Intergrated amp upgrade ?

deadhead1000,

Assuming low volume listening is frequent:

IF anyone adds a sub to their system, to 'normally' extend the low bass capability, and ALSO for bass boost at low volume, it is a bit tricky.

using a sub can work IF you have independent remote volume control of the sub. Normal setting for normal volume listening; boost a bit for low volume listening.

Next, you need to remember what/where you adjusted to get back to 'normal volume' setting.

Adjustable Crossover. Use the highest crossover to the sub, so that more low frequencies are boosted.

https://www.sweetwater.com/insync/music-instrument-frequency-cheatsheet/

also OP said: the adjustment does not need to be 'accurate', just provide/restore an enjoyable sound.

My McIntosh mx110z's 'Loudness' is also boosting the highs, but I don't focus on that, as I said, restoring bass at low volumes preserves involvement for me.

Jazz Bass involves frequencies above sub's range, thus even if you have added a sub or stereo pair of sub's for normal bass extension, a simple tone control for bass might sound better.

The Chase RLC-1, progressive/automatic loudness is the same, juicing the bass up as volume drops is the primary advantage for me.

McIntosh Pre-amp's 'Loudness', (most vintage preamps/receivers) I have forgotten to disengage it, you notice bloated bass right away.

Chase RLC-1, you simply turn it on/off to get it back to default volume with no FM adjustment. 

@elliottbnewcombjr 

Elliot is correct, you need an amp with a loudness control, or at least tone controls, you lose a lot of music at the top and bottom end playing at low volume, it's just the way the ear works. Both those amps are great sounding, but will not make a dramatic difference in sound at low volume, and will not accomplish what you want. 

Another solution is to add a small sub to what you have (there are many small powered subs now available that can fit almost anywhere), and try that first. 

https://www.usaudiomart.com/details/649994791-parasound-halo-hint-6-integrated-amplifier-with-built-in-dac-silver/

I owned a Parasound Halo Integrated 2.1...One of the greatest audio bargains I've ever had. The above is the upgraded version.

Great company, great support, and fabulous products.

BTW- my current system is around 80K....If I had o go back to the Parasound integrated....It would not be an issue.

There is a discussion about LOW VOLUME Listening currently.

https://forum.audiogon.com/discussions/high-end-speakers-at-low-volume

I would look for optional features, Vintage: 'Loudness' circuit, Modern, at least tone controls to boost bass, or a tape or processor loop and can optionally use the Chase RLC-1 I linked