Non-feedback amplification topology and frequency


Is it true that non-feedback topology amplification is prone to frequency limitations if not matched with the absolute perfect speaker system?
I'm trying grasp how to get a flat sound from my very much loved new PL5. I have resorted to EQ, that never mentioned term on these forum, to bring back the ultra-highs of cymbals and bells etc. I've also rolled the pre-tubes and switched out my ICs. Still very much a frown freq graph.
I'm willing to get new speakers to help this amp deliver on its promises. Focal seem nicely high in sensitivity.
jmacinnis
I had a Butler TDB-5150 (Tube/MOSFET hybrid multi-channel amp) that had no global negative feedback. It had these specs.:

Freq response: 20Hz to 20kHz (+/- 0.5dB)
Power Bandwidth: -3dB, 50kHz

So I would presume that not having feedback will not impose any audible frequency limitations...

-RW-
Jmacinnis, The issue here is how the amp will drive the speaker if it has no feedback. This article will explain what is going on:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

IMO/IME amplifiers that operate without feedback are more musical as they make less odd ordered harmonic distortion. Since our ears use odd ordered harmonics to figure out how loud a sound is, this is arguably one of the more important human hearing rules! The use of feedback violates this rule.

However the audio industry does not like to talk about this, and is something that separates the high end audio community from everything else; we talk about it occasionally instead of never :)

Ultimately you have to be more careful of your speaker choice; this is doubly important because a speaker that requires the amp to have feedback will never be able to sound like real music- it will at best sound like a good hifi.
very interesting article. So mass market audio companies are watching out for their best interest buy supressing this information? If they switched to this better sounding amplification, it could ostensibly eliminate many speaker companies and even their own speakers from being useable? Thanks for finally putting an end to this mystery of why my tube amp was sounding dull. I brought it to a shop yesterday and heard it come to life with appropriate speakers. thanks again and very very impressive website. I look forward to hearing some of those amps one day.