Lepai T-Amp with TA2020 - Page 21 - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 25th April 2009, 12:03 AM   #201
diyAudio Member
 
e_fortier's Avatar
 
Join Date: May 2001
Location: Montreal
Hi,

At $25 USD + shipping I coudn't resist so I bought the newer version (TA2020-020 v3.1) last night from Export-Genie on e-bay.

Did anyone came out with a list of mods yet ?

Cheers,
Eric
  Reply With Quote
Old 25th April 2009, 12:11 AM   #202
diyAudio Member
 
e_fortier's Avatar
 
Join Date: May 2001
Location: Montreal
Me again

By looking at the pics it looks like (I do not have mine yet) they have put a 14V Zener at the DC inlet, this is a neet idea.

Anyhow, maybe someone can confirm this.

Eric
  Reply With Quote
Old 26th April 2009, 01:07 AM   #203
diyAudio Member
 
Join Date: Feb 2005
Location: Kingston, NY
I just ordered one of these today. I guess T-Amps don't generate much buzz these days because this thread is the only discussion of the Lepai amps that I've come across, in English at least.
  Reply With Quote
Old 27th April 2009, 07:13 AM   #204
col is offline col  Australia
diyAudio Member
 
col's Avatar
 
Join Date: Feb 2008
Location: Melbourne, Victoria, Australia
just ordered one too.

col.
__________________
http://www.minirig.org.au
  Reply With Quote
Old 27th April 2009, 08:09 PM   #205
Gmorris is offline Gmorris  United States
diyAudio Member
 
Join Date: Mar 2005
Location: MusicCity
The amp arrived today. I hope to plug it in later tonight.

Now I just need some solar panels to trickle charge my SLA battery.
  Reply With Quote
Old 28th April 2009, 02:23 PM   #206
Gmorris is offline Gmorris  United States
diyAudio Member
 
Join Date: Mar 2005
Location: MusicCity
The little amp seems to work as it should. I still haven't had time for much listening. I did remove the op-amp and replace it with a socketed LM4562. I could only hear low-level hiss from my tweeters if I had my ear within an inch or two from them. There was also audible low-level hum (not noticable from more than a foot away) if I touched the case. DC on the output was around 55 mV. There was some turn-off thump but not too bad. The power button does not affect the blue LED....it stays on as long as the power supply is connected.

I also noticed that the two small electrolytics closest to the volume pot appear to be the input caps. Positive goes from input to the pot to the caps. These caps were labeled 2.2uF on the board but 10uF on the caps. Also, a 47uF cap between the opamp and the tripath chip (next to the heatsink) was labeled 100uF on the board.

Overall, it seems to be a great deal. And I like the metal case better than the plastic SI / Dayton amp...
  Reply With Quote
Old 28th April 2009, 03:02 PM   #207
diyAudio Member
 
Join Date: Feb 2005
Location: Kingston, NY
Well, if I remember correctly the SI T-Amp had a "floating" ground, which is part of the reason why they used a plastic enclosure, but that used a TA2024 instead of a TA2020, so I don't know if it's directly comparable. But it would seem to me that it probably shouldn't be grounded to the case, even though it is.

Also, can the DC at the output be remedied with a small cap across the terminals like on the SI T-Amp?
  Reply With Quote
Old 28th April 2009, 04:03 PM   #208
Gmorris is offline Gmorris  United States
diyAudio Member
 
Join Date: Mar 2005
Location: MusicCity
55mV dc offset would be pushing it for a headphone amp but I don't think it's too bad for speakers. Dunno about the cap across the terminals...

The board seems to be attached to the case through the potentiometers only. The hum might be reduced by isolating the pots. I remember the volume pot being grounded to the board by a wire.
  Reply With Quote
Old 28th April 2009, 04:52 PM   #209
diyAudio Member
 
e_fortier's Avatar
 
Join Date: May 2001
Location: Montreal
Hi,

If the input caps are 10uF this could be the case of the turn-off thump, depending on the input resistor these could probably be reduced to 2.2uF or 3uF.

The pot could be grounded to eliminate the hum while touuching the case or change the knob for a silver plastic one.

The led is an easy fix, I rather have the led ON when the unit is actually on.

Try to add a small cap across the speaker terminal (tantalum of very small value) this should reduce the hiss from your tweeter.

Looking forward to receive mine in about 2 wks.

Eric
  Reply With Quote
Old 28th April 2009, 06:53 PM   #210
Gmorris is offline Gmorris  United States
diyAudio Member
 
Join Date: Mar 2005
Location: MusicCity
Thanks for the tip Eric. I'll be interested seeing how you end up modding yours. I wasn't sure if the increased capacitance on the input was advantageous or not.

Some people earlier in the thread seemed to like the sound best after by-passing the op-amp and tone controls.

You can see the wire going from the volume pot case to the board in the attached photo.
Attached Images
File Type: jpg newtripat-1239032842-1667.jpg (38.8 KB, 1384 views)
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New ta2020 pcb'S ArjenShenzhen Vendor's Bazaar 98 14th November 2012 11:39 AM
Ta2020 Bengali Class D 0 29th September 2007 05:28 AM
Eb-ta2020 opentop Class D 16 30th May 2005 07:42 AM


New To Site? Need Help?

All times are GMT. The time now is 09:04 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2