At the carrier frequency and its first few harmonics, the FB amp will a have lower common mode output, provided it's a two level amp. This advantage is not very important unless hundreds of meters of speaker cable are attached.classd4sure said:
There's no difference in principle. I did a listening test once where one channel was a HB, the other a FB UcD. No problem...classd4sure said:
Such optimism. How many good class D desigers are there? I mean - people who can design a class D amp worthy of being called an amplifier (not smps'es that happen to respond to audio-bandwidth signals and further double as an involuntary FM transmitter).phase_accurate said:
I dare you to name 10 people worldwide.
In my view, the problem lies in the difficulty of following the diversification in audio technology in educational institutions. I'm not sure I've posted my vision on this before. If I have, sorry for repeating myself.
In the 50's and 60's, audio amplification counted for a sizable chunk of "electronics" as a whole. Therefore schools could devote a reasonable amount of time to the subject. The result is that still now, the number of people capable of designing a good valve amp is large (thoustands?).
In the 70's and 80's, when solid-state technology largely supplanted valves, the field of electronics grew so much that analog electronics started getting cornered. With a bit of luck, the average engineering student knew how to analyse a Miller amp, but was happy further to treat it as a triangle with 3 leads on it. Luckily, building a class AB power amp was considered an acceptable thesis subject, and quite some people graduated on it.
Now, designing a good solid-state linear amplifier from scratch is decidely more complicated than a valve amp. The result is that engineers able to design really good linear amps number only in the hundreds at most.
In the 90's, the new kid on the block became class D. At the same time, schools hardly mentioned the existence of something like an audio power amplifier. Understandably - audio is only a fringe activity compared with the rest of electronics. It's beginning hard to find decent audio engineers, let alone ones that understand a technology that's yet more complicated than the previous one?
Really Charles, this problem isn't going to go away anytime soon.
Jan-Peter said:
Hi Jan-Peter!
You're very welcome to my praise. You sure deserve it! 🙂
I also played it safe as I tested them for the first time. 😀
I played them for a few hours on a pair of old Pioneer speakers, which I never had any high thoughts of before, but the way they sang right from the start, really shocked me, although there was a bit of harshness around the edges initially.
I simply couldn't believe the realism these cheapo speakers presented. So when I was convinced everything was OK I immediately switched to the JBL 2445's and 075.😀
I'm not kidding, the experience overwhelmed me to the point, where I had to swallow a few times, trying to get rid of the lump in my throat. I just sat there for a while, totally flabbergasted, stammering the word Jesus over and over. How many times I really don't know.
BTW, what about my other questions/suggestions?
Pictures, well I'll try it once again. The first time the entire post just disappeared into cyberspace somewhere, just as I was almost done writing it.
Is this BTW a common problem? Should I write my postings in word or something and then paste them here, just before posting them?
/Roland
An externally hosted image should be here but it was not working when we last tested it.
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hi,
What kind of caps have you got there? They almost look like stiffening caps for car audio. Nice setup you have there, well done. Just going by your reaction to it, I'd say it looks like mid fi has come a long way, woulnd't you agree?
Regarding your question about composing in word, I wouldn't think so. I think the same thing has happened to me all of about two times, maybe they reboot the server once a month or something.. Usually things work very well here!
Thanks for those pics,
Chris
What kind of caps have you got there? They almost look like stiffening caps for car audio. Nice setup you have there, well done. Just going by your reaction to it, I'd say it looks like mid fi has come a long way, woulnd't you agree?
Regarding your question about composing in word, I wouldn't think so. I think the same thing has happened to me all of about two times, maybe they reboot the server once a month or something.. Usually things work very well here!
Thanks for those pics,
Chris
Hi again!
Please don't mind the finish on the amp.
This one was purely experimental and I have done absolutely nothing about the finish.
I hope you can appreciate my hurry to LISTEN to what they were capable of.
In future UcD projects I'll try to add a bit of finish and design improvements as well. 😀
However it's quite compact though. 22cm*12cm*21cm.
/Roland
Please don't mind the finish on the amp.
This one was purely experimental and I have done absolutely nothing about the finish.
I hope you can appreciate my hurry to LISTEN to what they were capable of.
In future UcD projects I'll try to add a bit of finish and design improvements as well. 😀
However it's quite compact though. 22cm*12cm*21cm.
