Tda 2003 sound quality.Show me your opinion!

[PetruV]

I think the lg variant is almost same,but some days ago there was a post saying that 5 pin chips were discounted,but maybe they reintroduced the tda2003 with a slightly different termination

 

[teumesmo]

What voltage rating does the 4700uF cap need to have? Is this one of the best schematics out-there? I bought some TDA2003 from China, any reason to believe these are counterfeit?

 

[danielwritesbac]

I think the lg variant is almost same,but some days ago there was a post saying that 5 pin chips were discounted,but maybe they reintroduced the tda2003 with a slightly different termination

Yes, inside the TDA2009. Its like a 2 for 1 deal! 😀

Edit:
As for sound, TDA2003/TDA2009 has singleton input which is fantastic IF you've got regulated power. Check out the the Tracking Pre-Regulator (aka "nested regs") for high performance from simple chips. http://www.pinkfishmedia.net/forum/showthread.php?t=44928

 

[whaleman]

I made the changes to my board...

I noticed however some roll-off, about 1.7dB by 20kHz. I'm unsure if this is the feedback network or inherent to the chip, I suspect the latter since it seems to begin as early as 5kHz and the network was designed to have a break at 40kHz (actually higher since I only had 33nF)! Needs further investigation. Another possibility is ineffective HF coupling through the large electro, which is a very cheap type. ...

Thanks, I got inspired in this thread w/this info and made some changes to Velleman K4001 boards that FMJunkie gave me. I did notice the serious roll off starting around 5K too and was able to correct that with 33 uF feedback capacitors (electrolytic). I did try 47 nF feedback capacitors, but those did not help a whole lot. Gain was mildly decreased in the final configuration, but my speakers being sensitive, I do not miss it. Overall sound is quite good and balanced. Other replacements highlighted and might not make sense, but the sound is much much better than stock. Some pics of it in final form as an integrated amp.

 

[danielwritesbac]

C4 is approximately 5 times too large. C7 is approximately 30 times too small. However, the size of C7 would depend on the size of the speaker. Therefore, you'd want a bigger large signal coupler if your speaker is bigger than 2".
EDIT: Try a parallel pair of identical 3300uF for C7 for a medium size speaker (8" woofer)...OR a parallel pair of 470uF for C7 and a bookshelf speaker (4").

 

[whaleman]

C4 is approximately 5 times too large. C7 is approximately 30 times too small. However, the size of C7 would depend on the size of the speaker. Therefore, you'd want a bigger large signal coupler if your speaker is bigger than 2".
EDIT: Try a parallel pair of identical 3300uF for C7 for a medium size speaker (8" woofer)...OR a parallel pair of 470uF for C7 and a bookshelf speaker (4").

C4 is standard 10 uF in the kit, but I had a 2.2 uF there and it seemed a bit bright, so I went back to the kit spec with the 10 uF. As far as C7, it was spec for 1000 uF in the Velleman kit, but I did not have any Elna Silmic II in that rating, so the 220 uF went in with the bypass. Works perfect and drives a 15" woofer. Like I said, it might not make sense, but it does sound quite balanced in my setup. Try it if you have large speakers. Next kit might have bigger C7 as you recommend.

 

[danuphonj]

TDA2003 output can up to 20w with 25 power supply

 

[asuslover]

I would not apply 25v to tda2003....