Audiokarma.org
Audiokarma Featured Sponsor

Go Back   AudioKarma.org Home Audio Stereo Discussion Forums > DIY


We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 08-23-2012, 06:32 PM
Gary Indiana's Avatar
Gary Indiana Gary Indiana is online now
AK Member
 
Join Date: Dec 2009
Location: SW Chicagoland, IL
Posts: 177
Lepai Tripath LP-2020A+ mini Amp dissected

Here is my new Lepai Tripath amp. What makes these amps attractive is their tiny size, high efficiency, very decent sound quality, and more than affordable price.

I bought my first Lepai amp a couple of years ago on ebay for about $25 shipped from China. The one and only thing I did not like about it then was loud pop in the speakers when powering ON and OFF.

New Lepai amps are upgraded with speaker relay that delays their connection until the circuitry is stable and no DC present on the outputs. There is still a little pop when turning the amp OFF, but that should be taken care of with an upgraded, larger filtering cap.

These amps are currently offered on Amazon for $20 shipped with a 12V 2A switched power supply. There is consensus among users that the power supply should deliver 4 to 5 Amps for the Lepai to kick some diaphragm. And so a better power supply should be put on the top of the list of upgrades. I got my good used 12V 5A power supply at local Goodwill for $1.99.

Second important IMO upgrade would be replacement of the filtering capacitor for a more beefy one. Ideally the 16V cap should be 4700uF or more if dimensions allow fitting it inside the case: the more uF - the better. The cap it came with originally is a measly 2200uF. I think this causes the slight pop in speakers since it discharges too quickly, before the relay turns OFF speakers. Bigger supply cap should also help with bass.

The blue LEDs don't tickle my fancy especially, so I replaced these with a pair of warm white LEDs, which resemble the glow of a light bulb. It looks better IMO.

As I'm posting this, my $20 Lepai pumps delightful jazz from a Chesky CD in my NAD C541 to a pair of Mission 773 towers. This "audiophile" setup cost me less than $100 thanks to Craigslist and Goodwill.

And so, here it is.

Comes nicely packed in a foamy cutout with a small 12V 2A switched power supply.



That's what it looks like inside. Tidy, tidy, tidy.



The black square relay is an upgrade to older design; meant to protect speakers from loud pops.



The Tripath TA2020 chip is the heart and soul of the little amp. Thanks to its great efficiency of 80% to 90% it does not require large heatsink.



This is the underbelly of the beast. Again: a tidy PCB design.



The PCB - printed circuit board - is made of decently thick double-sided copper clad fiberglass. It doesn't get much better than that.



Here is a bird's-eye view.



This one capacitor shall be upgraded soon.



Blue LEDs inside…



…and their original blue glow around the knob outside.



Warm white LEDs replaced the blue pair.



This "upgraded" look is better, IMO.

Last edited by Gary Indiana; 08-23-2012 at 06:43 PM. Reason: Pictures resized to 800x600
Reply With Quote
  #2  
Old 08-23-2012, 08:18 PM
tdx1's Avatar
tdx1 tdx1 is offline
AK Member
 
Join Date: Jan 2011
Location: Wichita, KS
Posts: 31
These little amps make great test beds for mods, I'd probably recap the whole thing since I'm not a fan of a lot of the questionable caps found in these things. I'm not certain it would dramatically improve the sound, but from a reliability standpoint caps are the biggest failure point of nearly any electronics these days. Good call on the LED swap, blue is way too overdone on electronics now and is believed to cause retina degradation.
Reply With Quote
  #3  
Old 08-23-2012, 08:42 PM
Ohighway's Avatar
Ohighway Ohighway is offline
AK Member
 
Join Date: Sep 2008
Location: In the woods.....in Howard County, Maryland
Posts: 8,904
Thanks for the pix and the info !
__________________
>
>
>
Speakers: Rotating between Allison Two, KEF 104/2, IMF-TLS80, and Fried C/2 - O/2. Currently playing: Fried C/2 - O/2
Amplification: Fisher 50a monoblocks , B&K Pro 10 Sonata preamp
Sources: Kenwood CD-206 cd changer, Denon DP-35f turntable with Grace F-9
Reply With Quote
  #4  
Old 08-23-2012, 08:43 PM
mhardy6647's Avatar
mhardy6647 mhardy6647 is offline
AK Member
 
