And I regret-it.
I share with you exactly the same story: "I WANTED this IC to become a workhorse".
On my side, I used to add two transistors to boost the output of TL072s with much better 'subjective' results than this NE5532 (at this time).
Just to enlighten that, may-be, the fact that two guys, from both sides of the planet, despite good data sheet and real hope, were disappointed the same way by their listening impressions about those NE5532 can make some sens ?
And that some will begin to accept that measurements numbers don't tell EVERITHING ?
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The context was op-amp rolling but the op-amps were not designed for audio so if someone's toe doesn't get tapping I'm not particularly upset.
Mr. Fremer likes these guys with the $179 TT, he even favorably reviewed their 5532 $89 pre-amp vs the Shiit one.
https://www.youtube.com/watch?v=BXHLXi0RsGM
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Two oldies have something in common. Hold the front pages it's a miracle.
7 billion people, finding two who believe the audiophool press line (possibly started by JC) on the 5532 is hardly earth shattering. Or proof of anything.
I also found and find to this day NE55xx series of op amps to be dull and relatively lifeless. I never liked at, and the more firends demonstrated their prowess the less I liked it. Sonically, I'll take the OPA27 over them any day, or better yet, OPA37, even though it's not stable with gain factors below 5:1. I also use AD829 for its low noise and high speed, as well as AD 818/828 for a general purpose gain block.
Esperado, John, try adding a pair of matched bipolars to the output of your op amos as current boosters. The one thing I have learnt is that ALL op amps best not be used for any serious currents into anything but high purely resistive loads. But hang a pair of bipolar current boosters (for me, typically MPSA06/56 or BC 639/640), and the whole situation changes for the better, most importantly and most obiously in case of RIAA eq/amps. The required nanofarad caps are so much more for the op amps than we even imagine, polypropylene or whatever. And, oh surprises of surprises, the more output voltage you want the more pronounced the effect.
Esperado, John, try adding a pair of matched bipolars to the output of your op amos as current boosters. The one thing I have learnt is that ALL op amps best not be used for any serious currents into anything but high purely resistive loads. But hang a pair of bipolar current boosters (for me, typically MPSA06/56 or BC 639/640), and the whole situation changes for the better, most importantly and most obiously in case of RIAA eq/amps. The required nanofarad caps are so much more for the op amps than we even imagine, polypropylene or whatever. And, oh surprises of surprises, the more output voltage you want the more pronounced the effect.
The other side of the coin, I see some rotational anomalies I wonder if they're audible.
https://www.youtube.com/watch?v=jr2Ji1poTos
https://www.youtube.com/watch?v=jr2Ji1poTos
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op amp buffering
One of the problems with current boosters is that adequate performance adds parts. You have to bias the output devices with something. If diodes (which are not more than a passable match for the transistors as far as tempco) are used, they need at least a pullup or pulldown resistor, and if symmetrically driven, both. But using resistors means the available currents diminish precisely when you want them to remain constant or even increase. If the output voltage range is restricted this isn't too bad.
But diodes are no cheaper nor space-saving than transistors, usually. And if you use transistors in the bootstrapped diamond topology you reduce dissipation shifts and drastically reduce input capacitance. Now add constant current sources in place of the resistors, and you've got something pretty high-performance --- but you also have quite a few parts. With LED-biased current generators you can swing pretty close to the rails too. With a slight performance reduction the current generators can be replaced with resistors and bootstrap caps from the output, if you don't have to preserve performance down to d.c.
In many cases if you want ~unity gain and aren't concerned too much about d.c. offsets, it may well be that you can dispense with the op amp.
One of the problems with current boosters is that adequate performance adds parts. You have to bias the output devices with something. If diodes (which are not more than a passable match for the transistors as far as tempco) are used, they need at least a pullup or pulldown resistor, and if symmetrically driven, both. But using resistors means the available currents diminish precisely when you want them to remain constant or even increase. If the output voltage range is restricted this isn't too bad.
But diodes are no cheaper nor space-saving than transistors, usually. And if you use transistors in the bootstrapped diamond topology you reduce dissipation shifts and drastically reduce input capacitance. Now add constant current sources in place of the resistors, and you've got something pretty high-performance --- but you also have quite a few parts. With LED-biased current generators you can swing pretty close to the rails too. With a slight performance reduction the current generators can be replaced with resistors and bootstrap caps from the output, if you don't have to preserve performance down to d.c.
In many cases if you want ~unity gain and aren't concerned too much about d.c. offsets, it may well be that you can dispense with the op amp.
All those guys must still be living with their parents and have free room and board.
I gather the customer supplies the box? And good luck getting the energy vampire slayers to allow the simple transformer adapter.
You can add an external pnp to the AD744 via the comp and output pin we actually did that for a customer (not audio).
Remind me Scott, what's the approx current drive capability of your lil 8-leg filled preamp?
It comes with box and wart. I confess to occasionally using the classic 5534 + WIMA cap RIAA run off of a +-15 lab brick (one of ours, so free). Lost track of my AD624/744 passive RIAA pre that Walt and I published in 1983 or so.
Their TT may be an excellent product but this RIAA pre isn’t.
It’s not the 5532 my target but any op amp in this circuit supplied by 9Vdc (no matter how well filtered) will have unacceptable low overload margin.
George
It’s not the 5532 my target but any op amp in this circuit supplied by 9Vdc (no matter how well filtered) will have unacceptable low overload margin.
George
Depends, the classics were meant for only 10mA or so, but with video lots more became fashionable. Now there are many that do 250-500mA no problem but one must be careful because the ADSL drivers were designed for huge crest factor signals and will smoke doing a full scale sine wave. Did you ever see jcx's massively heatsunk headphone amp. The big through hole SIP packages with tabs are just not cost effective in any comms market now.
??? The light flicker off the surface makes the non-flatness of the LP obvious, I didn't listen for it.
I recently found a 5532 to perform better on distortion after an AK4490 than either a 4562, a 1612 or a 2134, by about 50 percent....
I've seen a 12AC wart and diode multiplyer used with two 18V regulators in a cheap $100 RIAA box.
Yeah, like what JCX did there. Might try similar one day. But for balanced interconnect duty there is an acceptable level of overkill just for lolz.
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