Lepai T-Amp with TA2020

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Can someone tell me the minimum and maximum Voltage i can use it with?

I plan to use LiIon 18650 pack, so the Voltage can range
8V-12,6V (3S) or 11V-16,8 (4S)
So i think 3s would be safe to use, but has lower power and usage time than 4s.

Anyone tested exactly?

From the data sheet for the TA2020:

Min: 8.5V, Max: 14.6V (I havent tested these exactly though)

However, I wouldn't recommend exceeding 13.5V with the Lepai circuit.
 
Hi guys,

I have a Lepai which doesn't make any sound :/
The blue LED goes on, but nothing other happens.
He never have made any sound. I tried a few different power supplies, but this seems to be not the problem.

Any suggestions what I can do?

I just took two pics, to show what version I own.
 

Attachments

  • IMAG0079.jpg
    IMAG0079.jpg
    358.6 KB · Views: 803
  • IMAG0083.jpg
    IMAG0083.jpg
    844.8 KB · Views: 784
Hi, I am new to this forum, but have been following this thread for a while, and have just bought one of these to drive some new rear speakers in my MX5, as a result.

The Amp drove the speakers fine when powered from its mains supply and with my iPod plugged into its input, but in the car I seem to have an earthing problem.

I am using the rear speaker outputs from my head unit to drive the Lepai inputs, but these are not referenced to earth. All wires show high resistance to earth, and each other with the head unit switched off. Speaker -ve sits at 6V with headunit switched on.

I have connected the speaker +ve wires direct to the Lepai inputs, the speaker -ve wires I connected to the Lepai input earth via 33u capacitors. This worked well and sounded good. Possibly could do with a bit more sensitivity, pending trials.

However next day no sound came from the Amp at all! When I touched the metal case it burst into life for a few seconds then stopped again. It almost seemed like a bad connection somewhere, but I don't believe so. I think I have caused a DC offset somewhere by putting capacitors in my input earths. Perhaps the headunit outputs need some load. The headunit cannot need a DC load though, as the original car speakers had a series 47u capacitor (wonder why there was no bass?!).

I presume the earths are all internally connected in the Lepai, and it is not relying on the input earth for a DC path? Any suggestions would be very welcome.

Many thanks.
 
Ok, now I've paused to think about it I can see it's not that simple! The +ve and -ve outputs from the head unit are obviously trying to drive the two sides of the speaker differentially, so I cannot just try to make one an earth reference. I suppose I either need a proper differentail input to the Lepai, wonder if it can be modified, or I need to drive it through an audio transformer?

The thing I don't understand is how I seemed to have it all working at first!
 
Sorry I haven't kept up with this thread for a while. I did see the requests for the eagle schematic, so here they are.

Also some post modding pics:

attachment.php

This is from from when I started cleaning up the output section. I drilled holes for the 4 protection diodes to fit the heatsink grills.

attachment.php

Almost complete. The only thing I changed after this point were the pots. Those knobs were really hard to remove.

attachment.php

The bottom of the board. Checkout the bubbles on top left corner. That's Lepai quality for you!

I pretty much tested the amp after every change I made. By the end I had changed a few things from my original list. I settled with the opa2134 for the opamp. I like the sound better than the ne5532. I added ferrite beads for both power lines. I swaped C1 and C13, then eventually changed C13 to spare cap I have that's closer to what's on the datasheet. I replaced all the .1uf filter caps with the nicer ceramics I have (didn't really change the sound as far as I can tell).

Has anyone traced the newer Lepai to see the differences? Has anyone else done what DrLex suggested here?
 

Attachments

  • lp2020 v3.zip
    156.5 KB · Views: 157
  • IMG_6229.jpg
    IMG_6229.jpg
    288.4 KB · Views: 952
  • IMG_6241.jpg
    IMG_6241.jpg
    291.3 KB · Views: 916
  • IMG_6243.jpg
    IMG_6243.jpg
    313.9 KB · Views: 937
I've made the following mods to the new one:
1. Removed overvoltage circuit and relay circuit - tied mute to gound and added an LED to the fault pin.
2. Removed tone control/volume control and op-amp
4. Replace input caps with 2.2 uF (they were 1.75uF)

I'm very pleased with the result/QUOTE]

is there a step by step graphic picture for step 2 in particular for this newbie? I have no use of tone control and can replace pot to my liking.
 
