Pre-amp or cd direct to XA30.5 ?

I'm new to this, and this is my first forum.. so here goes. I have an old set of Tannoy D700's and have purchased a Pass Labs XA30.5 amp. I'm questioning
if I must adhere to traditional pre-amp (probably X2.5 or X1 2nd hand), or can I go direct from cd player with say digital inputs and volume control (say modwright oppo 105) or wadia? Any thoughts.. My reason for against pre amp is simply don't need that many inputs. Ideas pls.. and tks for any advise ..
As long as the source device has VARIABLE volume control, sure you can go direct into the XA-30.5 amp.

Some sources have both fixed and variable outputs. Make sure you use the correct one!
advantages / disadvantages?
This has been discussed quite a bit on the forums. Use the search function on the forums. Type in "direct to amp" (without the quotes) and that will come up with several discussions. You might try to search "no preamp" also.
Your Pass XA30.5 has 30kohm input impedance, this is fine for you to direct connect from a source that has a digital domain volume control.
Just remember that some digital volume controls can "bit strip" if used below 2/3rds of full output.
Bit striping is a loss of bits, IE: instead of 16bit resolution it can be 14bit at volumes less than 2/3rds, which in some cases is not too bad as 14bit has a softer sound, which is better for background music anyway, such as dinner party music.

Cheers George
Many tks. If direct.. was thinking Wadia or Esoteric. I'll see if these have this "bit strap" issue.. Many tks for your help.
modwright advised against direct for their oppo 105... for bit stream issue (ie. Loss in sound quality).
I think there is an ulterior motive for saying this, a standard Oppo 105 that has low output impedance would be fine driving into the XA30.5, but Oppo 105 with a modded tube output stage will be much higher in output impedance, and maybe have trouble driving into the low input impedance of the XA30.5

Cheers George
"02-20-14: Fsyme
advantages / disadvantages?"

You have to take it on a case by case basis. You can get great sound wither way. I used my Wadia's on Pass amps and was very happy with the results.

Also, I got together with a few friends and we tried to see if we could hear any loss in SQ at lower volumes. None of us could hear any difference at all. Wadia was the only brand we tried. Don't know if it will be true for all brands. One imporent thing to note is that Wadia players have different global gain settings that you can change using DIP switches. That way you can keep the volume as close to 99 as you can with just about any other components.
I had Mark Levinson No.39 a while back same setup, that's why Wadia did this also, so you could run it near full digital volume with the analogue gain selection so there was no risk of "bit Striping".
But to be honest the difference between full 16bit resolution and 14bit is not that huge, 14bit just sounds a little softened around the edges, which as I said is probably a good thing for dinner parties, or lift music.

Cheers George
I did some reading online and looks like my XA30.5 has max voltage at 0.77V. Wadia can set to 0.5V or 1.1V. To achieve max performance, better setting the wadia to .5v for 100% vs 1.1v?
I would set it .5v first and if you can get loud enough volume, then your your fine. I'm sure you will as that's around 2/3rds of the XA-30.5's full output.
If not then go to 1.1v

Cheers George
"02-21-14: Fsyme
I did some reading online and looks like my XA30.5 has max voltage at 0.77V. Wadia can set to 0.5V or 1.1V. To achieve max performance, better setting the wadia to .5v for 100% vs 1.1v"

There's more to it than that. Bit loss is only one of several factors to consider. For example, I have a pair of Wilson speakers I sometimes use. They're very efficient. If the gain on the Wadia is set too high, I get a hiss. Its a very common problem with efficient speakers. Other factors that will determine your overall gain settings are how loud you like to listen and how big your room is. You just have to experiment and find the best setting that works for you. Its also very easy. It shouldn't take you more than a few minutes to find out where you need to be.
If you can match the source to amp properly that has a good volume control, mated to a tube/solid state Hybred or just a tube player to a good solid state amp,, I can tell you that my findings is the source direct to amp is the best I have heard, mated with some very good cables, It's a done deal.
Ive around $2k right now.. and saving. Any advise on a good preamp other than pass X2.5 or X1.. (if i can find)?
"02-24-14: Fsyme
Ive around $2k right now.. and saving. Any advise on a good preamp other than pass X2.5 or X1.. (if i can find)?"

I had the X2.5. Didn't care for it. A preamp is a very important and personal choice. Its hard to give advice on something like that. That said, if you have a chance to listen to an Ayre K5, do so. Its great all around and should be pretty close to what your budget allows if you can find one used.
Anyone tried PS Audio perfectwave MKII with pass labs direct and running as digital. I've never heard a dac system, but sounds appealing in theory.
I forgot to mention.. i've a macbook pro and have a NAS (not in use). Everything cd wise is in apple lossless format, and typically use Audirvana Plus to listen using headphones. I'm wondering about the loss in quality "bit stearing" and also the pairing with XA30.5's 0.77v max gain if the dac has no adjust for voltage. Thoughts pls... Tks again in advance for any insight.

PS reason why this caught my eye, was falls into $2K budget for 2nd hand.