PCB designers rule🙂 well good ones.....
Funnily I have worked on quite a few analogue designs over the last couple of years that were all SMD and had to be both very accurate... seems OK for instrumentation but not audio....
MAX got any measurements of the crystals before and after fixing the case to the boards 0V, its something that use to be done a lot mainly for EMI reasons... Not done as much these days (requires manual intervention...) but more designs use crystal oscillators, where the case is already grounded.
https://la3pna.wordpress.com/2014/12/09/any-benefit-to-grounding-crystal-cases/
Some measurements for you at silly frequencies... wonder how on a well engineered design this would have an effect, but if you are drilling through the PCB its not likely to be a multilayer so is a flawed design to begin with. Just curious whether it would have such an audible effect considering the low frequency of operation and levels involved... I have my doubts🙂
Funnily I have worked on quite a few analogue designs over the last couple of years that were all SMD and had to be both very accurate... seems OK for instrumentation but not audio....
MAX got any measurements of the crystals before and after fixing the case to the boards 0V, its something that use to be done a lot mainly for EMI reasons... Not done as much these days (requires manual intervention...) but more designs use crystal oscillators, where the case is already grounded.
https://la3pna.wordpress.com/2014/12/09/any-benefit-to-grounding-crystal-cases/
Some measurements for you at silly frequencies... wonder how on a well engineered design this would have an effect, but if you are drilling through the PCB its not likely to be a multilayer so is a flawed design to begin with. Just curious whether it would have such an audible effect considering the low frequency of operation and levels involved... I have my doubts🙂
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Depends how precision you are, but a reel of 0.1% 1206 is 22p each. So only 3dB out.
Of course if you are going for 0.05% price jumps, but what's the point for audio 😛
I was talking in singles, since this is a DIYaudio site. And even for the APs, somehow I don't think they qualify as mass production, to buy components in the 1000's.
RG3216P-1000-B-T1 Susumu | Resistors | DigiKey
One of the cheapest 0.1% (hard to find worse tolerance), 44p in singles.
Thick film 1% (hard to find better tolerance) are 7p a pop.
RC1206FR-0710KL Yageo | Resistors | DigiKey
About 16dB.
Ah fairy nuff. When Jan mentioned a 10c part I assumed he was talking about how much Benchmark pay. Lets face it, once you go pick and place, you generally buy by the reel where you can 🙂
I had to defend the use of thin films in selected places of a phono pre and discrete headphone amp to a client recently. A fellow consultant asked me if he would hear a difference. Well, certainly if he were listening to the noise. I had my baptism by fire on another product when I had significant d.c. flowing in certain thick film parts. There are significant differences among manufacturers as well.
Yes, the thin films are damn near perfect now, as discussed by Hofer, and not that expensive in quantity. Now, having learned the E96 values, I have to learn the 0.1% ones as well 🙂
Yes, the thin films are damn near perfect now, as discussed by Hofer, and not that expensive in quantity. Now, having learned the E96 values, I have to learn the 0.1% ones as well 🙂
Yes that is true, I should have mentioned that. The standard values E24, E48 are like 30 cents, the less current values like 50 cents.
But imagine never having to fret again about the magnetics and composition and attachment method of those non-existing leads 😉
Not to mention the small size which makes them less sensitive to EMI and such.
I find the fact that AP are using them in their top units quite convincing.
Thick film is cheaper but measurably worse regards stability and V-coefficient, which starts to play a role when you cross the -100dB distortion line.
You can gold plate your power amp but with a thick film or metal film in the feedback path that becomes the limiting factor for linearity.
(Yes I know, you don't listen to test equipment).
Jan
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Bonsai - i would suspect your separate dac is all surface mount components, three terminal regulators, and op amps so with similar ingredients why would it sound much different - the internals of the Oppo are the same, different parts but the same construction philosophy. I don't want to say that there aren't audible differences in designs built with this type of construction, there are better implimentions and Oppo is better than the usual.
I don't doubt that surface mount resistors have performance advantages in applications requiring tight matching, low parasitics, and small board real estate. There isn't a direct relationship between resistor tolerance and sound quality, input CMR and gain setting aside - it's construction details such as steel materials, resistive material, termination etc come into play once a reasonable tolerance like 1% is met. I would rather buy a finished product at an affordable price that sounds realistic, but after 40 years of audio interest I still find that the commercial compromises made to meet price points can be audibly improved with better diodes, passive components, regulators, better op amps or discrete designs.
