quod erat demonstrandum...
how do you believe that DC is "magically" transformed into an AC (audio) signal? where does the audio current goes through? think current!
Voltage is just potential. Like a mass at a height. If you don't let it fall (let a current flow), no work is done (...physics 101). And, again, currents only flows in closed circuits. In many cases, PSU caps are exactly what closes the circuit for AC (signal, audio) currents.
"With Respect To"
a capacitor will not store AC
let see... 1800W/0.6V=3000A. If such a surge would be allowed, your house would blow out in fire!
OTOH a simple, tiny, cheap 1N4007 would survive repetitive peaks of up to 30A. Which is more than typical home fuses and/or mains breaker would allow (not to mention the amplifier own fuse).
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Then he should apply for a patent, although it might get denied due to "Prior Art." A voltage amp followed by a current amp is old technology. Doing it with chips may be unique, but the idea is not new.
Oops!
eBay was having "technical difficulties," again...
He hasn't responded to my PM so far.
Please give me the exact name of the buy group, because I only find threads from schro20 and udailey and the last message in each was posted in 2011.
There was no indication if it was current - the current one should be posted in the first message of the thread. That's how most DIY/interest groups do it.
And still, not one single source for the board, unless Siva has some.
But these are not sources for the finished boards, just resources if I had the time and could even buy the dangerous chemicals to make my own. I don't own a vector plotter nor the CAM equipment to manufacture my own.
None of which has had the boards available for sale so far.
Right now Jim's and Nimo are the only places that will sell me the boards. I'm sorry to be so insistent but this has been quite aggravating .
Please bear with my delayed responses for the next week or two - my only net connection is through a GPRS cellphone, and I haven't checked PMs for a while. I still have PCBs and kits - please email me at siva.chander at gmail dot com for details. Mauro's genius is in creating a topology that provides near Class-A sonics with Class-AB commodity chips - with *no adjustments or settings*. It just works, repeatably and reliably, as long as the initial assembly is carefully done.
Presuming you were talking to me: I don't need to watch presidential debates; I'm naturally "bickery."
You don't understand...or maybe I wasn't clear:
What I mean is simply that this design is different and can't be confused with a simple gainclone with input buffer.
My Ref Fremen Edition
When you asked you got answer, isn't it?
And, differently from most group buy, the files needed to order PCBs are available.
It means that even if you missed the GB you can have your PCBs done.
Yes, they are.
It's easy to send files to PCB manifacturers and have some PCBs done, though not cheap (as I wrote).
Right now Jim's and Nimo are the only places that will sell me the boards. I'm sorry to be so insistent but this has been quite aggravating .
Jim's one it's not a My_Ref clone... I thought I was clear about that...
This discussion, as Tom pointed out, is completely sterile and out of topic... this is my last post about it.
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Those posts do not seem to refer to any setup. But I think the critical parts are increasing C4 to 1uF X cap and also using 3300uF 80V in parallel on the main DC for LM3886, and I have C12 and C13 removed. These seem to have the major impact for me. C7 changed to an X cap of same value. Snubbers close to the LM3886 improved the detail a bit.
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I've taken some time away from active discussion to read the majority of this thread, starting from the first message. I've compiled some notes while reading. Of course, now I have a few questions.
My general observation is that we've reached the point where we're no longer dealing with gross changes circuit or major component changes, but are now fine tuning, "seasoning to taste," putting "the icing on the cake," or however it is said in your locale.
Perhaps it's time for soongsc to publish his own BoM for the rest of us to study. I would find it helpful, especially if he updates the title (soongsc_BoM_09/Feb/2012) whenever he makes a change. His snubber values and location in the circuit would be helpful.
You, too, Dario - you certainly continue to seek better sound.
Time for bed - got a job interview tomorrow.
I'm not going to be doing any kits, at least not any time this year, and probably never. I am just sharing some experience because this thread had provided lots of ideas. Some of the changes that I did not feel appropriate for this thread due to the magnitude of change I did not post any information on. So I guess, anyone interested in exploring options can just get whatever PCB others are providing and try things out. For me, this journey is still ongoing. And I don't think people will get same results that I hear, simply because I had to do everything from the speakers, interconnects (now commercially available), to amplifiers, as an effort to eliminate as much uncertainties as possible with a more tightly controlled interface of the devices such that speakers, interconnects, amplifier all need to have a reasonably flat load impedance over the audio spectrum presented to the driving device.I've taken some time away from active discussion to read the majority of this thread, starting from the first message. I've compiled some notes while reading. Of course, now I have a few questions.
My general observation is that we've reached the point where we're no longer dealing with gross changes circuit or major component changes, but are now fine tuning, "seasoning to taste," putting "the icing on the cake," or however it is said in your locale.
Perhaps it's time for soongsc to publish his own BoM for the rest of us to study. I would find it helpful, especially if he updates the title (soongsc_BoM_09/Feb/2012) whenever he makes a change. His snubber values and location in the circuit would be helpful.
You, too, Dario - you certainly continue to seek better sound.
Time for bed - got a job interview tomorrow.
Snubbers I use is 0.01uF + 1 ohm (I think it's 1/2W). The caps on the power rail, I felt that the different brands of X caps I used did not seem to make a bigger difference than the values, I do tend to like the same 1uF brand that came with the TP kit (grey color with that AV type logo on it, whatever that brand is). So I did not even make effort to remember which brands they were. As I always try to do, I'd choose the X caps that are physically larger for the same value capacitance. C12 and C13 I just removed all together since C12 caused the input impedance to vary in a similar way as do interconnects, and C13, I never used one in that position, simply because I have not found one satisfactory in terms of performance, price, and size. It make no sense to have a large cap that costs as much as the other components and not be able to perform better than without it.
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You, too, Dario - you certainly continue to seek better sound.
You can find the latest version of my BOM here.
BTW in this moment I'm focused on the Fremen Edition... but it could be possible that something reverbs on Rev C BOM.
And what better way to share your experiences than a journal (a BoM, in this case) of your thoughts. I'm not asking for a kit, just a listing of your parts as they change during your investigation. That's far easier for the rest of us to follow than reading the entire thread.
Thank you. A picture of the X cap would be helpful.
Not in an organized independent documentation, but just a the modifications that are done one the TP board, which would generally be common regardless what power supply arrangement one uses. This I do from when I reach the point of what I consider a milestone.And what better way to share your experiences than a journal (a BoM, in this case) of your thoughts. I'm not asking for a kit, just a listing of your parts as they change during your investigation. That's far easier for the rest of us to follow than reading the entire thread.
Thank you. A picture of the X cap would be helpful.
The X cap, Dario had posted a pic a while back.
This is about the best I can do at the moment because I seldom get simulation and measurement information from people whom claim to have done them, I do not intent to spend the extra effort to organize my results so much either.
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