Might try a tube preamp

Since your amplifier is integrated and there doesn't appear to be a direct input to the power amp section, I don't see how a preamp tube or solid state would help.
But the amp does have a set of balanced inputs and seems to be internally balanced, so a balanced tube preamp would be a nice option as it could minimize the effect of interconnect cables on the sound. And as others have mentioned, our MP-3 preamp is such a beast and actually supports the balanced standard. The used ones here on Audiogon would be a good place to start if you go that route. Like your amp, the MP-3 is fully differential and balanced with zero feedback and a minimal signal path.

I just took delivery of the Schiit Freya. $699. My mentor warned me of a solid 24/7 five day break-in period of near unlistenability (made up) so I cannot say yet if I will keep it. (14 day trial)

Other considerations for me were :

1. Audible Illusions  New $4700, Used $2500
2. EAR 868 . New $7,500 Used if you find one would be about $4,000.

Since you are new to the tube world, the trial period offer may be the way  to go.
 

The Linear Tube MicroZotl 2 is very good and is actually only about $2,000 new with external power supply. Linear Tube has come out with a dedicated preamp which Terry London of Home Theater review has gone nuts for and is $4500. All the other posters on the thread have given you excellent alternatives. 

rshad0000

atmasphere6,545 posts09-20-2018 1:48am
Since your amplifier is integrated and there doesn’t appear to be a direct input to the power amp section, I don’t see how a preamp tube or solid state would help.

I believe it can be used as a poweramp.
" RCA Input 3 of the Diablo and using the Menu to configure this input so that the signal bypasses all preamplifier stages in the Diablo."

My friend has one he says he uses it with his Lightspeed Attenuator passive preamp.

Cheers George

rshad0000 OP132 posts

This is what you should try before blowing 5k on a preamp.

It in your instructions to set up rca input 3 to be a power amp only input.

Set the Diablo 300 in the menu to make input 3 a "poweramp input" and this totally by-pass the preamp stage.

And because your Chord has such a great volume control, connect it to input 3 of the Diablo, and use the Chord to adjust your volume.

From Chord:

"The device’s lossless digital volume control outputs the signal direct to your power amplifier for the purest experience.

DAVE has a full-sized LCD display, showing input, sample frequency, volume and set-up configurations options, within Chord’s famous porthole design. On its fascia, DAVE also features a rotary encoder with a large stainless steel controller and ball buttons, enabling direct interactivity in addition to the supplied remote control."

From Gryphon:

" RCA Input 3 of the Diablo and using the Menu to configure this input so that the signal bypasses all preamplifier stages in the Diablo."

Cheers George