Modding the Lepai T2020A+

[vlad335]

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

Wow, same thing here. Should have read your post and left well enough alone. Now the Lepai is OOS at PE.

[sorue]

Re: Modding the Lepai T2020A+

I received my Lepais yesterday and had some time to listen to it. They sound shockingly good. I cannot imagine a better amp at this price! The cheapo volume potentiometer has the same channel imbalance at low volumes, same as all the other cheap carbon pots. I will probably swap them out for a stepped one.

What are the critical must-do mods for you guys? I believe i have the SMD version.

vlad335: Get as big as solder sucker as you can manage. The small ones don't have enough power to suck up all the solder in one go - a real PITA.

Oh, and btw, the default SMPS that comes with the amp is 100-240v.

[jmw0403]

Re: Modding the Lepai T2020A+

That is so funny. In a way I’m glad I’m not the only one to botch their amp. I guess misery loves company. Desoldering especially the little caps n the middle is a pain. I recently bought and Indeed Cute (http://www.ebay.com/itm/Indeed-Tripa...-/290622735502) and while its 2x the cost I've been pretty pleased with the performance (and looks). There is a new thread comparing it to the Lepai: http://techtalk.parts-express.com/sh...light=shootout

[jmw0403]

Re: Modding the Lepai T2020A+

Wow, same thing here. Should have read your post and left well enough alone. Now the Lepai is OOS at PE.

That is so funny. In a way I’m glad I’m not the only one to botch their amp. I guess misery loves company. Desoldering, especially the little caps in the middle is a pain. I recently bought the Indeed Tripath TA2020 Cute (http://www.ebay.com/itm/Indeed-Tripa...-/290622735502) and while its 2x the cost I've been pretty pleased with the performance (and looks). There is a new thread comparing it to the Lepai: http://techtalk.parts-express.com/sh...light=shootout

Update: I just noticed you have already seen the thread.

[vlad335]

Re: Modding the Lepai T2020A+

vlad335: Get as big as solder sucker as you can manage. The small ones don't have enough power to suck up all the solder in one go - a real PITA.

I borrowed this one from my brother. http://www.parts-express.com/pe/show...number=372-202

Should work great but it will not even melt the solder in the joint. I bought some replacement tips and hoping thats the problem.

[vlad335]

Re: Modding the Lepai T2020A+

That is so funny. In a way I’m glad I’m not the only one to botch their amp. I guess misery loves company. Desoldering, especially the little caps in the middle is a pain. I recently bought the Indeed Tripath TA2020 Cute (http://www.ebay.com/itm/Indeed-Tripa...-/290622735502) and while its 2x the cost I've been pretty pleased with the performance (and looks). There is a new thread comparing it to the Lepai: http://techtalk.parts-express.com/sh...light=shootout

Update: I just noticed you have already seen the thread.

I think I replaced a wrong value so I placed another order with Mouser. hopefully can swap the right one in and be good to go. The amp sounded so good with changing the big cap and the output caps. Should have left it alone right there... BAH! Who am I kidding?! I would be thinking how much more it could improve.

[Dirk]

Re: Modding the Lepai T2020A+

Well, my PSU went POP when I plugged it in today, and then the funny smells started. Looks like I'm in the hunt. Do you need to stay 12V?

[vlad335]

Re: Modding the Lepai T2020A+

Are you talking about the Vonage PS that came with the amp? If so, do yourself a favor and buy the Ebay PS that is linked at the beginning of this thread.

[XtremeRevolution]

Re: Modding the Lepai T2020A+

Well, my PSU went POP when I plugged it in today, and then the funny smells started. Looks like I'm in the hunt. Do you need to stay 12V?

The unit will go into overvoltage protection if you use anything significantly over 12V. 13V is too high.

Are you talking about the Vonage PS that came with the amp? If so, do yourself a favor and buy the Ebay PS that is linked at the beginning of this thread.

What he said. That power adapter is about the best option I've found so far.

[JimHRB]

Re: Modding the Lepai T2020A+

Anyone know for sure what size the power connector on the Lepai amp is? I note the one on the Ebay 5A one listed in this thread is 2.5x5.5 while the replacement one listed on the PE site is 2.1x5.5. Reason I'm asking is that the Vonage one that came with the amp I bought during PE's Black Friday sale fits a little loose and the amp will cut in and out if I wiggle the power cord. Doesn't do this with another 12V supply I had around, but I need that one for my NiCad battery charger. Plan to upgrade the PS but would prefer not to have the same problem with the replacement.

[XtremeRevolution]

Re: Modding the Lepai T2020A+

Anyone know for sure what size the power connector on the Lepai amp is? I note the one on the Ebay 5A one listed in this thread is 2.5x5.5 while the replacement one listed on the PE site is 2.1x5.5. Reason I'm asking is that the Vonage one that came with the amp I bought during PE's Black Friday sale fits a little loose and the amp will cut in and out if I wiggle the power cord. Doesn't do this with another 12V supply I had around, but I need that one for my NiCad battery charger. Plan to upgrade the PS but would prefer not to have the same problem with the replacement.

I have two of those upgraded power supplies I listed in the initial post and they have a secure fit.

[blossom]

Re: Modding the Lepai T2020A+

Hi guys. I plan to get one of these models to use as a portable boom box sort of a thingy with magnetic feet(some hard drive rare earth magnets) and sit it on the tractor while i pick fruit.

Will do the appropriate mods of course, caps, potentiometer, and as somebody mentioned an option power amp bipass/rca's

I intend to use some lifepo4 batteries. What concerns me is that at full charge they will be give upwards of 13 volts. I see people saying that this is a problem?

Can I get around this?

Thanks in advance.

[Chris Roemer]

Re: Modding the Lepai T2020A+

Hi guys. I plan to get one of these models to use as a portable boom box sort of a thingy with magnetic feet(some hard drive rare earth magnets) and sit it on the tractor while i pick fruit.

Will do the appropriate mods of course, caps, potentiometer, and as somebody mentioned an option power amp bipass/rca's

I intend to use some lifepo4 batteries. What concerns me is that at full charge they will be give upwards of 13 volts. I see people saying that this is a problem?

Can I get around this?

Thanks in advance.

I've bought several of those. The weakest link is the PS, which you'll avoid by running off a battery. From what I've HEARD, the 2020 has overvoltage shutdown "around" 13.5 volts.

[blossom]

Re: Modding the Lepai T2020A+

Thanks for the reply Chris. My mate and I have ordered 3 of them so we will see how things go. Quite excited really, I have played around here and there with things that needed repairing over the years(with the help of very capable mates) but have not really got this deep(as far as the mods I'm keen on go) before. Will post back and let you guys know how it all goes, will be a few weeks though knowing free shipping from china to NZ, although we in OZ I expect similar.......

Cheers, Blossom.

[blossom]

Re: Modding the Lepai T2020A+

In Orange are two 50v 1.7uf capacitors. I had initially bought two 2.2uf capacitors to replace these, but after replacing them, I had a great deal of distortion and discovered that the value needs to be kept the same, so I put the stock ones back in. Unless you can find 1.7uf capacitors to replace them, leave them alone.

In my attached pic you can see the caps that mine came with in that position. This is what the datasheet says about them, "AC input coupling capacitor which, in conjunction with RI, forms a highpass filter at". And the datasheet value is 2.2 as the ones in mone are.

And for somebody that might be in the know? The ones in mine are "Nichicon muse" or at least market as that. So would this mean that they are actually good quality and that theres no point in replacing them?