Modding the Lepai T2020A+

[XtremeRevolution]

Re: Modding the Lepai T2020A+

Excellent thread guys. Thanks for all the information and tutorial. Truly a lot of great stuff. I ordered a TA2020+ and when I got it, the sound cut in and out any time you moved the input chords even a little. PE sent me a new one no questions asked which is quite amazing. The guy I did talk to stated that they don't have too many problems, though they do have a couple of calls for defects. Not surprising with how many units they must move of these guys at these low prices.

Anyway, I ordered all the right stuff from Mouser and opened up the original unit yesterday to see if I could figure out why the sound was cutting out and to upgrade all the caps and other items... Turns out the ground was loose at the back of the unit where the RCA jacks are on the board. Looks like a really weak point, so if you have any issues with sound cutting out, that's a good place to look.

Before I upgraded the parts, the TA2020 sounded great. After I upgraded the parts, it sounded AWESOME. Interestingly, I tested the unit after replacing the output caps and didn't notice too much difference in the sound. After replacing the input caps, the unit really was awesome. No hissing from the speakers regardless of volume. Really good bass especially all through the spectrum and at all volumes. It really did make a noticable difference.

One point though - make sure you turn on the unit after using and after unplugging it to get rid of any charge. I didn't do that and saw a couple of sparks while I was replacing the input caps. Doh. Lesson learned.

Glad to hear you were able to improve your unit as well. I'm starting to realize that these upgrades are a must for these amplifiers.

I believe that peoples' results will vary based on the inconsistency of the parts used. As I showed earlier, even the units I purchased came with significantly capacitors. My results upgrading the output capacitors may have been more significant than others' due to that. Who knows. What we do know is that there are significant and audible gains to be had from replacing all of them to ensure consistency. In the end, even at under $50 for the unit including upgrades, this is really hard to beat. My primary amp has seen well over 70 hours of play time so far with these upgrades. I believe that with the exception of the parts being upgraded, these are fairly reliable and an excellent value.

One thing has been on my mind however. I've noticed many Tripath units are running higher voltage. This one is limited to 12V. Previous versions of these amps that were shipped with 13.2V power supplies were unstable, with the solution being to use a 12V power supply. Would it be possible (and if so, how difficult would it be) to modify this unit to accept a higher voltage and therefore a higher power output? Even at maximum power, these things have no thermal issues.

[Skywave-Rider]

Re: Modding the Lepai T2020A+

Is this the correct version of the TL082 op amp?
http://www.mouser.com/ProductDetail/...b6sSNiPRrgo%3d

Just got my amps delivered from back order.

[Skywave-Rider]

Re: Modding the Lepai T2020A+

Hey, I just did this to mine, and it is working great.

That mod bypasses the tone and volume controls, and the op amp too, apparently. So now it's a power amp. : )

I'll run it like this for a while and see if I want to upgrade some caps.

I had trouble soldering the NP cap side of the jumpers (C20/21.) I think next time I might use solid wire to help push through the double sided board.

[XtremeRevolution]

Re: Modding the Lepai T2020A+

Nice to see another modded amplifier. Well done!

[Skywave-Rider]

Re: Modding the Lepai T2020A+

Thanks, you were the inspiration!

I measured the NP electrolytics (C20/21) and though they are indicated as 1.75uF, my meter said they were 2.0. So I couldn't resist putting in some 2.0 uF film caps (Audiocap Thetas) that I had no use for. No, the board can't go back in the case now. Hahaa.

[sorue]

Re: Modding the Lepai T2020A+

Anyone knows if the power brick that comes with the lepai is dual voltage (120v/240v) capable or only 120v? Thanks

[XtremeRevolution]

Re: Modding the Lepai T2020A+

Anyone knows if the power brick that comes with the lepai is dual voltage (120v/240v) capable or only 120v? Thanks

I believe its 120V only.

[neildavis]

Re: Modding the Lepai T2020A+

I believe its 120V only.

Most of those little switching power supplies are rated for up to 240V. I don't know about that particular one, but it looks similar to the one at MPJA which is rated for 100-240 VAC 47-63Hz:

http://www.mpja.com/12VDC-2A-Regulated-Plug-Supply-Jasper/productinfo/18776+PS/

May need the right wall socket adapter, obviously

[Escher]

Re: Modding the Lepai T2020A+

Hi folks - I just registered to ask questions related to this amp....

