Nuuk said:
So it all works and then you install it in the amp (without connecting it to the amp or anything else it wasn't connected to when it worked outside the amp) and then it doesn't work? It *has* to be a short (or some other "environment" issue) doesn't it?
When you swap reg modules does the problem follow the module or the amp?
I know it's a pain, but maybe start swapping parts within the modules?
Hi Pedja,
Yes, the only change from testing is the two 10,000 caps. A pair of 'old ones (from a gutted Arcam A60) for the test rig and a pair of DNM slitfoils (10,000 uF) in the amp.
I even tested both these modules, in their 'cradles', with the same 10,000 caps prior to assembling the amp and they worked just fine.
Jeff, that will be my next move, to swap the 'faulty' module to the other 'cradle'/10,000 uF caps and see what happens.
...................................................
Yes, the only change from testing is the two 10,000 caps. A pair of 'old ones (from a gutted Arcam A60) for the test rig and a pair of DNM slitfoils (10,000 uF) in the amp.
I even tested both these modules, in their 'cradles', with the same 10,000 caps prior to assembling the amp and they worked just fine.
Jeff, that will be my next move, to swap the 'faulty' module to the other 'cradle'/10,000 uF caps and see what happens.
...................................................
geewhizbang said:
I compared what Carlos claims to be his best amp (design) to what I believe is my best amp (design). I'm not saying it is fair, but surely it is revealing. It gives me the opportunity to see that I am still on a right track. After reading some posts in this thread one might think that Carlos is indeed on something revolutionary "new". I now know that this is not the case.
BTW, it is not rough implementation, this is the exact implementation, in many cases using much better parts than Carlos did. I can't see a better way to do a layout or reduce the signal path length:
http://www.diyaudio.com/forums/attachment.php?s=&postid=426502
I will be comparing extensively this "new" amp to AC powered GCs today.
You are really convinced you made it well, Peter, and that says it all.
You mix PSU with the amp, you mix high level with low level, you put everything on the same bag.
You even put the regs on the same heatsink as the LM3875, so close to it... could you get them closer?
You just "glue" an op-amp there and that's it, done.
The speaker output on your "modified" PCB is some 3~4mm from the op-amp, what a nice job!
Everything on your amp is a mess and I'm not surprized of your results.
Some people may be impressed with "good looking" boxes, I don't.
Enjoy yourselves.
Cheers
You mix PSU with the amp, you mix high level with low level, you put everything on the same bag.
You even put the regs on the same heatsink as the LM3875, so close to it... could you get them closer?
You just "glue" an op-amp there and that's it, done.
The speaker output on your "modified" PCB is some 3~4mm from the op-amp, what a nice job!
Everything on your amp is a mess and I'm not surprized of your results.
Some people may be impressed with "good looking" boxes, I don't.
Enjoy yourselves.
Cheers
carlosfm said:
It surely gives impression that you "seem to have better engineering instincts overall", but unfortunately I've built enough of those amps to know what actually works and what not.
grrr.
I've been trying to put together a list of the things to do and things not to do, what little things made magic sound, by digging through all the old posts and I'm finding it difficult as heck.
As such, I'm not entirely surprised that Peter's layout falls short of your expectations Carlos. Many of the things I find are like this last list - calling out "what's wrong" but leaving people like me 100% in the dark (except that you may have expounded somewhere in the past and I have missed it). It's entirely frustrating!
I come here hoping I can learn things. I have some parts on the way that will get me started, and more to come later to try regulation and such. As others have suggested, I hope to just try the options as I can. But if I can't find those small little tidbits of things you tried that made a huge difference (I will eventually, I am sure) I wonder, will I be selling a design short?
My assumption is that anyone that posts a design along with their trials and tribulations does so with the intent to help others down the path. I also assume that one does not need an engineering degree to be allowed to enjoy working with this stuff. I know I'm missing some very basic rules along with what seem to be some more personal rules. I've picked up on a few of both already.
As such, looking at Peter's layout I see some creative strategy regarding component placement. I look at Carlos's response and, aside from some previous understanding of why one might not want the power boards by the amp section (and why one might want different heatsinks) I am completely baffled by the other criticisms.
Carlos, I would think you might be interested in constructive suggestions given some of the seemingly small changes I recall you making originally. Unless there's some other issue between you that we don't know about, I really just don't get your response.
C <-- back to post-digging for good information
I've been trying to put together a list of the things to do and things not to do, what little things made magic sound, by digging through all the old posts and I'm finding it difficult as heck.
As such, I'm not entirely surprised that Peter's layout falls short of your expectations Carlos. Many of the things I find are like this last list - calling out "what's wrong" but leaving people like me 100% in the dark (except that you may have expounded somewhere in the past and I have missed it). It's entirely frustrating!
I come here hoping I can learn things. I have some parts on the way that will get me started, and more to come later to try regulation and such. As others have suggested, I hope to just try the options as I can. But if I can't find those small little tidbits of things you tried that made a huge difference (I will eventually, I am sure) I wonder, will I be selling a design short?
