Should I replace ARC D130 for Bryston 4B-ST?

I am running my Sony XA-7ES straight into the ARC D130 using the digital volume control of the Sony. My speakers are Sonus Faber Grand Pianos(not HOMES) and using Nordost Blue Heaven speaker cables.

I am satisfied with my current system but feel that the ARC D130 is lacking in the bass department (bottom end sounded loose and doesn't go too deep) and the highs are not too extended.

Do you think I should go for the 4B-ST? I was mainly aiming to get a more 'lively' sound and better bass with the Bryston.

Please advice as I have found a unit in the used market and it's just a matter of time before I buy it from the seller.

Also, do you think by getting a dedicated preamp like the BP-25 the sound will be further improved? I only listen to CD's and nothing else so I didn't consider getting a preamp at the moment. Will getting a dedicated preamp yield better results than running the CD player straight to the power amp?
For Grand Piano you'll definitely need to increase power to get more bass.
I wouldn't recommend you going with Bryston preamps though -- just a waste of money.
You should look among the MacCormack models that are priced much lower and perform much higher.
I cant speak for the Bryston pre amp, but think that the 4B-ST will give you the "kick" your looking for with the SF's. I have owned several ARC SS amps and have found all to be very good, decent in the bass and better than average in the mids and upper end. The Bryston will wake up your speakers, but would be concerned that it may not be the ARC's equal in the upper mids and could add a touch of grain overall.Though many LOVE this amp for what it does, it seems to pair well in many systems.--Ken

I can't speak for the Bryston, but I had an ARC D130 and replaced it with a ARC 100.2 and the difference was stunning. The 100.2 is very very musical. It also gets great reviews.

Just my two cents.
the arc 100.2 is great, as are several mac tube amps...but for 2g's its hard to beat a bryston in the bass dept...its also a good all-rounder.
In most all systems a great pre is always better than going straight to the amp with a cd player's volume control. Then think about whatever amp.
Thanks for all your responses. Most likely I will get the Bryston.

I am well aware that the ARC D130 will be better in the upper mids but I'm willing to sacrifice that for a livelier sound, more controlled bottom end and extended highs(although some would say it as splashy treble with the Bryston). It's just that I prefer a more upfront sound.

As for the ARC 100.2, I do know that they are very good amps and certainly a marked improvement over the ARC D130, and probably better than the Bryston. But my concern is that a new unit of the 100.2 cost twice as much (or more) than a used 4B-ST. I'm a poor audio enthusiast so I have to make do with the Bryston....for now.

Well that's all folks. Looks like I still have to get a preamp and there's no way going round this one, and thanks for your advice Marakanetz on Bryston preamps. Nearly got one early last month but rejected the deal since it's black in colour(I wanted a silver one!).