Most expensive = most best? Would be nice!
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The most expensive are the worst.
That Technics regulator is a very interesting regulator! It seems that the op amp is used as an error amplifier to reduce the overall regulator output impedance at high frequencies. It might be annoying to build using generic 78xx and 79xx parts, because that feedback loop seems to depend on stuff that's not datasheet specified, but still, it's not a bad idea overall - I'm only guessing as to how it could fail - it might be easy to construct for all I know.
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So our heuristic goes around in circles...
Will you say the same thing when a famous manufacturer will sell Groner's topology in a 4...40k product?
Build that thing, apply it in your circuits and then come back with your feedback!
This is a DIY forum!
I do understand why you can dismiss a theoretical approach with another theoretical argument, but that Technics buffer was a product sold in so many variants , shapes and prices that can't be ignored!
Well I mentioned it because there was a discussion many years ago in the then Wireless World about Technics/Panasonic infringing on the Sandman patent. And Mr. Sandman was quite upset with T/P, they definitely did not work together! Don't remember the details anymore, I don't think it came to a legal process but the discussion was interesting to follow.
Jan
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I'm in a big danger of being strongly opinionated about anything these days, but it's very interesting when choosing to replicate a commercial product of a certain success becomes unfashionable just because you don't have a well known designer or fashionista name attached to it.
I still have no answer to why Denon used upc4570 in i/v stages before a passive filter and a ne5532 op amp as buffer if ne5532 was so much better than all the op-amps in the market in the 90's , yet you have so big Divas attached to ne5532/34 vs any other modern and 20...50x more expensive op-amps than upc4570 WARS, that you might believe into this war if you ignore the most successful commercial products of the past on various fashionable grounds.
I know somebody who spent about 5 years modding cd players to NOS and selling his services claiming all sorts of BS , and 10 years later he tells in all honesty: I think now that actually oversampling sounds better than NOS...
Well...i told him back" I knew that from the beginning just by listening before any mod and just by taking into consideration that Phillips, Sony, Denon and Nakamichi engineers were't stupid enough to tell the marketing department: we need to use one more oversampling chip so that you can claim better SNR, THD and cut our wages accordingly!
I see you in this discussion too:
Technics Class-AA / Sandman Bridge
I didn't see any proof of Sandman fighting back and why would you do it in his place?I'd only ask for the right money in a court of justice, not make a Holly DIY war
P.S.
Actually i found something:
Sandman v. Panasonic UK Limited, Matsushita Electric Industrial Co Ltd | England and Wales High Court (Patents Court) | Judgment | Law | CaseMine
Unfortunately i don't fully understand the language used in that document...
It might be a good exercise though for somebody in need to bear a legal fight with a big manufacturer...
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Elvee's 'De-Noizator' circuit reminds me of this topology/strategy. Although, his circuit is based on an single discrete transistor rather than an op-amp, so is less effective because of it's much lower loop gain.
D-Noizator: a magic active noise canceller to retrofit & upgrade any 317-based V.Reg.
I have seen lm317 been used as audio amplifier, but this is a new one. More bandwith, better regulation, makes sense. Nice to try out on a rainy afternoon.
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I'd have a question for anybody who's knowledgeable on this:
Is it possible that the 7805 regulators are faster than the rest of 78xx higher voltage regulator?
I saw the Audio Note dac 3-4 schematic and it made think about that.
In the end Groner's or other fast composite op-amp might need an equally fast regulator so we might turn this off topic into something useful.
Is it possible that the 7805 regulators are faster than the rest of 78xx higher voltage regulator?
I saw the Audio Note dac 3-4 schematic and it made think about that.
In the end Groner's or other fast composite op-amp might need an equally fast regulator so we might turn this off topic into something useful.
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Of course it is possible. It may not be true, but it definitely is possible.
All you need to do to answer the question, is to find out how the different models in the 78xx product line differ.
This is easily discovered by merely studying the schematics given in the datasheets.
The only difference between a 7805 and a 7818 is the value of the red resistor.
Now that you know this, just decide for yourself
- When we increase the value of the red resistor, does output voltage rise, or does it fall?
- When we increase the value of the red resistor, does the regulator get faster, or does it get slower?
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OPA211 CMRR is excellent way beyond 10kHz but PSRR isn't. These things matter in a -180dB THD amp. I would think tying the rails together as good as we can (with a large low-ESR/ESL ceramic) is very important here for this reason, we want to have any rail disturbance in perfect unison. Since the master opamp runs only quiescent currents I'd use large feed resistors to the local decoupling and use only small, ESR-degenerated rail-to-GND caps (to avoid CLC resonances).