Peter,
you don't get it, do you? I suggested you to try TDA7294 because it sounds good to me. My suggestion was based on my experience with various ICs and, sure, my taste. The best way to find out how something sounds is to listen it for yourself, but people like to take shortcuts and sometimes prefere to follow suggestions. That is probably the reason "everybody" is using LM3875. "Everybody" - who? Sakura Gaincard uses it, but Rowland is using LM3886, Linn is using TDA7293 (in Klimax Twin) and there are other amps with various ICs.
It's fine if you prefere TDA1543, but that's just you - it's not universal truth.
Also, I'm really sorry my suggestion costed you 3 days - don't follow advices - DIY.
you don't get it, do you? I suggested you to try TDA7294 because it sounds good to me. My suggestion was based on my experience with various ICs and, sure, my taste. The best way to find out how something sounds is to listen it for yourself, but people like to take shortcuts and sometimes prefere to follow suggestions. That is probably the reason "everybody" is using LM3875. "Everybody" - who? Sakura Gaincard uses it, but Rowland is using LM3886, Linn is using TDA7293 (in Klimax Twin) and there are other amps with various ICs.
It's fine if you prefere TDA1543, but that's just you - it's not universal truth.
Also, I'm really sorry my suggestion costed you 3 days - don't follow advices - DIY.
You actually didn't suggest it sounds good to you, I didn't get it like that. You obviously made a statement that TDA 7294 is best chip for a GC amp. You even made a grading of some other chips and LM 3875 wasn't at the first two places. This is obviously misleading. I tried that chip (TDA) and OPA549, and while the last one comes close to LM chip (and may be preffered by some people who are into more accurate sonic reproduction), TDA7294 doesn't even come close to what can be regarded as accurate reproduction. I wouldn't recommend it to anybody.
Who else is using LM3875? Almost everybody on DIY forums. Very few people are into other chips. Is it following suggestions?Probably yes, in most cases, but I've heard comments that people tried other chips and chose LM as best performer. I've noticed some people choosing OPA 549 and I can't blame them, because I had hard choice in deciding between the two. But TDA 7294? I knew from beginning it's no good and spend 3 days trying to improve it somehow, but I simply couldn't.
So next time you say it's good, make it obvious that it's only good for your taste. Who else is using LM3875? I know at least 3 other people whose judgement I can trust more than yours: Scott Nixon, Joe Rasmussen and Fedde ( who really inspired me to try it out).
As to DAC chips, I don't think this is the thread to talk about them here. So what else do I not get?
EDIT:
If you chose TDA7294 as a top performer, I'm not even slightly surprised you fancy buffer so much.
Who else is using LM3875? Almost everybody on DIY forums. Very few people are into other chips. Is it following suggestions?Probably yes, in most cases, but I've heard comments that people tried other chips and chose LM as best performer. I've noticed some people choosing OPA 549 and I can't blame them, because I had hard choice in deciding between the two. But TDA 7294? I knew from beginning it's no good and spend 3 days trying to improve it somehow, but I simply couldn't.
So next time you say it's good, make it obvious that it's only good for your taste. Who else is using LM3875? I know at least 3 other people whose judgement I can trust more than yours: Scott Nixon, Joe Rasmussen and Fedde ( who really inspired me to try it out).
As to DAC chips, I don't think this is the thread to talk about them here. So what else do I not get?
EDIT:
If you chose TDA7294 as a top performer, I'm not even slightly surprised you fancy buffer so much.
Peter Daniel
While i fully agree with your view on buffering (who would want an extra cap + PS + dubious 627/ECC88 follower in a minimum amp?) you should give a simple filter a listen. I use a 2k followed by 750pF to ground followed by 20k. It will only take you a few minutes to put together and by disconnecting the cap you can listen to filtered against non-filtered sound with minimum intervention. The filter values assume lowish and constant output resistance so it's ideally driven by an active pre.
