qusp
Member of the Trade: Twisted Cables
- Joined
- Jun 18, 2008
- Posts
- 7,743
- Likes
- 62
umm just calling their company esoteric says it all for me. its a ridiculously overpriced, underspecced part in an outdated package that just happens to use a copper leadframe (worth an extra 40 bucks dont you think?), which will be plugged into a brass dip socket.... its outgunned by opamps designed nearly 20 years ago, but it suits esoteric because they can say its an opamp designed for audio... whatever the hell that means. most 'audio spec' parts are rejects that couldnt make the cut for more demanding industrial/scientific applications.
just for example, I know they supply a ready made cop-out for this by saying it gives quality that cannot be measured, but
vs the $5 lme49990
3 x higher noise (minimum, they dont specify at what frequency they measure 4.5nV/Hz, could be up to 5x higher) actually it is closer to 5x looking at the graphs
3 x higher input bias current
4x lower slewrate, you dont want stupid slewrate for audio, but 5v/uS is pretty low
100x higher THD
etc etc, now the lme is a great chip, but not known for its low input bias current, something like the opa827 totally pwns the muse in this regard. sorry but having copper leadframe doesnt make up for it, that and the fact they only come in duals... forget it, its marketing. as ive said before, if I want to build for musicality, i'll build a discrete opamp.
there was nothing to defend about my comments above, for what they are the 5532 are a good chip, but the reason they are used so often is because its a known quantity, bulletproof, pretty stable and cheap.
as for NOS... hmm you know my feelings on that matter
Hey Nigel, no worries, i'm sure youve got better itches to scratch mate nothing wrong with it, its been used fairly successfully in dac IV stages because of having decent speed, but nothing really unique about it either. yeah the FiQ is a great amp, not getting much airtime with me though, been meaning to send mine back for an update for ages but never get around to it.
Nigel, this is what i'm using for transportable these days. zilch0md will appreciate the chunky battery that takes up about half the case volume
just for example, I know they supply a ready made cop-out for this by saying it gives quality that cannot be measured, but
vs the $5 lme49990
3 x higher noise (minimum, they dont specify at what frequency they measure 4.5nV/Hz, could be up to 5x higher) actually it is closer to 5x looking at the graphs
3 x higher input bias current
4x lower slewrate, you dont want stupid slewrate for audio, but 5v/uS is pretty low
100x higher THD
etc etc, now the lme is a great chip, but not known for its low input bias current, something like the opa827 totally pwns the muse in this regard. sorry but having copper leadframe doesnt make up for it, that and the fact they only come in duals... forget it, its marketing. as ive said before, if I want to build for musicality, i'll build a discrete opamp.
there was nothing to defend about my comments above, for what they are the 5532 are a good chip, but the reason they are used so often is because its a known quantity, bulletproof, pretty stable and cheap.
as for NOS... hmm you know my feelings on that matter
Thanks for the feedback Jeremy, appreciated mate. I'm rolling with the Fi-quest again, man I forgot what a great amp this is. I'm using AD797BRZ's at the moment with 5 stacked BUF634AU's for each channel. It powers my HE-6 better than anything else I have, desktop or otherwise. You still using yours?
Hey Nigel, no worries, i'm sure youve got better itches to scratch mate nothing wrong with it, its been used fairly successfully in dac IV stages because of having decent speed, but nothing really unique about it either. yeah the FiQ is a great amp, not getting much airtime with me though, been meaning to send mine back for an update for ages but never get around to it.
Nigel, this is what i'm using for transportable these days. zilch0md will appreciate the chunky battery that takes up about half the case volume