, but so far always combined with fuses...
Nuuk said:
Well, I used it so far to effectively fight ground loops. And in the ESP article (where I got the idea of using a current breaker in the first place) Rod does not mention omitting the fuses.
Is omitting the fuses when using a current breaker circuit really safe enough (apart from maybe being costy if you break a lot of bridges...)?
As I understand it, the circuit breaker is a direct replacement for a fuse. If something goes wrong and the circuit draws too much current, the fuse will melt while the circuit breaker will trip. After mending the fault you replace the fuse, or with the circuit breaker, you reset it.
A 1 amp circuit breaker will trip just as fast as a 1 amp fuse will blow so safety isn't compromised.
If you have an idea, out with it, Man
The Black Gate caps are very good and you may not have use the most expensive series. The standard series are very good and I have had great results with them. I know people don't have unlimited budgets (except Peter it seems) or the "mother of all surplus stores" that I have been lucky enough to find.
Use of voltage regulators is encouraged but don't use a small one that will current limit easily. I am using LT1084s that are rated for 5 amps. Input caps, transformers, and rectifier diodes are crucial to how a regulator sounds. Don't think you are off the hook for building a good unregulated supply to go with your regulator. Discreet designs are also worth examining including
simple source or emitter followers. I believe some of Mr. Pass's articles have some examples and Mr. Carr has posted a few schematics for regulated supply.
There are many diodes that are worth trying. I like high speed soft recovery types over the schottkys I have used. The recovery character seen seems to be more important than the speed of the diode. Do some searching:
http://www.diyaudio.com/forums/sear...d=164973&sortby=lastpost&sortorder=descending
http://www.google.com/search?hl=en&...speed+soft+recovery+diodes&btnG=Google+Search
Snubbers
http://www.cornell-dubilier.com/mica/design.pdf
http://www.hagtech.com/pdf/snubber.pdf
Last but most important, this is the Do It Yourself Audio forum not the "What would Fred or Peter do ?" forum. Plug in those soldering irons, crank up those Web Browsers, and do some listening and research. There are a lot very talented and obsessive people building audio equipment out there; with as many ideas as I have. Many of the seemingly latest and greatest ideas here have been around for over ten years. Why do you think some of these high end parts suppliers are selling many of these tweak parts? Seeing what they are selling can often be educational too. I also tend to take the top off really good sounding products and write down part numbers of what the gurus are using also. Several local high end dealers panic when they see me with a screw driver in my hand! Check out the following for interesting part suggestions:
http://www.percyaudio.com/
http://www.welbornelabs.com/
http://www.borbelyaudio.com/index21.htm
http://www.schuro.de/
http://www.thel-audioworld.de/
The Black Gate caps are very good and you may not have use the most expensive series. The standard series are very good and I have had great results with them. I know people don't have unlimited budgets (except Peter it seems) or the "mother of all surplus stores" that I have been lucky enough to find.
Use of voltage regulators is encouraged but don't use a small one that will current limit easily. I am using LT1084s that are rated for 5 amps. Input caps, transformers, and rectifier diodes are crucial to how a regulator sounds. Don't think you are off the hook for building a good unregulated supply to go with your regulator. Discreet designs are also worth examining including
simple source or emitter followers. I believe some of Mr. Pass's articles have some examples and Mr. Carr has posted a few schematics for regulated supply.
There are many diodes that are worth trying. I like high speed soft recovery types over the schottkys I have used. The recovery character seen seems to be more important than the speed of the diode. Do some searching:
http://www.diyaudio.com/forums/sear...d=164973&sortby=lastpost&sortorder=descending
http://www.google.com/search?hl=en&...speed+soft+recovery+diodes&btnG=Google+Search
Snubbers
http://www.cornell-dubilier.com/mica/design.pdf
http://www.hagtech.com/pdf/snubber.pdf
Last but most important, this is the Do It Yourself Audio forum not the "What would Fred or Peter do ?" forum. Plug in those soldering irons, crank up those Web Browsers, and do some listening and research. There are a lot very talented and obsessive people building audio equipment out there; with as many ideas as I have. Many of the seemingly latest and greatest ideas here have been around for over ten years. Why do you think some of these high end parts suppliers are selling many of these tweak parts? Seeing what they are selling can often be educational too. I also tend to take the top off really good sounding products and write down part numbers of what the gurus are using also. Several local high end dealers panic when they see me with a screw driver in my hand! Check out the following for interesting part suggestions:
http://www.percyaudio.com/
http://www.welbornelabs.com/
http://www.borbelyaudio.com/index21.htm
http://www.schuro.de/
http://www.thel-audioworld.de/
Re: If you have an idea, out with it, Man
When some friends and I were about to purchase our first
CD players back in the mid 80's we borrowed a large number of
players for evaluation. One of the dealers, who knew that we
were engineering students, said: I won't ask you to open the
players and have a look inside, because I trust you to do that
anyway.
