Kindhorman, in certain spheres of product manufacturing they are. The engineer chooses the best performing part from a particular manufacturer for a particular job, else there would really not be conformance of production.
There is the other extreme practised east from us that would choose the cheapest part with the same name regardless of its origin which definitely does not comply with consistence of product although they will claim the same specification for production unit as was for the prototype but not even near.
An easy parallel would be why your car has four exact same tyres from the same manufacturer. Try putting on four different manufacturers tyres even though they are all specified radial ply at the same R (speed rating). You will find yourself in the trees in no time.
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Shouldn't one try and keep the swapping of parts as scientific as possible, by only changing one component/characteristic at a time? Am I way out in left field here?
That is exactly what I did, swap one op-amp for another and compare, then swap back and refresh then swap for another and compare, etc.
My point was did you do the swapping in D.S.'s new pre-amp? If you didn't, then what relevance does it have to this design? My larger point centers around the issues raised by owdeo early on in this thread with post #207 on page 21. The whole focus and tenor of the thread changed to comparing this new design with the original Precision Pre 96 and apparent sonic signature that owdeo could not quite put his finger on and quantify - other then 'strangling' the music in some way.
I'm just suggesting that we get back to discussing the current design and quit speculating on how the design may sound relative to the 96 pre. Or, if changing op amps really make a difference? I'll ask again, has anyone built this new design preamp yet? And if they have, what evidence can be provided that in someway suggests it is inherently colored based on the design choices Doug made.
I'm just suggesting that we get back to discussing the current design and quit speculating on how the design may sound relative to the 96 pre. Or, if changing op amps really make a difference? I'll ask again, has anyone built this new design preamp yet? And if they have, what evidence can be provided that in someway suggests it is inherently colored based on the design choices Doug made.
Sorry then I missed the point completely when there was mention regarding the choice of NE5532 for this design and that used in the 96 version.
Sorry I retract all above comments, that suggest that the op-amp used may be from a specific manufacturer or its date of manufacture has no bearing on the characteristic sound of Doug's pre-amp, since op amps are neutral and they all sound the same regardless of progress made in manufacturing processes over 20 years and can be interchanged with no sonic effect.
Maybe the problem can be alleviated by shuffling the PCBs around a little <smile> because what I think you are suggesting is the characteristics of this particular pre-amp is attributable only to the passive components, the fact that it is spread across 9 PCBs and uses ribbon cable as interconnects. Maybe one should then even consider what solder and components are used since Rohs compliant is very different from that used almost 20 years ago.
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Hehe....I think you both just made excellent points
On the subject of component differences, I think AndrewT's accusation (still without satisfactory explanation) that I modified the design by using 0.1uF polypropylene instead of polyester (of similar physical construction) decoupling caps is an exaggeration. Using this logic any constuction that uses even different brands of components to the original prototype could be called a modification, and these would have to be specified in the design.
Of course he may be right, I just can't see why so I'm not keen to go and replace them all without further satisfactory explanation as to why it should make much difference. Simply saying they are different therefore a modification is a cop out as far as I'm concerned.
As for the sound quality, for the umpteenth time I'm not criticising the technical design. There is absolutely no basis to do so. I just think (my implementation perhaps ) doesn't sound as good as I expected it to. I don't think it's because it's based on 5532 opamps as in the past I have built and used much equipment based around these that sounded just fine to me. I'm speculating that the particular characteristic comes down to the actual circuit configuration. Unfortunately I have got no further finding out where/what due to family and work committments and my hobby getting pushed way down the priority list, but will certainly post an update if and when I get anywhere in this regard.
If you believe that measurements are the only acceptable means to prove the quality of sound that a design provides, there is of course no value in my subjective assessment, so please ignore all this but please stop telling me why I must be wrong - what's the point?
Finally, redjr I apologise for hijacking this thread. The 2012 preamp shares the basic architecture and active gain control configuration with the '96 design and hence I thought my findings may be relevant enough to add here. Trouble is it seems you're the guinea pig on the 2012 preamp... How does it sound by the way?
On the subject of component differences, I think AndrewT's accusation (still without satisfactory explanation) that I modified the design by using 0.1uF polypropylene instead of polyester (of similar physical construction) decoupling caps is an exaggeration. Using this logic any constuction that uses even different brands of components to the original prototype could be called a modification, and these would have to be specified in the design.
Of course he may be right, I just can't see why so I'm not keen to go and replace them all without further satisfactory explanation as to why it should make much difference. Simply saying they are different therefore a modification is a cop out as far as I'm concerned.
As for the sound quality, for the umpteenth time I'm not criticising the technical design. There is absolutely no basis to do so. I just think (my implementation perhaps
) doesn't sound as good as I expected it to. I don't think it's because it's based on 5532 opamps as in the past I have built and used much equipment based around these that sounded just fine to me. I'm speculating that the particular characteristic comes down to the actual circuit configuration. Unfortunately I have got no further finding out where/what due to family and work committments and my hobby getting pushed way down the priority list, but will certainly post an update if and when I get anywhere in this regard.If you believe that measurements are the only acceptable means to prove the quality of sound that a design provides, there is of course no value in my subjective assessment, so please ignore all this but please stop telling me why I must be wrong - what's the point?
