Thanks for listening with an open mind firstly. Most of my stuff is classical (lol and that didn't go down to well in times past) and so its difficult to know what to choose.
The tone control PCB just seemed to lend itself to this as a fun and informative little comparison. It was handy and tried and tested.
If you hear differences then go with your instincts. If you have something to say about one or more files then put it down 🙂
The boost and cut experiment was definitely uncharted territory, that's for sure, but as I keep saying, its the same for all the opamps.
You just might be surprised how close the boost/cut version is compared to a single pass from player to ADC i.e. no tone control in circuit.
That would essentially be just two opamps in the signal path. With the bass and treble centred there is no contribution from all the other devices. That can be seen in the simulation below where we are looking at the final output from the bass and treble networks prior to mixing with the incoming signal.
Edit... simulation running with 2vrms applied.
Distortion (if any is present) simply becomes part of the original signal. Because you have nothing to compare it to means you have to accept it 'as is'. Its a perfectly valid test signal that all the opamps see equally.
As I have said before, go with your instincts. Can you label any one file as being worthy of comment and perhaps suggest what device it might be.
Attachments
Hundreds and hundreds of vinyl consumers are listening to music through a 600v/us dual opamp in the phono stage.
What like some AC/DC after smoking half a dozen a bungys and gulping 12 pints of Fosters? Naaah. The Norah Jones is a great test - if it sounds good it probably is. 😉
Sure its not your system Dan - seriously?
😀
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Oh it had a sound. And I know I could design that EQ way, way better now. BTW that unit was designed for musical instrument applications. The goal on that was to get some effect on an instrument track in the studio.
Yes, I've found some in depth discussions on the superiority of the pure silver wiring you provided to Mr. Curl for using in the Blowtorch preamp. Very enlightening and educational.
I'm pretty sure I have that Norah Jones album myself and now that everyone is talking about it I do remember thinking the instrumental parts were really distorted. Her voice is okay but something about the music and specifically the piano comes to mind. Steely Dan always comes to mind as excellent recording quality for listening purposes and to hear fine details.
I would agree if there is only a binary choice, valid/invalid, then it's valid. If shades of gray are allowed, then I would not call it "perfect" for the purpose of identifying small differences between opamps. Others are free to disagree, of course.
Be careful with Nora Jones. She tracks to analog but mixes to digital.
But with slow opamps, well, maybe it really doesn't matter.
But with slow opamps, well, maybe it really doesn't matter.
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If I am understanding your drift correctly I'd hardly say this is the fault of the opamps (if not, apologies - I respect that you now have a very well regarded product). You could have used any opamp and still had a commercially unsuccessful product. I would imagine the guys that buy dedicated phono stages want things a certain way and adding these controls was a step too far or made it too complicated (but not to be confused with archival type phono stages like the one designed by Gary Gallo and featured in LA, or Torsten Loesch's similar product from AMR).
We have a discussion like this every few months with JC who believes if he used opamps in his top level products they would not get good ratings. He is right, but for the wrong reasons. We sit here as a community of geeks/nerds/introvs agonizing over this stuff. The guys that buy these products don't. They don't buy one phono stage over another because its noise level is 2 dB better, or the distortion is twice as good - just look at the specs of some of these things - abysmal. If we made them twice as good, a lot would still be crap electrically speaking. People are buying these high end products for largely non-technical reasons. Deciding that a discrete amplifier is better than an opamp based one is not a technical decision. Ditto feedback etc. Its a fashion choice. Further, if they like the sound on a casual listen and can detect no major anomalies, the look and the price is right etc they buy. High end audio has much more in common with the fashion business than say photography. Anyone who has had a close look at a $50k Gryphon amp want to tell me otherwise?
Hence, the great leveller in all these matters - if you want to hear a difference - is the DBT. If you don't, its below human audible thresholds*
*this excludes Jay of course 😉
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Okay, I will just make a speculation here:
BLODWYN
Based on that comparison in small segment to perceive musical bend around the lyrics "In fields..." this was the runner up. Like Scott, initially I perceived something wrong with this clip. I think it's the low drive, low capability to drive difficult load such that it shows that distortion symptom. I think this is TL072.
ESMERALDA
This shows dynamics that usually belongs to 4562. But this chip is not musical. It should be one of the two "high-end" chips (4562/OP275) but OP275 has JFET input so I think OP275 fits better with the other high-end file. I think this is 4562.
ETHEL
With blodwyn this is one of the most distorted sound. I tried to listen the sound of brush in order to find which one is 4558, because in my opinion, cheap low slew rate opamp will not be able to produce HF/brush well. I think this is 4558.
GLADYS
This is the most balanced. Perfect, hard to find anything wrong. This is the strength of 5532, but unfortunately I can't find the weakness usually associated with 5532. So I predict that this could be the chip originally used for this circuit. So I checked Mooly's thread and indeed the original Douglass Self preamp uses 5532. I think this is 5532.
MABEL
This was the winner regarding the musical bend at lyrics "In fields...". Detail and clear. But as a whole I found this fatiguing, like usually found in 4562. But that musical bend matches closely with JFET input opamp, even tho OP275 is I think a mixed between JFET and BJT. I think this is OP275.
The reason they buy them is because they sound subjectively better. They happen to produce a little euphonic distortion, which many people like. They may not want to admit even to themselves that they are buying an effects box, but they are. There may be some fashion buyers as well, but for people who actually listen, such as some of the better reviewers, the boxes have a sound they like. Of course, if somebody wants a job writing audiophile reviews, it is required to write in the genre, and use funny words to describe things. Not so different from other writing jobs. Even academic journals have mandatory writing style rules.
Morph the Cat is terrible in estimation.
The bass is totally compressed and overblown. Stick that on and crank it up and its like doing 10 rounds with George Foreman. The earlier stuff is much better - e.g. Aja
For test listening I like for example the LSO, Yo Yo Ma, Diana Krall and some George Benson stuff. I've got some fantastic DG classical recordings as well that I like to use. With these recordings its easy to check response extension, imaging and dynamics. I use Spotify for 320 kB/s MP3 - lots of good stuff on there but I don't think its quite as good as a good CD or SACD recording. I generally don't think Rock or heavy music is suitable for testing the subtleties of a good system. If you want to see if your 1000 Watt class D amp can levitate your bass cones off the speaker coil former, then ok, but not for anything serious (that's where the AC/DC comes in Dan )
Jay, that's great that you have put all that down 
but I'm not going to reveal anything just yet.
Can anyone else make anything out by listening ?
but I'm not going to reveal anything just yet.Can anyone else make anything out by listening ?
Agree, but does that somehow then exclude all opamp based designs, an imbue all discrete, tube and JFET designs with that sound? I don't think so.
If reviewers believe a certain type of design is better and they tell their readers that, then they will steer the market in that direction I am afraid.
I realize this was written off the cuff, but take a step back and ask yourself, "does this sound remotely reasonable?"
Indulge me an extrapolation, the latter is a hypothesis that different opamps in a circuit would cause a change in blood pressure.
Yeah, but what's your listening system? Surely your comments are solely based on its inadequacies and your envy of others...
Are you guys aware of Stuart Yaniger's test as described in his Linear Audio article in Vol 2 - Testing One, Two, Three ...?
https://linearaudio.net/authors/366
His findings are pertinent for the current discussion.
Jan
https://linearaudio.net/authors/366
His findings are pertinent for the current discussion.
Jan
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