Although I do not mind buying from Aliexpress, EBAY is still my first choice if I can get the same stuff. Usually the goods is a bit more expensive at EBAY but I feel more assure.
Now, I want to see whether the board is still usable or need salvaging. Definitely need to replace the inductor(s).
Regards,
I realized that the goods are cheap and shipping is included, but how much more would it cost to wrap the items in bubble wrap individually before shipping? As a customer, I do not mind pay a bit more to ensure the package is properly packed. The customers will be a lot happier when the order arrived in good shape and likely would buy again. Really do not understand their mentality.
Regards,
2nd set of 7498's
My second set of TDA7498's from Aliexpress arrived today. This time, they were impeccably packed in shrink plastic, then multiple layers of foam, then taped, then neatly fitted inside a cardboard box. All for $22/pair shipping included.
My second set of TDA7498's from Aliexpress arrived today. This time, they were impeccably packed in shrink plastic, then multiple layers of foam, then taped, then neatly fitted inside a cardboard box. All for $22/pair shipping included.
Attachments
My second set of TDA7498's from Aliexpress arrived today. This time, they were impeccably packed in shrink plastic, then multiple layers of foam, then taped, then neatly fitted inside a cardboard box. All for $22/pair shipping included.
That's excellent
!! Could you post the link to the store? Good vendor deserve our business. That's pretty fast too, right? I recalled you ordered them about 2-3 weeks ago? Have fun!Regards,
That's excellent
Regards,
Wholesale Product Snapshot Product name is TDA7498 100W+100W Class D Amplifier Board High Power Amplifier Board
I ordered it exactly 2 weeks ago.
Thought I'd tag this on here rather than start another 7492 thread (hope that's ok).
Just received this board from here:
TDA7492 D Class High Power Digital Amplifier Board 2X50W Amp Board with Radia | eBay
I have it mocked up on this board purely for testing before I go ahead and make a case for it (a good decision as it turns out)....
I am getting audio out both channels (and lots of it) but there is some weird sort of distortion in the upper frequencies, hard to describe but sort of like a ringing?....
I know it's hard to faultfind a sound that you can't hear but just wondering on the off chance somebody might have a suggestion on where to look or if there is anything wrong with the setup here?
The pwr supply is putting out 18.9V (I'll see if I can find another one tomorrow to try and isolate that side of things).
There is ample volume available and I can tell that the amp has got some potential as a good listener but at the moment it's definitely not.
Thanks
Just received this board from here:
TDA7492 D Class High Power Digital Amplifier Board 2X50W Amp Board with Radia | eBay
I have it mocked up on this board purely for testing before I go ahead and make a case for it (a good decision as it turns out)....
I am getting audio out both channels (and lots of it) but there is some weird sort of distortion in the upper frequencies, hard to describe but sort of like a ringing?....
I know it's hard to faultfind a sound that you can't hear but just wondering on the off chance somebody might have a suggestion on where to look or if there is anything wrong with the setup here?
The pwr supply is putting out 18.9V (I'll see if I can find another one tomorrow to try and isolate that side of things).
There is ample volume available and I can tell that the amp has got some potential as a good listener but at the moment it's definitely not.
Thanks
Check the polarity on your speakers. Try flipping one side and see if that HF ringing goes away. I suspect you may be hearing weird phase effects of flipped polarity. Your bass output will also be low. Also try disconnecting one speaker and see if it goes away.
Bypass your volume pot to eliminate that as the source.
Next is swap out those caps in the main LC filter with quality film caps.
Next is to check if 330pF cap in pre LC Zobel snubber is still good. It's a tiny SMT one under heat sink in between the two LC legs between IC chip and LC.
Bypass your volume pot to eliminate that as the source.
Next is swap out those caps in the main LC filter with quality film caps.
Next is to check if 330pF cap in pre LC Zobel snubber is still good. It's a tiny SMT one under heat sink in between the two LC legs between IC chip and LC.
Ok, firstly thanks for the info. I tried the easy one first, swapping speaker polarities, no change, at least no change to the fault. Plenty of Bass and SPL too, and the fault (almost sounds like a lisp on singers voices etc) is evident from the very start of the volume pot i.e. minimum. I can't go past about 1/4 turn as it's too loud (polk RT12's).
However, I did notice something else - there was a delay in the music starting and I thought it was some kind of speaker protection but then I realized it was taking too long. I started tapping around the board, on the heatsink etc and the music jumps straight back in (with the fuzzy fault) so I'm thinking a cold solder joint somewhere?
Am about to remove the board and look closely at all the joints and maybe run a solder iron around them all anyway.
Couple of other questions, if I have to remove the heatsink - how do I go about it? Is it just stuck on with heatsink compound? Apply a bit of heat with gun and pry off?
Also, the LC network, having a bit of trouble identifying the components as the board labeling seems a bit random. I took the black squares to be the caps as they have 220 stamped on them but i think they are the inductors - so 220uH? So where are the 220nF caps - are they the tiny surface mounts?
And, if I have 220uH inductors that indicates it's set up for 6ohm load (from the data sheet on page 1). All my speakers are 8ohm - would that cause my problem or if a cold joint be a further problem?
cheers
Steve
However, I did notice something else - there was a delay in the music starting and I thought it was some kind of speaker protection but then I realized it was taking too long. I started tapping around the board, on the heatsink etc and the music jumps straight back in (with the fuzzy fault) so I'm thinking a cold solder joint somewhere?
Am about to remove the board and look closely at all the joints and maybe run a solder iron around them all anyway.
