Thanks !
You are correct. It works ok on my board ( but i had to correct the sorted pin9 & pin10 problem done by mistake from factory).
Does anyone hear any kind if digital noises when you put your ear close to the chips underneath the heat-sink ???
You are correct. It works ok on my board ( but i had to correct the sorted pin9 & pin10 problem done by mistake from factory).
Does anyone hear any kind if digital noises when you put your ear close to the chips underneath the heat-sink ???
I just finished my first round of modding. I removed the transient voltage suppressors,
removed the input caps and made a print with these new input caps:
VISHAY ROEDERSTEIN|MKP1839 533 634HQ|CAPACITOR, AXIAL, MKP, 630V, 3 | Farnell Nederland
because I'm going to drive a subwoofer with the board I made a Y-splitter before the input caps.
On the power supply I added one of these:
PANASONIC|ECOS1JP152CL|CAPACITOR, 1500UF, 63V | Farnell Nederland
I plan on using those on the 24V rails on the output chip too, but that will have to wait.
I think removing the transient voltage suppressors helped most on making this things sound a whole lot better. I really have to say I'm impressed, because I only tested with a 75W pioneer speaker I had laying around and it didn't sound very good at first, especially Bass sounds and the very high tones sounded bad to me.
now (to me at least) it really sounds good. I'll have to test it with my passive sub (Canton PlusC), but I think it will work out nice
Quite a good review in my opinion.
With mods and money paid definitely deserves 6-7, maybe 8 (with better PS I guess as did not try that one).
Very sensitive to modification (at least for me who is not expert with soldering iron), hence I have one board with one channel working.
If anybody else has got one board with one channel working, I would be happy to buy?
With mods and money paid definitely deserves 6-7, maybe 8 (with better PS I guess as did not try that one).
Very sensitive to modification (at least for me who is not expert with soldering iron)
, hence I have one board with one channel working.If anybody else has got one board with one channel working, I would be happy to buy?
info
I mean a high frequency like a high speed clock. I wish i could attach an audio file at this forum for you to hear what i'm talking about. Sure told me that if it's not too loud it is ok (!#@$#%$) but shouldn't it be silent ???. I think the boards they sell via ebay are inferior quality & factory seconds than the ones they sell via their web store & i have proof for it.
I mean a high frequency like a high speed clock. I wish i could attach an audio file at this forum for you to hear what i'm talking about. Sure told me that if it's not too loud it is ok (!#@$#%$) but shouldn't it be silent ???. I think the boards they sell via ebay are inferior quality & factory seconds than the ones they sell via their web store & i have proof for it.
Last edited:
Hi guys,
as I wondered, like in a speaker XO, if the copper of a heatsink do change the value of the coil inductance, http://www.diyaudio.com/forums/clas...path-board-tc2000-tp2050-197.html#post2491044 , I'v had a try and checked it out. Sadly with the coils soldered on the amp's PCB, don't know if the coil would have measured the same off.
On the amp's circuit a 4.7uH coil measured 4.14uH at 1KHz, and with the copper heatsink it went down to 4.02.
0.12uH down, maybe not even audible...
I have copper sticker foil I can try, less cooling and less metal. Will report both, big equipments for stupid questions
as I wondered, like in a speaker XO, if the copper of a heatsink do change the value of the coil inductance, http://www.diyaudio.com/forums/clas...path-board-tc2000-tp2050-197.html#post2491044 , I'v had a try and checked it out. Sadly with the coils soldered on the amp's PCB, don't know if the coil would have measured the same off.
On the amp's circuit a 4.7uH coil measured 4.14uH at 1KHz, and with the copper heatsink it went down to 4.02.
0.12uH down, maybe not even audible...
I have copper sticker foil I can try, less cooling and less metal. Will report both, big equipments for stupid questions
another thing .
Just to finish with my review i want to add this one too.
There is a lack of depth with this board. It just gives you the impression that this is the Left channel & this is the Right. Instruments don't take place anywhere. It is just a 2d stereo performer. Like the feeling you get with PC speakers.
