You established that at the time there was no jfet inputs op amp
with caracteristics as good as the 5534 set apart the input impedance
and perhaps noise to a lesser extent....
Overall quality had increased, exigence accordingly.
I never used-it since more than 20 years.
In fact, it is not so bad sounding in absolute, it is just not transparent, heavy transients, not fast enough.
It is a long work, as i said, to find a part which feat all the needs, yes.Nice , but +-5.5V max supply voltage.....
When it is not the supply, it is a single where you want double, or the package you don't want etc..
There is a lot of current feedback @ AD too.
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Nice , but +-5.5V max supply voltage.....
With THX certified power amplifiers, it's more than you are likely to need.
I think 5534 is still like it was. May be we just now pay attention to its different quality aspect. First because this other aspect must be learned (not easily). Second because we learn about this aspect from newer/modern devices (where we found other opamps that don't sound like 5534 ON that aspect but may be as good at what we know 5534 is good at).
Wayne, which of JC's illustrious designs do you have?
You need zillion V/us to do well in the Quan PIM test. One day, JC will conduct Quan on Blowtorch and we'll see how a truly 'hand carved from solid Unobtainium by virgins' product performs.
If we're REALLY lucky, we might be able to see the results of a Blind Listening Test of this against an evil 4558 device too.
In the meantime, JC has some Hirata test results on Blowtorch.
Currently none , most recently Parasound Halo a21 , fact is i can hear and critique Johns work , i cant with ESP , i cant agree or disagree with his Op-amp statement..
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Christophe has mentioned the opamp type, and he assumed that you know how to make a good enough power supply and layout.
And I guess you have heard those THS opamps so if you think they are not as good as discrete, or still have that "opamp sound" then for me enough to conclude that Christophe cannot "hear" it.
What do you name "opamp sound" ? This tiny sound with a lack of body, or this sound under a cover ? I hate them.
Again, i do not listen to the "sound" of preamps, i compare them with wires.
May i remember-you a previous argument ? Most of the records you love (no "opamps sound") are recorded and mixed with hundreds of OPAs.
But, you know, i use more often tubes mikes preamps than solid states one. They are not transparent, but they are nice sounding, and hot.
I use fast solid state for some percussions, part of drums and some female voices..
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Can you publish a circuit of this JC? Surely its not secret anymore.
What performance advantages did you establish all those years ago?
Thank you for letting us grovel in shame in our lack of 'quality experience' at your exalted feet
We are not worthy Many facts in AUDIO have almost no clear technical support at present (for instance, obvious sound effects of various interconnect and speaker cables, passive parts, etc.). Technical approaches are being developed mainly for instrumentation needs, audio needs stand at a far background.
Some centuries ago there was no technical basis for proving that the Earth is rotating. (Excuse me for this comparison, but the discussion of IC applicability for audio has no good perspectives, if even more simple facts with cables are not measured and reasonably interpreted).
My 12 cents on this amplifier, if you do not mind. I know it quite well.
1st, I would like to congratulate to a very good amplifier at a very very good price. 2 x 400W/4 ohm at $2300. 4 pairs of 2SC2922/2SA1216 Sanken output devices per channel, MOSFET 2SK1529/2SJ200 driver makes a robust pre-stage for these output pairs. MOSFET is very important here. Complementary-differential JFET input BJT cascoded. Reasonably high idle AB current an thus robust heatsinks are used.
Decent sounding, enough power.
My only reservation about this amplifier is related to internal layout, wiring, input pot level setting - everything due to very affordable price. IMO with more careful wiring, no input volume pot and some further small improvement one might get even more defined sound, A21 is a way a bit too "forgiving".
Your taste is bad. It is still one of the best opamps with bipolar inputs.
the Quan tests do not require "infinite" slew rate
Quan's 2012 paper lists TL074 (13 V/us typ) as measureing at his residual on one test, the NE5532 (13 V/us) and AD823 (22 V/us) pass all
and the tests are at 10-20 Vpp, Av 25 - both rather higher than often found in consumer audio line level
so it looks like 1-2 V/us/V can be enough by Quan's meaurements of monolithic op amps
Quan's 2012 paper lists TL074 (13 V/us typ) as measureing at his residual on one test, the NE5532 (13 V/us) and AD823 (22 V/us) pass all
and the tests are at 10-20 Vpp, Av 25 - both rather higher than often found in consumer audio line level
so it looks like 1-2 V/us/V can be enough by Quan's meaurements of monolithic op amps
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You know how works a bus in a mixing desk. It is a good place to test OPAs in inverting mode. Neither Tl07x or NE 553x pass this test: Insert a single musical track, then add more tracks (insert them in off mode). You can clearly hear how the music lose presence and confusion appears between instruments each time gain is added to the OPA.
It was impossible to hear a difference with our current feedback OPAs: WON !
An other test is to use-it out of a DAC (laughter or crying).
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