Modding the Lepai T2020A+

[Dan Willett]

Re: Modding the Lepai T2020A+

I bought a Lepai - LP-2020A+ T-Amp from Parts Express on 9/3/2015 & plan on replacing the capacitors. I have the newest model ( model # 30418B) & the newest models don't have the model # printed on the board anymore, but instead printed on a sticker on the bottom of the chassis. I can't find a schematic anywhere for my model board on the internet & have a problem with finding out what the exact values of C30 & C31 are for my model board, these are the SMD chip capacitors on the input signal path circuit. I have found out that the 2013 models & up use a value of 2uF 63v or 2.2uF 63v or 3.3uf 63v for C30 & C31. The SMD Resistors on the input signal path circuit of the newest model boards all have the exact same values. What happens when you raise or lower capacitance of the input signal path circuit? Will I burn out my board if I try a 2uF 63v or 2.2uF 63v or 3.3uF 63v film capacitor without knowing what the value I have on my model board to replace it with correctly to exact specs? I need help with this & would greatly appreciate it if anyone can give me an expert opinion on this problem I have.

[Chris Roemer]

Re: Modding the Lepai T2020A+

(NOT an amp expert.)

I'd use 63v caps (or slightly higher, within +10% to +20% IF 63v caps aren't available) with 2.2uF or 3.3uF of storage. Given a choice between the two, MORE storage can't really be bad, RIGHT?

That said, I wouldn't go higher than 3.3uF unless you can verify that the supplying circuit can reliably handle the current demands that greater storage might require.

IF these are used for DC supply, then they need to be polarized electrolytics, right (which "film" caps are not - correct?)?

[Less Opinion]

Re: Modding the Lepai T2020A+ First attempt! And Questions.

I have purchased the amp and the specified caps. This will be my first attempt at amp mods, I have the soldering skills but I truly do not no squat about the electronics so I hope you know your stuff. I will post some results asap. If you can help please answer the following questions.

1. I am upgrading my computer power supply and intend to use the old one as the power supply for the Lepai That's 12v and approx 16 amp supply, do you fore see any issues with this concerning noise or over power/amperage? this is the 12v supply for the motherboard so I assume it would be a pretty clean source.

2. RE: the two 50v 1.7uf caps. You tried 2.2uf caps and had distortion issues, I can find 1.8uf and 1.6uf caps, would either of these be a viable option for the 1.7uf cap if so which would be the preference or just leave well enough alone.

3. RE: the Volume and tone Pots. I have read these are the cheapest form of junk that you can obtain, since they are the most used part of the amp wear and tear wise I would like to replace the just for the sake of doing it right (and I hate bad scratchy pots)
If you are aware of what I need as to the parts no.s manufacturer etc. Please advise.
P/S I'm not after the best of the best just a decent quality pot that will replace the stock junk without hassle.

4. RE: There is no polarity for the 6 output caps, is that correct?
Thanks for your help in advance. Less Opinion

[Mirskyman]

Hi everyone. I just joined these forums so I could post on this thread. I know very little about electronics but I just bought a Lepai 2020A+ from Parts Express. I also got a more powerful power supply after reading that it might make the Lepai's sound less distorted at higher volume.

This is the power supply I bought on Amazon after reading some reviews there from people who'd used the power supply successfully with their Lepai:

http://amzn.to/1pWkKKB

However, it didn't work with my Lepai. When I connected the Lepai to the power supply and turned on the Lepai, the blue LED light went on for a second, then went out. And the Lepai wouldn't work. So I'm now using the less powerful power supply that came with the Lepai.

I called Parts Express to see if they sold a more powerful power supply that might work with the Lepai and I was told they don't.

I don't want to waste more money on other power supplies that may not work with my Lepai.

However, I am confused and curious: why would the powerful supply that I bought from Amazon work with other people's Lepai 2020A+ but not mine? Do you think it's the power supply or my Lepai?

Thanks in advance for your replies.

[bullittstang]

The only difference I see in the PSU's is the stock one is 2.1mmx5.5mm where your replacement is 2.5mmx5.5mm, which might not be making good contact with the center pin since it's larger. I would check with the volt meter and make sure the new PSU is working properly. Otherwise, I don't see anything to keep them from working (the pin layout (center positive) is the same as original).

[Ynantr]

thanks for sharing, very useful information for me!

[Millstonemike]

Try running a 2020 on a 19 V laptop supply with a 3+ A rating. It will make a world of difference at higher volumes.

[Jake]

Try running a 2020 on a 19 V laptop supply with a 3+ A rating. It will make a world of difference at higher volumes.

Max supply voltage is supposed to be 14.6v