units, I'd love for them to NOT take up one of the line inputs on the d8b. If there's a way to get the output of those units on say FX1 or 2, that would be splendid. THAT'S what I'm trying to figure out.

Oh! The AES I/O on the back of the d8b... I ran the AES out from a DAT deck into the AES in on the board. Yet according to the manual, that "2-track" AES input only feeds studio monitors?! I'm missing something.

Aaron

[doktor1360]

I spoke to our Chief Engineer this afternoon and he swears the optical cables that connected between the HDR and the d8b are somewhere in the building. This is where it gets weird. Apparently the MDR we had was used as a remote recorder and those 25-pin to 1/4" TRS were used to connect the MDR to a remote mixer we were using. In the STUDIO, the HDR was connected directly the d8b using an optical snake which has not been located yet.

That snake is most likely the lynch pin of the operation for the Mackie gear, and sight unseen I'm pretty damn sure that's a pricey cable assembly too. Personally, I'd take it in NY minute... regardless. FWIW, my current platform here is ADAT connected and reliant...

I'm going to spend a lot of the evening trying to compare what I'm reading to what actually is happening on the board. I think I'm making it over complicated. For example, if I have two external EFX units, I'd love for them to NOT take up one of the line inputs on the d8b. If there's a way to get the output of those units on say FX1 or 2, that would be splendid. THAT'S what I'm trying to figure out.

I absolutely agree with ya... when you first get behind one of these desks (operational), it can be daunting just trying to figure out what's what and where... that kind of thing. Like just about everything else I've run into, the tech industry standard 'RTFM' applies here as well. Regarding the two external pieces of gear, the AIO-8 card mentioned would be ideal in the ALT I/O card slot available (next to the tape in/out slots)... and you have the DB25->1/4 TRS cabling already in house... problem solved...

Oh! The AES I/O on the back of the d8b... I ran the AES out from a DAT deck into the AES in on the board. Yet according to the manual, that "2-track" AES input only feeds studio monitors?! I'm missing something.

Probably not... it is routed into the console in the same manner as the 2-Track A/B/C inputs. Check the Signal Flow Diagram (Figure 1-5) at the top of Ch 1 page 13. However, also look at the Block Diagram at the top of the next page (pg 14) and you see where the signal is also internally connected to the input bus as a 2-Track digital input. Follow the signal flow from the switch and you'll see where that signal inputs into the 'Pre-DSP Insert' and 'Key Input' sub-sections...

It's the weekend, grab your favorite guilty pleasure and sit down with the manual, man... get a good understanding of the individual channel strip (multiply by 24 channels), then graduate to the subsections of the Master / Transport side of the console (right side). You'll most likely understand things to a better degree, and of course anything still confusing could be cleared up here with a simple post... *winks*

I stand corrected if any of this is erroneous, and of course you also knew this was coming so here it is:
[Standard Mgmt Disclaimer] - "Your actual mileage may vary..."

[juanbanzai]

Hey Dok.

I've got another one for you. I found several AIO-8 cards along with the optical cables that were used with this d8b many moons ago. I also found several plug-in disks AND the original OS disks for OS3 and OS5.

Like you mentioned in your previous reply, I can remove the ALT I/O card and inserted one of the AIO-8 cards I found. When I go into the Digital I/O setup, the AIO card is found. However, I can't for the life of me find in the manual where I actually assign the channels from this card to a fader on the board. Like you said, it would be ideal to put the external EFX and processing gear on the input from this card, but after following the signal flow on page 14 (left side where it shows the three "FROM TAPE inputs), I should be able to assign an input from these cards to the PRE-DSP in the Fat Channel. Nothing is showing up in the channel patch menu that looks anything like a source from the AIO-8 card.

I hope this makes sense what I'm describing.

What am I missing?

Aaron

[doktor1360]

Hey Aaron...

I've got another one for you. I found several AIO-8 cards along with the optical cables that were used with this d8b many moons ago. I also found several plug-in disks AND the original OS disks for OS3 and OS5.

Those AIO-8 cards are a nice find, I've got one myself used largely (now) for interfacing 500 series analog hardware much in the same fashion in what's being kicked around here (I think - LOL). The optical stuff is a definite asset too, I think you'll be glad you have these in the long run...

Like you mentioned in your previous reply, I can remove the ALT I/O card and inserted one of the AIO-8 cards I found. When I go into the Digital I/O setup, the AIO card is found. However, I can't for the life of me find in the manual where I actually assign the channels from this card to a fader on the board. Like you said, it would be ideal to put the external EFX and processing gear on the input from this card, but after following the signal flow on page 14 (left side where it shows the three "FROM TAPE inputs), I should be able to assign an input from these cards to the PRE-DSP in the Fat Channel. Nothing is showing up in the channel patch menu that looks anything like a source from the AIO-8 card.

I hope this makes sense what I'm describing.

What am I missing?

If you look at the manual's block diagram (ch 1 pg 14 / figure 1-6), this is the 'input' section of the console. You should see the 'ALT I/O CARD 65-72 (optional)' notation of the logical input box near the bottom of the page. That's gonna be the AIO-8 input coming from the output of any effect unit(s). Looking at that and following the connection point on the bus, the signal is routed on as the 'ALT RETURNS' and appears in the list for the 'KEY INPUT' section of the input circuitry. Physically, it should show up on one (or more) of the ch 65-72 channel strips and should be visually deflecting the meter for that channel with any signal(s) present.

The signal then exits the input section and gets coupled to the output bus, you should see this appear on the bottom of the following page (ch 1 pg 15) - the bus is hi-lighted (bold black ink). On the right margin of the page you should see the 'ALT I/O' functional output block - that's the signal going out of the console to the input of the effect unit(s). You'll also note that there's a switch that selects between the 'BUS TAP' and the 'AUX TAP' sections for outputting. Depending on the routing 'how's n why's' of all this as it applies to what you're doing, I think you should be able to walk yourself thru any signal connection(s) to your gear that are required...

This should most likely clear a few things up at a high level, but if not just reply here and we'll get it worked out.

However, if any of this is erroneous or not comprehensible in any way, I stand corrected. I'd be more than willing to explain things further in order to clear up any outstanding issues that I may not have understood myself regarding the issue...

And of course, the obligatory caveat as it always follows:
[Standard Mgmt Disclaimer] - "Your actual mileage may vary..."

[juanbanzai]

Well, Dok...

All I can say is "Shake hand with 'Mr. Utter Stupidity'". I had everything connected and routed correctly right from day 1. The problem was a setting on the back of my SPX-1000. The output has a pad that can be switched in and out. I couldn't tell which setting it was in due to the angle of my rack and my ability to see behind it. Once I switched out the -20db pad, I was hearing everything perfectly.

Wow! Utter stupidity. But really, thanks for hanging in there with me on this one.

Aaron

[doktor1360]

Well, Dok...

All I can say is "Shake hand with 'Mr. Utter Stupidity'". I had everything connected and routed correctly right from day 1. The problem was a setting on the back of my SPX-1000. The output has a pad that can be switched in and out. I couldn't tell which setting it was in due to the angle of my rack and my ability to see behind it. Once I switched out the -20db pad, I was hearing everything perfectly.

Wow! Utter stupidity. But really, thanks for hanging in there with me on this one.

Aaron

LOL

Interconnect fun... it happens, Been there, done that... got the T-Shirt, Hat and all the requisite scars... another glorious V8 moment with the D8B/HDR... *grinning widely*

Bottom Line - good to hear you got it all straightened out tho, Aaron...