The TA2020 was discontinued because it's a through hole package device. It's cheaper and easier to handle and mass produce boards with surface mount parts - i.e. the TA2024, TA2021B, etc. There was nothing wrong with the TA2020, it's just a matter of economics. They have different power output ratings because some can handle a slightly higher power supply voltage which will allow you to have a slightly higher output power (of course it could be horribly distorted but they'll never come out and tell you that).
Realistically, all of the TA2020 and TA2024 amps are capable of around 6-8W of decent (fairly undistroted) output into 8 ohms. Clean output up to about 11W is possible with a 4 ohm load. Note that these numbers are taken from the Tripath datasheets and were determined with the recommended supply voltage.
The TA2021B can do closer to a clean 9W into 8 ohms and 15W into 4 ohms. These were also taken from the part's datasheet with the same stipulation as above.
The passive crossover in 2 or 3 way speaker presents a much more difficult load for any amplifier because it's more reactive than just a single driver. An ideal load would be purely resistive, but we all know that isn't the case with any of the current loudspeaker drivers.
That's why these amps sound particularly good with full range speakers. At least that's my experience/opinion so far.
Realistically, all of the TA2020 and TA2024 amps are capable of around 6-8W of decent (fairly undistroted) output into 8 ohms. Clean output up to about 11W is possible with a 4 ohm load. Note that these numbers are taken from the Tripath datasheets and were determined with the recommended supply voltage.
The TA2021B can do closer to a clean 9W into 8 ohms and 15W into 4 ohms. These were also taken from the part's datasheet with the same stipulation as above.
The passive crossover in 2 or 3 way speaker presents a much more difficult load for any amplifier because it's more reactive than just a single driver. An ideal load would be purely resistive, but we all know that isn't the case with any of the current loudspeaker drivers.
That's why these amps sound particularly good with full range speakers. At least that's my experience/opinion so far.
That's bad news if the 2020 was dicontinued. Bad for the AMP6 and the Charlize. Wonder how many of the 2020s are still on the shelf?
I have had the "cut out" problem too with the Fenice board. Thought it might be temp. protection because if you back the volume down a bit the problem goes away. But if Charlize shows the same problem it might not be heat. Could be some other protection, maybe over voltage? Big inductors can kick back at lot of voltage.
I will do some testing on resistive loads vs. complex inductive. I haven't seen the problem on the test bench, but usually don't push the chip as hard as one speakers.
Never have seen the problem on either the Sonic or the Super-T, even when pushed way too hard. Hmmmmm.....
I have had the "cut out" problem too with the Fenice board. Thought it might be temp. protection because if you back the volume down a bit the problem goes away. But if Charlize shows the same problem it might not be heat. Could be some other protection, maybe over voltage? Big inductors can kick back at lot of voltage.
I will do some testing on resistive loads vs. complex inductive. I haven't seen the problem on the test bench, but usually don't push the chip as hard as one speakers.
Never have seen the problem on either the Sonic or the Super-T, even when pushed way too hard. Hmmmmm.....
That's what I think also vt4c. I have an old panasonic 2-way speaker that registers a 6ohm load, and no matter how hard I push the amp, it won't go into mute protection. Not so with my DIYed 3-way, it's 4-ohms but probably reaches 2 ohms or so in some frequencies thus causing the tripping of the protection. Volume is quite low, probably 84 or 85db output, chip itself has a heatsink and its cold to the touch even when it starts doing its funky muting. Hope this helps.
panomaniac said:
This is very true. That's why those diodes from the outputs to ground and the supply rail are necessary when you run the chips near their maximum supply voltage. What voltages are you guys running your amps at when you had them shut off?
On some poorly designed switching supplies I've seen transients up to twice the output voltage because of bad circuit board layout! Those diodes clamp the voltage spikes to a diode drop above the supply rail or below ground potential so they have less of a chance to destroy the output FETs.
It's quite easy to measure on your computer as well. I'm on a mac so I use Fuzzmeasure, but I think Speaker workshop is free for Windows. Once you have the software all you need is a resistor and some wire (mini jack or rca, whatever your computer takes). Probably the easiest way to measure impedence vs frequency.
