Noob! Please help me replace my old power amp, some candidates listed.

Another Parasound A23+ recommendation here. Auditioned a few class D amps the Buckeye line is very good and I would choose one for an AV application but for the money run cool performance and all around fantastic price for what you get...

Parasound A23+ you cannot go wrong for the price. 

Hello caseylol,

I can relate and went through something similar. Acquired some nice vintage gear, got it fixed as best I could. But there are limits. One exception is speakers, and I have a pair of 40 year old ADS 1290. I upgraded (at considerable cost) to PMCs, but after serving, the ADS speakers still sound amazing. I haven't tried class D, but in my system getting an external DAC made a huge difference. You don't need to spend a fortune, for instance Schiit modi+ is great and mimir is reportelly even better. Good luck

Casey:

I own the larger B&K amp (150 wpc . . . it’s >30 yrs old & working great) which, like the ST-140, uses mosfets for power. Though some criticize mosfets as less than ideally resolving (they harp on the "mosfet fog"), I beg to differ--music that isn’t hyped in the upper midrange and low treble to insinuate "resolution" simply sounds more like music. So I say if you can get the B&K, do it, revisions be damned.

I, too, do all my listening in a relatively small (13’ x 13’) home office using a nearfield configuration. With listening as close up as this, any component in the entire chain that hypes the music, makes it sound edgy and insistent, is going to give you a headache. These are the nearfield facts of life.

As for class D, I’m a big fan--but only because I did my homework (hours and hours of it) to find the few class D amps that are A. affordable for me; and B. said by at least some users as being "musical," or at least, pretty nice to appreciate music with. I ended up with 3 class Ds that sound pretty wonderful:

A. Wyred 4 Sound ST-500: This 250 wpc amp is based on ICEPower, which some deride as not state-of-the-art. Too bad . . . it sounds great to me.

B. Bel Cando 500S: Also 250 wpc based on ICEPower. Resolves a little better than the W4S, but truthfully, the W4S is more than resolving enough.

C. Bel Canto 600M monoblocks: These 250 wpc monoblocks are based on the newer NCore technology. They sound rather amazing.

Bel Canto is fairly expensive, even used. Wyre 4 Sound less so. But the prices will never get as low as the B&K, so it’s all kind of academic.

PS: The types of music you listen to are sometimes recorded "hot" in the studio, which makes it even more important to avoide edgy, bright compoments in your stereo rig IMO. 

Four days now with the Shiit Vidar 2 and using the SYS passive source selector (can't really call it a preamp.) It would be exhausting to relate the variety of music I've thrown at it. Overall I'm really pleased. I find the amp quite warm, stuff like dynamic range, transients, imaging etc is very good. In a word... speaker control! Still evaluating but I'm confident I'll keep it.

@hboden, I'm keenly interested in DAC experience. I've dedicated an iPad mini gen 5 with Plexamp (player) as a kiosk accessing my FLAC library. Now, for comparison I've also run off my SSL 2+ audio interface connected to a M2 Mac mini, so whatever DAC circuit SSL uses. I feel like there is a subtle but worthwhile improvement, sort of like the very subtly more revealing you get between pedestrian and good cables. On forums the science guys claim DACs are mostly snake oil in contrast to tons of non-scientific anecdotal DAC praise.

My budget would allow something like Modi 5 or Fiio K11 etc, or even Mimir.

Apart from DAC, I would like some tone control and while I'm not sure I need it I would also like some gain capability. So , for example, I could do a Schiit Saga pre but I'd still need a Loki Mini+ for EQ. Mimir w/Forkbeard has a parametric but only 3 band and using an app instead of knobs, plus it's not DSP, just microprocessor. To further confuse things, Schitt has the Eitr 2, and the Shiit Buf claims 12db gain.

I just don't know where to go with all this stuff, where to start. I'm thinking maybe I should start with adding some gain first then see if bypassing the iPad DAC still appeals. And apparently to bypass the iPad DAC I'll need the Apple Lightning to USB 3 cable and a USB 3 to USB C cable to connect a USB C DAC. Sheesh!

With DACs, best to try them out and trust your ears. There are many factors, including your system and room dynamic. A cheap option is the Apple dongle DAC, which is quite good. Most DACs will have USB-C input, which simplifies connecting an iPhone or iPad. For example, Schiit Mimir, Fiio K11 and K13 all have USB-C input. Those three DACs seem to be highly rated, but to be honest I haven't heard them.