I doubt any dealers would do that today. One local dealer
looked worried when I even mentioned the story above to him.
Fred Dieckmann said:
When some friends and I were about to purchase our first
CD players back in the mid 80's we borrowed a large number of
players for evaluation. One of the dealers, who knew that we
were engineering students, said: I won't ask you to open the
players and have a look inside, because I trust you to do that
anyway.
I doubt any dealers would do that today. One local dealer
looked worried when I even mentioned the story above to him.
What VA rating to choose??
Hi!
Well - I'm in a process of ordering some last missing components to finish my GC (the base for it is LM3875T) - and I still have to buy transformers - they will be custom made:
I've allready decided to order 2x18V secondaries; but - which VA rating??
I have 2 possibilities - 120VA (it's also a bit smaller) or 160VA;
With first one - it will definetilly be dual mono.
With second one - it might be only one trannie for stereo; but then again - why not again dual mono ...
The price for 120VA is around 18Eur and for 160VA 21Eur - so the price is not a problem in this decision.
Is 2x160VA too much - considering original GC philosophy that VA shouldn't be too low BUT also not to high. Or will it be just fine?? Or is it better to use 2x120VA (120VA ones are also a bit smaller - one friend said that for his GC from those two options he would use the ones that are smaller by dimensions)
Or will one 160VA be enough for stereo??
So - what would you do??
Thanks
Hi!
Well - I'm in a process of ordering some last missing components to finish my GC (the base for it is LM3875T) - and I still have to buy transformers - they will be custom made:
I've allready decided to order 2x18V secondaries; but - which VA rating??
I have 2 possibilities - 120VA (it's also a bit smaller) or 160VA;
With first one - it will definetilly be dual mono.
With second one - it might be only one trannie for stereo; but then again - why not again dual mono ...
The price for 120VA is around 18Eur and for 160VA 21Eur - so the price is not a problem in this decision.
Is 2x160VA too much - considering original GC philosophy that VA shouldn't be too low BUT also not to high. Or will it be just fine?? Or is it better to use 2x120VA (120VA ones are also a bit smaller - one friend said that for his GC from those two options he would use the ones that are smaller by dimensions)
Or will one 160VA be enough for stereo??
So - what would you do??
Thanks
- considering original GC philosophy
Amplifiers are not designed by philosphers but more likely by accountants. I would go with 160 VA. I am using 225 VA. I find most often that larger transformers sound better since they don't saturate as easily. I have used 1000 VA transformers for preamps before.
Many so called "design philosophies" are designed to maximize profits. There seems to be an excess of mysticism around these amps that may not be the best engineering for the best sonics.
Perhaps I am a cynic, but I found that many highly regarded products can be easily improved. I suppose that is why there are so many modifiers out there. I have heard way too many upgrades from maufactures for products that were as far as they knew how to take them when they were introduced to the market. Good designers grow in skill the longer they design. Many times the designers respond to modifications to thier designs by others or to techniques used by a competiters. Most due not design in a vacuum (well I suppose technically tube designers do....) and are pretty aware of what other people are doing. I prefer trusting my ears rather than someone elses Dogma.
Amplifiers are not designed by philosphers but more likely by accountants. I would go with 160 VA. I am using 225 VA. I find most often that larger transformers sound better since they don't saturate as easily. I have used 1000 VA transformers for preamps before.
Many so called "design philosophies" are designed to maximize profits. There seems to be an excess of mysticism around these amps that may not be the best engineering for the best sonics.
