heh heh, glad your a fan of the idea. 😀
Isn't it more of a class D buffered class A? Ah, nope, it's class D.
... your ' key's broken. 😱
Isn't it more of a class D buffered class A? Ah, nope, it's class D.
... your ' key's broken. 😱
i know. so far, i've had my keyboard replaced twice and now the ' button fell off, my processor blew up (stopped working) once, my bluetooth card went awol twice (as in that it fell out of its socket), my soundcard has a dc offset of about 1,8-2.2 volt (on both channels), i can hear my network card (peep-peeeeep-pep-peep etc), if i use the touchpad something's crackling in the soundcard. AND it's not even a year old !! 
Strange thing is, where i work there's about 40 other dell machines (both laptops & normal desktops) and no probs with them whatsoever.
stupid thing. Guess i'm just unlucky.
Strange thing is, where i work there's about 40 other dell machines (both laptops & normal desktops) and no probs with them whatsoever.
stupid thing. Guess i'm just unlucky.
An externally hosted image should be here but it was not working when we last tested it.
I don't want to spoil the fun here but has anyone looked at
http://www.psaudio.com/articles/sdat.asp
An excerpt:
"The SDAT™ circuitry is revolutionary for several reasons, among them the elimination of the load variant problem. SDAT’s™ will sound pretty much the same regardless of the type of speaker you have. With the Hybrid Class A’s SDAT™ technology, you can rely on the fact that your speaker will perform the way it was intended to sound."
I wasn't able to figure out what this has to do with class A (they are talking about their class-D amp !).
Regards
Charles
http://www.psaudio.com/articles/sdat.asp
An excerpt:
"The SDAT™ circuitry is revolutionary for several reasons, among them the elimination of the load variant problem. SDAT’s™ will sound pretty much the same regardless of the type of speaker you have. With the Hybrid Class A’s SDAT™ technology, you can rely on the fact that your speaker will perform the way it was intended to sound."
I wasn't able to figure out what this has to do with class A (they are talking about their class-D amp !).
Regards
Charles
haha..... wow that IS bad luck!!! Hope you were joking! If it's a DELL I'm sure if you call them and throw a fit they'll replace the whole unit just to keep you smiling, (and make you go away) I've known a few people to have done that, when all they needed was a format.
Hi Charles,
I checked out that site and I dont' think you could figure it out because they gave you nothing to work with.
There's absolutely no info on what makes it work, why it works, how it works... nothing! Kind of thing to ignore and stay away from.
Wonder if someone could dig up the patent info on it, if it's so revolutionary.... there should indeed be a patent.
We know they arent' the ones to have solved the feedback and dynamic load issue, as they almost seem to claim.
They don't even say if they take the feedback before or after the filter, or both.
Wonder if there's a UCD module inside there with the op amps tweaked into class A lol.
Maybe it's one of those hybrids where they input a class A type signal directly into the filter and use the error to modulate the power stage.
Didn't even see any specs on it.
Blah! Nothing more than sales hype.
Regards,
Chris
Hi Charles,
I checked out that site and I dont' think you could figure it out because they gave you nothing to work with.
There's absolutely no info on what makes it work, why it works, how it works... nothing! Kind of thing to ignore and stay away from.
Wonder if someone could dig up the patent info on it, if it's so revolutionary.... there should indeed be a patent.
We know they arent' the ones to have solved the feedback and dynamic load issue, as they almost seem to claim.
They don't even say if they take the feedback before or after the filter, or both.
Wonder if there's a UCD module inside there with the op amps tweaked into class A lol.
Maybe it's one of those hybrids where they input a class A type signal directly into the filter and use the error to modulate the power stage.
Didn't even see any specs on it.
Blah! Nothing more than sales hype.
Regards,
Chris
sorry for the off topic post but here i go.
i wasn;t joking about that laptop. I've tried to get the whole thing replaced but they wouldn't do it. nasty.,
i still don't get the class a part in the psaudio piece.
i wasn;t joking about that laptop. I've tried to get the whole thing replaced but they wouldn't do it. nasty.,
i still don't get the class a part in the psaudio piece.
Hi Jaka Racman,
Exactly what I was thinking, but either way they shouldn't be so afraid to not even say so. That makes me turn the other way in a hurry. Amps like that which I've read about all input the error into a hysteresis modulator. If that's indeed what it is, they seem to be staking claim to ideas they've had nothing to do with.
I can't recall exactly, but does that type of amp not have a class dedication of it's own?
Regards,
Chris
Exactly what I was thinking, but either way they shouldn't be so afraid to not even say so. That makes me turn the other way in a hurry. Amps like that which I've read about all input the error into a hysteresis modulator. If that's indeed what it is, they seem to be staking claim to ideas they've had nothing to do with.
I can't recall exactly, but does that type of amp not have a class dedication of it's own?
