New Preamp or go Integrated

@deep_333  a) Your parasound (A23+) is not even a great piece....

b) As is with most forum guys,  you are not exactly some grand chef in the kitchen who can mix/match different preamps/power amps ...especially after age 70+ and you have no idea how to characterize the sound of things.

a) The A23+ was rated around 9/10 based on professional reviews, not anecdotal impressions from casual users / average joe like you. Under that context, it is difficult to argue that it is not a great piece of equipment.

b) You appear to assume you know the original poster well enough to discount his assessment, even referencing his age (over 70) as a basis to question his ability to characterize sound. That is an ad-hominem argument, not a technical one. Familiarity with a person’s age does not supersede objective evaluation of sound quality.

If the discussion is about audio performance, then it should be grounded in engineering, measurements, and critical listening criteria, not assumptions about the listener. Most importantly, try to control yourself and avoid personal attacks. Doing otherwise will only reflect your own shortcomings.  Do you actually understand sound reproduction well enough to refute the assessment on technical or sonic grounds?

You should strongly consider this Bryston BP26 if it’s still available if you’re looking for clarity, transparency, and an expansive 3D holographic soundstage.  It’s like the proverbial “straight wire with gain” component if that’s what you’re looking for.  I owned the BP6 that’s very similar without the external power supply and balanced inputs so very familiar with the house sound.

https://www.usaudiomart.com/details/650213711-bryston-bp-26-preamp-amp-mps-2-psu/

I’ll be a detractor and say you can save a lot of money by going with a budget SS preamp because they are remarkably good these days. Both the Topping A90D and A70Pro (primarily hp amps but can double as preamps) outperformed the Mac C49 in my system. They are at least as good as the Benchmark LA4 which is one of the best SS units I have encountered at any sane price. To get something appreciably better (meaning they put more effort into tuning by ear rather than just measurements), you’d need to step up to something like a Boulder, Soulution or Gryphon pre, which probably start at double your budget. One of the measurement-perfect Toppings (perhaps a SMSL also) will allow you to make a worthy upgrade to your amp, which IMO makes the greater contribution to a system’s overall performance. 

If you’re wanting to add color/character to your sound, I recommend checking out pre-owned Allnic tube preamp. 

The aforementioned Electrocompaniet ECI 6II is a good recommendation for an integrated—measures well but the designers also focused on subjective quality. It has good connections and plenty of power for most speakers. The built in DAC is no slouch either. 

The Music Room has an EMM Labs PRE2 for $3600, outstanding solid state preamp, circa 2015, $15K MSRP. 

https://tmraudio.com/fresh-arrivals/emm-labs-pre2-stereo-preamplifier-fyxp/

Just giving my personal experience but last year I purchased a used Marantz SC-7S2 and was a CONSIDERABLE upgrade from either of my previous preamps sc-11s1 and the tube Schiit Freya+. I haven’t honestly spent a lot of time with integrated to truthfully compare but I certain like my separates. I saw a brand new sc-7s2 on ebay for $3999 and if mine wasnt in already great shape I would’ve pulled the trigger. It is a pure analog unit though so you wouldn’t be able to stream with it, and you would need to use quality (not expensive) interconnects from analog outputs of any sources you would want to use with it.

Anyways, my money would be on finding a preamp so long as you still really like your amplifier. Happy hunting!