Join Date: Sep 2002
Location: New England
Posts: 41,774
A remarkable sound value per dollar no matter how you look at it.
I - ultimately, and tentatively - tried mine on the Duplexes and I was very surprised by how well it acquitted itself.
__________________
Preamps need drive, not gain. - G. Kaufman
Reply With Quote
  #5  
Old 08-24-2012, 07:51 AM
Gary Indiana's Avatar
Gary Indiana Gary Indiana is online now
AK Member
 
Join Date: Dec 2009
Location: SW Chicagoland, IL
Posts: 177
Quote:
Originally Posted by tdx1 View Post
I'd probably recap the whole thing
IMHO the cap in near power supply jack could use more capacity, but I'd leave the rest as is. Radical cap replacement could cost more than the amp itself but without a noticeable sound improvement.
Quote:
Originally Posted by tdx1 View Post
Good call on the LED swap, blue is way too overdone on electronics
The first mass produced LEDs were red in 1968 soon followed by yellow and green, while blue LEDs were first factory made much later - in 1989. Perhaps now some try to over-compensate for the two decades without blue.
Quote:
Originally Posted by Ohighway View Post
Thanks for the pix and the info !
You're welcome!
Quote:
Originally Posted by mhardy6647 View Post
A remarkable sound value per dollar no matter how you look at it.
It's a poor man's McIntosh
Reply With Quote
Audiokarma
  #6  
Old 08-24-2012, 08:11 AM
Redboy's Avatar
Redboy Redboy is offline
a few good watts
 
Join Date: Aug 2006
Location: Twin Cities, MN
Posts: 10,113
Every now and then, I see something like this and I wonder why I bother to build tube amps, given the cost and overall quality of stuff like this!
__________________
Now Playing: Nate's interim
Reply With Quote
  #7  
Old 08-24-2012, 08:12 AM
68custom's Avatar
68custom 68custom is offline
AK Member
 
Join Date: Jul 2009
Location: sarasota fl
Posts: 4,742
the newer Lepai's look like they are built a lot better than the older ones!
http://www.ebay.com/itm/Indeed-Tripa...ht_9835wt_1202
I have one of these coming soon. hope I like it more than my DTA-1! BTW I really like the DTA-1.
Reply With Quote
  #8  
Old 08-24-2012, 09:50 AM
mhardy6647's Avatar
mhardy6647 mhardy6647 is offline
AK Member
 
Join Date: Sep 2002
Location: New England
Posts: 41,774
Quote:
Originally Posted by Redboy View Post
Every now and then, I see something like this and I wonder why I bother to build tube amps, given the cost and overall quality of stuff like this!
Your (erstwhile) handcrafted Simple 2A3 does sound better than the Lepai, buddy! The latter is a little zingy in the HF compared to the former.
__________________
Preamps need drive, not gain. - G. Kaufman
Reply With Quote
  #9  
Old 08-24-2012, 09:58 AM
mfhale's Avatar
mfhale mfhale is online now
ciao
 
Join Date: Nov 2007
Location: Houston
Posts: 3,554
Quote:
Originally Posted by Redboy View Post
Every now and then, I see something like this and I wonder why I bother to build tube amps, given the cost and overall quality of stuff like this!
Apples and cumquats, Nate.
Reply With Quote
  #10  
Old 08-24-2012, 02:47 PM
Rick Vestal's Avatar
Rick Vestal Rick Vestal is offline
Have a nice day and duck!
 
Join Date: Jan 2009
Location: Colorado Springs, CO
Posts: 1,733
This is yet another example... I have trouble looking at everything that goes into that, and believing it's only $20. Same with those $0.99 strings of Christmas lights at WalMart...
__________________

"It's all about placement. The HPM sounds best placed face down. If the room won't allow that placing them in a room you're not in works well." -Tom Brennan
Reply With Quote
Audiokarma
  #11  
Old 08-24-2012, 04:34 PM
mhardy6647's Avatar
mhardy6647 mhardy6647 is offline
AK Member
 
Join Date: Sep 2002
Location: New England
Posts: 41,774
Hourly labor costs are probably a little different where it was made compared to what you are used to.
__________________
Preamps need drive, not gain. - G. Kaufman
Reply With Quote
  #12  
Old 08-24-2012, 07:14 PM
Ballylongford's Avatar
Ballylongford Ballylongford is offline
AK Subscriber
 
Join Date: Apr 2005
Location: SFBay Area
Posts: 2,464
Got one of the much vaunted Arjen Helder DIY amps from his eBay store recently, and one of these same Lepai units.

