Re-soldered the casing connection, and the hum is gone. Weird, I tinned the case before I soldered the wire to it. Oh well. No more hum.
I am interested in doing some of your other mods, but I am having trouble finding some of your parts, possibly due to my inexperience with component values.
I am going through Digi-key, and I found the opamp, the 4700uf cap (c32), and the 2.2uf caps (c4 and c5). However, I am not sure what kind of caps MKT are, and I am unable to locate any 6 lug 100k log pots. Where did you get yours? Also, what wattage resistors are you using?
I'm mostly using existing parts I have around. I have a mix of 1/2W and 1/4W resistors. For the tone control section I'm using 1/4W and for the voltage divider section (mod 3.2) I'm using 1/2W like the original.
For the MKT caps you can use these digikey product ids:
495-1132-ND
495-1224-ND
BC1677-ND
495-2882-ND
495-1127-ND
MKT is the capacitor series' name. You can filter for metalized polyester film in the capacitor section of digikey to find them.
I'm using existing pots I extracted from other junks. I did look through digikey and didn't find anything suitable. Mouser does carry the ALPS and Bourns pots but they won't just fit on the board, you might need to improvise a little. And they're pricey too.
For the MKT caps you can use these digikey product ids:
495-1132-ND
495-1224-ND
BC1677-ND
495-2882-ND
495-1127-ND
MKT is the capacitor series' name. You can filter for metalized polyester film in the capacitor section of digikey to find them.
I'm using existing pots I extracted from other junks. I did look through digikey and didn't find anything suitable. Mouser does carry the ALPS and Bourns pots but they won't just fit on the board, you might need to improvise a little. And they're pricey too.
@Calamaro and all,
I got my Lepai today and wanted to your mods to bypass tone controls. Looking at the pics I got slightly confused:
What I've understood: Replace the 8,25K with 22K resistors. Have one leg floating....on the first pic on page27 it seems the right leg of the resistors placed towards the middle of the board is connected to the input cap, on the left one it seems to be the left leg.
I did that, but as a result I measured roughly 11V DC at the right speaker terminal. I am just glad I didn't connect the amp yet!
One more question: Which leg of the input cap is meant to be floating: the one that goes to the neg end of the previous electrolyte, or the positive one?
Please someone chime in - thx in advance.
I got my Lepai today and wanted to your mods to bypass tone controls. Looking at the pics I got slightly confused:
What I've understood: Replace the 8,25K with 22K resistors. Have one leg floating....on the first pic on page27 it seems the right leg of the resistors placed towards the middle of the board is connected to the input cap, on the left one it seems to be the left leg.
I did that, but as a result I measured roughly 11V DC at the right speaker terminal. I am just glad I didn't connect the amp yet!
One more question: Which leg of the input cap is meant to be floating: the one that goes to the neg end of the previous electrolyte, or the positive one?
Please someone chime in - thx in advance.
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Hi Dubai, you're right: replace input resistors with 22k and connect new input capacitors to left leg of left resistor and to right leg of right resistor. Solder the other terminal of capacitors to the negative end of the previous electrolyte. Please check pictures
http://www.diyaudio.com/forums/class-d/90500-lepai-t-amp-ta2020-27.html#post1838046
http://www.diyaudio.com/forums/class-d/90500-lepai-t-amp-ta2020-27.html#post1838046
It's official, I am thick. If I do as mentioned above I get one output with 12V DC. So what is wrong here? Both input caps soldered to neg. side of former electrolytes.
Both input R's soldered only on one side to board: right resistor= left leg to board, left resistor right left to board// the othere legs do not go to board but are connected to floating legs of input caps.....doesn't seem to work for me.....or it's just too late and I am too tired....????
Both input R's soldered only on one side to board: right resistor= left leg to board, left resistor right left to board// the othere legs do not go to board but are connected to floating legs of input caps.....doesn't seem to work for me.....or it's just too late and I am too tired....????
the drop in replacement pots to look for are the Taiwan Alpha:
Jaycar Electronics - Search results
col.
Jaycar Electronics - Search results
col.
How can i make it more reliable?
Hi! Im a newb in this forum. I have been reading the comments nd reviews from you guys and i have decided to purchase 1. Im now a believer that the t2020 is one of the best! However, after a week of using it for some weird reason it just died.... I just hear clicking sound from both speakers. I have another one coming nextweek. What can i do to make this amp more reliable?
Hi! Im a newb in this forum. I have been reading the comments nd reviews from you guys and i have decided to purchase 1. Im now a believer that the t2020 is one of the best! However, after a week of using it for some weird reason it just died.... I just hear clicking sound from both speakers. I have another one coming nextweek. What can i do to make this amp more reliable?
nice mods, I just bought this amp, I will try some mods!
First good thing, DC offset on mine is 10mV - 12 mV
While on my Sure Electronics TA2024 board, DC Offset was around 800mV !!
Fear SC59: yes lowering DC Offset could improve the sound but the main reason is that it could hurt the speaker
First good thing, DC offset on mine is 10mV - 12 mV
While on my Sure Electronics TA2024 board, DC Offset was around 800mV !!
Fear SC59: yes lowering DC Offset could improve the sound but the main reason is that it could hurt the speaker
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