you missed my point. Many reviewers like units that are effects boxes. True transparency often disappoints.
This is true. But there is also a point where you get transparent, but not quite there, then you do are excited and disappointed at the same time. At one point, one reviewer would tell me that customers will not notice the potential right away whereas a different sound would catch attention very quickly. This is when the designer has to decide which way the design should go. I often find that sticking to transparency lets you accumulate your improvements whereas once you start worrying about the effects, you could go in circles.
Most professional reviewers have expensive equipment on "long-term loans" (= receive as gifts) in exchange for a positive review. I know because I happen to know one of these reviewers. He used to write for one of the major HiFi magazines (forget which one).
~Tom
Yes, this can be a precarious place to be! The closer one is to true "transparency" the harder it may get, because it can be a most obscure, never thought of before, issue which is now key - and your mission, should you choose to accept it, 🙂, is to track that beastie down.
Worrying about effects is always a dumb move ... total confusion, and poor sound, will certainly be the result ...
So what speaker is the equivalent of the Modulus-86, measures well, performs well, diy or commercial?
Tom, I read the whole thread here over the last few weeks, and I must say I'm quite impressed. In recent years I've seen the threads on the "MyRef" and related composite chipamp designs, and probably like many others I assumed those were the best one could do with the LM3886 style chips. As good as they are compared to the LM3886 by itself, that assumption was clearly wrong!
So I hope you don't mind if I bring the thread back to a technical discussion of your design. 🙂
You've mentioned it's easy to make a bridged amp with your boards (with that balanced input, it takes no extra circuitry!), and I'm wondering... in recent years I've more and more liked the idea of a bridged power output design (except for the impedance seen by each amp being half that of a single-ended output. which seems to be the only possibly detrimental feature). The speaker is driven only from the + and - power rails, and so this high speaker current doesn't go through and pollute the ground line as it does in the usual single-ended output design.
Do you have any idea what the source(s) is(are) of this board's (very low) distortion figures? If the residuals of the speaker ground current has much to do with it, I'm thinking a bridged design would end up with significantly LOWER distortion. As I recall, you're already not far from measurement limits.
Also, thinking about going to the next level: The positive and negative power rails are of course capacitively coupled to the ground line through the power supply capacitors. As a bridged output will always pull the same current from the + and - caps at any instant, the ground theoretically stays perfectly in between the two, but if the capacitor values are unequal, there could still be an effect on the ground. The next step would be matching the values of the power supply capacitors.
So I hope you don't mind if I bring the thread back to a technical discussion of your design. 🙂
You've mentioned it's easy to make a bridged amp with your boards (with that balanced input, it takes no extra circuitry!), and I'm wondering... in recent years I've more and more liked the idea of a bridged power output design (except for the impedance seen by each amp being half that of a single-ended output. which seems to be the only possibly detrimental feature). The speaker is driven only from the + and - power rails, and so this high speaker current doesn't go through and pollute the ground line as it does in the usual single-ended output design.
Do you have any idea what the source(s) is(are) of this board's (very low) distortion figures? If the residuals of the speaker ground current has much to do with it, I'm thinking a bridged design would end up with significantly LOWER distortion. As I recall, you're already not far from measurement limits.
Also, thinking about going to the next level: The positive and negative power rails are of course capacitively coupled to the ground line through the power supply capacitors. As a bridged output will always pull the same current from the + and - caps at any instant, the ground theoretically stays perfectly in between the two, but if the capacitor values are unequal, there could still be an effect on the ground. The next step would be matching the values of the power supply capacitors.
I would dread the thought of any audio equipment be released without any audition reviews.
I have not heard any already out on the market. From published data, there are none that will mate well with amplifiers out there, that is why audiophiles are changing equip,net pretty often to fine a better match. If there were, I can go and take a long vacation around the world.
I am sure JBL really did not worry about what reviewers thought before they released the M2 which is considered to be one of the pinnacles of loud speaker design. They will have performed controlled listening tests, but no sighted subjective nonsense.
If you are asking who, I cannot reveal such. But if you know anyone whom deal with OEMs in Taiwan, you can aske them yourself. Most orders start with frequency response and distortion figures, then they will listen, and there is always a reference in storage in case of dispute.
You are making the assertion that JBL use sighted viewing to tune products despite all the papers from Toole and Olive that they do unsighted. The onus is therefore on you to provide proof or accept delusion.
If you want to know what goes on in reality, you just need to talk the them directly. I respect the obligation to maintain clonfidentialty of information specific to any company that I come in contact with.
benb,
Thank you for trying to bring the thread back to some relevancy.
I don't know the answer to your question but I have wondered it myself.
Best,
Anand.
Thank you for trying to bring the thread back to some relevancy.
I don't know the answer to your question but I have wondered it myself.
Best,
Anand.