connecting unbalanced sources to balanced TRS patch bay

[imo]

I have done a couple of searches and already understand the nature of connecting an unblanced source to a balanced TRS or XLR. I am trying to tie my cd player, which is RCA, into two points on the patchbay..I know it is optimal to use a transformer, but in lieu of that, what would be the best way? At one point i had the grounds tied on the two channels, but one was a few db's quieter, so i clipped them and now i have an even signal, but it is too high.
Would love any suggestions
Ian

[ashcat_lt]

have you tried turning down the input of the device you're running into?

[imo]

the issue would be side by side comparisons between two sources. For instance: A cd of a mix i like vs. a mix i'm working on. Its one thing to have a couple of DB difference, its quite another in this case when one level is significantly louder than the other. Also, i'm interested in different methods on how to do it to see what the consensus would be in tying an unbalanced stereo signal to two spots on a balanced bay
Ian

[Mark Alan Miller]

Regarding comparing things, the closer in level you can get the better. Because of how we hear (see Fletcher and Munson) louder sources will appear tp have more bass and treble, all other things being equal. Even as little as .25 db difference in level. the louder source will sound subjectively "better".

[Kitana_One]

Are you working in all analog, or is there a DAW somewhere in the setup?


The reason I ask is because as Mark stated, volume differences will skew your listening experience.

If you've got a DAW, import the track into your session and solo/unsolo as needed to compare the two, you can also visually verify the db of the tracks and match yours to the other to accurately see where it's falling short.

If you're running all Analog, it's going to be a bit hard to get 100% accurate measurements. Even really good VU's are going to differ slightly with a million different factors.


You really should want to simplify the signal chain and reduce the amount of variables in the setup, signal chain and ow many times it breaks, playback devices, measurement devices and monitoring devices. Te less variables and more simplified your chain is, the better.

[I'm Painting Again]

I think you may get better results going directly out to a good monitor contoller with a/b capability rather than patching through anything..

to connect rca unbal to XLR or TRS balanced:



The above drawn configuration is recommended. However, with the nowadays common electronically balanced (i.e. non-transformer) inputs, in some cases hum and or RF interference problems can be experienced. In this case the cable shield can be experimentally connected to signal ground at the unbalanced signal source side plug, either directly (in case of hum) or (in case of RF interference) by means of a 10 nanoFarad ceramic disc capacitor or a series network of a 47 Ohm resistor and a 10 nanoFarad ceramic disc capacitor. The best solution is situation dependent.

Note: Mixed interconnection of balanced and unbalanced equipment remains prone to hum and noise problems since these two types of signal operation are incompatible. The above diagram is the recommended simple solution, though best is to apply an audio isolation transformer when connecting balanced to unbalanced or vice versa.