Looking for audio amplifier for Radio - Page 1
Forum section: electronics / rf-microwave

author: jtronix
author_rank: Regular Contributor
timestamp: December 09, 2017, 04:15:45 pm
content: Hi,I got easy design from ST TDA2822 but only problem is TDA2822 original chip from ST is not available easily from local supplier. Chinese supplier has cheap TDA2822 but not have idea whether it will work stable or notAny one has idea about TDA2822 chinese IC performance and stability??

author: orbanp
author_rank: Regular Contributor
timestamp: December 12, 2017, 09:26:09 pm
content: They are cheap on eBay, both the IC and the amplifiers based on that chip.Any reason you doubt the fitness of the IC? - Chances are those ICs are just fine.There are also amplifiers there built on different ICs.Regards, Peter

author: whalphen
author_rank: Regular Contributor
timestamp: December 17, 2017, 05:11:13 pm
content: Extremely cheap on AliExpress. Why don't you buy an amp and some chips from there? If you don't like them, throw them out. Total cost will be under $3.I buy thousands of parts from China. And from the US. My experience shows little difference in performance, but a huge difference in price.

author: Audioguru
author_rank: Super Contributor
timestamp: December 17, 2017, 05:39:22 pm
content: Why does everybody talk about cheap, cheap, and more cheap? Instead of buying old Chinese junk or fakes, why not buy modern genuine good parts locally?Texas Instruments bought National Semi and now they make many modern audio amplifier ICs that are not cheap. Instead they are excellent, reliable and inexpensive.

author: jtronix
author_rank: Regular Contributor
timestamp: December 18, 2017, 03:20:13 am
content: My definition of cheap is,Consider a example of LM4871 IC which is available at $1.47 at texas store and same original IC available for 0.18$ at aliexpress. that why we are looking for cheap supplier NOT a cheap solution for audio amplifier which compromise a quality.If you are getting same output at lower cost then why would spend more?TDA2822 is a old IC and original ST make is not available at local store that is why little worried and considering whether it is suitable for new design

author: ThomasDK
author_rank: Regular Contributor
timestamp: December 26, 2017, 05:59:41 pm
content: Why not look at more modern alternatives rather than old expensive junk?(Or chinese fakes of the same old junk, which may or may not work)A PAM8403 can be bought for less than 50 cents in low quantities from mouser/digikey etc.

author: jtronix
author_rank: Regular Contributor
timestamp: December 27, 2017, 03:39:44 am
content: PAM8403 seems to be good if volume control not required.If you know any amplifier with volume control then please share itI got one TDA7052A but also searching for new device

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: December 27, 2017, 01:19:35 pm
content: Spending hours debugging a circuit because you got bad parts that don't meet spec because they are fakes is much more of a pain than the extra half-a-dollar you have to spend to get one from a reputable dealer or the original manufacturer. Just my opinion ofcourse...

author: gibbled
author_rank: Regular Contributor
timestamp: January 06, 2018, 03:20:52 am
content: Speaking of the PAM8403, has anyone successfully used a class d amp in a homemade receiver? I haven't used anything other than old class a/b chips as I thought the rf emissions of a class d would cause trouble with reception.

author: Yansi
author_rank: Super Contributor
timestamp: January 06, 2018, 05:47:49 pm
content: Yeah, using a cheap shitty class D amp in an RF instrument like a receiver is a great idea. (Sarcasm).But mum, it was modern!

author: dmills
author_rank: Super Contributor
timestamp: January 06, 2018, 08:14:26 pm
content: Depends, I have switchmode power supplies in my transceiver and it does fine (Kind of difficult not to when you need 1V @ 15A for the math core).Granted I put some thought into switching frequencies Vs the bands I was interested in and made sure the switchers were synchronised, but it is not rocket science.I would expect that a class D amp could do just fine with suitable layout and some due consideration to filtering.Regards, Dan.

author: Yansi
author_rank: Super Contributor
timestamp: January 06, 2018, 08:44:18 pm
content: Filtering, of course yes. If I remeber correctly, almost all those shitty cheap D amps are filterless noise generators.