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: https://www.sonicelectronix.com/item-24164-Mackie-MR5.html

Equipment:

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.

Room:

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.

 

 

 

 

 

jazzjunkie80923

@jazzjunkie80923 Are you using the stock EL34 tubes? And are you sure your speaker cables are in phase? Are you using the 8 ohm taps or 4 ohm taps?

Given the size of the room, your amp should be able to power these speakers sufficiently, even if it's not endgame performance.

Square rooms are really tough, though and are more prone to phasing issues, so this could be the problem.

I believe the Primaluna Evo 400 can accept KT150 tubes. If true, try them ... they definitely have much punchier and impactful bass than EL34's. But you might miss the special midrange sauce that EL34's add to the flavor. 

I’ve owned PL gear in various forms and with various speakers over the last few years in addition to SS amplification.  While you may also have room issues, all things being equal I have found that the PL bass has good quantity but lacks attack, or speed, compared to a good SS amp like a Bryston or Luxman.  This has been the case for me in all my trials without exception.  At one point I had two HP amps (the predecessors to your Evo 400) running as monos with KT120s, and in the bass/speed department a Luxman 509 integrated at the same w/ch rating into 8 ohms handily defeated the PL.  But the PL still have other great qualities.  It seems like an amp should have good bass or no bass, but IME it’s not that simple, it’s further nuanced.  As I said earlier, the PL have bass in quantity (a sustained organ note for example will be on par with, or close to, the SS amp) but the attack, or transient response is slower.