johninCR, Thanks for the links.
I read some of the material on the Class-D/Class-T amps.
The tripath seems like a good choice.
It has few disadvantages:
1) Most listeners say that the powerwave has a hum while no music plays. They say the 2020 doesn't. I think the 2022 and the 2032 are the most suited for my speakers.
2) It doesn't have a decoupling circuit. It can burn expensive drivers if not protected. How do I add a decoupling circuit?
3) it is recommended to replace some parts (caps especially) to better ones.
Can anyone suggest a power supply for the tripath boards (2x200W and the 6x50W) except for battery source?
I found on the tripath discussion link the following:
Zappulse 2.2SE
http://www.lcaudio.com/
Any opinions on that amp?
It seems as an amazing amp (some compare it to the best class-A's out there, as the author says).
It is not cheap though (230$ per ch).
It seems that with these amps for active speakers there isn't a need for class-A amps. What do you think of that?
When I started this thread I haven't thought of chip amps (the only place I read about Class-D's is the alpine site, now I know what amps to use in my car - active system as well).
Now it seems as the best suited amps for active speakers, even for a very high-end sound. Am I wrong? Is it still worth putting mini-Alpeh's for the highs and the mids?
Thanks,
Boaz
I read some of the material on the Class-D/Class-T amps.
The tripath seems like a good choice.
It has few disadvantages:
1) Most listeners say that the powerwave has a hum while no music plays. They say the 2020 doesn't. I think the 2022 and the 2032 are the most suited for my speakers.
2) It doesn't have a decoupling circuit. It can burn expensive drivers if not protected. How do I add a decoupling circuit?
3) it is recommended to replace some parts (caps especially) to better ones.
Can anyone suggest a power supply for the tripath boards (2x200W and the 6x50W) except for battery source?
I found on the tripath discussion link the following:
Zappulse 2.2SE
http://www.lcaudio.com/
Any opinions on that amp?
It seems as an amazing amp (some compare it to the best class-A's out there, as the author says).
It is not cheap though (230$ per ch).
It seems that with these amps for active speakers there isn't a need for class-A amps. What do you think of that?
When I started this thread I haven't thought of chip amps (the only place I read about Class-D's is the alpine site, now I know what amps to use in my car - active system as well).
Now it seems as the best suited amps for active speakers, even for a very high-end sound. Am I wrong? Is it still worth putting mini-Alpeh's for the highs and the mids?
Thanks,
Boaz
Just to be clear, there is a difference between the typical "chip amp" and Class D variants like the zappulse and tripath modules. Chip amps are essentially gainclones, while the others are switching amps.
One thing to be careful of is the EMC isolation/shielding requirements for these Class D (zappulse, tripath, etc.) modules. Ever wonder why lcaudio doesn't sell finished PWM amplifiers? They only sell kits because the EMC issues are not trivial to address, and the testing and certification requirements to sell such a product in finished retail form could be difficult and expensive.
Not that this sound necessarily discourage you from taking that approach. You are correct that Class D is a natural choice for active speaker systems... small, efficient, powerful, economical, low distortion, and cool running. What more could you want? Just be aware that you will probably need to construct a shielded metal enclosure, be meticulous with wire routing, and probably use shielded speaker cables if they are of any significant length to cut down on EM emmissions. Otherwise you might notice that your TV doesn't like your new speakers!
Gainclones are not quite as economical, not quite as small, and not as cool running... but still make for a very good choice and are much more user friendly re: sheilding and isolation requirements.
One thing to be careful of is the EMC isolation/shielding requirements for these Class D (zappulse, tripath, etc.) modules. Ever wonder why lcaudio doesn't sell finished PWM amplifiers? They only sell kits because the EMC issues are not trivial to address, and the testing and certification requirements to sell such a product in finished retail form could be difficult and expensive.
Not that this sound necessarily discourage you from taking that approach. You are correct that Class D is a natural choice for active speaker systems... small, efficient, powerful, economical, low distortion, and cool running. What more could you want? Just be aware that you will probably need to construct a shielded metal enclosure, be meticulous with wire routing, and probably use shielded speaker cables if they are of any significant length to cut down on EM emmissions. Otherwise you might notice that your TV doesn't like your new speakers!
Gainclones are not quite as economical, not quite as small, and not as cool running... but still make for a very good choice and are much more user friendly re: sheilding and isolation requirements.
Boaz,
I'm pretty new to all of this stuff and really only have practical experience with the speaker side of audio. I ran accross Tripath about 9 months ago when I was researching digital amps. It appeared to be different and interesting. When the powerwave topic came up I bought one and it's sound is everything discussed, rich and smooth compared to my midfi SS Denon AVR-1804. The difference is not subtle.
Instead of trying to learn all of the electronics, I'm just going to wait it out until these amps are used to create a true audiophile quality all-in-one unit at a reasonable price. In the meantime, I'll stick to working on speakers and room treatments.
I'm pretty new to all of this stuff and really only have practical experience with the speaker side of audio. I ran accross Tripath about 9 months ago when I was researching digital amps. It appeared to be different and interesting. When the powerwave topic came up I bought one and it's sound is everything discussed, rich and smooth compared to my midfi SS Denon AVR-1804. The difference is not subtle.
Instead of trying to learn all of the electronics, I'm just going to wait it out until these amps are used to create a true audiophile quality all-in-one unit at a reasonable price. In the meantime, I'll stick to working on speakers and room treatments.
The comment about shielded speaker cable was in reference to using a Class-D (or digital, as some call them) switching type amplifier. These designs use a high frequency carrier wave modulated by the audio frequency signal, with a subsequent low pass filter to remove the carrier wave (usually a square wave) and leave only the audio signal content.
While the output low-pass filter should remove all high frequency components, no filter is ever perfect and it is good design to take proper precautions. If there is high frequency content left on the outputs, your speaker cables become broadcast antennas that can interfere with TV's and other devices (dependent on the switching frequency of the amplifier in question). Using a shielded cable, grounded at the amplifier end, is rather effective for taking care of any stray high frequency energy before it is broadcast.
It may not be absolutely necessary for many switching amp designs out there, but it is a cheap and sensible step to take. Better safe than sorry.
While the output low-pass filter should remove all high frequency components, no filter is ever perfect and it is good design to take proper precautions. If there is high frequency content left on the outputs, your speaker cables become broadcast antennas that can interfere with TV's and other devices (dependent on the switching frequency of the amplifier in question). Using a shielded cable, grounded at the amplifier end, is rather effective for taking care of any stray high frequency energy before it is broadcast.
It may not be absolutely necessary for many switching amp designs out there, but it is a cheap and sensible step to take. Better safe than sorry.
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