Regards,
Chris
(on PS audio)
Apparently they were afraid simply to call their amp "class D". Class A refers to one of the buffer amps in the signal path, but the amp is class D as far as I know.
Has anyone heard it by any chance? Seen the inside?
---
(on biasing op amps)
I've seen quite a number of discussions on biasing op amps in class A. The ones I've seen were all wrong in their interpretation of what's happening and what they're trying to achieve.
Here's how it should go:
A current source is tied between output and the rail where the miller VAS is located. This rail can be recognised from the data sheet because it´s got 20dB worse PSRR than the other one.
By biasing the output transistor off, this current source will insure that this rail sees only a constant DC load, thus removing signal-related content from it.
From this you can see that it's not about class A, but about power supply effects. Some people think they can get round by using a resistor instead of a proper current source. Wrong, because the power supply will be affected same as if that resistor was just the load to ground. Only a proper current source will do, and if it's tied to the wrong rail - no cigar either.
(on laptop PCs) One day the mouse pointer started walking away. It transpired the purple "g-spot" (strain gauge pointing device) had gotten mechanically biased. There was no way of telling the software to ignore it (I don't use it anyway). I called up IT support and they told me the keyboard had to be replaced. So I opened up the thing and pulled the plug on the purple button (flex foil) and that's that.
Cheers,
Bruno
Apparently they were afraid simply to call their amp "class D". Class A refers to one of the buffer amps in the signal path, but the amp is class D as far as I know.
Has anyone heard it by any chance? Seen the inside?
---
(on biasing op amps)
I've seen quite a number of discussions on biasing op amps in class A. The ones I've seen were all wrong in their interpretation of what's happening and what they're trying to achieve.
Here's how it should go:
A current source is tied between output and the rail where the miller VAS is located. This rail can be recognised from the data sheet because it´s got 20dB worse PSRR than the other one.
By biasing the output transistor off, this current source will insure that this rail sees only a constant DC load, thus removing signal-related content from it.
From this you can see that it's not about class A, but about power supply effects. Some people think they can get round by using a resistor instead of a proper current source. Wrong, because the power supply will be affected same as if that resistor was just the load to ground. Only a proper current source will do, and if it's tied to the wrong rail - no cigar either.
(on laptop PCs) One day the mouse pointer started walking away. It transpired the purple "g-spot" (strain gauge pointing device) had gotten mechanically biased. There was no way of telling the software to ignore it (I don't use it anyway). I called up IT support and they told me the keyboard had to be replaced. So I opened up the thing and pulled the plug on the purple button (flex foil) and that's that.
Cheers,
Bruno
Hi,
Class A in the signal path, could be anywhere, input buffer, or the other type we had mentioned, with a small class A amp driving the load directly. They're calling it a hybrid so I'd think it's the later.
Oh, look what I found!
http://www.psaudio.com/products/hca.asp
Some info on it there, according to them, Bruno, Jan-Peter, you're old news 😀
"This is the power amplifier that will set the standard for all "under $3000" power amplifiers on the market today. Revolutionary in its design, devleopment and performance, the Hybrid Class A " (sic)
HCA-2 Amplifier [Silver] $1,695.00
HCA-2 Amplifier [Black] $1,695.00
🙄
More to laugh at:
"Frequency resonse - 10 - 20 KHz (+/- 0.5 dB) "
They didn't even proof read their hype.. I wonder if the same level of attention to detail went into making the amp itself.
You'll notice they don't have a single graph in their manual or on their website for it.
I think the Sharp 1 Bit finally has a competitor. I agree they do seem afraid to call it class d... Thanks for the laugh guys.
Regards,
Chris
Class A in the signal path, could be anywhere, input buffer, or the other type we had mentioned, with a small class A amp driving the load directly. They're calling it a hybrid so I'd think it's the later.
Oh, look what I found!
http://www.psaudio.com/products/hca.asp
Some info on it there, according to them, Bruno, Jan-Peter, you're old news 😀
"This is the power amplifier that will set the standard for all "under $3000" power amplifiers on the market today. Revolutionary in its design, devleopment and performance, the Hybrid Class A " (sic)
HCA-2 Amplifier [Silver] $1,695.00
HCA-2 Amplifier [Black] $1,695.00
🙄
More to laugh at:
"Frequency resonse - 10 - 20 KHz (+/- 0.5 dB) "
They didn't even proof read their hype.. I wonder if the same level of attention to detail went into making the amp itself.
You'll notice they don't have a single graph in their manual or on their website for it.
I think the Sharp 1 Bit finally has a competitor. I agree they do seem afraid to call it class d... Thanks for the laugh guys.
Regards,
Chris
Well, this one will set the standard in my living room:
An externally hosted image should be here but it was not working when we last tested it.
hahaha! Give them time I say... give them time.