This started with an early Threshold power amp (800a) that used an LM 310 unity gain buffer before the input differential pair - bypassing the buffer lead to an improvement in sound quality, and lead to further investigations ( i must have written off of at least a half dozen CD players that didn't survive changing diodes, regulators, bigger filter caps, and opamps, even being silly enough to try and replace surface mount resistors with Holcos, Resistas or Dales). Ocassionaly a player would survive and I could listen for changes - sometimes there were none that I could hear.
I don't doubt that surface mount resistors have performance advantages in applications requiring tight matching, low parasitics, and small board real estate. There isn't a direct relationship between resistor tolerance and sound quality, input CMR and gain setting aside - it's construction details such as steel materials, resistive material, termination etc come into play once a reasonable tolerance like 1% is met. I would rather buy a finished product at an affordable price that sounds realistic, but after 40 years of audio interest I still find that the commercial compromises made to meet price points can be audibly improved with better diodes, passive components, regulators, better op amps or discrete designs.
This started with an early Threshold power amp (800a) that used an LM 310 unity gain buffer before the input differential pair - bypassing the buffer lead to an improvement in sound quality, and lead to further investigations ( i must have written off of at least a half dozen CD players that didn't survive changing diodes, regulators, bigger filter caps, and opamps, even being silly enough to try and replace surface mount resistors with Holcos, Resistas or Dales). Ocassionaly a player would survive and I could listen for changes - sometimes there were none that I could hear.
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Thick film is bad, agreed, but metal film is ultimately... thin film (vacuum deposited plus laser trimming). The film material and process, that's a different story, but I believe you can find as many good leaded "metal film" as poor quality SMD "thin film".
Magnetic leads, etc... YMMV, but I'm not buying into that crapola.
SY’s Marantz CD player does not spare on number and quality of components where needed (plus discrete analog out buffers 🙂).
It also addresses all points that ticknpop highlighted at post #79810, despite the ample use of 3 leg voltage regulator ICs 😀
It’s a very good and honest product (and it’s 24bit DAC full capabilities are only partially used).
George
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Have you ever looked into a standard instrumentation amplifier topology (the very basic building block of a balanced input amplifier)? If not, I would strongly recommend doing it, in particular calculating the CMR sensitivity as a function of resistors tolerances. You'll be surprised, to put it mildly.
Semiconductor manufacturers are doing parametric on chip trimming (better than you could ever do with discretes) for a good reason, not because it's cheap or convenient.
Yes, I know, pesky engineering details, nothing beats peeking while listening.
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Mind you given the slew of single ended audiophool interconnects that have different metals for send and return CMRR is shagged unless you use a whitlock bootstrap!
so you had 2 of each, used a AB/X switch box, the rest of the required controlled listening conditions?
even just a few 1% R tolerances on gain R could add up to know audible threshold for loudness difference
in fact you really should "blueprint" in the engine rebuilding sense the 2 identical players before the mods
Don't worry ticknpop. No matter what you do, you will be found to be wrong. '-) It certainly happens to me on a daily basis.
If so, it was a nice job. Performs nearly as well as the Marantz.
Parasound Halo CD 1 CD player Measurements | Stereophile.com
No, I don't generally design CD playback for Parasound. I did try once back about 20 years ago, but they did not build the product. I do advise on the linear parts sometimes, and I like Rcore transformers over toroid when possible.
I was more intrigued by the button on the front that switches between op-amp and discrete output. From the marketing blurb
Seemed an odd thing to do rather than have 2 different buffer stages.
Seemed an odd thing to do rather than have 2 different buffer stages.
Don't worry billshirv, double blind testing will remove any difference between the output stages. '-)
But the feedback loop already removes any differences. That was my confusion. Why put in a discrete buffer INSIDE the opamp feeback loop? Especially as the owner can randomly switch it in and out. Sure there was a good reason for the decision, but it eludes me.
EDIT: X-post shows you can take no blame for this decision.
EDIT: X-post shows you can take no blame for this decision.
Andrew, in those days Marantz was owned by Philips and had the first draw of the transports they made. They stopped being a big name for CDs about the time they split from Philips and joned up with Denon.
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