3w amplifier for portable stereo speaker - Page 1
Forum section: electronics / beginners

author: Adhith
author_rank: Frequent Contributor
timestamp: August 28, 2016, 04:45:59 pm
content: Hello everyone...I have a sony ericsson mps60(model name) stereo speaker,but the amplifier is damaged.So can anyone give me the circut diagram with the same specifications?? It is a 3w amplifier and i would like to connect usb for power supply & 3.5 jack for audio input.The pic of the amplifier is attached with this.

author: madires
author_rank: Super Contributor
timestamp: August 28, 2016, 05:16:42 pm
content: Please try to identifiy the amplifier IC and check out its datasheet. Usually the reference circuit in the datasheet is used.

author: Adhith
author_rank: Frequent Contributor
timestamp: August 31, 2016, 04:26:39 pm
content: The only thing i can see is the writing 7 2 220 6k component.its a transistor right..?

author: MosherIV
author_rank: Super Contributor
timestamp: August 31, 2016, 04:33:23 pm
content: QuoteNope, they look like surface mount capacitors.Is there anything on the underside of the circuit board?

author: Zero999
author_rank: Super Contributor
timestamp: August 31, 2016, 04:56:12 pm
content: A little off-topic but 3W from a 5V supply, with no boost converter sounds a bit optimistic. The voltage drop in the power stage would have be about 100mV or less to put 3W into a 4 Ohm speaker and even then it will probably be very distorted.Turn the board over. There should be an IC on the other side, which is the actual amplifier. Those capacitors are just for AC coupling and to bypass the power supply at audio frequencies.

author: Adhith
author_rank: Frequent Contributor
timestamp: August 31, 2016, 05:18:24 pm
content: The back side consist of 2 small black ic like component.Written k 994 Y728

author: madires
author_rank: Super Contributor
timestamp: August 31, 2016, 06:18:28 pm
content: Maybe TS4994, which got the marking K994? But it's an 1W amp.

author: Audioguru
author_rank: Super Contributor
timestamp: August 31, 2016, 06:49:40 pm
content: Maxim make the MAX98306 class-D stereo amplifier IC that is similar. With a 5V supply, it produces 3 Whats per channel into 4 ohm speakers with horrible 10% clipping distortion or 2 Watts with fairly low distortion. The Sony-Ericsson (when did Sony buy Ericsson?) speakers (squeakers?) are tiny and their cost 9 years ago was very low.

author: tooki
author_rank: Super Contributor
timestamp: September 01, 2016, 06:41:43 pm
content: I would just replace the board with one of the PAM8403 amplifier boards you can get on eBay for a dollar or so. It's a similar 3W, 5V class-D amp.Audioguru: Sony didn't buy Ericsson. Sony Ericsson was a joint venture between Sony and Ericsson. (Sony's mobile phone designs were abandoned and Ericsson's were simply relabeled with the new brand.) Both parent companies continued. In 2012 Sony bought Ericsson's shares in the joint venture, making it a fully owned subsidiary of Sony, renamed Sony Mobile. (Ericsson continues to be a major vendor in cellular tower equipment, AFAIK.)

author: Zero999
author_rank: Super Contributor
timestamp: September 01, 2016, 07:09:51 pm
content: Quote from: tooki on September 01, 2016, 06:41:43 pmI agree. The PAM8403 looks like a good IC.http://www.diodes.com/_files/datasheets/PAM8403.pdf

author: Adhith
author_rank: Frequent Contributor
timestamp: September 03, 2016, 04:54:01 am
content: Thank you everyone..I saw a simple audio amplifier circiut with lm4954 & thought to give it a try, all the capacitors in figure are electrolytic ones right??(what about ci) also i want to know that if i replace ground with neagtive terminal, should i connect the ground from the audio jack to it(what i meant was will there be any reverse flow of current to the jack through the ground of the jack).

author: Zero999
author_rank: Super Contributor
timestamp: September 03, 2016, 09:00:20 am
content: Quote from: Adhith on September 03, 2016, 04:54:01 amYes, that will work but it's class AB rather than class D so will use more power.If you can find it on a pre-assembled board, then go for it, otherwise it comes in a microbump package which can only be soldered using a reflow oven, forget hand soldering.