cheers
peter
While i fully agree with your view on buffering (who would want an extra cap + PS + dubious 627/ECC88 follower in a minimum amp?) you should give a simple filter a listen. I use a 2k followed by 750pF to ground followed by 20k. It will only take you a few minutes to put together and by disconnecting the cap you can listen to filtered against non-filtered sound with minimum intervention. The filter values assume lowish and constant output resistance so it's ideally driven by an active pre.
cheers
peter
analog_sa said:
So finally today I gave a simple LPF a listen. I used minimized GC circuit with 10k series and 220k feedback resistors in monoblock chassis. I added a Vishay 1k resistor and Wima 1n8 cap which supposed more or less form a LPF. I connected a cap in such a way that I can switch on and off its connection to ground and effectively have the filter in and out of the circuit. I'm not using any pot in this setup (what you see in a pic is disconnected and Grayhill switch is used only to connect the cap to the ground. The signal is fed directly from TDA1543 non oversampling DAC with passive I/V conversion (1k resistors) using Kimber Silver Streak interconnects.
Attachments
The speakers used for evaluation are my recent creation. Those are infinite baffle arrangement (in wall separated two rooms in a basement). Tweeter is Raven2 with one series cap used for filtering and 2 PHL units with no crossover at all. While this may not be the crossover choice yet (I'm still working on it), yet the system is very revealing and with proper setup can play amazingly well. I measured freq. response and it's pretty flat especially in crossover region (5k, my estimate). The speaker cables are very short and soldered directly to drivers (Alpha Core copper foil, not insulated).
Attachments
And now the question, what the filter does?
In short, I'm not impressed by it at all. It just confirmed what I suspected already. While the difference is quite big and one can recognize without any doubts when the LPF is applied, it actualy, in my system degrades the sound. I didn't noticed any improvement to the soundstage, the midrange balance is shifted a bit, making the vocals sounding a little lower, the resolution is subjectively decreased.
The main disadvantage of the filter is the smearing of high frequencies and loss of resolution there. Also the ambience is gone to some degree.
While I understand that it may be the advantage in some systems, that are build without proper attention to construction details and parts choice, and it tames the agressivness in trebles (which is caused by that lack of attention), but in properly tuned amp it simply doesn't work and creates less than desired effect.
I'm in a process of building tube buffer to see if this helps to improve the LPF performance. So far, unbuffered filter is not something I will be using. Please note that there is no potentiometer being used in a test circuit, so don't blame it on that
In short, I'm not impressed by it at all. It just confirmed what I suspected already. While the difference is quite big and one can recognize without any doubts when the LPF is applied, it actualy, in my system degrades the sound. I didn't noticed any improvement to the soundstage, the midrange balance is shifted a bit, making the vocals sounding a little lower, the resolution is subjectively decreased.
The main disadvantage of the filter is the smearing of high frequencies and loss of resolution there. Also the ambience is gone to some degree.
While I understand that it may be the advantage in some systems, that are build without proper attention to construction details and parts choice, and it tames the agressivness in trebles (which is caused by that lack of attention), but in properly tuned amp it simply doesn't work and creates less than desired effect.
I'm in a process of building tube buffer to see if this helps to improve the LPF performance. So far, unbuffered filter is not something I will be using. Please note that there is no potentiometer being used in a test circuit, so don't blame it on that
>>While I understand that it may be the advantage in some systems, that are build without proper attention to construction details and parts choice, and it tames the agressivness in trebles (which is caused by that lack of attention), but in properly tuned amp it simply doesn't work and creates less than desired effect<<
So nobody can build good gainclones other than you.???
>>I'm in a process of building tube buffer <<<
Don't bother we already know your reply,difficult when you have a commercial product without a buffer
So nobody can build good gainclones other than you.???
>>I'm in a process of building tube buffer <<<
Don't bother we already know your reply,difficult when you have a commercial product without a buffer
PeteM said:
It seems like you are upset with my assesment.
Let me try to reply in a similar way as you did:
"So nobody can build a good sounding gainclone without using LPF?
If you continue to post in such manner, don't bother to do it at all."