My assumption is that anyone that posts a design along with their trials and tribulations does so with the intent to help others down the path. I also assume that one does not need an engineering degree to be allowed to enjoy working with this stuff. I know I'm missing some very basic rules along with what seem to be some more personal rules. I've picked up on a few of both already.
As such, looking at Peter's layout I see some creative strategy regarding component placement. I look at Carlos's response and, aside from some previous understanding of why one might not want the power boards by the amp section (and why one might want different heatsinks) I am completely baffled by the other criticisms.
Carlos, I would think you might be interested in constructive suggestions given some of the seemingly small changes I recall you making originally. Unless there's some other issue between you that we don't know about, I really just don't get your response.
C <-- back to post-digging for good information
Isn't compact layout the core design principle of the GainCard? I'm new here, but I thought that and esoteric parts selection are the principle elements which differentiate a GC from this chip's implementation in TVs and receivers.
Peter Daniel said:
Those amps?😱
You build amps with 3 resistors and two caps.
This is a little more advanced...
Oh, brother..........
Gee....that's all it takes to have better engineering instincts is to build one chip amp?
That you can copy from an app note........
You really don't expect us to believe that, do you?
Coming from you.....yeah.....probably.
Wow......why did the rest of us waste some much of our lives trying to learn this stuff, when all we have to do is follow you....
"No one takes you seriously anymore."
I'll let everyone decide for themselves who that applies to.
Jocko
Gee....that's all it takes to have better engineering instincts is to build one chip amp?
That you can copy from an app note........
You really don't expect us to believe that, do you?
Coming from you.....yeah.....probably.
Wow......why did the rest of us waste some much of our lives trying to learn this stuff, when all we have to do is follow you....
"No one takes you seriously anymore."
I'll let everyone decide for themselves who that applies to.
Jocko
As usually you don't even know what you are talking about. No wonder some have trouble taking you seriously.
geewhizbang said:
Just because you think that I don't doesn't mean that you are right.
Oh, wait......sorry.......you are always right.
Never mind.
Jocko
Oh, wait......sorry.......you are always right.
Never mind.
Jocko
Listening impressions.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=36727&pagenumber=2
😀
http://www.diyaudio.com/forums/showthread.php?s=&threadid=36727&pagenumber=2
😀
The observations Carlos just made about the way that highlevel signals are routed right next to low level ones makes some technical sense.
Meanwhile, peter is trying all sorts of other esoteric stuff that probably won't make much difference if he is getting crosstalk in his low level signals.
Peter has been in this forum, which is about a Regulated-Buffered-Inverted gain clone, and his posts from the very beginning were extremely argumentative dissing this design alternative as wrong.
Yet he had not heard Carlos amp.
Meanwhile, peter is trying all sorts of other esoteric stuff that probably won't make much difference if he is getting crosstalk in his low level signals.
Peter has been in this forum, which is about a Regulated-Buffered-Inverted gain clone, and his posts from the very beginning were extremely argumentative dissing this design alternative as wrong.
Yet he had not heard Carlos amp.
geewhizbang said:
If I had thought that this design was wrong I wouldn't spent 10 hours building it. I thought that this design was a new, ground breaking approach to GC building, that what I had actually thought.
Carlos didn't hear my amp either.
Does this make any sense?
Peter Daniel said:
come on, Peter, why would you have to insult all engineers out there this way?
It is like an assembly worker claiming that he knows how to engineer a Porsche just because he has built some of them.
Logic, logic.
Peter Daniel said:
"drunks usually insist that others are drunk."
I picked that up while in Japan.
My sincere apologies for a post that is back on-topic but....
I removed the blown cap and then powered up again.
Measuring the volage across the blown cap (X to Y) I find that it is -25.7 volts! So it's the correct voltage but wrong polarity and that explains why the cap went pop!
Measuring the voltage on the output, (between A and B) I get +26.2 volts!
So I checked the input voltage (IN and IN) and it is +36 volts.
Any suggestions chaps? 😕
(Thanks to Pedja for circuit diagram)
I removed the blown cap and then powered up again.
Measuring the volage across the blown cap (X to Y) I find that it is -25.7 volts! So it's the correct voltage but wrong polarity and that explains why the cap went pop!
Measuring the voltage on the output, (between A and B) I get +26.2 volts!
So I checked the input voltage (IN and IN) and it is +36 volts.
Any suggestions chaps? 😕
An externally hosted image should be here but it was not working when we last tested it.
(Thanks to Pedja for circuit diagram)
Nuuk,
Do you mean :
voltage of (X-Y) = -25.7?
voltage of (A-B) = +26.2?
If so, then it is very strange....
How do you put your C2's polarity?
Alex
Do you mean :
voltage of (X-Y) = -25.7?
voltage of (A-B) = +26.2?
If so, then it is very strange....
How do you put your C2's polarity?
Alex
My guess is that he has one of the center-tap wires reversed with a outer tap wire. Or perhaps he has the center taps going to the wrong side of the circuit.
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