why distortion and what is the cure


Hi , this is my 1st post so go easy pls!!
I have an old sugden a21 amp and a crap pair of celestion F2 f/standers - 87db / 8ohm. When i turn up the amp past about 1 oclock the sound just breaks up/distorts.This also happened with a MF b1 amp. Is it the speakers or the amps that are faulty? I am thinking of getting the A28 sugden as i like the sugden sound and if it is the speakers at fault can anyone suggest Fstanders to partner? (under $700 s/h pls )
gar1
Hi Guys - thanks so much for your answers - today i took the MFidelity to a used hi fi shop and ran it thru 4 sets of speakers and no real distortion at volume so my guess is that the speakers are kaput !!
I will definately keep the Sugden as i love its sound - i think i will have a hard time finding speakers to match it that i can afford tho. Greg - which triangle and are they expensive?
Gary -
Triangle: any sporting their new tweet. Yes they're expensive, unfortunately. Staying within yr budget, another idea would be a kit. There are many around; some reasonably priced UK examples are here or here.

If you're willing to invest some time & (possibly) save some money on diy/kit speakers, there's a load of info on the Net. Take a look at these outstanding sites: jpo's or the LDSG here.

Cheers
Thanks so much Greg - the Ibl line looks interesting and they are only about 40 mls from me. I have seen a 2nd user pr of Linn Tukans but i cant find out the sens. of them. Would they be a good match ? Great reviews and a clean detailed sound by most accounts.