Finally, redjr I apologise for hijacking this thread. The 2012 preamp shares the basic architecture and active gain control configuration with the '96 design and hence I thought my findings may be relevant enough to add here. Trouble is it seems you're the guinea pig on the 2012 preamp... How does it sound by the way?
I have some pretty old NE5532 (>10yrs) from Texas, some from On-Semi and also Fairchild.
I use HD800's with Lazy Cat's L-MOSFET SSA being on hand and I think a very revealing amp.
I first used a simple inverting and then a non-inverting socketed configurations so that I can swap op-amps and listen.
Each manufacturer's NE5532 sounded subtly different from another more so did inverting from non-inverting.
When saying subtle, I mean exactly that I think I heard something different, maybe better high end definition whatever....Hard to tell with one of the worlds best sounding speakers one centimetre from my ear and zero room acoustics and other distractions.
Just to spoil the broth completely.... I dropped in an AD711 and I thought it sounded best.
What does that prove, I think absolutely nothing it was purely a choice I made based on what I thought I experienced.
If I do the same test tomorrow it might have a different outcome.
Glad to hear I'm not the only one hearing differences between the 5532 brands and that it's not unique to this design - thanks Nico.
How did you find the TIs? I tried these also and was surprised how different they were. The midrange was quite nice but the bass just seemed to have dissapeared and the treble seemed a bit grainier.
My two choices are JRC and On Semi. The JRCs are more musical and enjoyable to listen to, but the On Semis seem a tad cleaner and perhaps more "accurate".
That reminds me - someone was telling me that Ken Ishiwata (spelling?) of Marantz likes to use JRC 2114, which appears to be a selected or tweaked 5532. Does anyone know more about these?
Many high-end audio products are lauded for their carefully tailored harmonic distortion rather than the lack of it, so have you considered that you might be describing the effect of eliminating something from your audio chain that had been affecting the music programme? The clue to me is in your use of the term "strangled" which to me implies flat response and very low HF distortion. I've seen DestroyerX refer to it as "muffled" and there it infers no sweetening harmonics. Combined with intentionally flat response monitors, that could well add up to a purity of sound that perhaps you hadn't anticipated.
I think few of us us really want technically perfect reproduction, though it is the basic principle of high fidelity audio, which we somehow feel obliged to uphold, even though it doesn't mean we'll enjoy it most. On the other hand, if I wished to process the audio for broadcast, recording, relay, PA etc, I wouldn't hesitate to go for the most linear equipment available. You can get funky at the listening end any time without affecting other uses.
Yes I did consider that but don't think it is the case. By strangled I mean more a feeling that the sound/music isn't "flowing freely", it is somehow constricted. This is comparing it with several other preamp designs both opamp and discrete. One of my discrete preamps was measured using a friend's Cyril Bateman distortion meter and the second and third harmonics were at around 0.0002% at 1 and 10 kHz, so I'm fairly sure the problem is not that this design is too "clean".
The way I see it is that I absolutely want technical perfection and if I have it I will like the resulting sound given a good recording. I just don't agree that the way we assess it is adequate as differences in sound quality between amplifiers with the same basic measured performance clearly exist. There should be better ways of characterising this. I think what I'm hearing is measureable. I just don't know how to measure it.
I work in the medical imaging industry and I see parallels there. Every manufacturer claims they have the best detector technology that delivers the best image quality and they have the measurements to prove it. But the radiologists' trained eyes are what determines which equipment is actually best. There is no adequate or complete way of measuring the final image quality. Ignoring human perception and concentrating only on the pure science seems to be missing the point. We use audio equipment to enjoy music and we should be trying to measure things relative to their potential to affect our perception, not just eg linearity/distortion in isolation. THD tells you a lot about how linear the circuit is, but very little about how the existing non-linearities might affect the sound quality. I think that's what I mean anyway....
According to thousand of posts, across hundreds of threads here on DIYAudio, there can be a slight degree of 'coloration' of the sound with op amps from different manufacturers. Whether it's enough to be measured with test equipment, or simply more audiophile snake oil I don't know. However, I'm not that 'into' tweaking PCBs components or values for the sake of trying to gain a subjective (or even dubious) infinitesimal amount of 'improvement'. More to your point, if op amps are indeed neutral than it must be other aspects of the circuitry (active/passive components) that influence how the op amps operates and ultimately sounds within a given circuit?
(not sure if this is sarcasm or not) I'm not suggesting it's just the passive components! What you mention are just a few of the 'external' attributes of this pre-amp that 'could' make the sound different from the original design. After all, DIYAudio is replete with the amount of minutiae of changes that some will go to to try and 'alter' or 'improve' the sound. So, one could argue that it goes without saying that the new D.S. design with it's multiple PCBs, inter-connects, etc, cannot be directly compared to the original - fairly. Aren't there enough obvious changes to suggest something may sound different - both with new active circuitry and total topology? Note - I did not say sound bad. Especially when we are trying to make that argument in the theoretical realm!
