Been looking forward to this video

@razenby

2 жыл бұрын

It is a useful little module.. I would spend another 10 to 20 quid and get one of the better equipped versions.

There must be a market for implementations of reference designs with quality components.

@razenby

2 жыл бұрын

I would think so. There are other TDA8954 modules available for about £10 more that seem to be better designs. The reference designs are OK but there is often a lot more nuance to getting it reliable. Case in point is the FBT amplifiers that use the same chip. There are a lot more components dotted around the device - mostly decoupling and significant componentry dedicated to detecting fault or main power failure and putting the device in standby before the DC power supply lines drop even slightly. The datasheet says all this is accounted for by the chip's own circuity, but the brutal fact remains is that these chips fail often. For some reason the professional amps do not enable the Thermal rollback, instead they have a thermistor next to the chip that feeds the temperature back to the DSP processor's application to control and monitor. The other mistake that is often made is to lace a great clump of 4mm thick silicone putty material placed between the device and the metal heatsink. These need to run Metal to Metal with silver HS compound.

@SuperBoobaloo

2 жыл бұрын

@@razenby Do you think the amplifier ICs on these boards are even genuine? The caps aren't after all.

Hello bro, I have such an amplifier. I have only been using it for 2 days but while I was using it I heard an SMD capacitor explode. Can that still be fixed? thanks for the answer. I'm sad because I still owed the money I bought for that amplifier and it broke right away 😢

@razenby

2 жыл бұрын

They do that a lot. It isn't a proper implementation of such an amplifier. Depending on what cap has blown, it may have destroyed the amplifier chip. I can't say from here. You can see the schematic of this board on the Amplifier chip datasheet. If the device isn't happy with its implementation circuit they blow very quickly.

Hi ya, I found your video while looking for repairing washing/dryer machines and came across your chips n fuses repair I am now subscribed, "click" ,, very informative and easy on the ears NICE JOB ,,, I wonder if you can help my LG dryer just packed up with a loud bang and the smell of cows as you describe ha ,,, i've repaired it once before by replacing the main board and motor as the same, everything worked perfect for a few years now its is over heating and I just want to replace the component thats blown as I can keep buying mainboards just of one component haha i've tracked down the problem to a Triac BCR8PM-14L that went Ka BOOM but its a discontinued transistor so no one in the uk has it not RS Components or Farnel,, would you know of an equivalent I can use to replace this transistor BCR8PM-14L for a LG TDC70045E dryer, its Main PCB Module is 6871EC1113G

@razenby

2 жыл бұрын

You can buy the triac here for a couple of quid inc shipping: www.aliexpress.com/wholesale?cat Id=0&initiative_id=SB_20210823050143&SearchText=BCR8PM-14L+ Otherwise any 6 to 10A 600 Vtriac with the same pin out should work. Pay attention to anything connected to the gate as that may be blown too.

Maybe you mod something like this for optimum performance over the winter. Probably not cost-effective, I suppose. Would an inexpensive car amp strapped to 12v HP server supply make more sense.

@razenby

2 жыл бұрын

I certainly would use one of these modules from anything other than for a novelty. If you turn it up and get to the end of the track you are doing well!

Have you ever designed your own amp PCB? If you sold a kit you designed I'd buy it.

@razenby

2 жыл бұрын

Not done nay amplifiers recently. I design mostly switch-mode power supplies and Bluetooth related products. I would like to do an Amp if someone would pay the design fees!

hey, i have the same board as yours, the one with less capacitors, i have 2 150w rms /300w peak speakers (i actually dont want to break them, they're some high quality speakers, from the 90s) i have a powered mixer from the same brand, which has a class AB power amplifier in it, but even if on the back it claims 2x120W at 8 ohms, while pushing it to the limit, and measuring the power drawn from the outlet with a chinese power meter, the meater reaches max 119W, which is less than 40W per channel, probably 25 watts considering class ab losses/efficiency.... so i wanted to use that board to reach atlest the RMS value of each speaker, so 150W, or some close values so 120W for example..., do you think it would be possible with some modifications to the board? if yes, what would you modify besides the output filter capacitors? or should i desolder the chips and make my own pcb? i dont think i have enough knowledge to make a good pcb, i can make a bad one, but not a good one xD also the inductors become really hot while in use, so i guess these got undersized and must be replaced too, right? thx :)

@razenby

Жыл бұрын

The copper tracks and components (inductors) are underrated on this board. There are better and more reliable options to achieve a powerful amplifier. This layout will never be reliable. These chips have thermal fold-back and should only be driven hard if you have the safety feature in the support circuitry. It is very easy to destroy these chips.

@xzVice

Жыл бұрын

@@razenby what is thermal fold-back in this case? a logic that reduces the input signal if the temperature rises too much? like a "throttling"? also what is the transistor Q1 for? iirc you need a 5V logic to use the mute/stby functions, how are they achieving it without a voltage linear converter?

@razenby

Жыл бұрын

@@xzVice See the datasheet for the chip. It is all explained there. If the chip gets to hot the preamp can throttle back the drive signal to alleviate the load. This can happen fast a long loud bass note can push it over fast.

