Hi all,
I have repeated much times that my_ref is not GC.
To build it I have developed and make a will a lot of techniques.
The LM3886 "current pump" is been never used by any, in "ordinary audio applications".
I have not invented nothing, but I have studied much and have built a "original" circuit.
Pass, Walker, atc... have not "invented" the "composite NFB" but only applied in original way... (but this is an other matter, my circuit is not done to is patented...)
This experience it has taught me doesn't share with any my work.
The better method is that of Pass ( FIRST patent and THEN divulge ).
I won't divulge more nothing, because have not the moneys to patent the circuits...
To all the detractors of my ideas:
They don't worry you, I won't give other "original" circuits to the "simple" persons. I leave space to Your "hallucinations"...
I hope only that anyone has built the circuit is satisfied. The technical debates, with non experienced persons, not are of interest me.
ciao
Mauro
I have repeated much times that my_ref is not GC.
To build it I have developed and make a will a lot of techniques.
The LM3886 "current pump" is been never used by any, in "ordinary audio applications".
I have not invented nothing, but I have studied much and have built a "original" circuit.
Pass, Walker, atc... have not "invented" the "composite NFB" but only applied in original way... (but this is an other matter, my circuit is not done to is patented...)
This experience it has taught me doesn't share with any my work.
The better method is that of Pass ( FIRST patent and THEN divulge ).
I won't divulge more nothing, because have not the moneys to patent the circuits...
To all the detractors of my ideas:
They don't worry you, I won't give other "original" circuits to the "simple" persons. I leave space to Your "hallucinations"...
I hope only that anyone has built the circuit is satisfied. The technical debates, with non experienced persons, not are of interest me.
ciao
Mauro
Thou shalt not hum
Used a grey hamburgian morning to clean up the innards of my REV C Mauro. Any hum and noise is one now ...
Used a grey hamburgian morning to clean up the innards of my REV C Mauro. Any hum and noise is one now ...
An externally hosted image should be here but it was not working when we last tested it.
You built a fine amp! Nice compact, and clean. My hat is off to you!
(Becks)
Re: Re: Snubber Theory
Not true, it's a bipolar inpup (power) op-amp, and the resistor from NI to ground must be relatively small (22k on BGT) to control DC-offset.
Of course, this is shunting a pot.
The lower the impedance of the pot the better (10k is fine, but not perfect) but even then there are benefits in using a good input buffer or gainstage.
Comparing the unbuffered BGT amp with Mauro's amp is comparing completely different things.
A good pre is a good pre, and the LM3886 needs it.
Russ White said:
Not true, it's a bipolar inpup (power) op-amp, and the resistor from NI to ground must be relatively small (22k on BGT) to control DC-offset.
Of course, this is shunting a pot.
The lower the impedance of the pot the better (10k is fine, but not perfect) but even then there are benefits in using a good input buffer or gainstage.
Comparing the unbuffered BGT amp with Mauro's amp is comparing completely different things.
A good pre is a good pre, and the LM3886 needs it.
Re: Thou shalt not hum
Gerd,
What size are those HS? I bet the amp is running nice and cool.
SmellOfPoo said:Used a grey hamburgian morning to clean up the innards of my REV C Mauro. Any hum and noise is one now ...
An externally hosted image should be here but it was not working when we last tested it.
Gerd,
What size are those HS? I bet the amp is running nice and cool.
Re: Please, Carlos
I know that for long, and that's not my use of snubbers.
On that pdf: "I was reading my first issue of Audio Amateur when my eye caught the letter from Scott
Morovich (TAA 3/94 p.46) regarding snubber design in power supply diode circuits."
Who confuses what and why I am applying snubbers with the use of snubbers on diodes didn't understand ANYTHING of what I'm talking about since the beginning.
I use snubbers in different places and for different reasons, I use them not only on power amp PSUs, but in many other circuits, I make my calculations and I've been getting very good results.
I can't be bothered to discuss this indefinitely for all my life, so don't ask ME, ask the experts, there are lots of them here. Russ arms himself as a wise guy, but in reality he knows NOTHING. Anyway, ask him, he says it's a very well known technique, blah blah blah... diodes.
Mauro says a good thing above, that's really what I feel too: I don't have the money to patent, so I simply don't reveal.
The schematics are done and published, they work extremely well for their application, case closed.
Everyone is free to build it, try it, use it.
Right on spot. Can I say the same?
Thank you.
Now all, back to your diode "hallucinations".........................
bg40403 said:
I know that for long, and that's not my use of snubbers.
On that pdf: "I was reading my first issue of Audio Amateur when my eye caught the letter from Scott
Morovich (TAA 3/94 p.46) regarding snubber design in power supply diode circuits."
Who confuses what and why I am applying snubbers with the use of snubbers on diodes didn't understand ANYTHING of what I'm talking about since the beginning.
I use snubbers in different places and for different reasons, I use them not only on power amp PSUs, but in many other circuits, I make my calculations and I've been getting very good results.
I can't be bothered to discuss this indefinitely for all my life, so don't ask ME, ask the experts, there are lots of them here. Russ arms himself as a wise guy, but in reality he knows NOTHING. Anyway, ask him, he says it's a very well known technique, blah blah blah... diodes.
Mauro says a good thing above, that's really what I feel too: I don't have the money to patent, so I simply don't reveal.
The schematics are done and published, they work extremely well for their application, case closed.
Everyone is free to build it, try it, use it.
mauropenasa said:
Right on spot. Can I say the same?
Thank you.
Now all, back to your diode "hallucinations".........................
Re: Re: Please, Carlos
Wow Carlos, your ego must really be on the line to make an attack like that. I will be the first to tell anyone I know NOTHING. That is the first step to learning ANYTHING.
