How many watts should the zener diodes be rated for and what series would you suggest?
This has also bee pointed out by the designers earlier in this thread. Mind to read the thread carefully?
The TL071 servo opamp doesn't draw that much current, so a zener current of 10 mA should be more than sufficient. This calculates to a dissipation of 150 mW per diode, so the smallest (0.5 W) ones will do. The resistors need to dissipate the difference between supply and zener voltages, times the zener current. It IS really that easy!
And don't forget to put 'lytics of, say, 100 µF in parallel with each zener.
Best regards!
The TL071 servo opamp doesn't draw that much current, so a zener current of 10 mA should be more than sufficient. This calculates to a dissipation of 150 mW per diode, so the smallest (0.5 W) ones will do. The resistors need to dissipate the difference between supply and zener voltages, times the zener current. It IS really that easy!
And don't forget to put 'lytics of, say, 100 µF in parallel with each zener.
Best regards!
Here's the relevant post from earlier in the thread, didn't take long to find it with a thread search.
https://www.diyaudio.com/forums/chip-amps/365002-xmas-amp-dibyas-tda7293-jhofland-7.html#post6465054
https://www.diyaudio.com/forums/chip-amps/365002-xmas-amp-dibyas-tda7293-jhofland-7.html#post6465054
Does anyone know where to get a legit TDA7293 right now?
I have had them on order from RS Components for over two weeks now, but there is no sign they are ever going to ship. They had stock when I placed the order, but now stock shows Zero.
I have had them on order from RS Components for over two weeks now, but there is no sign they are ever going to ship. They had stock when I placed the order, but now stock shows Zero.
Out of curiosity I performed a search and came up empty-handed at the “big” North American suppliers. Surprise!
It appears that Micro-Semiconductor in Hong-Kong has >20000 in stock. TDA7293V - STMicroelectronics Stock available. The distributor Micro-Semiconductor.com offer the best price with new original products..
I have never purchased from this company.
It appears that Micro-Semiconductor in Hong-Kong has >20000 in stock. TDA7293V - STMicroelectronics Stock available. The distributor Micro-Semiconductor.com offer the best price with new original products..
I have never purchased from this company.
What worries me is at that price are they are either the dreaded "V6" edition everyone says not to use, or outright fakes.
Octopart shows the usual "common" places to get one,
Octopart regular TDA7293V vendors
Digipart shows the questionable places to get one,
Digipart TDA7293V stock
And I don't really know much about FindChips,
FindChips TDA7293V search
Anyone bought a real one from any of the vendors that show stock?
Octopart shows the usual "common" places to get one,
Octopart regular TDA7293V vendors
Digipart shows the questionable places to get one,
Digipart TDA7293V stock
And I don't really know much about FindChips,
FindChips TDA7293V search
Anyone bought a real one from any of the vendors that show stock?
I never bought from this company and I wouldn’t buy from them just because they are selling too cheap. Same with lm3886 , starting price is 2.5$ each ...
See post #63 for the original alarm put forth by Dibya..
I’ve bought several V6 chips from either Digikey, Mouser or Newark Electronics (all USA houses) and have had no issues. It could be a possibility that he got a counterfeit batch and made the assumption that all V6 batches are bad. Let him, and other folks, weigh in..
Cheers,
Pete
I’ve bought several V6 chips from either Digikey, Mouser or Newark Electronics (all USA houses) and have had no issues. It could be a possibility that he got a counterfeit batch and made the assumption that all V6 batches are bad. Let him, and other folks, weigh in..
Cheers,
Pete
V6 print does not mean that the chip is fake , but V6 print will be found on most of the fake chips, just buy from authorized distributors.
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Would 10uf be too much for the input capacitor. I have some Panasonic ECQ polyester that have the correct lead spacing.!
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In terms of C value, too much isn't an issue for an input capacitor, too few is (cutting low frequencies)...
I hope this helps
Claude
I hope this helps
Claude
Thanks Claude. I know the schema show 1uf but 2.2 to 4.7 is advised. I guessed 10uf would give me a lower cut off but didn't know it it made for any ill effects.
Thanks
Thanks
Well, the only ill effect is that at 10uF you are likely to use electrolytic caps, or perhaps X7R ones. Better caps wouldn't be resonable, both in terms of cost factor (vs the rest of the amp) and form factor.
Lower values enable the use of reasonable PPP caps, which are IMHO much better in terms of sonic quality, but these ofen don't come cheap if seaking more than 4.7uF.
Have fun either way
Claude
Lower values enable the use of reasonable PPP caps, which are IMHO much better in terms of sonic quality, but these ofen don't come cheap if seaking more than 4.7uF.
Have fun either way
Claude
I had to drop the input value from 4.7uF back down to 2.2uF (both WIMA MKP4 PPs) as I heard a lot of low frequency rumbling (on occasion) during music playback on my speakers (8" active w/10" passive radiator woofers). 10uFs may really accentuate the lower end but, as ClaudeG said, try both and see what suits your system and tastes.
Pete