Couple of other questions, if I have to remove the heatsink - how do I go about it? Is it just stuck on with heatsink compound? Apply a bit of heat with gun and pry off?
Also, the LC network, having a bit of trouble identifying the components as the board labeling seems a bit random. I took the black squares to be the caps as they have 220 stamped on them but i think they are the inductors - so 220uH? So where are the 220nF caps - are they the tiny surface mounts?
And, if I have 220uH inductors that indicates it's set up for 6ohm load (from the data sheet on page 1). All my speakers are 8ohm - would that cause my problem or if a cold joint be a further problem?
cheers
Steve
Problem solved! Turned out be the cheap junk POS power supply, I dug up a 10 year old laptop brick 19V 4.7A and it was like night and day. This thing is incredible - easily the loudest amp in the house at the moment and sounds good doing it. I'm more of a quality over quantity guy but I'm amazed out how such a small device can produce so much room/house filling sound.
Not sure if the other pwr supply is faulty or just cant supply enough current (rated at 3.95A) or is just junk but it's going in the bin. I'll save the IEC cord and open it up just out of curiosity though.
Anyway, I can get on with building a case now.
Cheers
Not sure if the other pwr supply is faulty or just cant supply enough current (rated at 3.95A) or is just junk but it's going in the bin. I'll save the IEC cord and open it up just out of curiosity though.
Anyway, I can get on with building a case now.
Cheers
My TDA7498 arrived today in a heavy cardboard box, wrapped in several layers of foam, and sealed in thick plastic film. It took about 2 weeks to the States and was easy pie. Nice board.
There are cobwebs on my soldering iron and I don't know what connector fits this 3pin, what I assume to be Input, to the board.
I would appreciate knowing what to call this connector and how to wire it to RCA. I assume there is a common ground, and maybe there is a standard cable that fits this end and terminates in L/R RCA.
Thanks in advance.
There are cobwebs on my soldering iron and I don't know what connector fits this 3pin, what I assume to be Input, to the board.
I would appreciate knowing what to call this connector and how to wire it to RCA. I assume there is a common ground, and maybe there is a standard cable that fits this end and terminates in L/R RCA.
Thanks in advance.
Glad that worked out. The amp is some serious bang for your $6 bucks isn't it
It's not the current rating - even with 1 amp you should be able to play most music at modest levels.
Those are 3-pin header connectors. Measure the pitch between pins - this is probably 0.100in. There is a smaller one than this. You can order RCA jack to header pin connector but easier to take an old RCA cable cut it and solder to the exposed pins on the bottom side. Middle is GND and pins on either side go to respective output amp input on same side. Note that the right output polarity may be reversed. That is it is labeled -/+ left to right from front of board. Should be +/- and you can confirm by listening for lack of bass if wrong.
Good and not so good news ...
Still haven't received my new power brick, but since i am getting it replaced and didn't need to send it back, I opened it.
Bad: The screws holding the box together were all rusty. There is a pool of goo holding stuff together on the board.
Good: I placed the multimeter on the outputs directly on the board, and measured 36V. So the board seems to work fine, but there's a problem with the cable.
Still haven't received my new power brick, but since i am getting it replaced and didn't need to send it back, I opened it.
Bad: The screws holding the box together were all rusty. There is a pool of goo holding stuff together on the board.
Good: I placed the multimeter on the outputs directly on the board, and measured 36V. So the board seems to work fine, but there's a problem with the cable.
Attachments
This thing might be interesting if I wanted a 5.1 surround system for computer games (but I don't play) or movie watching in a small room on computer screen.
A TDA7498, 6x100w.
Specs from the site...
Main features:
Size: 152.40mm (L) × 122.30mm (W) × 35.00mm (H) ± 2mm
Great class D products
Adjustable gain Group 4 volume set: 25.6 dB, 31.6 dB, 35.1 dB and 37.6 dB
Line-level audio signal input
Mounting holes is very easy to install
A plurality of wiring can facilitate connections
Great and powerful radiator cooling fan so you do not worry about the heat dissipation products
More or less voltage is switched off, current overload protection, overtemperature protection
Parameters:
Power requirements range: 14V ~ 39VDC
Channel Crosstalk: 70dB 1 kHz
Total quiescent current: 40mA standard
Frequency response: 22Hz ~ 22KHz
Total input noise: <50μVf = 22 Hz ~ 22 kH
100W output power THD = 10%, 6 Ω 36 V
80W output power THD = 10%, 8 Ω 34 V
Operating temperature range: 0 ° C ~ 50 ° C
Storage temperature :: -20 ° C ~ 85 ° C
Price: about $50.
A TDA7498, 6x100w.
Specs from the site...
Main features:
Size: 152.40mm (L) × 122.30mm (W) × 35.00mm (H) ± 2mm
Great class D products
Adjustable gain Group 4 volume set: 25.6 dB, 31.6 dB, 35.1 dB and 37.6 dB
Line-level audio signal input
Mounting holes is very easy to install
A plurality of wiring can facilitate connections
Great and powerful radiator cooling fan so you do not worry about the heat dissipation products
More or less voltage is switched off, current overload protection, overtemperature protection
Parameters:
Power requirements range: 14V ~ 39VDC
Channel Crosstalk: 70dB 1 kHz
Total quiescent current: 40mA standard
Frequency response: 22Hz ~ 22KHz
Total input noise: <50μVf = 22 Hz ~ 22 kH
100W output power THD = 10%, 6 Ω 36 V
80W output power THD = 10%, 8 Ω 34 V
Operating temperature range: 0 ° C ~ 50 ° C
Storage temperature :: -20 ° C ~ 85 ° C
Price: about $50.
