Adding a 24Ai to my 828es for more analog inputs?

[James Steele]

Okay... so I got my 828es and busy getting my new studio configured. The 828es is awesome but it doesn't have a ton of analog inputs which is what I'm looking for as I previously had a 24 I/O with my old system that I connected several hardware synth modules to. (Actually I had them connected to a patch bay which was normalled to the 24 I/O, which allowed me to patch a module's outputs to two Avalon U5s connected to XLR inputs on my HD192. I could track synths through the U5s and also set just the right amount of level.)

Okay... so that said, I'm thinking I want to add a MOTU 24Ai to this setup. It doesn't have TRS jacks on the back though... it has D-Sub and Phoenix connectors...

rearpanel24ai.png (441.12 KiB) Viewed 893 times

I'm thinking the D-Sub breakouts would be expensive and kind of a pain. Looks like I can use these Phoenix connectors which it appears I could just take the cable runs from my synths currently, snip it off at the connector, strip the wire back and screw the bare wires into the connector and attach to the back of the 24Ai.

PhoenixConnector.png (340.68 KiB) Viewed 893 times

Of course the synths aren't balanced connections, just regular 1/4" jacks... so I'm guessing I would just connect the positive wire (tip?) to the first slot on the connector, the negative/shield to the second slot... and the nothing on the third. Should be golden then. Also should be able to set the trims using the Pro Audio Control mixer to match the outputs level of the synth. The inputs are "digitally adjustable -96 to +22" according to MOTU's specs.

I should be able to connect it to the back of my 828es with an Ethernet cable and be good to go. Anything wrong with this plan??? Besides having to spend another grand?!! (I have been looking but it appears there are no currently manufactured Analog to ADAT optical units. I could conceivably get more analog I/O by connecting something like that to optical inputs on my 828es. But I don't get the trims and I'd have to get two of such units used to get 16 inputs. I prefer the idea of just running one ethernet cable to where I want to position the 24Ai.)

[CharlzS]

Maybe look at a short d-sub TRS breakout snake(s) with 1/4" TRS couplers. May not be pretty, but avoids making your own cables and connectors.

[James Steele]

Maybe look at a short d-sub TRS breakout snake(s) with 1/4" TRS couplers. May not be pretty, but avoids making your own cables and connectors.

That sounds like a possibility. I'm just having a few problems with that so far... although I just started searching:

1) I need DB25 break to 1/4" FEMALE TRS jacks. Everything I've seen goes to MALE plugs. Which makes sense... but I don't want them all one length. I want to plug existing male 1/4 into a female jack at the end of a DB25 breakout.

2) If I find one, it will probably be TRS. Will it work properly when I insert unbalance TS plug into it?

3) Expense: What I'm seeing ain't cheap. Saw one that was to 1/4" female jacks that was Mogami and over $200! NOPE!

The Phoenix connectors are 10 bucks for 5. This is going to be a somewhat permanent installation so I may just go with my plan of snipping off the connectors cables (I'm using thin foil-shielded Belden cable) stripping it back, tinning the wires and attaching to the connector with a screw driver. I'll probably detach the cables from the output jacks of the modules, label the 1/4 connectors (of course!), connect the whole business to the back of the 24Ai, then drop the cable bundle connectors first through the slot in the rack, screw down the 24Ai, and then snake the connector ends to where they need to go.

If something changes, it's probably not too hard to measure out a length of cable, solder a 1/4 connector to one end, prep the bare wires on the other end and then pull the connector and attach and then reconnect.

Again, this is going to be a somewhat permanent studio installation, so I'm not looking at frequently connecting and disconnecting where you'd want the robustness and reliability of a DB 25 connector. At least that's how I see it for now.

[CharlzS]

I was suggesting male TRS with couplers to convert to female. The Mogami stuff is way out of bounds.

One of these https://www.amazon.com/Elite-Core-DB25Q ... JEW6L&th=1

With some of these https://www.amazon.com/Devinal-Coupler- ... 9LF5Y?th=1

[HCMarkus]

Phoenix connections look like the winner to me!