@xzVice

Жыл бұрын

@@razenby so you say that it wont be able to save it from death

@xzVice

Жыл бұрын

@Magic Smoke could you send me the name of your supplier? i need some of these ICs

Hi there mate. I'm thinking maybe you can help me somehow. I have the same board, the one with less capacitors, bought from china. I build one amplifier using this, with a Bluetooth module and a tone correction with base middle and treble adjustment. I've supplied this with a toroidal transformer of 2x30v and 2x12 volts at about 500w. it was working perfect. I've sold this amplifier to someone and he brought back to me next day, saying that it was playing just 2 songs. What I saw, all the potentiometers were at maximum level and he was playing on a 700w speakers, but I don't know if it was at 4 or 8 ohms. Now the amplifier module it gives me DC voltage on one of the outputs. I've supplied this time with a normal transformer of 2x12volts at 7amps, I have the blue light on but no sound, removed heatsink, it is not getting hot, but as I said I'm getting around 17volts on one of the output. I am not an electrician, but I like to play with DIY audio modules. Could you help me what to check and maybe repair it?? I did not remove any of the main chips, but few capacitor to check them out of board, because one of them from right channel looking from the top, it shows me shorted on continuity. Even after removed this one, the pcb is still shorted on their pads. It's about C50. Also the 2 resistance R12 and R8 shows me different values on the board. Any advice would be helpful. Thanks in advance

@razenby

6 ай бұрын

These AMPS will never survive working at power. The PCB layout is very bad and to boot the chips are very suspect. NXP retired these chips in 2019. Genuine ships on the new old stock market are selling for around US$25 a piece. We have used hundreds perhaps thousands of them over the last ten years. I though to use these salvaged from these cheap Chinese amps as donors to service our usual semiprofessional amps that employ them. I was wrong, they lasted less than an hour , sometimes only a few minutes on test. With the genuine NXP parts they rarely if ever failed. Whatever they fitted to these amps last less than an hour in some case just a few minutes. Look at the feedback protection mechanism as specified in the datasheet. The chip has thermal and clipping alarm pin that relies on the driving pre-amp to throttle back the input. With no response to its cries for mercy they self destruct.

@iulianvasile2870

6 ай бұрын

thanks a lot mate. So basically speaking i just can bin it@@razenby

Can you recommend an alternate amp-board that uses this chip? thx

@razenby

Жыл бұрын

The chip is obsolete - The TDA8954 was always a nasty stain on the reliability of products that used it. There are a large number of Amps that have been scrapped because it went obsolete. The last time buy batch was sold off to China. I have a feeling they obsoleted it because they had production and reliability issues. I haven't been ale to find a replacement/equivalent device. If you don't need to use it then steer well clear. The parts I have managed to buy didn't work reliably.

I have Same this board with 8 capacitor of 1000mfd currently i use transformer 25 0 25v - 10A But maximum i get 240w rms per channel so please tell me that can i use more ampere transformer for this board Because 25+25V x 10A = 500W And i observed that the board take 12.5 ampere on max volume on 60hz frequency So can i use 25 0 25V AC 15 Ampere Transformer on this board?

@razenby

8 ай бұрын

Hmm, the main problem with these boards is that they are a simple layout of the datasheet circuit. The copper tracking thickness (conductivity) and layout leaves a lot to be desired. I blew up my test ones when I tried it at full at rated power. You can get the details of the max ratings from the manufacturer's datasheet for the TD amp chip.

Hi, I used 30-0-30 ac and on switch on R10;12;24 and c4;39 burned out. Can you help. Regards Ray

@razenby

2 жыл бұрын

Oh dear - I think that the are probably toast... The magic smoke is released from the TDA8954TH very easily. That is why they have withdrawn the chips from the market. Somebody probably blew out all the rejected stock from device test as a last time buy to China. I noticed that the printing on the chips in the modules differs very slightly from the original. This might be significant or not but they don't work the same. I was using these modules as source for replacement chips for powered PA equipment but half of them don't work or just fail after a while. I have used new stock from the UK distribution channel for years and never had these problems.

@davidrobertson671

Жыл бұрын

@@razenby Is there a successor chip to this?

I've got a similar board with the same chip, but the choke heats up like crazy.. so much as to enamel of the wire started burning, this is at 24v AC 8amp supply

@maynellrodrigues9862

Ай бұрын

With no input or load

@razenby

12 күн бұрын

My advice is to bin it, this module is a waste of effort.. It will be a constant source of pain...

@maynellrodrigues9862

11 күн бұрын

@@razenby 💯😂 thought so

Hope you’re well mr Smoke? Seems very quiet 🤫

@razenby

2 жыл бұрын

I am good thanks. I have a couple of design contracts that I am working on so no free time. I will upload soon. Thanks for asking. Hope you are well too.

@cockneybrian

2 жыл бұрын

@@razenby I’m all good just missing my education fix. Good to hear you’re feeling better bud.

So in a nutshell these arent worth bothering with, by the time youve paid out for all the upgrades

@razenby

Жыл бұрын

No, it is passing interest until it goes POP. Thanks for watching.

@MasterBlaster220

Жыл бұрын

​@@razenby Im looking for an amp that has rectifier build in, heap would be nice. Do you know any other chinese made ones, reliable that directly accept AC with > 100W/ channel?

always burn smd capacitor 4ohms load

@razenby

2 жыл бұрын

Not a good implementation on the PCB layout. It is rubbish.

Punya sy ic konslet

@razenby

2 жыл бұрын

That is the fate of all these amps. These were built with junk chips from the factory reject bin