I have never claimed to have any special knowlege, I have only asked those that do for answers. And I will continue to do so, it is what a wise person does, that is ask questions.
You do not have to answer, in fact it would probably be more pleasant for everyone if you didn't as you do not seem willing to truly contribute on the theory and the facts, only in advice.
I am sorry you have been offended Carlos, but I am not sure why.
Cheers!
Russ
carlosfm said:Russ arms himself as a wise guy, but in reality he knows NOTHING. Anyway, ask hime, he says it's a very well known technique, balh blah blah... diodes.
Wow Carlos, your ego must really be on the line to make an attack like that. I will be the first to tell anyone I know NOTHING. That is the first step to learning ANYTHING.
I have never claimed to have any special knowlege, I have only asked those that do for answers. And I will continue to do so, it is what a wise person does, that is ask questions.
You do not have to answer, in fact it would probably be more pleasant for everyone if you didn't as you do not seem willing to truly contribute on the theory and the facts, only in advice.
I am sorry you have been offended Carlos, but I am not sure why.
Cheers!
Russ
It has been suggested to me and I agree. Snubber talk is diluting this thread. It remains an area of interest for me, however it distracts from the topic: Mauro's work that he has so generously shared with us. I will watch with interest the development and further discussion of snubbers. I think it better served with a thread of its own.
float said:Here we go again...
Anyway, I see the kit includes a polyester for input caps c13/c29.
I'd like to use a polyprop I think; could anyone say how big a cap will fit and the pin spacings- I notice Russ gives us a choice here
Thanks
HI Float,
I am sorry about all the noise.
The pin spacing is 10 and 15mm if your cap will not fit there it is easy to mount it externally as SOP did. Some caps are simply too big to really plan for on a PCB.
Would it help to define the different kinds/uses of snubbers that are being discussed/confused here
1) snubbers across the secondary transformer windings
2) snubbers across the diodes
3) snubbers across larger capacitors
4) snubbers directly across pin power pins
I personally think that 2) is a waste of time but all others, if done with proper values bring good results.
For number 1) have found that 0.1uF + 1uF in series with 47ohms works ok for most transformers.
There are varying opinions about values for 3) & 4) so I will not venture to suggest any values
1) snubbers across the secondary transformer windings
2) snubbers across the diodes
3) snubbers across larger capacitors
4) snubbers directly across pin power pins
I personally think that 2) is a waste of time but all others, if done with proper values bring good results.
For number 1) have found that 0.1uF + 1uF in series with 47ohms works ok for most transformers.
There are varying opinions about values for 3) & 4) so I will not venture to suggest any values
Thanks mikelm,
Exactly where I was hoping this would lead. Carlos also correctly pointed out that snubbers are used in a variety of places for many reasons and need to be analyzed and matched to each place they are used.
In a previous life, we did snubbers on a radar to match a 7000V multi- amp supply to a multi-kilowatt transmitter to get a clean class C waveform out of the tubes. They were in multiple places in the distributed power chain.
I also think the suggestion made that started this was for your item 4 and whether there is any improvement to the my refs in using a snubber in that place. This is where Carlos suggested it recently and I believe Mauro made a point of stressing low ESR caps in that position, even leaving room in the rev A for larger low ESR caps (I used SILMIC's in rev A). The kits and my rev C use the Panasonic FC's, which everyone so far has agreed work fine, or has not reported any experiments with that I know of.
I will go with the group if we need to move this to another thread, but there might be an area to continue to understand with your item 4.
Exactly where I was hoping this would lead. Carlos also correctly pointed out that snubbers are used in a variety of places for many reasons and need to be analyzed and matched to each place they are used.
In a previous life, we did snubbers on a radar to match a 7000V multi- amp supply to a multi-kilowatt transmitter to get a clean class C waveform out of the tubes. They were in multiple places in the distributed power chain.
I also think the suggestion made that started this was for your item 4 and whether there is any improvement to the my refs in using a snubber in that place. This is where Carlos suggested it recently and I believe Mauro made a point of stressing low ESR caps in that position, even leaving room in the rev A for larger low ESR caps (I used SILMIC's in rev A). The kits and my rev C use the Panasonic FC's, which everyone so far has agreed work fine, or has not reported any experiments with that I know of.
I will go with the group if we need to move this to another thread, but there might be an area to continue to understand with your item 4.
mauropenasa said:
Hi Mauro,
It's a pity that your experience with sharing your work with us leaves you dissapointed. From what I see, the majority of people on this thread are very enthusiastic about your design. In fact, I don't think I have read a negative comment about the amp from anyone who has built it.
For the record, I'm very satisfied with my Rev_A, it's a great amp. I would build other designs from you if you released them...
Don't worry too much about the detractors, on the internet, everyone has an opinion, and no-one is wrong
Michael
Re: Re: Thou shalt not hum
They are ~ 6,5 x 9 x 3 inches and they are less than tepid even after 3 hours with moderate listening level. I´m driving a pair of Fostex FE103E Buschhorns, the impedance minimum of these is roughly 8 ohms.
Next week I´ll hook up a pair of Canton LE109, (http://www.audioenz.co.nz/2002/canton_le109.html) giving a heavier load of ~ 3 ohms. I guess they will let my Mauro run cool.
Russ White said:
They are ~ 6,5 x 9 x 3 inches and they are less than tepid even after 3 hours with moderate listening level. I´m driving a pair of Fostex FE103E Buschhorns, the impedance minimum of these is roughly 8 ohms.
Next week I´ll hook up a pair of Canton LE109, (http://www.audioenz.co.nz/2002/canton_le109.html) giving a heavier load of ~ 3 ohms. I guess they will let my Mauro run cool.