"We start at the beginning
Our goal for the new power amplifier series from PS Audio was to create a product that jumped the final hurdle – crossed the elusive barrier all amps in the past have been striving to achieve –(snicker) to sip from the Holy Grail of the elusive unified theory of power amplification."
Here's the page to read for a real good chuckle
http://www.psaudio.com/products/hca_overview.asp
According to them, they've "re-invented" the wheel!!!
Whew~ That's about all I can handle.
Regards,
Chris
"We start at the beginning
Our goal for the new power amplifier series from PS Audio was to create a product that jumped the final hurdle – crossed the elusive barrier all amps in the past have been striving to achieve –(snicker) to sip from the Holy Grail of the elusive unified theory of power amplification."
Here's the page to read for a real good chuckle
http://www.psaudio.com/products/hca_overview.asp
According to them, they've "re-invented" the wheel!!!
Whew~ That's about all I can handle.
Regards,
Chris
UsRV: Neat!
Not that it's so critical for the 180W module (for the 400W it's more important), but I'm not seeing how the heat from the blue "T" gets conducted away to the box. If you bolt them to the box by the tapped holes in the T, you get the box to cool the amp.
Cheers,
Bruno
Not that it's so critical for the 180W module (for the 400W it's more important), but I'm not seeing how the heat from the blue "T" gets conducted away to the box. If you bolt them to the box by the tapped holes in the T, you get the box to cool the amp.
Cheers,
Bruno
how necessary are heatsinks with these modules ? I;m talking about normal, in-house use with normal sensitivity speakers. It;s pretty efficient so...
btw, seems i was right about that class a class d amp marketing bs stuff 😉
btw, seems i was right about that class a class d amp marketing bs stuff 😉
I run the 180w modules without additional heat sinking in open air. The Tee becomes like 60ºC.
The problem is when you lock them up in a closed box, the heat can't get out. Even a mere 3W of heat can build up to quite a temperature if you keep it in a box.
The story that "class D runs cool" is one that keeps bouncing back from marketing people. They grab the heat sink and complain hey this thing gets warm!
They don't realise that if you cash in on the efficiency advantage by reducing heat sinking, the heat sink temperature will go up again! Of course you'd feel the difference in heat output by holding your hand 10cm above the amp but that's beyond them.
The problem is when you lock them up in a closed box, the heat can't get out. Even a mere 3W of heat can build up to quite a temperature if you keep it in a box.
The story that "class D runs cool" is one that keeps bouncing back from marketing people. They grab the heat sink and complain hey this thing gets warm!
They don't realise that if you cash in on the efficiency advantage by reducing heat sinking, the heat sink temperature will go up again! Of course you'd feel the difference in heat output by holding your hand 10cm above the amp but that's beyond them.
“HCA-2 Hybrid Class-A Amplifier
The novel design combines a balanced JFET input stage with a digital class D switching digital output stage. The Analog stage was designed by PS Audio's Paul McGowan, the digital circuitry is the work of John Levreault of Orvelle Technologies."
Sounds like, Class A input stage - followed by analogue Class D Output stage - with FB after the filter (But maybe dual loop) fed back to Class A input stage....
Nothing new am afraid…. Just marketing BS
John
Edit :- 0.2% 1KHz 150W er ... "you know I would do this job at half the price" 😉 with this "performance" level you can forget about dual loop FB...
The novel design combines a balanced JFET input stage with a digital class D switching digital output stage. The Analog stage was designed by PS Audio's Paul McGowan, the digital circuitry is the work of John Levreault of Orvelle Technologies."
Sounds like, Class A input stage - followed by analogue Class D Output stage - with FB after the filter (But maybe dual loop) fed back to Class A input stage....
Nothing new am afraid…. Just marketing BS
John
Edit :- 0.2% 1KHz 150W er ... "you know I would do this job at half the price" 😉 with this "performance" level you can forget about dual loop FB...
Bruno Putzeys said:
Thanks Bruno,
No worries. The T is bolted to a normal 5 mm thick L profile (20 * 50 mm) using Arctic Silver Compound between them (since it is well away from the FETs, which are insulated already as it seems, and no side effects should occur) and that L profile is bolted to the finned sides using the same compound. The shiny piece at the connector side of the PCBs is just a profile to get them same height using the 10 mm stand-offs. This means that the modules are only attached to the sides of the box and the whole sides may be removed easily. The assembly should be OK to transfer and dissipate the generated heat without too much effort or temp rise.
UrSv said:
Fooling around. Why on earth would I do that? Did you doubt me?
😀
On a serious note, BS... oops. PSAUDIO has received an invitation to join our happy forums to further discuss their successful re-inventing of the wheel, with an audience who can appreciate the technical aspect of it.
Don't hold your breath, and I won't either.
😎