Specifically - The input coupling caps... can I go with film instead of electrolytic?

..(previous post edited for accuracy - I had misinterpreted some info)...

Thanks!!

[vmed_cha_gr]

Re: Modding the Lepai T2020A+

I never use it and I don't like unnecessary parts in the audio pathway. Wherever there are tone controls there should be a "Direct" button. I like it when different records sound different.

You can drill a small hole on the back panel, make a small cable with 2 female rca plugs, connect 2x 2.2uf mkp caps at the positive, ground the negatives & solder the other end of the caps directly on the right leg of the 2 bipolar 1.7uf caps. By this way you can use the amp as small power amp & also keep the internal pre-amp for any other audio sources that don't have a variable output. Works great for me. No hum or pink noise.

[jmw0403]

Re: Modding the Lepai T2020A+

I’m wondering if someone can help me trace a problem. First off this is my only electronics project to date (short of soldering up a crossover or two) I just finished replacing the set of caps as prescribed by Xtreme. After replacing the 6 output caps I gave the amp a try and everything was great. This got me jazzed to replace the rest on the list. I carefully removed the other caps and replace them making sure to observe the markings and polarity. After soldering it up, I gave it a try and no sound at all. It seems to power okay and there is no smoke or anything catastrophic. (The board looks okay, no delamination or anything I can see.)

I am thinking maybe I have a cold solder of somehow have a break in continuity. I reexamined the solder joints to make sure that there were no shorts. I have a multimeter but have never used it for anything other than checking outlets and batteries. Based on the symptom described does anyone have any tips on how I might test to zero in on the problem?

Any help is much appreciated. John

[XtremeRevolution]

Re: Modding the Lepai T2020A+

I’m wondering if someone can help me trace a problem. First off this is my only electronics project to date (short of soldering up a crossover or two) I just finished replacing the set of caps as prescribed by Xtreme. After replacing the 6 output caps I gave the amp a try and everything was great. This got me jazzed to replace the rest on the list. I carefully removed the other caps and replace them making sure to observe the markings and polarity. After soldering it up, I gave it a try and no sound at all. It seems to power okay and there is no smoke or anything catastrophic. (The board looks okay, no delamination or anything I can see.)

I am thinking maybe I have a cold solder of somehow have a break in continuity. I reexamined the solder joints to make sure that there were no shorts. I have a multimeter but have never used it for anything other than checking outlets and batteries. Based on the symptom described does anyone have any tips on how I might test to zero in on the problem?

Any help is much appreciated. John

I'm not sure how you can test, but I'd start by removing and re-soldering each capacitor you replaced one at a time. Its strange that you'd get no output.

Also check to make sure there isn't a break in the RCA jacks connection to the board. I had that happen to me on one of the amps and had a fun time fixing it.

[jmw0403]

Re: Modding the Lepai T2020A+

Are you sayign replace each cap one at at a time and with luck it will be the first one I replace? Im kicking myself for now doing that in the first place. I got cocky after replaceing the output caps. Live and learn I guess.

[XtremeRevolution]

Re: Modding the Lepai T2020A+

Are you sayign replace each cap one at at a time and with luck it will be the first one I replace? Im kicking myself for now doing that in the first place. I got cocky after replaceing the output caps. Live and learn I guess.

Pretty much, yeah. You can put the old ones back in, one at a time, until you discover which one is problematic.

Its nice that you had the ability to use a $20 amp to experiment with.

[vlad335]

Re: Modding the Lepai T2020A+

In Green are a bunch of electrolytic capacitors. These are rated as follows. Disregard the two in orange for now:
2 x 16v 100uf
1 x 16v 470uf
2 x 16v 220uf
2 x 50v 1uf

Can you do me a huge favor?

Can you label what these values are for the caps in green? Sorry but I think I messed something up.

Tonight I changed the big cap and the output capacitors with some difficulty but hooked up the amp afterward and it sounded great. Amazing improvement actually. Anyway, I went back and started changing the others and now the amp doesnt work. :( I just want to verify that I placed the values where they are supposed to go before placing another Mouser order.

Would be greatly appreciated.

Also, what do you use for a solder sucker? This is where I had the most trouble actually.