author: rob77
author_rank: Super Contributor
timestamp: September 03, 2016, 09:46:57 am
content: +1 for the PAM8403 board from ebayi bought them the other day (10 of them for approx 5$) and the performance is surprising, after connecting speakers and powering the thingy it was silent, no hissing sound from the speakers - i was pretty much surprised surprised. and the sound quality is pretty good/acceptable for such a cheap solution

author: ebclr
author_rank: Super Contributor
timestamp: September 03, 2016, 11:04:42 am
content: Let's try this 0.30 usdsolutionhttp://pt.aliexpress.com/item/1pcs-lot-PAM8403-Super-mini-digital-amplifier-board-2-3W-Class-D-digital-amplifier-board-efficient/32477442965.html?spm=2114.30010508.3.2.0tOv50&ws_ab_test=searchweb201556_0,searchweb201602_3_10057_10056_10065_10037_10055_10054_10069_301_10059_10033_10058_10032_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_2&btsid=a24ada90-efbf-431a-844b-c75b51fa24f3

author: Adhith
author_rank: Frequent Contributor
timestamp: September 10, 2016, 03:47:41 pm
content: thank you everyone...i have made the amp with TDA7052 & its working, but the ic gets heated after 5 minutes of operation also the sound clarity is disappointing. The actual circuit have a 4.7k potentiometer, but i have replaced it with a 4.7k resistor does this makes any difference in clarity?? does making another amp with TDA 1015 make any difference??

author: Audioguru
author_rank: Super Contributor
timestamp: September 10, 2016, 04:56:31 pm
content: The TDA7052 is in an old 8 pins dual inline package. With a 6V supply its output into an 8 ohm speaker is 1.2 Whats with 10% clipping distortion or about 1 Watt with fairly low distortion. Its heating is almost the same as its output power so of course it will get hot but not too hot.The TDA7052A is also in an 8 pins dual inline package and produces 1.1 Whats or about 0.9 Watts into 8 ohms with a 6V supply. It gets hot like the TDA7052.The TDA7052AT is in a tiny package and gets too hot when driving an 8 ohm speaker so its speaker must be 16 ohms when it produces 0.55 Whats or 0.45 Watts with a 6V supply and it gets hot.The very old TDA1015 produces only 0.3 Whats into 8 ohms with a 6V supply or about 0.25 Watts.

author: Adhith
author_rank: Frequent Contributor
timestamp: September 10, 2016, 05:17:58 pm
content: Quote from: Audioguru on September 10, 2016, 04:56:31 pmso what should i do to get a good clarity audio output?? what type of ics are commonly used in speakers??

author: Zero999
author_rank: Super Contributor
timestamp: September 10, 2016, 08:00:19 pm
content: Quote from: Adhith on September 10, 2016, 05:17:58 pmPlenty of people have recommended the PAM8403 which you can get pre-assembled on a board. Can you not get hold of it where you live?

author: Shredhead
author_rank: Regular Contributor
timestamp: September 11, 2016, 12:01:57 am
content: Here are some chipamps that I've made and tested. All of the below power numbers are sustained sines at 1kHz, and I list peak power numbers. If you are used to seeing average power numbers, simply divide the number by 2.LM386N-1http://www.mouser.com/ProductDetail/Texas-Instruments/LM386N-1-NOPB/?qs=QbsRYf82W3GLguMHc1jDPg%3D%3D9.24V supply4 ohms – 1.06W8 ohms – 1.3W14.85V supply4 ohms – 1.1W8 ohms – 2.12WLM386N-4http://www.mouser.com/ProductDetail/Texas-Instruments/LM386N-4-NOPB/?qs=QbsRYf82W3FsJPldcpZj5g%3D%3D14.98V supply4 ohms - 1.41W8 ohms – 2.52W21.78V supply – 13.7mA idle current4 ohms – 1.58W8 ohms – 3.04WTPA1517http://www.mouser.com/ProductDetail/Texas-Instruments/TPA1517NE/?qs=sGAEpiMZZMtxdzBvM0rKcec3clR2XnYWHJGwvAdjFhI%3d-You need a heat sink with this chip. They make ones for it or you can tie some copper or aluminum to the top of the chip with some heat grease.12V Supply4 ohms – 5.4W8 ohms – 3.8WLM4752http://www.mouser.com/ProductDetail/Texas-Instruments/LM4752TS-NOPB/?qs=%2fha2pyFadujGkk%2f7%252blJjSLISy9c1AEvWoJnbngNJ47Q%3d-This is an SMD part. I attached wires to the leads that went to a through hole PCB. I paper clipped a piece of aluminum to the chip for a heat sink. Pretty impressive power for a tiny chip.24.5V Supply4 ohms – 19.5W8 ohms – 13.38WIf the chip you are using now sounds bad because it is overheating, see if you can get some metal on it with some thermal compound. It might be enough to do the trick and keep what you're using. I'm just listing the above stuff for anyone who might be interested.

author: tooki
author_rank: Super Contributor
timestamp: September 11, 2016, 02:07:23 pm
content: Quote from: Adhith on September 10, 2016, 05:17:58 pmWhat's the point of asking for advice if you're just gonna ignore it? You asked, you got the same answer from several people, so it's probably good advice.