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I never suggested you are or did.Hehe....I think you both just made excellent points
On the subject of component differences, I think AndrewT's accusation (still without satisfactory explanation) that I modified the design by using 0.1uF polypropylene instead of polyester (of similar physical construction) decoupling caps is an exaggeration. Using this logic any constuction that uses even different brands of components to the original prototype could be called a modification, and these would have to be specified in the design.
Of course he may be right, I just can't see why so I'm not keen to go and replace them all without further satisfactory explanation as to why it should make much difference. Simply saying they are different therefore a modification is a cop out as far as I'm concerned.
As for the sound quality, for the umpteenth time I'm not criticising the technical design.
Agree.
Again, I never said you were wrong. At least I don't remember saying so, if I did. People hear what they hear. And if something sounds different or out of place we like to investigate and possibly figure out why.I just think (my implementation perhaps
If you believe that measurements are the only acceptable means to prove the quality of sound that a design provides, there is of course no value in my subjective assessment, so please ignore all this but please stop telling me why I must be wrong - what's the point?
You didn't hijack the thread, I just felt it moved in a particular direction that influenced the larger focus intended by the OP. It certainly stirred a lot of comments. I may very well be the guinea pig, but alas it's not all interconnected yet, so I have nothing to report as of now.Finally, redjr I apologise for hijacking this thread. The 2012 preamp shares the basic architecture and active gain control configuration with the '96 design and hence I thought my findings may be relevant enough to add here. Trouble is it seems you're the guinea pig on the 2012 preamp... How does it sound by the way?
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Not at anyone here in particular as I am following the logic and arguments of both sides of this discussion. I think that we can agree that there are multiple differences going on in both the design of the newer preamp and the component interactions that are hard or at this state not possible to qualify or quantify. Yes we do need not just the same measurements but additional measurements to get to the bottom of what everyone is trying to describe here. I also hear the argument that we are supposed to be discussion this particular design, not a previous one, but this specific implementation. I have another question based on some of the comments here. The comment about the multiple boards and the ribbon connections and other whether shielded or not wires are another phenomena that is involved here. I know that some here are excellent circuit board designers and I am wondering if it is possible for someone to take this entire circuit design and create one that would be on a single board? Is that allowed or is there something that would stop you from doing that. I am not trying to take anything away from Elektor and them making their money. just would that change the character of the final preamp if that was done? Are you watching this thread Doug Self, what say you about that? I'm sure there will be many different replies to this suggestion, I can take it.....
Steven
Steven
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1k (dual gang) linear pots
Here's a possible idea to convert a for eg, a 10k Lin Pot to almost 1k, in my screenie below.
This trick could be used on other value Pots too. Just calculate as if you were wanting to use 2 x resistors in parallel.
Also Very low cost pots are available from here,
Min Dual Pot Lin 10k - Order Code: JM81C - ONLY GBP £1.09 - Dual Miniature Potentiometers : Potentiometers : Maplin Electronics
Even with postage, for a group buy, or otherwise, it looks like a Very good deal
By the way, i built DS's PreAmp several years ago, but with OP27 OpAmps, & modified the Tone Control frequencies more to my liking. It sounds just fine !
Here's a possible idea to convert a for eg, a 10k Lin Pot to almost 1k, in my screenie below.
This trick could be used on other value Pots too. Just calculate as if you were wanting to use 2 x resistors in parallel.
Also Very low cost pots are available from here,
Min Dual Pot Lin 10k - Order Code: JM81C - ONLY GBP £1.09 - Dual Miniature Potentiometers : Potentiometers : Maplin Electronics
Even with postage, for a group buy, or otherwise, it looks like a Very good deal
By the way, i built DS's PreAmp several years ago, but with OP27 OpAmps, & modified the Tone Control frequencies more to my liking. It sounds just fine !
Attachments
Pure speculation on my part... but I believe there would be some copywrite issues with Elektor in either merging all the boards into one, or coming up with some new PCB design. However, given the 'modular' design of the new pre, I'm sure we will see some clever implementations of the PCBs in the DIY community. In my view, there are numerous ways to layout the PCBs in an enclosure to minimize wire lengths and potential electrical interaction.
Tayda2009 on ebay have a huge range of pots I haven't found anything to complain about.
2 x 250K OHM Linear Dual Taper Rotary Potentiometers B250K 250KB POT ALPHA items in Tayda2009 store on eBay!
If you don't mind TI NE5532s, you can get 20 for $4.59. Delivery takes a few days. I've bought other things from there without complaint.
2 x 250K OHM Linear Dual Taper Rotary Potentiometers B250K 250KB POT ALPHA items in Tayda2009 store on eBay!
If you don't mind TI NE5532s, you can get 20 for $4.59. Delivery takes a few days. I've bought other things from there without complaint.
i'm already well down the rabbit hole with this. i have the phono stage done, line stage almost done. the rest goes pretty quick.
yep that works, noise powers add so it even noisier than just using a 10k outright.
Isn't the 10K "shorted" by the 1K noise wise ?
The real problem is the impedance seen at the wiper is nothing like a true 1K pot.