Connecting Grace 101 to unbalanced input.

[skiltrip]

I just picked up a used Grace 101 pre. I'll be hooking it up to an M-Audio 1814 fw interface. The Grace's output is balanced, and the 1814's input is unbalanced. Grace says you can use a TRS cable for the connection as long as the Ring is left floating and unconnected on the unbalanced side.

If I'm thinking correctly, and regular unbalanced Tip-Sleeve 1/4" connector leaves the ring floating right?

I'm just checking to make sure I can simply use a TRS cable to connect my 101 to my 1814. Thanks.

[Studiodawg]

It will cause problems. Call Grace and speak with them directly. It is risky to the Grace 101 plus you'll hear audio problems...I know from experience. Grace 101s use balanced connections.

[skiltrip]

It will cause problems. Call Grace and speak with them directly. It is risky to the Grace 101 plus you'll hear audio problems...I know from experience. Grace 101s use balanced connections.

I'm currently emailing with a tech from Grace, but no one seems to be understanding.

The deal according to grace is... the RING on the unbalanced end must be floating, like, not connected to anything.

Now, regular TS tacks... unbalanced 1/4" jacks have one little metal piece that "clicks" into the ridge on the tip, and the RING part (should the cable be a TRS cable) doesn't actually touch anything. I don't have a jack and plug in front of me to confirm that, but basically I'm asking if that's the case. If that is the case it would seem to me that using a TRS patch cable would work fine. Now, of course using a TS cable would be bad, but that's not what I'd be doing.

[The Scum]

If I'm thinking correctly, and regular unbalanced Tip-Sleeve 1/4" connector leaves the ring floating right?

No. On a regular TS connector, the spot that lines up with the ring on a TRS connector is a part of the sleeve. If you plug a TS into an output that's looking for a TRS, you'll be grounding the ring. Grounding is not floating.

Now, regular TS tacks... unbalanced 1/4" jacks have one little metal piece that "clicks" into the ridge on the tip, and the RING part (should the cable be a TRS cable) doesn't actually touch anything. I don't have a jack and plug in front of me to confirm that, but basically I'm asking if that's the case.

Plugging a TRS into an unbalanced input? There are no guarantees. If they used a TS for the input, there's likely nothing that'll touch the ring, so it'll be floating, and you're OK. But they might have used a TRS connector, and you'd be guessing about that they did with the ring. It might have been left floating, and you'll be OK. They could have also assumed that you'll always be plugging in a TS connector, in which case they could have grounded it...not a problem for TS cables, but it'll make the Grace unhappy.

If you've got an Ohm-meter, you can measure the input to see what the ring connection looks like. If it's shorted to the sleeve, you'll need a special cable.

[skiltrip]

If I'm thinking correctly, and regular unbalanced Tip-Sleeve 1/4" connector leaves the ring floating right?

No. On a regular TS connector, the spot that lines up with the ring on a TRS connector is a part of the sleeve. If you plug a TS into an output that's looking for a TRS, you'll be grounding the ring. Grounding is not floating.

Now, regular TS tacks... unbalanced 1/4" jacks have one little metal piece that "clicks" into the ridge on the tip, and the RING part (should the cable be a TRS cable) doesn't actually touch anything. I don't have a jack and plug in front of me to confirm that, but basically I'm asking if that's the case.

Plugging a TRS into an unbalanced input? There are no guarantees. If they used a TS for the input, there's likely nothing that'll touch the ring, so it'll be floating, and you're OK. But they might have used a TRS connector, and you'd be guessing about that they did with the ring. It might have been left floating, and you'll be OK. They could have also assumed that you'll always be plugging in a TS connector, in which case they could have grounded it...not a problem for TS cables, but it'll make the Grace unhappy.

If you've got an Ohm-meter, you can measure the input to see what the ring connection looks like. If it's shorted to the sleeve, you'll need a special cable.

I have an ohm meter, just not sure how to use it. What do i do to check on the 1814's jack? I Assume I'd plug the TRS cable into my 1814, and check the ring part to see if I get a reading. Is this correct? If so, what setting on my ohm meter should I be using? Or can I just plug the TRS plug into the 1814 jack and test for continuity between the sleeve and ring
? let me know the proper way to check this.

[Studiodawg]

You will need a balanced connector or you will risk damage to the Grace 101, as per Grace...you either will need to interface using the XLR out or the 1/4" TRS out with TRS-to-TRS or TRS-to-XLR male interconnect...those are the two correct options for the Grace 101...good luck.

[skiltrip]

You will need a balanced connector or you will risk damage to the Grace 101, as per Grace...you either will need to interface using the XLR out or the 1/4" TRS out with TRS-to-TRS or TRS-to-XLR male interconnect...those are the two correct options for the Grace 101...good luck.

So just to clear this up once and for all.

I can do it like this using one standard TRS patch cable, correct?...

Grace101 OUT - TRS---------TRS - IN M-Audio 1814

I have no intention whatsoever of sticking an unbalanced cable into the Grace101. The question all along has simply been can a 1/4" TRS-TRS patch cable work.

Grace actually responded and said, yes, no problem.

[I'm Painting Again]

if you have the m101 it has an unbalanced out..

the older version does not and you wire it like in eithr figure 9b OR 11 on this chart depending on if the grace has a cross coupled or transformer balancd or pseudo balancd output:

http://www.rane.com/n110fig4a.gif

I'm not sure which the grace has..you'd have to ask Grace that..

though this:

The deal according to grace is... the RING on the unbalanced end must be floating, like, not connected to anything.

seems to indicate pseudo, i.e., wired like in 9b..

unbalanced and balanced connections are incompatable and prone to problems..sometimes it works just fine though..the best way to connect them is using a transformer in the middle..

[I'm Painting Again]

oh and no a 1/4" TRS - TRS won't work..

[skiltrip]

Well... I manned up and just made the cable as per Grace's specs. All better.

Thanks everyone for your thoughts!