Class t-amp-2020 Kit - Check it!

[Fin]

Russell

Thanks for the unsolicited review of this eBay store - but I was only asking if anyone knew anything about this particular Class T amplifier.

BTW - some of his items are reasonably priced if you a in my part of the world - and his service is excellent. Also, don't forget, he is Chinese and English is not his first language - so describing items in useful "English" terms might not be his forte. You seem to have a gripe against this seller??

[lousymusician]

This thread got resurrected a bit off topic. So to bring it back on track, I received my TA2020 kit from Audioconstruire yesterday and had it built and running before bedtime. It's built as supplied (for now), with the .22 uf caps (8 ohm speaks) and including the 'optional' diode string and output Zobel network. Here it is in its naked glory:

[lousymusician]

The speaker wire is Cat 5 cable. I'm running the output from the CD player (JVC 1050TN, practically an antique now) straight into the 2020. Speakers are Hemp Acoustics FR8's in vented boxes.

So how's it sound? Pretty good overall! Bass is tight and well controlled, highs are smooth, not grainy. I don't quite hear the level of detail that I get from my tube amp (Dyna ST70, with Joe Curcio's input board and regulated PS), hall ambience is not as readliy apparent. But, the 2020 has only a few hours on it, and is sure to improve with time (and some judicious parts upgrades). For the cost, I'm satisfied.

Here's a pic of the whole system. The amp pretty much disappears at this scale! You can see the reflection from the back of the Tripath chip on the book in front of the Flexi rack. The knob on the vloume pot is nearly as big as the whole amp.

[prorms]

impressive

[ssmith]

I got the autocostruire 2020 (assembled, with Litz wire inductors option) over the summer, and have been modding it since:

- removed the pot, added off-board Alps 'black' pot, not a major upgrade... was slightly disappointed actually. I've since ditched the pot altogether, and have been using my PC to control volume. Huge improvement over these pots.

then:
- Changed 2200uf caps for Elna Silmics.
- It came with .33 caps for 6 ohm output. Changed these for Vishay MKP1837 0.22uf, for 8 ohm.
- changed 2.2uf input caps for Intertechnik Audyn Cap Plus poly caps.
- lowered gain, using 4x20k resistors (not upgraded ones though).

I think sound has improved, but to be honest it's difficult to say because I cannot compare side by side and the gain has changed.... and the amp is now in a different setting, with components that have also been burning in.

Next upgrades;
- change input caps to obbligato caps (just curious)
- change resistors to AN tantalums and put gain back up slightly.


Overall, I like this board. Very solid, even for a noob solderer like me. With everything thru-hole and no SMDs, it's very easy to work on and mod.
Sound is first rate. I have the amp paired with planet10's frugel horns.

[ssmith]

also forgot to mention that I'm powering it the linear regulated PSU also sold by autocostruire.
Next round of experimentation will involve SLA battery and an SMPS.

[Fin]

Well - I got one of those Chinese Lepai T-amps and they are indeed based on TA2020. The PCB is all through hole stuff - so no fiddly SMDs. It comes in an aluminium case and is ready to go. The sound is also quite good - better than my stock SI T-amp....smoother treble and much better bass.

If you are interested in one - look here:
TA2020 T-amp

[psgary]

I'm interested in possibly putting together one of the 2020 amps but don't know what parts to buy from Autocostruire. The module with the RCA inputs would be my choice. Can someone tell me what transformer, power supply, case, speaker posts, etc. would be needed to make a fully operating amp? A friend will help me assemble it, so that is no problem.

Thanks for any advice.

[lousymusician]

Autoconstruire sells a suitable power supply and transformer, but the combination cost nearly as much as the amp! Other options would include a solid lead acid battery (and a suitable charger) or a 12 volt switching mode PS. I use one of the latter, bought on e-bay, with the voltage tweaked up to 13.5V. Looks kind of like this one.. Cheapest solution I could find. I put a couple of extra caps across the output for extra filtering. Works fine and the amp sounds pretty good, though I have not compared its sonics to a battery or a linear supply.

Case? Whatever you want. Wood, metal, plastic, cardboard, almost anything has been used. Mine's still caseless, I figure I'll run across an interesting box for it one of these days.

Speaker posts, anything from Radio Shack cheapies to fancy WBT posts that cost more than the amp would work. For now, my wires hook striaght to the screw terminals on the board. I think they may just stay that way, simple is good!.

[Nuuk]

psgary, this may give you some ideas but there is plenty of other information out there to help even a complete beginner to get one of the class-T amps completed!