Will this amp trick work for increasing bass performance?

Guys, what about a pre amp with a built-in EQ, like this McIntosh MA9000 https://www.mcintoshlabs.com/products/preamplifiers/C53

@onhwy61 You mentioned tape loop. Like this "tape output" https://www.ayre.com/wp-content/uploads/2018/05/KX-R_BACK_Web.jpg

And how/where do I add the equalizer in that scenario?

I have to chime in here. Paul McCowen from PS Audio said the best way to connect your subs was to connect them directly from the speakers to the high level inputs on the sub. (he has a video on the topic) In this way it picks up the dynamic characteristic of the amp. Connecting straight from the pre-amp is passive.

The result of this change was nothing short of amazing. For so many years I had my subs connected 'passively' to pre-amp. This change has added dynamic 'punch' and tightness like I've never had before. I now pick up the punchy personality of the amplifier. Not more bass but tighter bass. Exactly what I had been searching for over many years. Bass you can feel. Provided your sub can accept high level input connection this is a game changer. It's a simple, cheap connection taking a few minutes to change and the results are huge!!

I have two 12" inch subs in stereo connected directly to my McCormack amp and my search for better bass has ended thanks to Pauls simple trick. Makes me wonder why the entire industry suggests connecting to the pre-amp. 

Tidal question... from what device are you streaming from? How is the connection made?

@gdaddy1 Did you say "connect them [subwoofers] directly from the speakers". Can you elaborate on the exact wiring in this scenario?

I play Tidal via Chromecast to my streamer, wirelessly. I also have a AudioQuest Dragon Cobalt that I attach to my iPhone or MacBook, then via a 3.5mm to RCA to the pre-amp.

I got suggested that Roon can play the Tidal library too, which superior results

Robert,

I just positioned Two xa60.8's in my listening room. They are paired with Paradigm Personal 7F's and a Premaluna Preamp (EVO 400), streaming Qobuz on Lumin. I am literally 30 hours into burn in. Our specs are not exact, but similar. You're getting a lot of great advice from some qualified folks. To fill my knowledge  gaps, l called Pass and spoke to Kent ( long term technical support), he was excellent to work with. I was looking at all the same amps and he astutely guided me to the 60's. I purchased the from Reno HiFi. Mark is the owner and excellent to work with. I wont speak for him, or the options he will positioned, but I was very confident he would work with me until I had the amp/s I wanted. The bass generated is significant tight and very detailed. I have two subs from the previous configuration that are unlikely participants in the new line up. This is not an advertisement for either, my first exposure to both, just an excellent experience I want to advocate.