The MUSE op-amp has totally pedestrian specs and fits the "what is wrong with op-amps" thread to a tee. The full factory cost of a DIP op-amp is essentially the same within pennies, this is marketing 101.
API made a module for themselves, I doubt it would find use elsewhere. As I said yesterday a "signature sound" implies lack of fidelity in the absolute sense as in amplifying an electrical signal which would make any product less useful in another application.
In general no. The 627 is an exotic legacy part on an old DI process and TO cans are rare these days and it's expensive to keep assembly capability for them around.
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I wonder why they are still making them. If any superiority compared to the other modern production opamps?
Is a pre-amp not an analog computer of sorts. just doing multiplication on the input signal?
for a laugh https://www.gearslutz.com/board/high-end/28322-what-api-sound.html
Big thing in their marketing 'Most importantly, THE BOX provides the legendary "all discrete" API sound in an efficient, cost-effective package.'
Big thing in their marketing 'Most importantly, THE BOX provides the legendary "all discrete" API sound in an efficient, cost-effective package.'
I have no experience with Muse, so I have no clue what their claim, "high quality sound", means. Since there is no technical explanation how Muse could achieve "high quality sound", so only I can guess is that, A. It is a marketing BS, or B. they were actually tried to achieve subjectively "high quality sound" by listening sessions.
I wonder how you could conclude it is A. Have you ever talk to anyone in that company?
Quite simply that companies all generally have signature products that are rarely any better than the basic ones but at 10x the cost. Marketing and the market insist on it. in audio the laws of physics and the work of Maxwell, Heaviside and others is regularly thrown away and some magic woo used to sell a product. Having said that Wayne from Pass Labs was impressed by the Muse chip in a demo, but he doesn't use it in his pre-amps.
But note that precision analog (you know LIGO, cat scanners etc) is a world away from high end audio which is another world away from popular music creation.
I was not asking the question to you, but thank you for your reply. I do not disagree your statement in general, but it doesn't mean they selected certain design of opamp for their signature product without listing sessions. If you guys believe it for some reasons, that is what I call fantasy, sorry. It is quite natural to think they held some listening sessions to select one of their prototype designs for their final product based on their completely subjective impressions.
You must understand that I'm disagreeing with Scott saying NO opamp has been designed for subjectively "good sound" reproduction.
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The API schematic looks like something out of ancient history like a uA702 or uA709 with a power output stage. If by good sound you mean behavior when overloaded or driven into the rails, I would suspect no IC op-amp ever was.
To think an IC was listened to and sent back for $100's of thousands of dollars in layout and masks/wafers based on anything but measurable specs is ridiculous. You will notice the chase for more zeros on the THD numbers for one thing.
If you are not aware of things like MRI, CT, Ultrasound, or any number of medical/scientific instrument applications. There's also the telecom industry all specification
The 627 BTW probably owes its existence to a single customer who I will not name.
OPA627 is $25 for PDIP or SOIC. Twice that or more for cans.
At those prices the customer must need them badly, or think they do. Or maybe it's not a price sensitive application, like military.
API op-amps are for people who want that "vintage" sound, not necessarily driven to the rails. The sound adds a little distortion that some people like for some things, like maybe for percussion. Not everybody's cup of tea, but lots of records have been made with them.
At those prices the customer must need them badly, or think they do. Or maybe it's not a price sensitive application, like military.
API op-amps are for people who want that "vintage" sound, not necessarily driven to the rails. The sound adds a little distortion that some people like for some things, like maybe for percussion. Not everybody's cup of tea, but lots of records have been made with them.
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Take 2
Don't know about you folk but I think this has been one of the best threads for a long time
There are many nuggets of information/opinions/thoughts scattered throughout the last 500 or so posts, far to many to quote and expand upon.
Pavel's implementation has been impeccable (with apologies to Mark re the self appreciation society), and coming out of that was an idea that a lesser design may (or may not) be susceptible to external RF and outside influence. And I still can't reconcile the fact I couldn't pick a 1458 from the best of the rest and so the experimenter in me set about recreating a similar test using my own methods.
I took Pavel's basic circuit and built it up 'dead bug' style (although with a decent star ground) and powered it from two 9 volt batteries. The opamp was decoupled rail to rail with a 'lossy' 22uF cap. The output series resistor is now 91 ohm and the output coupling caps 220uF feeding a 3k3 load which gives all the opamps something to do.
The junk box through up some RCA 1458's from way back yonder (marked CA1458) that have been used and abused over the decades. That along with an OPA2604 and a TLE2072 (the upmarket version of the TL072) completed the line up.
If there is sufficient interest I can make the files available.
Don't know about you folk but I think this has been one of the best threads for a long time
There are many nuggets of information/opinions/thoughts scattered throughout the last 500 or so posts, far to many to quote and expand upon.
Pavel's implementation has been impeccable (with apologies to Mark re the self appreciation society
), and coming out of that was an idea that a lesser design may (or may not) be susceptible to external RF and outside influence. And I still can't reconcile the fact I couldn't pick a 1458 from the best of the rest and so the experimenter in me set about recreating a similar test using my own methods.I took Pavel's basic circuit and built it up 'dead bug' style (although with a decent star ground) and powered it from two 9 volt batteries. The opamp was decoupled rail to rail with a 'lossy' 22uF cap. The output series resistor is now 91 ohm and the output coupling caps 220uF feeding a 3k3 load which gives all the opamps something to do.
The junk box through up some RCA 1458's from way back yonder (marked CA1458) that have been used and abused over the decades. That along with an OPA2604 and a TLE2072 (the upmarket version of the TL072
) completed the line up.If there is sufficient interest I can make the files available.
Even if someone wanted to do that, (and I am convinced that is not the case), you can't, because you cannot define subjectively good sound. How do you know you have or have not done that? Just a few guys personal opinion?
Jan
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