Missed that bit. Even later CK522s or 2N107s wouldn't do. So by the 60's when transistors would have been useful, he was no longer doing much. But he did realize the topography and why it was a better way.
I think that purely passive EQ is the very best, but most manufacturers over the years have used active RIAA Eq. including Marantz, MacIntosh, Dyna tube equipment and even me with the Levinson JC-2. It works, but not as well as a 2 stage design. I don't know exactly the reason why. No, it is not overload or clipping, noise, or anything like that. Sometimes slew rate is a problem with a single stage feedback RIAA stage. Dyna is especially bad in this way.
If I may continue the analogies:
'Those that brag that they can do 100 push-ups are never called on it, however'.
Jan
Times up !
Yes, I confess to it...... in late 1970's......a modern ss passive RIAA phono using jFET diff on input, diff second stage and compl push-pull follower ops. Two of these and passive RIAA between. The line stage was the first CFA -- compl push-pull.... direct coupled. First published In TAA 3/80.
I improved on the line stage wiith cascoded ips and ops and dc servo. TAA 89.
[E.Borbely did similar afterwards and in 1993 did (in TAA) all fet version.]
It was the first and my only phono/line I ever designed and remains so until today. Ditto a unique MC pre-pre in TAA 1/82. First and last.
Afterwards moved on to CD/digital. Next analog design for audio was 2012 - a headphone amp because I didn't like what I bought (IC based-sorry)- sound wise - and so again out of necessity had to design my own if I wanted best performance/sound/accuracy..
So, why did I go passive RIAA?
THx-RNMarsh
Yes, I confess to it...... in late 1970's......a modern ss passive RIAA phono using jFET diff on input, diff second stage and compl push-pull follower ops. Two of these and passive RIAA between. The line stage was the first CFA -- compl push-pull.... direct coupled. First published In TAA 3/80.
I improved on the line stage wiith cascoded ips and ops and dc servo. TAA 89.
[E.Borbely did similar afterwards and in 1993 did (in TAA) all fet version.]
It was the first and my only phono/line I ever designed and remains so until today. Ditto a unique MC pre-pre in TAA 1/82. First and last.
Afterwards moved on to CD/digital. Next analog design for audio was 2012 - a headphone amp because I didn't like what I bought (IC based-sorry)- sound wise - and so again out of necessity had to design my own if I wanted best performance/sound/accuracy..
So, why did I go passive RIAA?
THx-RNMarsh
I am chill. Spending your evenings with a sproglet throwing up on you keeps the perspective 🙂
My point I was making is that, one person gets a week in the bin (not the first time I should note) and suddenly moans and grumbles and 'ban them' get trotted out rather than actually addressing the points that were being made, which is that there is almost zero forward momentum and in general 40 year old designs are being tweaked with pseudo-scientific trinkets. The people that won't change appear to be in their 70s 🙂.
BTW you were right on the resistor selection. With my borrowed solartron I've cobbled a jig that will get me to 0.05% (load R, wander off to be vomited on, wander back to see if its stablised). Any more than that is beyond both my equipment and my patience and not needed beyond the usual audiophile mind games.
Years ago GK and AndyC and others were coming out with high transistor count designs and having very technical discussions. We learned a lot from that and and a some of it was foundational to recent designs on this forum. Sometimes I think of those times and wish I could contribute with the knowledge I have now. I'm sure I could.
I'm not old or wise enough to understand exactly why things have come to pass the way they have.
At the same time I don't see another forum that these guys have moved to and continued their discussions. I think AndyC used to have a forum where his group talked but it didn't seem to get anywhere and either it was shut down or I can't find it.
I'm not old or wise enough to understand exactly why things have come to pass the way they have.
At the same time I don't see another forum that these guys have moved to and continued their discussions. I think AndyC used to have a forum where his group talked but it didn't seem to get anywhere and either it was shut down or I can't find it.
Yes but the question was popular, I doubt if even .01% of the phono stages in the world are. Mine is, but I confess I don't fuss about the historical research. I assume someone did it with valves in the 40's so the conceptual part is over and done.
You left out Mr. Popa, I figure they got tired of the usual fantasies and recurring themes.
If you haven't noticed there is a great fear in those that have not kept up with what is going on and they must defend themselves at all costs.
How so? Do you mean that people haven't kept up with developments in theory, hardware, patents, circuits, etc.? In other words, engineering technical knowledge? If so, would that be necessary? Could someone listen to the latest, greatest designs and decide they are lacking without fully knowing how to design them? Maybe you could explain better what you mean?
Also, regarding issues fear and defense, how do you come to those attributions? Maybe there is some alternate explanation that you missed?
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I believe both Altec and Langevin had passive RIAA equalizers to use with microphone preamps in the 1950's. Building blocks for consoles for radio stations etc. I had one once but lost track of it.
Maybe. Maybe not. Like said by others passive RIAA occurred with tube designs first. Generally low gain phono/LP circuits weren't sufficient for RIAA in neg feedback path.
But with a modern circuit (not cap coupled and more than 2-3 transistor circuit) high gain is easy and opamp existed also. So why still use passive RIAA?