/Roland
heh, don't worry, that went without saying. Really if you cared I guess you could take a belt sander to the front panel or something.
I like the way it's assembled, only I'd probably solder everything out of habbit, looks like you cut no corners where it matters. Dual full bridge rectifier, nice stuff. That's about what I'd like to have. Aifa caps? From what I've found they make remote controls..
Anyway once again, nice work. I'm sure someone else will tackle your other questions.
I like the way it's assembled, only I'd probably solder everything out of habbit, looks like you cut no corners where it matters. Dual full bridge rectifier, nice stuff. That's about what I'd like to have. Aifa caps? From what I've found they make remote controls..
Anyway once again, nice work. I'm sure someone else will tackle your other questions.
Hi Chris!
The caps are Swedish high quality caps RIFA 6800uF/100V.
What do you mean by mid-Fi???
Perhaps I haven't had the opportunity to listen to the most expensive gear out there, but I'd say I have listened to some quite highly regarded stuff, like Tac-T Millennium and Classé, some esoteric OTL tube amps, big B&W's, Dali's and so on and I don't mind stating that these UcD180 modules don't come in second to any of the stuff I've listened to before.
If you wan't to call this mid-Fi, then that's fine with me. I can only congratulate you to the standards you're obviously used to and the gear you surely must have.
/Roland
The caps are Swedish high quality caps RIFA 6800uF/100V.
What do you mean by mid-Fi???
Perhaps I haven't had the opportunity to listen to the most expensive gear out there, but I'd say I have listened to some quite highly regarded stuff, like Tac-T Millennium and Classé, some esoteric OTL tube amps, big B&W's, Dali's and so on and I don't mind stating that these UcD180 modules don't come in second to any of the stuff I've listened to before.
If you wan't to call this mid-Fi, then that's fine with me. I can only congratulate you to the standards you're obviously used to and the gear you surely must have.
/Roland
paradigm said:
Hi,
Rifa! Looked like Aifa from the pics, thanks for the info I'll have to dig up some info on them. They look, robust, to say the least.
What I meant by mid fi, just a joke to an earlier post.
Regards,
Chris
Here you can find the info:
http://www.elfa.se/en/
Just type in: "RIFA PEH" in the search box.
/Roland
http://www.elfa.se/en/
Just type in: "RIFA PEH" in the search box.
/Roland
Paradigm,
Thanks for the idee of swapping pin#2 with pin#3. In future we will also supply cable kits, to make it easier to connect the amp to an input cich or something else. But please when you don't want to use the symmetrical input, solder the -input line to ground/screen at the source side and NOT at the side of the amplifier connector. This will improve the quality of the signal.
Nice pictures!
Peranders;
In don't think a full bridge will have less EMC, because you have now two "hot outputs". An half bridge has only one "hot output" and a reference ground. In this case it is much easier t remove the HF-dirt.
It has no sense to use a N-FET and P-FET, becuase they are used as pure switches. Thereby a N-FET is much better as a P-FET, so with both N-FET you have it more symmetrical 😉
Why does the UcD sound so good? I guess Bruno can explain this much better, but I will give it a try.
With a Class-D amplifier, the gain comes from a comparator and not from liniear components. In the original UcD amplifier the gain of the amp is 4.5x without any liniear components! So in a way there is no active analog amplification, just a comparator who creates the gain.
The less active components in the signal chain the better the sound...........
This gain without liniear components is valid for more Class-D amplifiers, but there are very less who use the feedback behind the outputcoil! A further improvement in the sound 😀
Regards,
Jan-Peter
www.hypex.nl
Thanks for the idee of swapping pin#2 with pin#3. In future we will also supply cable kits, to make it easier to connect the amp to an input cich or something else. But please when you don't want to use the symmetrical input, solder the -input line to ground/screen at the source side and NOT at the side of the amplifier connector. This will improve the quality of the signal.
Nice pictures!
Peranders;
In don't think a full bridge will have less EMC, because you have now two "hot outputs". An half bridge has only one "hot output" and a reference ground. In this case it is much easier t remove the HF-dirt.
It has no sense to use a N-FET and P-FET, becuase they are used as pure switches. Thereby a N-FET is much better as a P-FET, so with both N-FET you have it more symmetrical 😉
Why does the UcD sound so good? I guess Bruno can explain this much better, but I will give it a try.
