Ebay cheap TDA7498 boards

easp · 2016-10-21 7:15 pm

Mayuri said:
I ordered two of the Sanwu 7498 boards without the volume pot and no RCA inputs. They sound excellent so far, so I can recommend.

I have one of those. I can't complain about the sound. The inductors sure do heat up though. Interestingly, their "deluxe" TDA7498, with RCA and volume pot, has the same inductors, but they run much cooler. That's probably partly due to a bit of spacing between the pairs of inductors, but from photos, it also appears to have additional filtering before the inductors relative to the smaller board.

Bobsone · 2016-10-23 12:32 pm

Thanks for the links,
These amps really are everywhere, I have even seen some rated as 1 and 2kW even 2.5kW.
It is my plan to run a phono preamp and a Bluetooth board into one of these amps so I am wondering how everyone is connecting inputs to one of these. Are people simply plugging their signal source into the amp or are some putting a preamp between the source and the 7498 boards?
Regards.

nenad88 · 2016-11-06 11:29 am

I want to buy this tda7498e red sanwu board. Can someone share are those good, did you have any problems with it? Thanks.

mrmax063 · 2016-11-17 5:45 pm

I'm attaching a few pictures of the Feixiang TDA7498E board that can be found on eBay and AliExpress.

Output section of the board follows manufacturer recommendations. All the necessary components are present, output RC snubber, catch diodes, hybrid LC filter and second EMI snubber. Only thing that they skimped on is the main bulk capacitor and used a single capacitor for both channels, instead of two like on manufacturer's evaluation module. However, the quality and genuineness of certain components is questionable. Output inductors are not precisely wound: one of the inductors on each channel measure 22uH, while the other one on each channel measure 26uH (manufacturer's evaluation module uses 15uH inductors). With the values of used components, output filter is tuned for 4 ohm load. Alignment of through-hole components is surprisingly good, the volume pot is the only major component that has been soldered crookedly. In a few places the soldering flux has not been cleaned completely from the board. Main AC coupling capacitors are ceramic. There's also an auxiliary buck regulator that can be used to power up an external fan or something similar.

I have been testing the board using a laboratory power supply and 6 ohm test speakers. There is no power up or power down thump. The heatsink does get warm, but not too much and you can safely touch it with fingers. As far as sound quality is concerned, when compared to a class AB amplifier that has been hooked to the same speakers previously, upper end of the audio spectrum sounds a little bit harsh to my ears, which may be related to the fact that output filter is not tuned to the impedance of the test speakers.

All in all, if someone is looking for more power, this TDA7498E board is among the cheapest offerings that are currently available.

Buehgemeiste · 2016-11-20 3:24 pm

I finally oredered the red sanwu yesterday.
I could not resist that offer:
https://de.aliexpress.com/item/TDA7...32761996927.html?spm=2114.13010608.0.0.asOEaS

Lo_Tse · 2016-11-20 4:02 pm

Buehgemeiste said:
I finally oredered the red sanwu yesterday.
I could not resist that offer:
https://de.aliexpress.com/item/TDA7...32761996927.html?spm=2114.13010608.0.0.asOEaS

Please keep us posted on how it sounds

Regards,

Series2 · 2016-12-27 2:31 pm

Mark2727 said:
I have no doubt about your statement. But, the fact is, I own a bunch of chip/class D amps with power switches on the DC side.

No matter. It seems people are clueless about the cause of the situation so I will proceed on my own.

Thanks,

Mark

The problem is caused by arcing of the switch contacts when switching capacitive or inductive loads . A switch rated for 5A resistive may only be capable of 1A when there is a large capacitance to deal with. The ideal situation is to switch the A.C. side, but this isn't always desirable so a workaround is needed.

One option is to use a higher rated a switch, with a different contact material, but an easier option is to put a suppression cap across the switch contacts, 220 - 470nf at 250vdc ought to do it, this will suppress the arc before it has chance to burn the contacts.

I also noticed that you are switching the ground line, while this makes no difference from an operational point, it can be unsafe as poking around in a grounded chassis with the supply still present can cause a short or hurt you, even 32v can cause a nasty shock if your hands are a bit sweaty. I suggest breaking the supply line, or both.

seantkezm · 2016-12-27 4:44 pm

Hey Buehgemeiste,
Any word on the red Sanwu 7498E? What are you using to power it?

ravels · 2016-12-27 5:27 pm

I also have this board. The build quality appears to be excellent. It sounds significantly better than a cheap TDA7498E board I tried before. I use it with a pair of Pioneer SP-BS22-LR speakers which are 6-ohms. I haven't tested the coils yet, but I will check them out and I might even try replacing them with 15uH.

Another thing I like about this board is that i also has a differential input option using the five pin connector to the right of the potentiometer. You have to remove R20 and R21 to use this option.

mrmax063 said:
I'm attaching a few pictures of the Feixiang TDA7498E board that can be found on eBay and AliExpress.

Output section of the board follows manufacturer recommendations. All the necessary components are present, output RC snubber, catch diodes, hybrid LC filter and second EMI snubber. Only thing that they skimped on is the main bulk capacitor and used a single capacitor for both channels, instead of two like on manufacturer's evaluation module. However, the quality and genuineness of certain components is questionable. Output inductors are not precisely wound: one of the inductors on each channel measure 22uH, while the other one on each channel measure 26uH (manufacturer's evaluation module uses 15uH inductors). With the values of used components, output filter is tuned for 4 ohm load. Alignment of through-hole components is surprisingly good, the volume pot is the only major component that has been soldered crookedly. In a few places the soldering flux has not been cleaned completely from the board. Main AC coupling capacitors are ceramic. There's also an auxiliary buck regulator that can be used to power up an external fan or something similar.