I just expressed my opinion and that's all. Because it works for me like that, it doesn't mean that it has to work for everybody and be the same to everybody. I'm also fed up with all that noise about buffers and filters and the opinion that it is the only way to build properly sounding GC in general. My experiment today shows that it's not exactly the case. If the buffer is an improvement, I don't see a reason not to incorporate sort of buffer in my next amp design, so it's not really the case for me not liking LPF. I also noticed your tendency to claiming that your amp sounds fantastic and I don't recall myself ever doing such claims about my product.
I also wonder how many of you got into trouble of actually building a test circuit, where LPF can be switched in and out for proper comparisons?
Remeber, I still don't feel like manufacturer and I'm not insisting that my GC is the best. I'm always looking for better ways to improve the circuit and I'm still into DIY.
>>If you continue to post in such manner, don't bother to do it at all<<
Well I make this my last post then..
But history on this site shows YOU will not accept any other form of gainclone,besides your own..
Also when i came here I noticed it was a DIY forum..and YOU have created the some of the largest threads on this forum...
http://www.diyaudio.com/forums/showthread.php?threadid=9112
http://www.diyaudio.com/forums/showthread.php?threadid=17878
If I can share MY opinion you feed of a DIY community for your own gains.
Mighty funny how YOU post furiously then go silent when YOUR amp goes commercial.
I also find strange why YOU hide your online status,especially when YOUR amp had it's review..Even on AA what was YOU worried about negative post
So you must feel Joe Rassmusen's JLTi is inferior to yours,well atleasty Joe has given this community a chance to sample a buffered gainclone..Beside he has posted some hard evidence with measurements to support his claims...
Well thats me off this forum..But Peter I can see through YOU where others may not..
Well I make this my last post then..
But history on this site shows YOU will not accept any other form of gainclone,besides your own..
Also when i came here I noticed it was a DIY forum..and YOU have created the some of the largest threads on this forum...
http://www.diyaudio.com/forums/showthread.php?threadid=9112
http://www.diyaudio.com/forums/showthread.php?threadid=17878
If I can share MY opinion you feed of a DIY community for your own gains.
Mighty funny how YOU post furiously then go silent when YOUR amp goes commercial.
I also find strange why YOU hide your online status,especially when YOUR amp had it's review..Even on AA what was YOU worried about negative post
So you must feel Joe Rassmusen's JLTi is inferior to yours,well atleasty Joe has given this community a chance to sample a buffered gainclone..Beside he has posted some hard evidence with measurements to support his claims...
Well thats me off this forum..But Peter I can see through YOU where others may not..
I'm beginning to notice that fame is like double ended sword. I feel almost like a politician being questioned for bad behaviour. What is wrong with some of you guys? You can't take it more easy and enjoy the free flow of information that is like a river from which you can take some water whenever you feel like and in any spot you choose? And then contribute a bit of your own findings, instead of right away critisizing others. How can you be so sure of anything to the point of not accepting other POV? Where is DIY spirit and exchange of information. I found some threads, even from Joe, where he clearly states that Thorsten minimized circuit is inferior to his buffered amp. I just couldn't wait any longer and decided to check it myself. Well, I'm not saying that Thorsten amp is better. I'm only saying the LPF might not work for everybody. In my current setup, it's definitely not for me. But how many of you, actually make an effort to make up a proper rig to test it, instead of building one amp after another, which obviously is not the same. To check the performance of the buffer, I will just plug it in to the input and voila, I can see how good it really is. Some of you already know the answer, too bad you won't be here to read it
While the first thread you specified, is indeed second largest thread on a forum, the second one is barely visible. I'm not quite shure what you mean linking it here.
While the "This is not just another GC" thread gave the beginning to the GC craze on this forum (IMHO), it also was beneficial to everybody reading it, and again, I don't see what you are trying to say, linking it here.
If I feed the community for my own gains, please show me how exactly, because for me, it's hard to understand. I'm not signing off with triple links to my site, actually I don't have a site at all and I'm not selling anything related to GC on the forum at all. If you would like to buy one of my amps, I guess you wouldn't even know where to find an info for it.
While you can actually blame me for posting a link to a review of my GC on the forum, it was caused more by my excitement, than the actual commercial reasons. I also think that it benefited all the members interested in GC building to help them realize what can be achieved with such simple circuit and it increased their belief that what they do makes sense and is worthwile.
