Is your amp the type with all through-hole components on the board, or is it the newer version with some surface-mount components?
I was thinking of purchasing one of these, but it appears they've changed to surface-mount components, which would make it a lot harder to replace or eliminate parts.
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Yep. And if the gain is too low, you can adjust the gain with the 2 resistors after the decoupling-caps(c20/21) next to the TA2020 chip, according to the datasheet.
They were 15k and 20k for me, which sets the gain to: 12*20k/15k ->16x Vrms.
At 9Vrms you have 20W into 4 ohms / 10W into 8 ohms, which is about maximum for the ta2020. You reach that with 560mV.
I don't know how sensitive you can make the TA2020 though.
They were 15k and 20k for me, which sets the gain to: 12*20k/15k ->16x Vrms.
At 9Vrms you have 20W into 4 ohms / 10W into 8 ohms, which is about maximum for the ta2020. You reach that with 560mV.
I don't know how sensitive you can make the TA2020 though.
well i am gonna need to read all this pages to understand what i need to do to bypass the tone circuit.. or at least, so i can take it to a eletronic shop and tell them what i need.
You should look into this one:
http://www.diyaudio.com/forums/class-d/223389-lp-2020a-mod-thread.html
Only covers the newer 2020A+ model, so you can save yourself the 100+page journey
http://www.diyaudio.com/forums/class-d/223389-lp-2020a-mod-thread.html
Only covers the newer 2020A+ model, so you can save yourself the 100+page journey
They are both dual, that's the 2 in 2134. The single is 134 and the quad is 4134.
I agree with Bare, removing the opamps completely is the best thing I did for the sound of my LP-2020A+.
Also, since the wiki and this thread are more about the older versions:
http://www.diyaudio.com/forums/class-d/223389-lp-2020a-mod-thread.html
http://www.diyaudio.com/forums/class-d/223389-lp-2020a-mod-thread.html
Can someone please tell me if its possible to perform a "Power on pop suppressor" on the V2 board - LP-2020B.
The amount of movement on my speakers bass drivers and the loud pop on switch on in very concerning! I'm not to bothered about other mod's for now...I want to prevent damage to my vintage Wharfdale speakers by getting rid of the switch on thump.
Much obliged.
The amount of movement on my speakers bass drivers and the loud pop on switch on in very concerning! I'm not to bothered about other mod's for now...I want to prevent damage to my vintage Wharfdale speakers by getting rid of the switch on thump.
Much obliged.
Hey I just did the tone and volume control bypass. Now the amp gain is too low when using my phone as an input certain videos and songs.
Does anyone have and suggestions what I should change these resistors to. Also a photo of which resistors I need to change would be awesome.
Hey fellas,
I'll have a proper look through in the morning, but was there ever a fix for the imbalance issue? Mine is definitely outputting a lot more in the left channel than the right and it's really starting to annoy me. This is only a replacement while my PM66SE-KI is sick (almost conceding and taking it to a professional now) but i do quite like it and would like to fix it if it's quite a simple thing!
I'll have a proper look through in the morning, but was there ever a fix for the imbalance issue? Mine is definitely outputting a lot more in the left channel than the right and it's really starting to annoy me. This is only a replacement while my PM66SE-KI is sick (almost conceding and taking it to a professional now) but i do quite like it and would like to fix it if it's quite a simple thing!
If you want to correctly bypass and adjust the gain on your lepai then you need to connect directly to the RCA inputs instead of pads on R35 and R34 ( C31 and C 30 on pcb 120305 ) you should know that:
R8 and R10 and the Rin resistors while R9 and R11 are the Rfeed resistors. These are the resistors that adjust the gain. Look into the TA2020 datasheet to get the full explanation.
- For ipod and portable players with built in volume control use 22K for Rin and 39K for Rfeed
- If you want to play it safe with and set your lepai for general use you should use 22K for Rin and 22k for Rfeed.
- For signals coming from a pre-amplifier you can go for 56K for the Rin and 22K for the Rfeed
I will post an definitive mod list for the lepai in a few days . I just need the time to do it correctly with pictures and everything else.
I will also show how to make the "switch" button work as it should; bypassing tone controls for real.
[]'s
R8 and R10 and the Rin resistors while R9 and R11 are the Rfeed resistors. These are the resistors that adjust the gain. Look into the TA2020 datasheet to get the full explanation.
- For ipod and portable players with built in volume control use 22K for Rin and 39K for Rfeed
- If you want to play it safe with and set your lepai for general use you should use 22K for Rin and 22k for Rfeed.
- For signals coming from a pre-amplifier you can go for 56K for the Rin and 22K for the Rfeed
I will post an definitive mod list for the lepai in a few days . I just need the time to do it correctly with pictures and everything else.
I will also show how to make the "switch" button work as it should; bypassing tone controls for real.
[]'s
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