System too bassy - Primaluna & Usher

Location, location, location! Don't spend a dime on 'stuff' until you have set up your speakers and listening chair as best possible. There have been a lot of posts on 'proper set up' and should be in the archives, both here and on AudioAsylum. Putting the speakers against the wall and or/a corner ALONE (And it appears you have done both!) could be causing your problem, but placing your listening chair is very important as well. Locating it in a bass node could cause excessive bass, albeit over a small frequency range.

Another issue to consider it the tubes you are using on the Primaluna, both small and large(power) tubes, which can make a big difference. FWIW if you haven't already tried them try some good linear 6550's or 6l6GC's, especially the latter if you want less bass but a good linear tone. I've used SED's and they are not fat! You might also try some Sovtek 12AX7LPS which have a fine mid-range and HF tone but are also not fat in the bass.

Deetothevee, I hate to say this, but considering the fact that you cannot change speaker placement, I think your ability to significantly alter the excessive and, I assume loose, bass will defy significant alteration just by changing 'stuff'.

You might pick up an SPL meter and a test disc w/ 1/3d octave test tones and measure your set up to verify/locate the area of boost and the extent of the boost you are trying to cure. Do not overlook my comments about the listening position - you can also reduce the bass some by putting your chair in a null in the bass frequencies.

There are two other possible solutions. 1) Use of a sub placed away from the wall/corner, and a cross over so you can roll off the bass (excess) from your main speakers. I don't know enough about a sub's implementation with your integrated though - it might not be possible for you.

2) If you are using one source for most all of your listening you might put a 1/3d octave equalizer between your source and integrated and reduce the bass hump there.

FWIW, if you are going to consider using acoustic products to reduce bass be sure to identify where the excessive bass frequencies are. Medium to low bass frequencies are difficult, if possible, to control in a small room (if at all) in a home, especially when it is a 'shared' room.

Changing wires is for fine tuning adequate systems but not for making major alterations in frequency aberrations due to room dimensions (your is one of those as well) and speaker/listening positions.

It is possible that if you can accept listening at low levels that the excessive bass may not appear so excessive. At low levels the apparent bass response of many systems in many rooms falls off appreciably (that is why pre-amps used to have tone controls, to boost the bass).

I hope you can find a solution, but it won't be easy and will require a compromise. Good luck.

Al, FWI you can change modes on the fly without risk so A/B comparisons are easy. The difference is that in triode mode the top end is rolled and the mid-range is somewhat sweeter. You can hear the decrease in power output. The change is not so much different from other amps with mode switching, IME. And I doubt that this will solve any of the OP's issues with the bass, although it will make edgy recordings far more listenable.