author: Adhith
author_rank: Frequent Contributor
timestamp: September 11, 2016, 04:08:59 pm
content: Quote from: tooki on September 11, 2016, 02:07:23 pmI haven't thought of ignoring anyone sir..& I apologize for my ignorance if everyone thinks in that way. i know that using the PAM8403 board is a good solution, but i thought to built the amp by myself with any alternate circuit rather than purchasing the pre assembled kit.

author: Zero999
author_rank: Super Contributor
timestamp: September 11, 2016, 04:56:31 pm
content: If you're after some soldering practise then the PAM8403 is available as a bare IC from various distributors:http://www.mouser.co.uk/Search/Refine.aspx?Keyword=PAM8403http://uk.rs-online.com/web/p/audio-amplifier-ics/7902975/

author: tooki
author_rank: Super Contributor
timestamp: September 12, 2016, 01:52:54 am
content: Quote from: Adhith on September 11, 2016, 04:08:59 pmI understand the desire to build, but any DIY solution is going to cost 10x as much and will not perform better. (Options are limited when a 5V supply is specified for several watts output.) If you want to tinker, get a PAM8403 or PAM8406 board, study the datasheet, and then figure out what traces to cut and where to add things to implement soft power (i.e. no pop on powerup), mute, etc. (Some boards break out those pins, but most are hard wired without such niceties.) And add a decent capacitor on the power rail, because standard USB chargers' 1A is plenty of power for listening, but may not be enough to feed the PAM chip during peaks at high volume -- the voltage may sag and cause it to cut out.

author: Audioguru
author_rank: Super Contributor
timestamp: September 12, 2016, 02:05:05 am
content: I do not know why the LM386 amp IC was mentioned and its "1.3W peak" power when its supply is a little more than 9V. Its datasheet shows that its maximum very distorted output into 8 ohms with a 9V supply is only 6V peak-to-peak which is 3V peak. Then its peak output power is (3V squared)/8 ohms= 1.125W. Its real output power is only 0.35W just before clipping then its distortion is low.

author: Shredhead
author_rank: Regular Contributor
timestamp: September 12, 2016, 09:40:48 pm
content: Quote from: Audioguru on September 12, 2016, 02:05:05 amI measured 3.22V peak into the 8 ohm load for the 1.3W peak power number. I assure you, my testing methodology is thorough and repeatable. The waveform was not clipped which is usually indicative of 1% or less THD. I was surprised to see higher output from this chip than the datasheet lists too but the LM-386N-4 was the same story.

author: Zero999
author_rank: Super Contributor
timestamp: September 12, 2016, 09:57:34 pm
content: Did you test a range of ICs at different temperatures?Data sheets often give the worst case scenario so it's not surprising your tests show better performance than the manufacturer's specifications. I've found this to be the case with other ICs: for example, I noticed an oscillator built with th 74HC04 would work down to 1V but I wouldn't expect all ICs to perform the same, across the rated temperature range.

author: Shredhead
author_rank: Regular Contributor
timestamp: September 13, 2016, 01:24:50 am
content: That's a good point Hero. When testing amplifiers of any kind I record the maximum output when the amp or chip is relatively cool or at idle temp. I test amps that are rated in the kW's too so it's generally not a great idea to push them with sine waves for an extended period of time. I run the sines for up to 30 seconds tops usually to see if there is a drop in output due to heat or PSU sag.I didn't test this chip anywhere near it's thermal limits, maybe it would show much different readings if I did. Real world content wouldn't be as stressful as sine testing though so I think you can count on my numbers for playing dynamic source material.

author: Audioguru
author_rank: Super Contributor
timestamp: September 13, 2016, 01:38:03 am
content: 1% distortion from an audio amplifier is pretty bad. The peaks are squashed because it is actually clipping but the clipping is not severe. The graph of distortion vs output power shows the distortion suddenly increasing as the output power is increased.

author: Shredhead
author_rank: Regular Contributor
timestamp: September 13, 2016, 02:47:24 am
content: Quote from: Audioguru on September 13, 2016, 01:38:03 amIn my experience with testing many amp topologies at different power ratings, when the peaks are squashed or cut off this indicates higher levels than 1% THD. 1% THD is not "pretty bad" in fact it is unlikely that you would detect 1% THD at 1kHz. Here is an article where a blind test was conducted in the detection of THD:http://www.axiomaudio.com/distortionIn this article an interesting conclusion was stated:"For detecting distortion at levels of less than 10%, the test frequencies had to be greater than 500 Hz. At 40 Hz, listeners accepted 100% distortion before they complained. The noise test tones had to reach 8,000 Hz and above before 1% distortion became audible, such is the masking effect of music. Anecdotal reports of listeners' ability to hear low frequency distortion with music programming are unsupported by the Axiom tests, at least until the distortion meets or exceeds the actual music playback level."In the vast majority of cases where an amplifier is reaching it's max output at 1% THD into a dynamic load, the drivers in the system are producing substantially more THD than the amplifier anyway.