Primaluna. Evo 400 - bass issues

This will be long, I really need some help determining why I’m getting poor bass response. I’m pretty sure it’s this amp, the PrimaLuna Evo 400 power amp. I’ve been trying speakers with it with poor results. In the interim I’ve been using cheap Mackie MR5 studio monitors out of my preamp, the Evo 300. I’ve had great results with these and that is the problem. These are tiny 5” near field monitors and the bass response I’ve been getting is excellent. The bass has been so good I decide to try to find a bookshelf speaker that is similar as I like how they disappear and based on the bass I was getting from these I thought I’d be good to go. I listen to predominately jazz so I’m not looking for thunderous bass just enough to fill in the rhythm section and bass walks etc. These Mackie’s do that. With that said, they don’t compare in the mids and highs but the bass is there. Here are the specs on the Mackie:


VPI Prime Signature, Hana ML, Herron VTPH-2a, Evo 300, Evo 400, Audioquest Niagara 1200. Stock tubes in the 400, Evo 300 has upgraded Psvane and 1960 Mullard rectifiers.


16.5 feet long 15 feet wide (room opens to the right another 12 feet) 8 feet ceiling

Mackie’s are 2 feet of the side wall and the back walls. I keep that for all the speakers I’ve tried.

Speakers I’ve tried:

Tannoy Turnberry’s

B&W 805

B&W 606

Ascend Acoustics Sierra 2EX

Probably my favorite were the 805 but there was no bass. With all of these speakers I found very minimaL bass response. I thought the Ascend would be good because of the impedance curve but they sounded the worst.

Personally I think the issue is the room, but then how am I getting good bass with the Mackie’s? So now I think it’s the amp. When I read about other peoples experiences with this amp bass doesn’t seem to be an issue. What gives? Am I just use to the solid state monitors and how they provide bass vs tubes? Is it the room? Poor speaker matching? I recently had the 606’s over again as they are a friends that he uses in a surround setup. They really sounded nice but again poor bass and they are rated to go deeper than the Mackie’s.

Thanks for reading.








I don’t believe that is true. But nothing wrong with trying the amp plugged into the wall.


Perhaps add a subwoofer(s) one that can be tuned to the room like a JL F-112,113


A friend of mine had a similar issue using PL amps and not getting enough bass from his Von Schweikert speakers. Hi tried several things and ended up using a used ss amp to drive the woofer and keeping the PL for the mid/trebble, was very happy with this solution.

I'd first recommend contacting Kevin Deal at Upscale Audio. He can help you with all things PL.

Have you tried to move the speakers much closer to the rear wall? Have you tried to move them much further into the room? These tests will help you to determine if the room is causing some or all of the bass loss.

I'd also make sure to plug your amp directly into the wall. The AQ1200 could be the problem, or at least contributing to it. Example, my amp plugged into a Shunyata Research Hydra 6 resulted in total loss of bass. Plugging the amp into an IsoTek Aquarius kept most of the bass, but lost the top end and sounded a little like a blanket had been put on the speakers. Tried the IsoTek Sigmas and it was able to deliver the power my amp needs and it actually sounds overall a little better with strong defined bass and great mids and upper frequencies. Using the Sigmas to this day and loving it.

Good luck in figuring this out for your room.

B&W used to be a bit hard to drive. Maybe the new ones aren't. I listened to Fyne speakers at a store and liked them. They are pretty easy to drive and has good bass for their size. F500 or F500SP may be an option for you to try.

Best bass from small speakers I've heard was probably Boenicke W5 but they cost around $7k.

Maybe switching amp is easier.