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Primaluna & Klipsch Cornwall frustration HELP

Well this is a little frustrating. I have a Primaluna preamp and Primaluna Dialogue 5 power amp. Found a great deal on some Klipsch Cornwalls. Heard Klipsch and tubes were made for each other. Hooked them up and it had very little bass. I was expecting a BIG sound. Sounded almost anemic. Hooked them up to a class D audio amp through the Primaluna preamp and it was fantastic. Lots of slam. A great rock and roll sound. These are very efficient speakers so I don't get why they don't sound good through the tubes. 42 watts per channel at 8 ohms. Happened to talk to a Primaluna guy and he told me I needed a more powerful Primaluna amp. That has got to be BS. Do I have bad or weak tubes?? These are KT88's! Maybe they are going out. Who knows. Tried to call Kevin Deal at Upscale but he is out of town. I am not buying a bigger Primaluna amp. Kind of offended that I was even told that. Would the KT120's make a difference? Could it be something else wrong with the amp. Thanks for any help. By the way the amp sounds sweet with small monitors where I don't expect much bass. Thanks for any direction.
128x128dylanfan
newbee
4,767 posts
 
To give you something to look forward to, with my speakers, the difference between using the 4 ohm and 8 ohm taps is substantial. In 4 ohm the bass is nice and tight - very present. In 8 ohm it is less transparent in the bass - but not necessarily boomy, just makes the sound a bit foggy. My speakers are nominally 8 ohm speakers.

And, in my Dialogue 2, I use Tong-sol 6550's which I find add some tonal richness in the upper bass/lower mid range when compared to other 6550's and KT88 (that I have on hand, anyway).

Out of curiosity are you using a Dialogue 3 pre-amp, or are you using its predecessor, the PL3. I ask because until I matched my old PL5 with the PL3 its bass was weak/thin (when using ARC and a Magus pre-amps.
atmasphere's avatar
atmasphere
11,784 posts
 
OK- in review, here are the things you need to try:

1) try a different tap (4 ohm)

Notes: the speaker is nominally 8 ohms and likely has a nice impedance bump in the low end that might help your amp out. Any notion that this amp cannot control the woofer is nonsense- this speaker was designed for amps with high output impedance.

I am thinking that the impedance is not the issue here.

2) try reversing the phase of one speaker *only* (not both!).

Notes: If it appears that you have your speakers wired correctly in phase, it may be that your amp has its output out of phase in one channel. In a zero feedback amp, this could happen due to a wiring error as there is no feedback to cause the amp to oscillate (which it certainly would do if it had feedback).

IOW, I suspect phase is the problem.

FWIW, we have customers using that speaker with our M-60 amplifier, which also has a fairly high output impedance and they report impressive results. So you should be able to make this work unless something is outright wrong with the amp.
dylanfan's avatar
dylanfan OP
139 posts
 
I am using it with a Primaluna Premium preamplifier. Thanks for the advice stmadphere. I will reverse the phase of one speaker when I get home over Labor Day. This amp hardly gets played because I travel so much. I would like to just go home, turn it on for the little bit of time me I am home and enjoy it instead of trying to figure out why it doesn't sound right.
almarg's avatar
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almarg
9,670 posts
 
08-22-15: Dylanfan
By the way the amp sounds sweet with small monitors where I don't expect much bass.

08-24-15: Dylanfan
It sounds good just missing the low end. Not as clean as my LS50's or Dynaudio speakers but will probably be a great rock and roll speaker when I get the bass added in.
FYI, in addition to causing a lack of bass a polarity inversion in one speaker (i.e., + and - being interchanged, either due to a connection error or due to a wiring error in the amp), would result in imaging that is vague, diffuse, and hard to localize, and would probably also cause the midrange to sound a bit strange.

I suspect that going to the 4 ohm tap will strengthen the bass at least a little. But to what degree, and with what other effects, are hard to predict. It's definitely worth trying, though, as several of us have suggested.

Regards,
-- Al
atmasphere's avatar
atmasphere
11,784 posts
 
If the amp has not been played much, it may also need some break-in time. Filter capacitors don't like to sit around discharged; its best for them to be played and as they are played they get more efficient. As this happens, they become more effective at their job (power supply bypass) and one of the results can be better bass.
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