THx -RNMarsh
But with a modern circuit (not cap coupled and more than 2-3 transistor circuit) high gain is easy and opamp existed also. So why still use passive RIAA?
THx -RNMarsh
Why not? But the real point is one or two stage and all the folklore surrounding phono reproduction. For instance high gain with feedback is hardly necessary considering the distortion of an LP.
Passive still has benefit. Its a question for the minds here. After all this forum is about LP system so it may be one of the more important questions for DIY'ers with High-End interest. Should get some serious discussion time.IMO.
THx-RNMarsh
Many of y'all are able to make either passive or active RIAA that grossly exceeds the base performance of the vinyl/mechanical drive. So it's almost arbitrary. I guess overload margins are really the only place worth conversing?
Unfortunately, for those who actively listen to differences in phono stages, purely passive EQ has subjective advantages that is impossible (I think) to prove by just distortion measurement differences. It takes the subjective listening opinion of a number of people that shows this difference in any significant way.
For those of us who are data driven, how do we reconcile this "trust me, it's subjectively better." Especially when one could design an active and a passive phono that behave very similarly and two different passive phonos that behave totally different. Cutting wide swaths here erodes any sort of argument one way or another.
It is easy to listen first and then make measurements. Making measurements first can have you chasing artifacts that are not perceived by normal humans.
If I can't hear it, nor can others I have come to trust, then it probably doesn't matter. But it may later when you have fixed something that was masking the first artifact.
Now for a useless trivia question, who invented the first rock? (Really trick question if you are focused on the wrong definition.)
You personally don't have to trust anybody, but it can be useful to get subjective feedback, especially from people who's listening opinion you respect, and IF they don't necessarily completely like your latest design (subjectively) for some reason, that you look for alternate approaches to making the design.
For example: Up to 1973, I used either a MacIntosh C22 or a Dyna PAS3X as my phono reproduce with an Ortofon MC cartridge and the transformer that came with it. It was a difficult drive, but the transformer did some filtering of extreme hi frequency transients produced by mistracking, scratches, etc.
Late in 1973, Mark Levinson and I released the JC-1 active pre-preamp or transformer eliminator and we removed this filtering, while improving the listening performance. Now, I am not attacking transformers in general, but the crummy transformer that Ortofon supplied was barely up to the task.
Then we found that many tube preamps had a harder time handling the input signal. Because I was aware of this, I designed the new Levinson JC-2 phono stage with much higher class A output current than normal, and a reasonable intrinsic slew rate (over 20V/us). We were very successful for a few years, but I got occasional feedback from serious audiophiles that liked other phono stages better in direct comparison, and these phono stages always had two gain blocks with at least some passive EQ.
Finally, in 1977 while working as a consultant at HK, the new 2 stage phono stage by Electrocompaniet came out, and HK found it to sound very good, so I started to design a 2 stage phono preamp for the first time, and in direct comparison with the JC-2, it sounded clearer to just about everybody who tried it. I have been making 2 stage phono stages ever since, but not usually with full passive EQ. Normally, I have used a combination of passive-active EQ, and this includes the Dennison JC80, the Vendetta Research SCP-2, the Constellation Perseus and Orion phono stages, and finally the Parasound JC-3 IC based phono stage.
Now, is this good enough? No, I am now working on an all passive EQ, with no loop feedback in either gain stage. This is an almost impossible challenge, and I still haven't yet got it optimized, but I think that is the best approach based on subjective opinion up to today.
For example: Up to 1973, I used either a MacIntosh C22 or a Dyna PAS3X as my phono reproduce with an Ortofon MC cartridge and the transformer that came with it. It was a difficult drive, but the transformer did some filtering of extreme hi frequency transients produced by mistracking, scratches, etc.
Late in 1973, Mark Levinson and I released the JC-1 active pre-preamp or transformer eliminator and we removed this filtering, while improving the listening performance. Now, I am not attacking transformers in general, but the crummy transformer that Ortofon supplied was barely up to the task.
Then we found that many tube preamps had a harder time handling the input signal. Because I was aware of this, I designed the new Levinson JC-2 phono stage with much higher class A output current than normal, and a reasonable intrinsic slew rate (over 20V/us). We were very successful for a few years, but I got occasional feedback from serious audiophiles that liked other phono stages better in direct comparison, and these phono stages always had two gain blocks with at least some passive EQ.
Finally, in 1977 while working as a consultant at HK, the new 2 stage phono stage by Electrocompaniet came out, and HK found it to sound very good, so I started to design a 2 stage phono preamp for the first time, and in direct comparison with the JC-2, it sounded clearer to just about everybody who tried it. I have been making 2 stage phono stages ever since, but not usually with full passive EQ. Normally, I have used a combination of passive-active EQ, and this includes the Dennison JC80, the Vendetta Research SCP-2, the Constellation Perseus and Orion phono stages, and finally the Parasound JC-3 IC based phono stage.
Now, is this good enough? No, I am now working on an all passive EQ, with no loop feedback in either gain stage. This is an almost impossible challenge, and I still haven't yet got it optimized, but I think that is the best approach based on subjective opinion up to today.
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