My only question is whether you are going to want to short sleeve and ring; if you inserted an unbalanced TS plug into a TRS Jack, that's what would happen. Maybe it won't make any difference, but you might want to test and compare before putting it back in the rack.

[James Steele]

Phoenix connections look like the winner to me!

My only question is whether you are going to want to short sleeve and ring; if you inserted an unbalanced TS plug into a TRS Jack, that's what would happen. Maybe it won't make any difference, but you might want to test and compare before putting it back in the rack.

Not sure. My synths are all unbalanced. So I think I’m just going to take the tip (red) and connect to the + on the Phoenix connector and then wrap the shield to the black and connect to the - on the connector and not use the ground. I often lift the shield wire at the destination connection anyway.

[James Steele]

Well, it seems these aren't the right ones.

https://www.amazon.com/dp/B095NP9Y12?re ... KRVFZ8YPK5

I haven't tried hooking up the 24Ai in earnest yet, but I took some of the male connectors I ordered and just tried to see how they fit into the sockets on the back of the 24Ai, and they don't stay seated or fit snugly as it seems they should. MOTU gives a link to a distributor and part number on their site, but I wish they had a more specific link. If anyone has connected one of these units (either the 24 Ai or 24 Ao) using the Phoenix connectors on the back, if you could share a link to a male connector that you KNOW works, I'd be appreciative. I don't want to have to to do DB-25 if I can avoid it.

[James Steele]

Striking out here. Like I'm gonna have to use more connectors and inexact cable lengths to use DB-25??? Ugh.... I miss my 24 I/O where it had all TRS jacks. Ugh.

[HCMarkus]

May be a bit of trouble, but I like the low-cost of the Phoenix connectors. Should be a one-time job, right?

[James Steele]

May be a bit of trouble, but I like the low-cost of the Phoenix connectors. Should be a one-time job, right?

Totally. Just that the ones I bought don’t fit right and having a hard time finding the right ones online. Plus prices vary wildly. I think I’m gonna just take the whole unit with me down to Willie’s Electronics and show it to someone there and ask them how I can order what I need. I wish Mauser was still there in Santee or Lakeside.

[HCMarkus]

May be a bit of trouble, but I like the low-cost of the Phoenix connectors. Should be a one-time job, right?

Totally. Just that the ones I bought don’t fit right and having a hard time finding the right ones online. Plus prices vary wildly. I think I’m gonna just take the whole unit with me down to Willie’s Electronics and show it to someone there and ask them how I can order what I need. I wish Mauser was still there in Santee or Lakeside.

I used to love Mouser! It was almost ridiculous, having that parts supply house so close.

Look where Mouser stands today:

https://www.mouser.com/aboutus

A sub-subsidiary of Berkshire Hathaway

[James Steele]

Well, I feel a little silly. I took the 24Ai down to Willy's Electronics on D Street in National City. As typical I was over-prepared. Brought the connectors I'd purchased on Amazon. Print outs of MOTU's tech note with the Phoenix connector part number and a spec sheet from the Phoenix company presumably. Walked in... very nice gentleman behind the counter greeted me... I explained the problem... he said "Let me took at that." Then proceeded to take one of the connectors I'd bought on Amazon out of the little bag, lined it up, and popped it right in! Uhmmm... duh!

Apparently, it takes a little more pressure to click them into place than I was comfortable with having just purchased a $1000 piece of gear. But turns out I DID buy the correct connectors... just I learned long ago that if you're not sure... don't force a connection. Well, now that I know how they work... I'm snapping them in and snapping them out! Duh. So turns out THESE ARE the correct connectors:

https://www.amazon.com/dp/B095NP9Y12?ps ... ct_details

Just don't be timid about snapping them into place.

Well... once I'm feeling better, I can get started with wiring my synth modules into my system. Speaking of Amazon... now that I've figured out where I'm going to place the 24Ai, I need to order about a 6' length of CAT5e to connect the 24Ai to the network port on my 828es.