Here's a list of upgrades and the differences I noticed, by category:
AMP:
Luxman integrated to Bryston 4B NRB -- HUGE
Bryston 4B to Bryston 7B-ST -- sound difference was noticeable, esp. in highs, biggest difference was that I never clipped again
PREAMP:
Luxman integrated to Sonic Frontiers SFL-1 -- HUGE, although this happened at the same time as the Bryston 4B, so tough to seperate one upgrade from the other
SFL-1 to Melos SHA-Gold -- (done to get remote control) -- not a vast improvement in sound, but WOW, what a headphone amp!
Melos to Rogue 99 (done to get phono without losing headphone capability) -- pleasant upgrade, but again, not vast, as the Melos was a very nice sounding unit
INTERCONNECTS:
crap to Cardas microtwin interconnects-- some difference, not much
Cardas Microtwin to Tara Decade -- unbelievable. Turned me into a "cables are components" convert. After the initial upgrade from the Luxman to seperates, this was the biggest difference in my audio system
one interesting note -- my big system is temporarily in storage, and I am again using the Luxman integrated. I inserted the Tara Decade for the crappy IC I was using, and the difference was noticeable, but not 1/10th as dramatic as with better components.
SPEAKER CABLE:
crap to Monster -- little diff.
Monster to Kimber 8TC -- terribly disappointing. I am not a Kimber fan after this big expense with little to show.
Kimber 8TC to Tara MGII -- pleasant change. I guess Tara and I are a good match, although I still feel like there is a better cable looming in my future.
CD:
Kenwood to Micromega 2 -- nice change, but the Kenwood is a pretty good unit, so it wasn't a vast difference
Micromega to Meridian 508-24. Blackness. The background noise level went to nearly zero.
SPEAKERS:
ADS monitors to Hales Rev 3's. WOW.
I just sold the Hales as I no longer have an appropriately sized room, and I will be travelling for the next chunk of my life, but boy, they are an amazing speaker. Poor Paul Hales -- who would have thought that Wadia would screw him over so badly. He is a talented man, and I am certain we haven't heard the last from him (pun intended).
When I am back in the US and in another decent house, I will be shopping again for speakers, expecting that the biggest change in sound comes with different speakers. Maybe a minimonitor? Maybe planars? Maybe Hales will be back in business then....
BOTTOM LINE: The better your system, the less ability there is for an upgrade to matter. That said, if I were to recommend places to upgrade, they would be AMP first (clean power can't be beat), IC's next, SPEAKERS next, and assuming that your cd and preamps are decent, I'd do these last. At least, that was my experience in terms of sound quality difference per dollar.
AMP:
Luxman integrated to Bryston 4B NRB -- HUGE
Bryston 4B to Bryston 7B-ST -- sound difference was noticeable, esp. in highs, biggest difference was that I never clipped again
PREAMP:
Luxman integrated to Sonic Frontiers SFL-1 -- HUGE, although this happened at the same time as the Bryston 4B, so tough to seperate one upgrade from the other
SFL-1 to Melos SHA-Gold -- (done to get remote control) -- not a vast improvement in sound, but WOW, what a headphone amp!
Melos to Rogue 99 (done to get phono without losing headphone capability) -- pleasant upgrade, but again, not vast, as the Melos was a very nice sounding unit
INTERCONNECTS:
crap to Cardas microtwin interconnects-- some difference, not much
Cardas Microtwin to Tara Decade -- unbelievable. Turned me into a "cables are components" convert. After the initial upgrade from the Luxman to seperates, this was the biggest difference in my audio system
one interesting note -- my big system is temporarily in storage, and I am again using the Luxman integrated. I inserted the Tara Decade for the crappy IC I was using, and the difference was noticeable, but not 1/10th as dramatic as with better components.
SPEAKER CABLE:
crap to Monster -- little diff.
Monster to Kimber 8TC -- terribly disappointing. I am not a Kimber fan after this big expense with little to show.
Kimber 8TC to Tara MGII -- pleasant change. I guess Tara and I are a good match, although I still feel like there is a better cable looming in my future.
CD:
Kenwood to Micromega 2 -- nice change, but the Kenwood is a pretty good unit, so it wasn't a vast difference
Micromega to Meridian 508-24. Blackness. The background noise level went to nearly zero.
SPEAKERS:
ADS monitors to Hales Rev 3's. WOW.
I just sold the Hales as I no longer have an appropriately sized room, and I will be travelling for the next chunk of my life, but boy, they are an amazing speaker. Poor Paul Hales -- who would have thought that Wadia would screw him over so badly. He is a talented man, and I am certain we haven't heard the last from him (pun intended).
When I am back in the US and in another decent house, I will be shopping again for speakers, expecting that the biggest change in sound comes with different speakers. Maybe a minimonitor? Maybe planars? Maybe Hales will be back in business then....
BOTTOM LINE: The better your system, the less ability there is for an upgrade to matter. That said, if I were to recommend places to upgrade, they would be AMP first (clean power can't be beat), IC's next, SPEAKERS next, and assuming that your cd and preamps are decent, I'd do these last. At least, that was my experience in terms of sound quality difference per dollar.