Perhaps I am a cynic, but I found that many highly regarded products can be easily improved. I suppose that is why there are so many modifiers out there. I have heard way too many upgrades from maufactures for products that were as far as they knew how to take them when they were introduced to the market. Good designers grow in skill the longer they design. Many times the designers respond to modifications to thier designs by others or to techniques used by a competiters. Most due not design in a vacuum (well I suppose technically tube designers do....) and are pretty aware of what other people are doing. I prefer trusting my ears rather than someone elses Dogma.
Re: - considering original GC philosophy
Now, this is interesting. I brought up the general question of
choosing VA-rating and what factors are relevant, in some thread
a while ago . Transformer temperature is obviously an
important factor, but I hypothesized that perhaps there are also
problems with magnetic saturation or similar effects. I have
always been lousy at magnetics (time to read up, perhaps) and
nobody seemed to think there were such problems. Actually,
I was more specifically suggesting that perhaps the condution
angle matters since smaller conduction angle means higher
peak current, which might require a larger transformer if there
are saturation phenoma. Your comments on this would be
appreciated, Fred.
Fred Dieckmann said:
Now, this is interesting. I brought up the general question of
choosing VA-rating and what factors are relevant, in some thread
a while ago . Transformer temperature is obviously an
important factor, but I hypothesized that perhaps there are also
problems with magnetic saturation or similar effects. I have
always been lousy at magnetics (time to read up, perhaps) and
nobody seemed to think there were such problems. Actually,
I was more specifically suggesting that perhaps the condution
angle matters since smaller conduction angle means higher
peak current, which might require a larger transformer if there
are saturation phenoma. Your comments on this would be
appreciated, Fred.
Fred,
Look, I didn't say build an amp for me, I was humorously refering to your comments saying we have it all figured out and in the same post post making an obscure comment to "really good diodes". If you don't want to share info about things like this, don't bring it up. If you read back during the time you were gone you'll find I have been doing quite a few experiments on a GC design and posting my own conclusions and decisions. I built an OPA541 prototype yesterday and did some listening test against my LM3875 GC while matching my Aleph 2 and Aleph X mosfets. I, and others in this forum, realize you have a lot of experience in this field and we would like to hear what you have to say. Ys, I am sure there are alot of great ideas that have been around for a while, but many of us are not aware of them. The guys, like yourself, who have been around for a while are the knowledge base for this DIY community and can distribute that knowledge if they like and help out others. I know someone elses opinion of parts doesn't guarantee a good sounding amp and many other do as well. I honestly appreciate your contributions here in the forum, but I guess I prefer a more open and less obscure exchange of ideas.
Look, I didn't say build an amp for me, I was humorously refering to your comments saying we have it all figured out and in the same post post making an obscure comment to "really good diodes". If you don't want to share info about things like this, don't bring it up. If you read back during the time you were gone you'll find I have been doing quite a few experiments on a GC design and posting my own conclusions and decisions. I built an OPA541 prototype yesterday and did some listening test against my LM3875 GC while matching my Aleph 2 and Aleph X mosfets. I, and others in this forum, realize you have a lot of experience in this field and we would like to hear what you have to say. Ys, I am sure there are alot of great ideas that have been around for a while, but many of us are not aware of them. The guys, like yourself, who have been around for a while are the knowledge base for this DIY community and can distribute that knowledge if they like and help out others. I know someone elses opinion of parts doesn't guarantee a good sounding amp and many other do as well. I honestly appreciate your contributions here in the forum, but I guess I prefer a more open and less obscure exchange of ideas.
The best advice comes from a person who tried something. Not everybody has enough time though, to go through a lot of testing. The good advise from Fred is a word of support and praise for those amps. I'm sure that sooner or later someone will try regulated supply and reports on comparison with a passive one. Because only then, I will believe it's better. Unfortunately I can't try it myself at the moment, because I'm too busy with preparing all those amps and PS.
I believe that most of the highly regarded equipment can be improved. The manufacturer simply has to draw the line where the things cease being practical and slightly inferior method or part is just more justified or profitabe. It is different to built one unit and hundreds or thousands of it.
I'm using 400VA transformer with my amps and I didn't see any bad results. Just looking at the gauge of the secondary wire makes me happy.
