Craig Sawyers

Yes that is what I meant.

A hissing/rustling noise sounds like corona breakdown somewhere. Unlikely to be physical damage during shipment, but not impossible. Justin should be able to help more specifically than me. Your unit seems to have the super-expensive super-dooper Alps RK50 pot BTW. Very nice.

When you see movies of someone as a young person you forget they grow old and die. RIP Ryan. On a similar topic, was watching Die Hard last night, filmed when Bruce Willis was in his early/mid 30's. Born a year before me in 1955, he is now down the dementia road at 68. In his last movies a couple of years ago, he would turn up and wonder why he was at a movie set, and had to repeat his lines coming through an earpiece having lost the ability to learn them.

Yes. It it based on a spreadsheet implementation of a model in a National Semi databook. But with more frequency data points, and with amplifier noise taken into account. And yes, you can always parallel opamps, summing their outputs via 10 ohm resistors. But even a single NE5534A is less than 2.5dB worse than the SNR with a noiseless amp (which is -80.4dB - depending on cartridge R and L) - so it is diminishing return. Parallel two NE5534A and you get to 1.6dB - so all you have found is 0.7dB in SNR. Parallel 4 and you find another 0.4dB and hence get to around 1dB of a noiseless amp.

Woah - how did I miss this? Belated happy birthday Todd!

A bit of good news - the OPA210 (single) and OPA2210 (dual) have a lower voltage noise, crucially the same current noise, as the NE5534A. They also has lower 1/f corners and stupidly low distortion. Introduced in 2018 it looks like it will be around for a good long time. The critical number is - how does an RIAA stage with an opamp with vn and in compare with a noiseless amp? With an NE5534A - 2.32dB noisier than no amp at all With an OPA210 - 1.61dB noisier than no amp at all Both numbers with a realistic MM cartridge load of 610 ohms and 0.47H Both amps are very close to the maximum possible SNR with a noiseless amp - but the OPA210 is even closer than the NE5534A. SOIC (or smaller) only and about 2.5 times the price of the now defunct NE5534A - but it looks like it does the job very nicely.

Suffers from the same problem as the OPA1611 - similar high current noise (4 times higher than the NE5534A). Predicted SNR is 75.3dB - so identical to the OPA1611.

Indeed. The combination of noise voltage and current was ideally matched to the resistance/inductance characteristics of a moving magnet cartridge. And lots of commercial designs used the NE5534. I have a spreadsheet that calculates S/N ratio with RIAA. AT 5mV the NE5534A returns 77.9dB with a typical MM cartridge of 610 ohms and 0.47H. The nearest equivalent IC is the much more recent OPA1611/12. Lower voltage noise but critically higher current noise. That gives 75.3dB, so 2.6dB worse s/n. My spreadsheet does not take account of 1/f noise. The OPA1611 has much better performance here than the NE5534A, so some of the 2.6dB will be eroded by that effect and it will make the comparison a closer run thing. Discrete opamps can give lower noise for RIAA EQ, and indeed Sam Groner developed a discrete version of the NE5534A that was better performance all round https://groupdiy.com/threads/just-for-fun-discrete-ne5534.57544/ . No surprise that the low noise dual he specified in 2004 is obsolete though.

Heads up - the best (ie best noise performance) single opamp for moving magnet cartridges - the NE5534 in all variants has been obsoleted by both TI and ONsemi. So if you need some for stock before this excellent device is obsolete sand, now is the time to buy. I've just ordered 50, which is enough to see me out.

Happy birthday!