I've made the following mods to the new one:
1. Removed overvoltage circuit and relay circuit - tied mute to gound and added an LED to the fault pin.
2. Removed tone control/volume control and op-amp
4. Replace input caps with 2.2 uF (they were 1.75uF)

I'm very pleased with the result/QUOTE]

is there a step by step graphic picture for step 2 in particular for this newbie? I have no use of tone control and can replace pot to my liking.
The location of the components will depend on the version of the amp you have. I just located the input capacitors to the Tripath chip (see data sheet for schematic - input capacitors are to pins 10 and 13 via resistors) and removed everything forward of these capacitors. There was some schematics for the lepai posted earlier in this thread - see here: http://www.diyaudio.com/forums/class-d/90500-lepai-t-amp-ta2020-60.html#post2258949
 
Hi there.

We are building a portable stereo with this amp and want it to be as efficient as possible, so do you know if I can remove the blue LED's or replace them with something else that doesn't drain any power?

Also, a friend made a boombox which distorts if there is too much bass below 150-200Hz and I read that you can alter the input components on this amp to cut off these frequencies. Anybody know how to do this?

Thanks!
 
Hello all;
I've been reading around the forum and catch bits and pieces of threads regarding the Lepai amps. I was recently given one and love the way it sounds but have a few problems with "POP" at ON/OFF.....and terrible Humming when connected to my PCs HP jack. When connected to my MP3 player it sounds good, but hums if I touch a metal part of the player. The model number is LP-838 2.1 stereo amp and I believe it has a TDA8566 IC in it. Is there any way to stop the hum and pop? I would love to have this amp connected to my PC.
An externally hosted image should be here but it was not working when we last tested it.
 
Just wanted to throw some thumbnail pics up.
 

Attachments

  • DSCN0627 (800x600).jpg
    DSCN0627 (800x600).jpg
    343.2 KB · Views: 174
  • DSCN0626 (800x600).jpg
    DSCN0626 (800x600).jpg
    397.5 KB · Views: 235
  • DSCN0625 (800x600).jpg
    DSCN0625 (800x600).jpg
    389.6 KB · Views: 255
  • DSCN0629 (800x600).jpg
    DSCN0629 (800x600).jpg
    317.5 KB · Views: 167
  • DSCN0630 (800x600).jpg
    DSCN0630 (800x600).jpg
    312.9 KB · Views: 161
  • DSCN0631 (800x600).jpg
    DSCN0631 (800x600).jpg
    319 KB · Views: 142
  • DSCN0632 (800x600).jpg
    DSCN0632 (800x600).jpg
    294.7 KB · Views: 131
  • DSCN0633 (800x600).jpg
    DSCN0633 (800x600).jpg
    371.4 KB · Views: 147
  • DSCN0634 (800x600).jpg
    DSCN0634 (800x600).jpg
    332.3 KB · Views: 190
  • DSCN0670 (800x600).jpg
    DSCN0670 (800x600).jpg
    303.7 KB · Views: 213
Where to buy?

Hi, I'm new here and truely amazed with all your knowledge.

I tried to buy the Lepai TA2020 from Parts Express, but since they found it wise to have a minimum order amount for international buyers, there is no way I'm getting it from there.

I did a search on Ebay, and here's my question: does anyone have an Ebay store or seller to recommend?

EBAY SEARCH LINK (hopefully)


Cheers
 
Hi All,

This morning I got a stranger issues on my Lepai TA2020A+ (2011 release)

Previously, It was working fine with 12V 2A adapter. After I plug in, the relay will switched on and started to play music.

This morning I changed it to 12V 5A adapter. There's no sound and the relay didn't seems able to switched on.

This is weird. Anybody have this issues before.

Thank you
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.