Leolabs said:
Do you want to read comparisons?
http://www.avguide.com/features/class-d/controversial.php
I don't know if you read that link/interview above, and maybe it's just me over-reacting, but I got a strong wiff of condescending snootyness. Like all those big names getting together for a good chin wag "let's dump on class-D today today, pass me the scotch please". (real polite like). My modded Trends t-10 is unpretentious but it sure is musical. I wouldn't be so foolish as to compare it to Red Dragon or Nu-Force or Red Wine or any of the other "serious" attempts. I may be losing it, but from years of listening to some really good gear, I know what makes music and what fakes it. Either those big names are grinding a collective axe or they're covering their ***! Wanna bet in short order they will be offering classy, expensive versions of "our" stuff?..as if they always were believers...so if you read between the lines, all the work and enthusiasm represented here and elsewhere is delusional and misguided??? comments please.
It's all about the money... I think these amps (particularly the Tripath designs) really are the future of high quality amplification. That some of them sound so damned good already, and at such cheap prices, must have the more established names using - comparatively - old fasioned designs secretly very worried indeed. When it gets to the point where just about everyone can afford high quality amplification because of these designs where will that leave the so-called 'high class' expensive manufacturers? I think the next 5 years are going to be very interesting ones as far as Hi-Fi and amplifiers are concerned.
I've listened to alot of high quality gear over the years, and am still surprised at how good some of these Class T amps hold up in comparision.
Sorry this is a little off topic - back to your scheduled program ;-)
I've listened to alot of high quality gear over the years, and am still surprised at how good some of these Class T amps hold up in comparision.
Sorry this is a little off topic - back to your scheduled program ;-)
Hmm..Why particularly the Tripath? It seems T.A.S. more likes the UcD based design..johnm said:
BTW, why noone want to buy the future if it so cheap (Mkt Cap:1.23M http://finance.google.com/finance?q=OTC:TRPHE )?
Maybe it's simply the past? I don't know, i'm just wondered. 🙂
Leolabs said:
DIY kits are avalaible with NewClassD, ColdAmp and ... some UCD clones. What else?
All majors have a class D chip on catalog: National, IRF, AD.....
I found interesting the Analog Devices AD1994: it is the only one, beside Tripath, to use sigma-delta modulation.
Hi IVX,
Tripath has filed for chapter 11 bankruptcy, that means reorganization of business without interrupt production (they have 14M year income). This is the only way to buy a company with many debts. Maybe this is a new start for Tripath technology with new owners? 🙂
The clowns in the avguide link are full of it, indeed. But they do make one very valid point--high-end audio is the industry of mediocrity.
The switching-mode technology is difficult and probably out of range for most high-end companies. (Some people on the PSU forum say it's not difficult to make a good SMPS. They are wrong.) Switching-mode seems to be a technology primarily for the electronics giants. That will also mean a market for the lowest bidder. But at least the gap between the lowest bidder and "cost-no-option" will shrink.
To draw a somewhat farfetched parallel. It's expected that at most 3-4 plasma screen manufacturers will survive worldwide (meaning Korea and/or Taiwan). The rest will not have the money to compete. Considering the world isn't big enough for a competitor to Intel and AMD, 3-4 plants is probably overly optimistic.
The switching-mode technology is difficult and probably out of range for most high-end companies. (Some people on the PSU forum say it's not difficult to make a good SMPS. They are wrong.) Switching-mode seems to be a technology primarily for the electronics giants. That will also mean a market for the lowest bidder. But at least the gap between the lowest bidder and "cost-no-option" will shrink.
To draw a somewhat farfetched parallel. It's expected that at most 3-4 plasma screen manufacturers will survive worldwide (meaning Korea and/or Taiwan). The rest will not have the money to compete. Considering the world isn't big enough for a competitor to Intel and AMD, 3-4 plants is probably overly optimistic.
hello thomaseliot,
I can repeat one more time: sigma-delta modulation is the most popular (if not single at all) approach in the selfoscillating class D amps, IRDAMP (IR), B&O ICE Power,i'm not sure about UcD maybe, but why not, if it's a comparator->time delay->integrator->feedback? Sigma-delta or not, it's a question of terminology rather, so tripath isn't something unique. Let's ask phase_accurate about it, Charles, i'm right?
I can repeat one more time: sigma-delta modulation is the most popular (if not single at all) approach in the selfoscillating class D amps, IRDAMP (IR), B&O ICE Power,i'm not sure about UcD maybe, but why not, if it's a comparator->time delay->integrator->feedback? Sigma-delta or not, it's a question of terminology rather, so tripath isn't something unique. Let's ask phase_accurate about it, Charles, i'm right?
IVX said:
Hi Ivan
I've learned that by Charles (or I believe it, I'm not an expert...). This is a quote from AD1994 datasheet:
I personally use the term delta-sigma strictly for a modulator topology that uses a clocked modulator like AD-converters do.
OTOH self oscillating topologies using hysteresis and some of the delay-based ones as well show a behaviour (specially the signal-dependant switching frequency) like the aforementioned modulator topology.
They can therefore be called delta-sigma if one is generous regarding terminology.
The AD chips use the "real" delta-sigma modulator AFAIK.
Regards
Charles
OTOH self oscillating topologies using hysteresis and some of the delay-based ones as well show a behaviour (specially the signal-dependant switching frequency) like the aforementioned modulator topology.
They can therefore be called delta-sigma if one is generous regarding terminology.
The AD chips use the "real" delta-sigma modulator AFAIK.
Regards
Charles
phn said:
Tell you what, they're not that hard. We're making a class-D amp for our analog circuit design class and my partner slapped one together on a breadboard with discretes he had on hand; it's running strong at ~750KHz switching speed. He also made a 3-phase switching 12VDC->3x120VAC microcontroller-based supply which, apart from some issues setting up a good output inductor, is running fine. Class-D just requires a different way of thinking, but it's not that big of a deal.
I can agree with the first part of this statement.
I only partially agree with the 2nd part though: There is quite a difference between setting up a class-d amp and a good class-d amp. It is even more difficult to construct an excellent class-d amp than a good one.
The requirements regarding switching precision, EMC etc are much stricter by some orders of magnitude than they are for simple SMPS, motor control etc.
Regards
Charles
- Status
- Not open for further replies.