Imput levels on 192 I/O

[freespirit]

I am having trouble getting good strong imput levels from my 192 I/O. I am new to pro tools and don't know if there is a problem with the I/O. I have connected my sampler and synths directly to the unit via balanced cables and patchbay with screw trims at maximum travel. The only way I can get hot levels is to connect it though my Behringer digital board and pushing the fader levels to achieve a strong signal and only at the -10dbv connector. My questions are as follows:
1. Should'nt I be able to get hot signals at the imputs of the I/O when connected directly to my equipment's outputs with all balanced connections?
2. Is there any loss of fidelity using the -10dbv connection over the +4dbu?
Any help will be appreciated.

[Richard Barrie]

In my experience the average output level of an average keyboard or sampler is about 0bBU (-4VU). As I recollect a 192 has a maximum input level of 0dBU = -16 dBFS (0VU = -12dBFS) so you need about 16dBs gain on your keyboard outputs to get close to maximum level on ProTools even with the input level trim at maximum.

Going in on the -10bBV inputs will give you another 12dBs gain so you will still be at least 4dBs short of maximum level.

The -10dBV inputs are balanced inputs so as long as Digidesign have done their job well, there should be no difference in sound quality (other than the noise floor being raised slightly due to the extra gain - but this would happen with any extra amplification).

It is incredibly easy to design and build a set of extremely high quality unbalanced / balanced input to balanced output preamps to give switchable gain in 6dB steps. Using readily available OP amps and a bit of vero board the component cost is under $20 a channel (plus a fair bit of bench time). This kind of interface can also be used to cope with all of the different grounding configurations that the keyboard equipment manufacturers present us with.

[freespirit]

Richard, thanks. This is the best explanation that has been offered to me and it clarifies the imput issues.