Apogee Ensemble Line/Mic Patchbay Routing

[forumuser793886]

Hi there,

I'm just after some advice for wiring up or patching the inputs to my Ensemble interface.

The ensemble is slightly quirky in the mic/line inputs are on the same XLR (no TRS inputs) and are switched internally via a relay. Great that the line-inputs completely bypass the preamps, but fiddly in that they both go in on the same XLR input (lots of annoying re-plugging around the back when switching between line/mic sources).

I thought one solution could be to include a half-normalled patchbay with female XLRs half-normalled to female TRS so either could be connected from the front, but this would require a patch bay and lots of extra cabling.

I'm not sure of the electronics, but would there be a problem soldering up Y-split cables - female XLR and female TRS both going to a male-XLR into the interface?

Would that have problems regarding impedances, signal loss, or shorting if both were accidentally plugged in at the same time?

Not an electronics expert here, so not sure the best way.

Many thanks!
Jason

[Hugh Robjohns]

I thought one solution could be to include a half-normalled patchbay with female XLRs half-normalled to female TRS so either could be connected from the front, but this would require a patch bay and lots of extra cabling.

I'm not sure of the electronics, but would there be a problem soldering up Y-split cables - female XLR and female TRS both going to a male-XLR into the interface?

Would that have problems regarding impedances, signal loss, or shorting if both were accidentally plugged in at the same time?

It is certainly possible to wire a TRS socket in parallel with an XLR female and then on to an input of the ensemble. A reverse Y-split if you like. However, with such a setup there are two inherent serious risks.

1. Accidentally plugging a line source into a channel set for mic with phantom power turned on. The danger is two-fold. Phantom can destroy some line output circuitry, and high line level signals can destroy mic input circuitry.

2. Accidentally plugging a line source in with a mic already connected, which would be likely to damage or destroy the mic.

The latter risk could be overcome by wiring the XLR through the break contacts of the jack socket, thereby automatically disconnecting the XLR by plugging in a TRS plug. The downside is that you now have slightly dodgy open-air contacts passing low level mic signals from the XLR, which is not a great idea.

Personally, I'd leave the Apogee to handle mics only (via a more accessible XLR patch panel if necessary), and invest in a second preamp connected via the Ensemble's ADAT port for line sources. A cheap option would be a Behringer ADA8200. Higher quality options could be an Audient ASP880 or 800, or their new SP8... but there are many other 8-channel ADAT connected preamps that could serve equally well as a safe dedicated line input device.