I have been testing the board using a laboratory power supply and 6 ohm test speakers. There is no power up or power down thump. The heatsink does get warm, but not too much and you can safely touch it with fingers. As far as sound quality is concerned, when compared to a class AB amplifier that has been hooked to the same speakers previously, upper end of the audio spectrum sounds a little bit harsh to my ears, which may be related to the fact that output filter is not tuned to the impedance of the test speakers.

All in all, if someone is looking for more power, this TDA7498E board is among the cheapest offerings that are currently available.

Glasrandkante · 2016-12-28 12:53 pm

Nabend!

I am new here, but read a lot of sites of this thread, since I am a bit fanatic about Speakers and Amplifiers - as long as they are cheap

Why I registered to this forum: I have a few questions:

Are the last two Amps I ordered "good", compared to the ~$100 Sure?
The first one (blue heatsink) has only caps up to 35V on it (according to one review) - I would like to change them, but on one picture they are 1000µF, on the photo of the reviewer, they are 2200µF - I would go for 2200µF and 50 or 63V - or is there a better way?
I would like to build both amps into one casing (with fan inside) with a big 36V PSU - but which one? MeanWell is good but expensive and I fear that a cheap PSU could affect the white noise or something like that?
Since those Amps don't really have a Name, the threads about them are hard to find - do you know threads about modding the boards to make them sound even better?

Thank you very much!

Buehgemeiste · 2016-12-28 6:39 pm

seantkezm said:
Hey Buehgemeiste,
Any word on the red Sanwu 7498E? What are you using to power it?

It is still in transit.
The seller has 22 days left before i can start a dispute on aliexpress.
Something is wrong with shipment from china to my adress in the last few months.
It was much quicker before.

fulvio · 2017-01-13 1:47 pm

Hi, I have some questions about TDA7498 boards:
- did anybody test these boards with a 4 ohm load?
- did anybody measure the damping factor of one of these boards?
- did anybody test the stand-by mode?
(I’m considering the possibility to use the stand-by condition as an alternative to the complete switch off operated by a switch in series with the power supply line)

Thanks

Yatsushiro · 2017-01-13 6:43 pm

I have 3 TDA7498 boards; I use the stand by and mute modes on all 3. Quite simply, it works...

coffeeguy1898 · 2017-01-18 9:43 am

TDA 7498 Subwoofer board

TDA 7498 Subwoofer board
I have been thinking about using this board as an amp for a passive subwoofer I have and was wondering if anyone has had any experience with this? I was searching through this thread and it looks like the 7498 boards that are being used here are stereo boards as compared to this one.

Would also appreciate it if anyone could point me in the right direction for a datasheet for this board. The only ones I am able to find seem to be for the stereo boards.

TIA.

Yatsushiro · 2017-01-18 10:29 am

I looked at that amp for a subwoofer build I've just completed, but ended up buying and using one of these (I preferred not to have the volume control on board):

https://www.aliexpress.com/item/TDA...32682783085.html?spm=2114.13010608.0.0.ONOjyT

Built it at the weekend, running @ 32v, with an ALPS pot for volume control and push button mute/standby switch. Works very well, produces the noise and volume it's supposed to.

It uses the TDA7498MV chip, datasheet etc here:

http://www.st.com/en/audio-ics/tda7498mv.html

t-minik · 2017-01-18 3:36 pm

hello.

I read most of the topic and i'm a bit confused ! sooooo many boards.
i want to try one of these tda7498e boards.
i seen that sanwu boards were prety good.

So sound quality wise, which one should i buy :
the 160+160 red board ?
or 100+100 blue one ?

best regards

Yatsushiro · 2017-01-18 4:42 pm

t-minik said:
hello.

I read most of the topic and i'm a bit confused ! sooooo many boards.
i want to try one of these tda7498e boards.
i seen that sanwu boards were prety good.

So sound quality wise, which one should i buy :
the 160+160 red board ?
or 100+100 blue one ?

best regards

The TDA7498e are the 160W boards, the 100W are TDA7498 (and for completeness, the mono are TDA7498MV)

For sound quality (driven by a Pi running Rune through a Kali and Mamboberry LS DAC+), this is my favourite:

Amplifier Board 2x100W TDA7498 D Class High-Power & Radiator 7A DC20V to 36V | eBay

I tried this Sanwu, which allows full access to the gain, standby and mute controls, but I found it very 'noisy' and not as nice to listen to as the one above...

12V 24V TDA7498 Class D 2X100W Dual Channel Audio Stereo Digital Amplifier Board | eBay

t-minik · 2017-01-18 7:19 pm

thanks a lot.

I just bought the 1st one you point me in.
what are the three 2pins connectors ? i guess Mute, StdBy but what's the third ?

I bought a red sanwu TDA7498E too .

will see for a big linear psu if it sounds good with smps fx-audio one (32V 5A).

thanks again

Yatsushiro · 2017-01-18 7:44 pm

The third jst socket is a voltage out, apparently up to 13v, controlled by the potentiometer next to the heatsink.

ravels · 2017-01-19 12:54 am

If you are going to use 4-ohm speakers and max (36V) power supply, you may want to get a TDA7498E board. This is a good one:

TDA7498E 2x160W Amplifier Board

It lets you configure gain settings with a mini-DIP switch, has an auxiliary adjustable DC output (e.g. to drive a fan) and also provides access to differential inputs (but you have to remove a few resistors).

Ebay cheap TDA7498 boards

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