With a Class-D amplifier, the gain comes from a comparator and not from liniear components. In the original UcD amplifier the gain of the amp is 4.5x without any liniear components! So in a way there is no active analog amplification, just a comparator who creates the gain.
The less active components in the signal chain the better the sound...........
This gain without liniear components is valid for more Class-D amplifiers, but there are very less who use the feedback behind the outputcoil! A further improvement in the sound 😀
Regards,
Jan-Peter
www.hypex.nl
Hi Jan-Peter!
I didn't quite understand what you mean. But as long as I use only balanced inputs, it doesn't matter, right!?
Could you please make a drawing, showing the schematic on:
"solder the -input line to ground/screen at the source side and NOT at the side of the amplifier connector."
/Roland
I didn't quite understand what you mean. But as long as I use only balanced inputs, it doesn't matter, right!?
Could you please make a drawing, showing the schematic on:
"solder the -input line to ground/screen at the source side and NOT at the side of the amplifier connector."
/Roland
RIFA
Those caps are indeed very good, (and very expensive). Nice to see that you are giving the UcD180 modules the power supply they deserve.......
I was a father for the third time last night - and i still look at the forum today....
Oh, if only i had a life😉
Best Regards
Sheriff
Those caps are indeed very good, (and very expensive). Nice to see that you are giving the UcD180 modules the power supply they deserve.......
I was a father for the third time last night - and i still look at the forum today....
Oh, if only i had a life😉
Best Regards
Sheriff
Roland,
Indeed with a symmetrical input everything is ok!
But supose you would use an asymetrical input so must put one wire to ground. Normaly to keep everything in phase you put the -input to ground. The question is at which place do you put this to ground? The best would be at the side where the source is. So you will pick up the signal at the side of the source.
Regards,
Jan-Peter
www.hypex.nl
Indeed with a symmetrical input everything is ok!
But supose you would use an asymetrical input so must put one wire to ground. Normaly to keep everything in phase you put the -input to ground. The question is at which place do you put this to ground? The best would be at the side where the source is. So you will pick up the signal at the side of the source.
Regards,
Jan-Peter
www.hypex.nl
Hard at it....
Hi Jan - Peter,
Nice to see you hard at it, at this time in the evening. At the rate you are going, you will have paid for that new building of yours before you have even moved into it.....!
All the best
Sheriff
Hi Jan - Peter,
Nice to see you hard at it, at this time in the evening. At the rate you are going, you will have paid for that new building of yours before you have even moved into it.....!
All the best
Sheriff
Sheriff,
...hm ok I am working late. But who is here on the forum and get a new born Child 😉
Congratulations to your new born Child!
Roland,
Indeed this is completly right! Now you take your signal still "slightly symmetrical", because the small signal voltage what is on the screen does not go to the input.
Jan-Peter
...hm ok I am working late. But who is here on the forum and get a new born Child 😉
Congratulations to your new born Child!
Roland,
Indeed this is completly right! Now you take your signal still "slightly symmetrical", because the small signal voltage what is on the screen does not go to the input.
Jan-Peter
Thanks for the info! It's good to know, should I, or anyone else need to go unbalanced.
/Roland
/Roland
paradigm said:Like this you mean?
/Roland
Hang on... your drawing depicts a preamp with a balanced output! In that case you just connect "normally" ie pin2:+input, pin3:-input, pin1:shield. Depending on the output stage of the preamp, shorting one of the signal lines to pin1 is not always a good idea...
The connection whereby the shield and - wire are tied together at the source is used when the source has an RCA output connector. In that case shield and - connection at the preamp output are indeed both ground.
...Bruno, you had a better eye as I
Ofcourse the best is a symmetrical output and it would be VERY stupid to connect it in an asymmetrical way!
Can you share your experience why the UcD sounds so good, and how the sounds is in comparing with very high end amplifiers?
Jan-Peter
www.hypex.nl
Ofcourse the best is a symmetrical output and it would be VERY stupid to connect it in an asymmetrical way!
Can you share your experience why the UcD sounds so good, and how the sounds is in comparing with very high end amplifiers?
Jan-Peter
www.hypex.nl