Hot Rodding the Lepai TA2020
Had a good go at my Lepai last night. On the PCB the values are marked for each component. If you start looking closely at the components though a lot of them are wrong. I replaced a whole heap of stuff. The biggest improvement is to be had from clearing up the tone control section. By removing all the resistors and putting in matched pairs of the correct values and then changing the Pots (i used Tawian Alpha 100k log pots), this balances everything out nicely. changed most of the electros and put some poly film caps in as input caps. Changed the op-amp with a socket and LM4562. The amps is transformed and the tone controls are actually nice and smooth once working correctly.
some photos:
http://minirig.org.au/2009/05/08/hot-rodding-the-lepai-ta2020/
col.
Had a good go at my Lepai last night. On the PCB the values are marked for each component. If you start looking closely at the components though a lot of them are wrong. I replaced a whole heap of stuff. The biggest improvement is to be had from clearing up the tone control section. By removing all the resistors and putting in matched pairs of the correct values and then changing the Pots (i used Tawian Alpha 100k log pots), this balances everything out nicely. changed most of the electros and put some poly film caps in as input caps. Changed the op-amp with a socket and LM4562. The amps is transformed and the tone controls are actually nice and smooth once working correctly.
some photos:
http://minirig.org.au/2009/05/08/hot-rodding-the-lepai-ta2020/
col.
Dear All,
Last month, I brought a Lepai TA2020 from Taobao. The sound is quite good in fact.
After I read your post, I am interest in mods. Somebody, change the Opamp and somebody is by pass the Opamp.
Which one produce better sound?
One more thing, I cannot find the link how to by pass the Opamp.
Thank in advance.
Last month, I brought a Lepai TA2020 from Taobao. The sound is quite good in fact.
After I read your post, I am interest in mods. Somebody, change the Opamp and somebody is by pass the Opamp.
Which one produce better sound?
One more thing, I cannot find the link how to by pass the Opamp.
Thank in advance.
change tone control ceremics to green caps
Iv'e just done one more mod to the tone section. I replaced all the ceramics with green caps.
http://pix.minirig.org.au/main.php?g2_itemId=976
I think the advantage that the Lepai has over the other TA2020 amps is that it has a tone control and op-amp pre. In it's un-modded state though this is poorly implemented. If you want to get the best sound for less cost then it is probably better to bypass the tone controls and op-amp. However, if you are willing to buy new pots, op-amp, resistors and green caps, then keep the tone control! It actually works really well and opens up the potential of having a nice op-amp pre.
I replaced the 10uF input caps with 2.2uF, the other 10uF caps I replaced with better quality 10uF. I still have the turn on pop. I don't think replacing them with 2.2uF will change that but I don't have any 2.2uF to try it. If it works for someone else I'll give it a go.
cheers,
col.
Iv'e just done one more mod to the tone section. I replaced all the ceramics with green caps.
http://pix.minirig.org.au/main.php?g2_itemId=976
I think the advantage that the Lepai has over the other TA2020 amps is that it has a tone control and op-amp pre. In it's un-modded state though this is poorly implemented. If you want to get the best sound for less cost then it is probably better to bypass the tone controls and op-amp. However, if you are willing to buy new pots, op-amp, resistors and green caps, then keep the tone control! It actually works really well and opens up the potential of having a nice op-amp pre.
I replaced the 10uF input caps with 2.2uF, the other 10uF caps I replaced with better quality 10uF. I still have the turn on pop. I don't think replacing them with 2.2uF will change that but I don't have any 2.2uF to try it. If it works for someone else I'll give it a go.
cheers,
col.
I find below message from commerial site.
No turn-on 'pop' noise
Yup, without the input cap, there's no charging of cap during power up. Thus, no more "power up pop". Just a soft 'tick' sound.
http://diyparadise.com/charlize2.html
No turn-on 'pop' noise
Yup, without the input cap, there's no charging of cap during power up. Thus, no more "power up pop". Just a soft 'tick' sound.
http://diyparadise.com/charlize2.html
would be good to be able to place a switch in the circuit so that you could turn the tone controls on or off. Anyone got any ideas?
There has been some work done on bypassing the tone controls on the 1st version of the Lepai, there are some posts and photos about that earlier in the thread. The circuit board has significantly changed since then though.
col.
There has been some work done on bypassing the tone controls on the 1st version of the Lepai, there are some posts and photos about that earlier in the thread. The circuit board has significantly changed since then though.
col.
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