couple different ways you could go - you could upgrade both and take a small step forward in both or you could upgrade your speakers and maybe another component. Either way, you must do some demoing.

The Music Hall A15.3 is a nice unit but is going to be a small step forward from the Marantz. IMO, might not be worth it. I think the Rega Brio R is the first big step forward and that is $900. It has a minimalist design but sounds amazing for the money. Rega uses the same basic design in its much more expensive Elex R and Elicit R. It is very detailed and extremely neutral. The internal phono stage is outstanding.

a few options for speakers - PSB Imagine B $1099. Peachtree Audio D5 $999, Monitor Audio Silver 2 $1050. I like all three of these speakers very much. The PSBs are probably most detailed of the three and for classical, I think I would find them most appealing. The Peachtrees are awesome. I really liked them when I heard them. Neutral and a touch more forgiving than the PSBs. The Monitor Audios sound amazing, are very forgiving but lack a bit of the detail you get with the others. If you have some older records, these are a nice option. I would encourage you to listen to all three and anything else that's in that price range that you can find.

Alternatively, the PM6004 is actually a pretty nice sounding integrated amp and could be used to drive a nicer pair of speakers. You could step up to the next rung in speakers and consider the Dynaudio Excite X14, Revel Performance 3 M105, B&W CM5 - all at $1500. These are all extremely transparent, detailed speakers. The B&Ws are perfectly neural and ultra detailed. I find them a touch too detailed, others love them. The Dynaudio are perfectly neutral with a touch less detail but still more transparent than the PSB, Peachtree or Monitor Audios. The Revel Performa3s have the tiniest bit of warmth with the same level of detail as the Dynaudios.

If it was me, I would rather have the Marantz with any one of the $1500 speakers vs the Rega with any one of the $1000ish speakers. Although that would be right for me, you may prefer it the other way. I personally own a Rega Brio R and have it driving Revel Performa3 M105s.

One note, a lot of folks think you can't hook a subwoofer up to the Rega. That is not true. You need a subwoofer with speaker level inputs and you just need to validate that it is internally common grounded. This is an easy question that any manufacturer can answer either in there FAQ or via an e-mail to support. I have a Sunfire Tru sub in my system.

I think you will really like those. for classical, I think they sounded better than any speaker I demo'd.

I recently replaced a set of those Boston A26 speakers with some Dayton B652 speakers that cost $40 per pair; it was a big improvement.

The Wharfedale Diamond 10.2 speakers are only $495, and I think they would be a perfect match for your amplifier. They are excellent speakers.

I do not think your amp has the power required for the CM5 speakers. They need an amp with at least 80 watts per channel IMO.

I am just curious why you feel so much power is required for those? I ask this because the specs would suggest the PM6004 has plenty of power to drive them. I am not trying to be contrary, I really am curious.

I looked at it from this POV - they have an 88dB Sensitivity and with 30w of power (low end reco from B&W for power) they would output 98dB of volume at 8 feet which is pretty loud. That is only 2/3 of the power output of the Marantz. I have even listened to this exact combo at BestBuy and thought it sounded pretty good.

What is it about that higher power output that would make a difference with these speakers in particular?

deleted