The Arjen Helder unit shuts down on its own and he has refused to stand behind it.

The Lepai sounds great (definitely sounds better w/ the more robust aftermarket power supply I am running it w/), and is very reliable.

From what I have read of the quality issues w/ the earlier Lepai units there seems to have been improvement.

Hard to beat for the price.
__________________
All The Best
Bally
Quote:

“They say best men are molded out of faults,
And, for the most, become much more the better
For being a little bad”
William Shakespeare
Reply With Quote
  #13  
Old 08-25-2012, 01:58 AM
OJNeg's Avatar
OJNeg OJNeg is offline
AK Member
 
Join Date: Jun 2012
Posts: 18
Nice job!

Have you tried testing the power output yet? I know that Lepai rates the amp for 12W into a 8 ohm load, but I've seen some tests where it only puts out something like 1.5W (into an 8 ohm load) before reaching 1% distortion and it clipped not too far after that. I know personally that I was able to get my TA2020+ to clip easily into a pair of inefficient bookshelves. I'd like to see if it performs any better running off a beefier power supply.
Reply With Quote
  #14  
Old 08-25-2012, 08:02 AM
Gary Indiana's Avatar
Gary Indiana Gary Indiana is online now
AK Member
 
Join Date: Dec 2009
Location: SW Chicagoland, IL
Posts: 177
Quote:
Originally Posted by OJNeg View Post
Have you tried testing the power output yet?
Yes, I am running it on a bigger power supply and there is an improvement. In the picture below there is the wallwart that came with the amp: 12V, 2000mA (=2A), next to one I use now, picked used at GW store for $2, rated 12V, 4.58A. The bigger one, wherever it came from originally, is heavier and, likely, much better quality with the barcode and serial number on it. Cheap adapters don't have serial numbers.

With the bigger supply I'd need to crank up the volume way higher before getting distortions and clipping. From what I'm hearing I'd say the max. undistorted volume could be compared to a "normal" amp rated 2x20 Watts, or be very close to it.

EDIT: Someone did proper bench tests of this amp and posted results on youtube.


Last edited by Gary Indiana; 08-25-2012 at 07:46 PM. Reason: Updated info
Reply With Quote
  #15  
Old 12-14-2012, 01:54 AM
Hat Alto's Avatar
Hat Alto Hat Alto is offline
AK Member
 
Join Date: Feb 2011
Location: Temple City, CA
Posts: 211
Thanks for posting this very good Lepai 2020a+ thread. LED mod = instant improvement in class. Ordered one last night. I'll go GW for a power supply as you suggest and probably swap those two caps - and maybe shoot the case with some blk spray to cover up some of that ugh labeling. I mean $20 - come on!
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

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

Forum Jump


All times are GMT -5. The time now is 11:30 PM.



Friends of Audiokarma
We appreciate your help in keeping this site going.
Black Swamp Audio
Organ Donor Parts
Sonneteer
 
Sound Stage Direct
Parts Connexion
AudioClassics
Atlantic Systems
AV Solutions
Take Five Audio
Tone Arm Audio
Audio Salon
Musical Paradise
Audience AV
Classic Sound Repair
Simply Speakers
McIntosh Cabinets
BD Enterprise
Cabledyne
Howard Products
BOI Audio Works
FM DX Antenna
Amplifiedparts
Siliconray
RSL Speakers
Vinyl Magic Record Cleaner
Salk Sound
Grant Fidelity
Urban Antigue Radio
Yesterday's Audio
Many Moons Audio
DeWick Repairs
The Tube Store
Vintage Electronics Repair
Audio Doctor
Politicalchat.org
MCM Electronics
Antique Radio Classifieds
Herbies Audio Lab
Videokarma.org
   
Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
©Copyright 2002-2014 AudioKarma.org, All rights reserved.