When Voyager 1's camera was turned back towards earth, five and a half light hours away in 1990 (it is now 23 light hours distant), Earth was captured in less than a single pixel in the image. Of this pale blue dot, Carl Sagan said "From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam. The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known. — Carl Sagan"

Last night saw Kenneth Branagh playing King Lear in London. https://kinglearbranagh.com/ from third row from the front. Branagh has developed a policy of using young and not well known actors in the other roles - and they were all superb. He'd pared the script down from the normal 3h15m to 2h without an interval, but kept the key themes intact. At the end Lear carries his dead daughter Cordelia onto the stage, and after some tough lines simulates dying from a heart attack and also dies. With only them on stage, the stage rotated - and neither of them were perceptively breathing, viewed from close up. That takes some doing. Now we have seen some great Lear productions. Glenda Jackson, Ian Mckellen, Frank Langella (Nixon in Frost-Nixon), and the Branagh was right up there. The only slight criticism is that Branagh looks too young (he's 62) to be the elderly and progressively dementia suffering Lear. Jackson and McKellen were in their 80's in their productions and really looked the part. Now I'm nit picking here because when Branagh was on stage you simply could not take your eyes off him - his stage presence and the force of his portrayal is why he is one of the acting titans.

Fawkes was caught and tortured in the Tower of London. Being sent to the Tower for interrogation was a truly fearsome prospect, and the torture chamber had all sorts of horrors. At the end of several days of this, his signature on his confession was nearly illegible, probably at this stage missing fingernails and with finger joints broken with a thumb screw. And perhaps a session on the dreaded rack. But in the end he defeated the executioner. The first stage of hanged, drawn and quartering was a period of slow hanging. To that end a step ladder was set up, and the condemned was forced to walk up, noose around neck and dangled there. Fawkes forced himself much further up the ladder and jumped, so that the drop, rather than just strangling him a bit, broke his neck. So the gruesome bits they did to his already dead body.

On the basis of your measurements for PSU applications perhaps they have the edge. But for audio signal use they are absolutely lousy. It is latish here in the UK so I'm not going to haul my HP gear out. But I'll try some stuff tomorrow.

Time to power up my HP 4275A LCR meter https://www.testequipmenthq.com/datasheets/Keysight-4275A-Datasheet.pdf and put this to the test 😉

OK - I've been through the whole thread trying to answer the question of why tantalum bead caps for the four 47u (C7, C9, C13, C15) and the two 10u caps (C3, C16)? I failed in the quest. So - what is the reason for using tantalum bead rather than aluminium electrolytic in those locations?

That is truly amazing. I actually have tears in my eyes.

My wife at the time was the CEO of a residential care charity - Brendoncare https://www.brendoncare.org.uk/. When the government came up with the wheeze of sending thousands of recovering Covid patients from hospital to residential care homes Carole refused point blank, as did the Trustees, to do this. Turns out that this directive was in fact unlawful, and is something that will be a feature of the enquiry. As will the idiot policy of "Eat out to help out" in which the government, via Rishi Sunak (who was Chancellor then) stumped up a billion in subsidy to reduce the cost of going out for a meal. Many months before there was a vaccine. Not surprisingly with restaurants crowded there was a surge in infections and death as a result. And how come those in the government staff and ministers who were found to by guilty of parties during lockdown received a nominal £50 fine. But those of the public who did something similar have been financially ruined with fines of £10k plus. Still three years later being processed in the courts. Different rules for those in power. All this and much more will come out in the public enquiry.

Thanks guys. That is a good steer to transistors that I can buy! What about the driver transistors? I have a load of MJE340/350 that might fit the bill. Also very linear with flat beta vs Ic? Any thoughts?

I thought that was some sort of joke, until I looked at the Guardian - and those foul mouthed outtakes are all absolutely correct.

Or MJ11021 and MJ11022?

Here's a question. Has anyone tried replacing the discrete Darlingtons of Q5/7 and Q9/4 with power Darlingtons such as the MJ11015 and MJ11016? At least I can get my hands on them!

Well, because OnSemi are a bunch of fuckwits who seem to have forgotten how to make semiconductors Example from Mouser for the MJW21193 308 Expected 23-Aug-24 1,020 Expected 03-Mar-25 Farnell reckons 33 weeks, which is consistent with Mouser. FFS! Same with the high current version with TO3 power transistors. MJ15023 no problem but MJ15024 1,997 Expected 19-Mar-24 2,200 Expected 24-Jun-24

That is so truly awful. On many levels.