I believe that most of the highly regarded equipment can be improved. The manufacturer simply has to draw the line where the things cease being practical and slightly inferior method or part is just more justified or profitabe. It is different to built one unit and hundreds or thousands of it.
I'm using 400VA transformer with my amps and I didn't see any bad results. Just looking at the gauge of the secondary wire makes me happy.
Transformer size.
Using large capacitors with low power circuits like preamps WILL result in 'very short' bursts of current in the transformer. If this results in very large current peaks ( as there is less time to fill in the drooping voltage) and needs a large transformer to reduce it's effects, a method could be evolved to sort this out with a lower power transformer.
In fact one problem gets transformed into something else.It
proves the "no free lunch rule in engineering" .
Cheers.
Using large capacitors with low power circuits like preamps WILL result in 'very short' bursts of current in the transformer. If this results in very large current peaks ( as there is less time to fill in the drooping voltage) and needs a large transformer to reduce it's effects, a method could be evolved to sort this out with a lower power transformer.
In fact one problem gets transformed into something else.It
proves the "no free lunch rule in engineering" .
Cheers.
Peter Daniel said:
Hi,
In past, I was building few amps GC like ( STK..,TDA2030,40, 7293,7294) with unstabilisated power supply. In testing amps, I use Leader bench power supplies with maximal current of 5A. In sound test and in comparing two principles I notice some bass and speed problems when use stabilisated power supply. With steady signal (sinus on input), stabilised power supply is better. But music is not sinus....
My explanation is simply: stabilised power supply is another power amp (but slow) with low DF. I think that exist possibility of making power supply dedicated for amps, but I am not sure in sound result. My bench supply obviously is not GC ready.
Picture of my work place can be found on
http://www.diyaudio.com/forums/showthread.php?s=&threadid=7322&highlight=moamps
Regards
Fred
Yes, you're right, we all have ears and sensability but the reason we hold members like you, Peter, Grey, Frank and Bernhard and many others is because you have more experience in the reproduction of music than many of us and we consider you leaders. A field general will take a troop into the zone of battle where individual soldiers left on their own will wander, get lost or just go home and watch the results on the news. Your advice and that of the other leaders in this forum gets us close enough to the mark and encourages us to experiment when and only after we have achieved an initial success. I have built a minimized gainclone with a cheap 120VA frame transformer, 50V Schottkies and four 560uF 110V Panasonic FC caps and a 2.2 uF split foil Solens as the input cap and the amp sounds pretty good to my ears. Very open and fast on the top of my speakers with excellent placement. I will be building another for the Dayton bottoms (the minimized Gainclone sounds quite anemic when biwiring my speakers) so I will post then to clue you in on what happens but until then, the advice sought here will be important so please don't be stingy with it.
"Really good diodes."
Philo,
I'll take a stab at this:
You've been around here as long as I have. Fred has posted several other links to diode information in older threads and there has even been some discussion concerning diode choices. I would be willing to say that Fred probably likes the IXYS diodes. I seem to remember him talking about using them when he modded an Aleph.
Christer, ashok,
As to the relationship between diodes and conduction angle...
Diode conduction angle influenced directly by capacitance quantity and load demand definitely relates to the proper selection of diodes in the power supply. If you know that your design will be experiencing very short charging pulses then it only makes sense to invest in FRED's and HIPerFRED's.
Transformers are another story...
Later,
Philo,
I'll take a stab at this:
You've been around here as long as I have. Fred has posted several other links to diode information in older threads and there has even been some discussion concerning diode choices. I would be willing to say that Fred probably likes the IXYS diodes. I seem to remember him talking about using them when he modded an Aleph.
Christer, ashok,
As to the relationship between diodes and conduction angle...
Diode conduction angle influenced directly by capacitance quantity and load demand definitely relates to the proper selection of diodes in the power supply. If you know that your design will be experiencing very short charging pulses then it only makes sense to invest in FRED's and HIPerFRED's.
Transformers are another story...
Later,
The strength of that forum is that people try different things and then share their observations. I'm not a kind of person who holds some secrets because that might help him to win in a marketplace. Whenever I find that something works better, I imediately post it here. I guess it gives me more satisfaction than making more profit on my creations, (at least for now)
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