"Small" eval.boards....
Hi!
Yes you keep telling me it's Tripath's board, but they have no reference to it on their web, and you would not provide any.
Anyway, reverse-engineering it, I found it differed quite a lot from Tripaths (existing) EB. And used cheaper & slower mosfets.
I have now sent it to the forever playing-ground, and used all "tweak-components" on Tripath EB 0103 & 0104 .
Have just finished the 0103...still running in & tweaking.
(It sounds better now than my first report).
ArneK
Hi!
Yes you keep telling me it's Tripath's board, but they have no reference to it on their web, and you would not provide any.
Anyway, reverse-engineering it, I found it differed quite a lot from Tripaths (existing) EB. And used cheaper & slower mosfets.
I have now sent it to the forever playing-ground, and used all "tweak-components" on Tripath EB 0103 & 0104 .
Have just finished the 0103...still running in & tweaking.
(It sounds better now than my first report).
ArneK
Actually I did produce one about 15 years ago that we showedphase_accurate said:
at CES. Gordon Holt said he liked it, but we were giving away free beer at the time.
It was a classic self-clocked PWM rated at about 40 watts. Currently one channel seems to be broken, and I suppose I'll have to fix it one of these days.
Hi!
"Yes you keep telling me it's Tripath's board, but they have no reference to it on their web, and you would not provide any."
you could ask them (and not just make and post asumptions) if you are interested to find out.
"Anyway, reverse-engineering it, I found it differed quite a lot from Tripaths (existing) EB. "
let me hear about those differences, to my best knowledge these are graphical but in no way funtional.
"And used cheaper & slower mosfets"
i think we used faster mosfets, (with lower gate capacitance).
did you buy this board 2 years ago or so?
some changes/improvements has happened since then , one of them is tweaking the fets turn-off time , this has some impact on the efficiency.
another change is filtering the feedback loop.....
rgds karsten madsen - www.cadaudio.dk
"Yes you keep telling me it's Tripath's board, but they have no reference to it on their web, and you would not provide any."
you could ask them (and not just make and post asumptions) if you are interested to find out.
"Anyway, reverse-engineering it, I found it differed quite a lot from Tripaths (existing) EB. "
let me hear about those differences, to my best knowledge these are graphical but in no way funtional.
"And used cheaper & slower mosfets"
i think we used faster mosfets, (with lower gate capacitance).
did you buy this board 2 years ago or so?
some changes/improvements has happened since then , one of them is tweaking the fets turn-off time , this has some impact on the efficiency.
another change is filtering the feedback loop.....
rgds karsten madsen - www.cadaudio.dk
Dear Mr. Madsen...
Yes, the board probably was a couple of years old.
And I got it secon-hand, unused.
And I asked you by e-mail 3 times for doc, as I told I could not get
any from Tripath, and the board differed from their range.
Anyway, by-gones......
Leave it, and I might purchase some other stuff from you...
Arne K
Yes, the board probably was a couple of years old.
And I got it secon-hand, unused.
And I asked you by e-mail 3 times for doc, as I told I could not get
any from Tripath, and the board differed from their range.
Anyway, by-gones......
Leave it, and I might purchase some other stuff from you...
Arne K
hi.
ok to leave it , i was just curious to hear what big differences you have found between the lage tripath eval board and our small version.
about the docs i think i told you (at least once) that the docs for the board is the tp0103 eval board manual (which was available from tripath and now from us....) so i dont really understand your statement.....
we had both boards here (as said) and we didnt find any functional diferences, tripath told us that the mentioned docs should apply to both boards.
let me hear if you have anything to add.
rgds karsten madsen - www.cadaudio.dk
ps. too bad about your new tp0103 board...
ok to leave it , i was just curious to hear what big differences you have found between the lage tripath eval board and our small version.
about the docs i think i told you (at least once) that the docs for the board is the tp0103 eval board manual (which was available from tripath and now from us....) so i dont really understand your statement.....
we had both boards here (as said) and we didnt find any functional diferences, tripath told us that the mentioned docs should apply to both boards.
let me hear if you have anything to add.
rgds karsten madsen - www.cadaudio.dk
ps. too bad about your new tp0103 board...
hi.
cobra wrote : "I also have a "story" about the LC-Audio PWM boards. (First gen.)"
can you share the story with us?
i dont think im the only one interested....
rgds karsten madsen - www.cadaudio.dk
cobra wrote : "I also have a "story" about the LC-Audio PWM boards. (First gen.)"
can you share the story with us?
i dont think im the only one interested....
rgds karsten madsen - www.cadaudio.dk
Re:
Nothing special, they were sounding good, for the price, but not as good as the Tripath (before it decided to self-destruct).