If I post furiously, or go silent for a while, shouldn't be none of your concern and I don't think I have to explain myself on that. It just happens that it's holiday season now and I take a rest. I also have some other projects, which took me away from amp building (like 2 speaker systems) and it only means that I'm not into commerce, but still DIY.
I don't show my online status, because with my provider, it would show that I'm always on line and it could be misleading, while I'm not on line.
I didn't get the impression that my AA appearence was reflected negatively. As you read all the posts, you'll noticed that it was done mostly by die hard GaiCard fanatics who were mostly into the copying aspects of the whole affair. I actually gained some better perspective after that and made some positive e-mail exchanges with Yoshi Segoshi of Sakura Systems.
I have no opinion on Joe's amp and even if I would build one according to his schematic, I will not comment on it as this would be unethical and hurting to his business. It is you who starts competition between both configurations and YOU actually start making claims what is better and what is not.
If you note my post you will see that I didn't make any comments whatsoever on the amp comparisons, I only stated that my amp works better without LPF applied. I didn't even comment on buffer and the performance will definitely be different when it's included.
So what exactly is your problem? Is it that your pride with your new creation just suffers a bit because I don't like LPF. If that's the case, you behave like a child whose good time was spoiled by somebody taking away his toy. Can I say that I see through "YOU" as well?
I also realise that my commercial GC amp is far from being perfect and there is still a lot to be improved. That's why I'm trying to figure out smart way to built cheap monoblocks. High price of my first amp definitely affects sales and I still don't know if it's better than GainCard or not. Chassis is one area that can make or break performance and the aluminum chassis is too big to perform that well (it also is too sensitive to placement). PS is big, the cords are expensive, so all in one mono unit should be better. I don't want to use pots and coupling caps as this is too much of a affecting variable. I didn't say it before, but I seriously believe that building the best SS amp with those chips IS possible (in specific amp category).
Although some guys might provide a lot of graphs, measurements and theory behind it, at the end of a day the subjective listening performance is all that matters. If somebody chooses feedback resistor on the base of a gain number only and still didn't compare it subjectively in controlled listening test how good performer the amp can be?
This might be one of my longest posts so far, but well, that's what my whole life is all about now, too
While the first thread you specified, is indeed second largest thread on a forum, the second one is barely visible. I'm not quite shure what you mean linking it here.
While the "This is not just another GC" thread gave the beginning to the GC craze on this forum (IMHO), it also was beneficial to everybody reading it, and again, I don't see what you are trying to say, linking it here.
If I feed the community for my own gains, please show me how exactly, because for me, it's hard to understand. I'm not signing off with triple links to my site, actually I don't have a site at all and I'm not selling anything related to GC on the forum at all. If you would like to buy one of my amps, I guess you wouldn't even know where to find an info for it.
While you can actually blame me for posting a link to a review of my GC on the forum, it was caused more by my excitement, than the actual commercial reasons. I also think that it benefited all the members interested in GC building to help them realize what can be achieved with such simple circuit and it increased their belief that what they do makes sense and is worthwile.
If I post furiously, or go silent for a while, shouldn't be none of your concern and I don't think I have to explain myself on that. It just happens that it's holiday season now and I take a rest. I also have some other projects, which took me away from amp building (like 2 speaker systems) and it only means that I'm not into commerce, but still DIY.
I don't show my online status, because with my provider, it would show that I'm always on line and it could be misleading, while I'm not on line.
I didn't get the impression that my AA appearence was reflected negatively. As you read all the posts, you'll noticed that it was done mostly by die hard GaiCard fanatics who were mostly into the copying aspects of the whole affair. I actually gained some better perspective after that and made some positive e-mail exchanges with Yoshi Segoshi of Sakura Systems.
I have no opinion on Joe's amp and even if I would build one according to his schematic, I will not comment on it as this would be unethical and hurting to his business. It is you who starts competition between both configurations and YOU actually start making claims what is better and what is not.