Joe
Joe
Yay! My Charlize is all suited up in Black Aluminum Armor! Its actually quite cramped in there. I managed to put a video card heat sink on there with some fancy work with lexan and a dremel to make a nice mounting frame with standoffs (no pics cause I'm too lazy to remove rear screws and risk breaking something, but I might remove front later). Front switch is dpdt one side is for + the other is for ground. All the wiring is very short. Silver solder for connections, cat5 for inputs, solid core copper for speaker wire.
Used this enclosure
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=262-074
Used this enclosure
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=262-074
Attachments
Brent,
Cool little amp. Isn't it amazing that you can get such great sound out of such a little box?
I'm tempted to purchase another Charlize and try it out with some premium film caps.
I haven't heard of a lot folks using Dynamicaps, but I have them in my Cary tube preamp and they sound really good in there. They have a nice blend of transparency, dynamics, speed, warmth, and smoothness which I didn't observe with VTV Ultratones (very rich, warm, lush, intimate, and lucid but slightly slow on transients and not the most airy sound - very involving, though), Jupiters (didn't come alive in my system - a little flat sounding, but maybe not enough burn in time), Russian Teflons (very fast, slick, slippery sound, but sounded small and shut-in, and not a lot of romance or soul), Auricaps (good choice, but tended towards a very slightly homogenous sound, with a slightly plasticky, very slightly rounded sounding transient attack and not as open or as startling with dynamics as Dynamicaps - nice overall, though), or Hovland Musicaps (similar to Auricaps but slightly cooler sounding, slightly leaner, and a little bit of an edge in the treble).
Dynamicaps need to burn in for a long time, though, before they open up and need to be oriented correctly.
One thing I like about the Dynamicap is the way they handle dynamics. For example, when you hear a tympany in real life, there's a startle factor when it's struck. There's weight and speed in the attack that makes the hairs on your neck stand up if your not expecting the strike.
I find that Dynamicaps reproduce significantly more of that quality than the other caps mentioned above. Additionally, they are open, airy, and smooth at the same time, which is a nice balance.
OK, enough of that. Where is the Tripath wiki, btw?
Best,
KT
Cool little amp. Isn't it amazing that you can get such great sound out of such a little box?
I'm tempted to purchase another Charlize and try it out with some premium film caps.
I haven't heard of a lot folks using Dynamicaps, but I have them in my Cary tube preamp and they sound really good in there. They have a nice blend of transparency, dynamics, speed, warmth, and smoothness which I didn't observe with VTV Ultratones (very rich, warm, lush, intimate, and lucid but slightly slow on transients and not the most airy sound - very involving, though), Jupiters (didn't come alive in my system - a little flat sounding, but maybe not enough burn in time), Russian Teflons (very fast, slick, slippery sound, but sounded small and shut-in, and not a lot of romance or soul), Auricaps (good choice, but tended towards a very slightly homogenous sound, with a slightly plasticky, very slightly rounded sounding transient attack and not as open or as startling with dynamics as Dynamicaps - nice overall, though), or Hovland Musicaps (similar to Auricaps but slightly cooler sounding, slightly leaner, and a little bit of an edge in the treble).
Dynamicaps need to burn in for a long time, though, before they open up and need to be oriented correctly.
One thing I like about the Dynamicap is the way they handle dynamics. For example, when you hear a tympany in real life, there's a startle factor when it's struck. There's weight and speed in the attack that makes the hairs on your neck stand up if your not expecting the strike.
I find that Dynamicaps reproduce significantly more of that quality than the other caps mentioned above. Additionally, they are open, airy, and smooth at the same time, which is a nice balance.
OK, enough of that. Where is the Tripath wiki, btw?
Best,
KT
The wiki is normally accessible on the front page. From there you enter Amplifiers, and than the Tripath FAQ.
Direct link is
http://www.diyaudio.com/wiki/index.php?page=Class+D+Amplification
There is a section on input caps if you want to add your input. Its not very organized yet but in time that section should be.
Direct link is
http://www.diyaudio.com/wiki/index.php?page=Class+D+Amplification
There is a section on input caps if you want to add your input. Its not very organized yet but in time that section should be.
Another glowing review....
http://202.186.86.35/audio/story.asp?file=/2006/3/30/audiofile/30charlize&sec=audiofile
http://202.186.86.35/audio/story.asp?file=/2006/3/30/audiofile/30charlize&sec=audiofile