And the ZapPulse also generated extreme amounts of RFI, and had no short-circuit protection.
Been there, done that....
BTW, do you have any clue about the behavior of the Tripath?
(no response on e-mail to them...).
Arne K
Nothing special, they were sounding good, for the price, but not as good as the Tripath (before it decided to self-destruct).
And the ZapPulse also generated extreme amounts of RFI, and had no short-circuit protection.
Been there, done that....
BTW, do you have any clue about the behavior of the Tripath?
(no response on e-mail to them...).
Arne K
hi.
what is the condition of the powerfets?
and of the driver chip?
do you mute at power on/off?
did you by chance run the amp without the 12v floating supply?
what fets and deadtime do you use?
rgds karsten madsen - www.cadaudio.dk
what is the condition of the powerfets?
and of the driver chip?
do you mute at power on/off?
did you by chance run the amp without the 12v floating supply?
what fets and deadtime do you use?
rgds karsten madsen - www.cadaudio.dk
Re:
Thanx ;
1) internal short on one ch, ok on other. (STW34NB20)
2) ? - will find out later....
3) yes, mute over "double" powerswitch, + alternative extra sw.
4) no, use on-board 12V.
5) bbm=factory setting, gave a steady 750kHz idle.
Have a bunch of MTW35N15E powerfets, I will try/test them later.
Arne K
Thanx ;
1) internal short on one ch, ok on other. (STW34NB20)
2) ? - will find out later....
3) yes, mute over "double" powerswitch, + alternative extra sw.
4) no, use on-board 12V.
5) bbm=factory setting, gave a steady 750kHz idle.
Have a bunch of MTW35N15E powerfets, I will try/test them later.
Arne K
Re: update on this tread...:
http://www.diyaudio.com/forums/showthread.php?threadid=15926&perpage=15&pagenumber=1
Arne K
http://www.diyaudio.com/forums/showthread.php?threadid=15926&perpage=15&pagenumber=1
Arne K
Power Electronics and Class D
Some may not reailze that these types of circuits have been around since well before '77, and are already the norm in inverters, motor drives, and all sorts other power electronics issues.
For the most part, it's these applications that are continuing the push the technology seen in class D amps, not the audio market.
The crown amp circuit topology is pretty interesting. I'm actually working with a PhD student who is doing something very similar, but with a focus on preventing "shoot-though", the condition were both switches are turned on in a standard half bridge (usually some smoke involved with this...).
I found Nelson's comment on efficiency interesting, but after thinking about it, it's certainly the true. Higher pwm switching frequencies result in more losses, and the frequencies you need to get decent resolution with audio are probably beyond the efficient range of the devices.
In general, I don't think that class D will amount to much until we start seeing switches that are specifically designed for audio. However, this segment of the market is really taking off, so this should happen in the near future, if it hasn't already.
Nate
Some may not reailze that these types of circuits have been around since well before '77, and are already the norm in inverters, motor drives, and all sorts other power electronics issues.
For the most part, it's these applications that are continuing the push the technology seen in class D amps, not the audio market.
The crown amp circuit topology is pretty interesting. I'm actually working with a PhD student who is doing something very similar, but with a focus on preventing "shoot-though", the condition were both switches are turned on in a standard half bridge (usually some smoke involved with this...).
I found Nelson's comment on efficiency interesting, but after thinking about it, it's certainly the true. Higher pwm switching frequencies result in more losses, and the frequencies you need to get decent resolution with audio are probably beyond the efficient range of the devices.
In general, I don't think that class D will amount to much until we start seeing switches that are specifically designed for audio. However, this segment of the market is really taking off, so this should happen in the near future, if it hasn't already.
Nate
Interesting reading in this thread.
Many of us remember the sensational Sony TA-N88 when it first came out. Even in those days, SONY could make a simple design, that was simply beautiful. However at that time the guts parts were simply not ready to give a performance good enough to compete.
I think today however you can easily get the parts, that will run without losses at high frequencies, and give you audio performance comparable to the best Class A Amplifiers around.
But with a major difference in efficiency.
And that efficiency not only transforms into a lower utilities bill, but also allows for small size, sleek design and high power / dynamics at lower cost.
Many of us remember the sensational Sony TA-N88 when it first came out. Even in those days, SONY could make a simple design, that was simply beautiful. However at that time the guts parts were simply not ready to give a performance good enough to compete.
I think today however you can easily get the parts, that will run without losses at high frequencies, and give you audio performance comparable to the best Class A Amplifiers around.
But with a major difference in efficiency.
And that efficiency not only transforms into a lower utilities bill, but also allows for small size, sleek design and high power / dynamics at lower cost.
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