If you note my post you will see that I didn't make any comments whatsoever on the amp comparisons, I only stated that my amp works better without LPF applied. I didn't even comment on buffer and the performance will definitely be different when it's included.
So what exactly is your problem? Is it that your pride with your new creation just suffers a bit because I don't like LPF. If that's the case, you behave like a child whose good time was spoiled by somebody taking away his toy. Can I say that I see through "YOU" as well?
I also realise that my commercial GC amp is far from being perfect and there is still a lot to be improved. That's why I'm trying to figure out smart way to built cheap monoblocks. High price of my first amp definitely affects sales and I still don't know if it's better than GainCard or not. Chassis is one area that can make or break performance and the aluminum chassis is too big to perform that well (it also is too sensitive to placement). PS is big, the cords are expensive, so all in one mono unit should be better. I don't want to use pots and coupling caps as this is too much of a affecting variable. I didn't say it before, but I seriously believe that building the best SS amp with those chips IS possible (in specific amp category).
Although some guys might provide a lot of graphs, measurements and theory behind it, at the end of a day the subjective listening performance is all that matters. If somebody chooses feedback resistor on the base of a gain number only and still didn't compare it subjectively in controlled listening test how good performer the amp can be?
This might be one of my longest posts so far, but well, that's what my whole life is all about now, too
Invaluable work
I always use to build my own circuits and get my own conclusions, and if something works for me, I do not care whar other poeple say.
However, I think is of big help that people like PD takes this "hobby" so seriusly to just build and test different setups and then CARE to share with the rest of us.
Each one sould take their own conclusions, but sometimes it saves a great deal of time- always in short supply-just to read someone else impressions.
Now going to the filter issue:
To date I've built 17 GC, all of them working wiith different configs day by day at my post-production facility. I discovered that the filter help me in situations where the amp or its asossiated cables are near diigital circuit like fast computers o some digital processors we use.
Also, another more esoteric- and difficult to swallop- variable is the room.
What?
Yes, we have a two story facility, with concrete in the lower floor and glass and a somewhat open environment in the upper floor. So GCs that live upstairs sound better with the filter on, I assume we have heavy radio frecuency polution which is filteres by the concrete downstairs. I know that "filtering" takes place because cell phones do not work in that rooms.
So, you se, every situation is a particular situation.
cheers
Ric
I always use to build my own circuits and get my own conclusions, and if something works for me, I do not care whar other poeple say.
However, I think is of big help that people like PD takes this "hobby" so seriusly to just build and test different setups and then CARE to share with the rest of us.
Each one sould take their own conclusions, but sometimes it saves a great deal of time- always in short supply-just to read someone else impressions.
Now going to the filter issue:
To date I've built 17 GC, all of them working wiith different configs day by day at my post-production facility. I discovered that the filter help me in situations where the amp or its asossiated cables are near diigital circuit like fast computers o some digital processors we use.
Also, another more esoteric- and difficult to swallop- variable is the room.
What?
Yes, we have a two story facility, with concrete in the lower floor and glass and a somewhat open environment in the upper floor. So GCs that live upstairs sound better with the filter on, I assume we have heavy radio frecuency polution which is filteres by the concrete downstairs. I know that "filtering" takes place because cell phones do not work in that rooms.
So, you se, every situation is a particular situation.
cheers
Ric
tbla said:
You see, that's the right and mature response. I can't understand why the other guy got so upset about.
Now, this is my take on that. It's seems like it's becoming a popular belief that anybody who built's minimized IGC, has the same amp. IMHO, this is not the case. Every little aspect makes a difference, and I say EVERY. And ea. amp will sound different and proper tunning is VERY important. I spent 3 months optimizing my circuit and I didn't spare on anything. So if I see somebody using single bridge, Panasonic electrolytics, not properly dumped (or built) case, coupling caps, output resistor, questionable pot, no audiophile resistors, PCB, no damping on caps, too many parts, wiring too long, regular connectors, what do you think I might think? I went through all of this and I know the results.
There is one area I didn't experiment enough, and this is transformer issue. I just received two transformers from Plitron (same voltage but 225VA, with a shield between windings) so I will see how they compare.
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