I will start doing some modifications. Lets see if it can gain a higher rate. So far still 5 out of 10...
Just to finish with my review i want to add this one too.
There is a lack of depth with this board. It just gives you the impression that this is the Left channel & this is the Right. Instruments don't take place anywhere. It is just a 2d stereo performer. Like the feeling you get with PC speakers.
I will start doing some modifications. Lets see if it can gain a higher rate. So far still 5 out of 10...
I think you got a bad batch?
For 40 bucks I have never tried anything that images as well as the T-amps with a very dark background. I have a lot of sure amps and they are not as good as the 41hz amps (not close even), but for the money they perform very well. They beat every "low-fi" receiver I have pitted it against (sony, yamaha, onkyo, technics). BTW this is for the TK2050 amp, the 2024 sure amps are basically toys as they require a lot of modding to get the noise level down. An amp32 from 41hz is a better bet in that case.
Have you measured the offset? Change the crappy input caps. That very simple mod gives more bass and better imaging. After that, I swapped the bulk caps with some panasonic FMs instead of the noname ones. Low ESR is really important with these amps.
Swapping the coils is also beneficial, but at that point you might as well have bought a Hifimediy or a 41hz in my opinion.
For 40 bucks I have never tried anything that images as well as the T-amps with a very dark background. I have a lot of sure amps and they are not as good as the 41hz amps (not close even), but for the money they perform very well. They beat every "low-fi" receiver I have pitted it against (sony, yamaha, onkyo, technics). BTW this is for the TK2050 amp, the 2024 sure amps are basically toys as they require a lot of modding to get the noise level down. An amp32 from 41hz is a better bet in that case.
Have you measured the offset? Change the crappy input caps. That very simple mod gives more bass and better imaging. After that, I swapped the bulk caps with some panasonic FMs instead of the noname ones. Low ESR is really important with these amps.
Swapping the coils is also beneficial, but at that point you might as well have bought a Hifimediy or a 41hz in my opinion.
Thanks !
This is my opinion for an unmodified board. I will do these modifications and re evaluate .
This is my opinion for an unmodified board. I will do these modifications and re evaluate .
Stumbled apon this 4 Channel 100Watt TDA7498 and was wondering if it would be suitable to power 1 silk dome tweeter per channel at 8 ohms with 100 watts. going to be building a pair of AR-LST mains for live sound usage with 100 watt tweeters, I would be using 2 of these amps per cab to power the highs.
Would I get 100 watts out of each channel when loading it with 8 ohms? asking because I see that it is 100 watts per channel at 6 ohms.
Would I get 100 watts out of each channel when loading it with 8 ohms? asking because I see that it is 100 watts per channel at 6 ohms.
So far so good
Removed diode suppressors from the input. Changed input caps with 2x ERO MKC1820 polycarbonate (bypassed with vishay mkp1837 10nf). Put a 1000uf panasonic fc at the 5v rails.
Put some extra nichicon muse 1000uf per channel, now total capacitance is about 2000uf per channel. I'm waiting for parts to build a zobel filter with 0.47uf & 10ohm resistor. Offset with a 6ohm load is set at 5mv (that was the best i could do).
I'll finish it soon and post my reviews here. Havoc8 ! Lets see if it is worth it.
Removed diode suppressors from the input. Changed input caps with 2x ERO MKC1820 polycarbonate (bypassed with vishay mkp1837 10nf). Put a 1000uf panasonic fc at the 5v rails.
Put some extra nichicon muse 1000uf per channel, now total capacitance is about 2000uf per channel. I'm waiting for parts to build a zobel filter with 0.47uf & 10ohm resistor. Offset with a 6ohm load is set at 5mv (that was the best i could do).
I'll finish it soon and post my reviews here. Havoc8 ! Lets see if it is worth it.
Last edited:
First post, plenty of questions...
Hey gang,
First post. Been doing PLENTY of reading/research on here and the net before attempting this project. I just got myself one of these amps (AA-AB32181 to be exact). Powered with the S-145-24 MW amp (28v). I have put the infamous blue Zalman heatsink on it already (with Arctic Silver Ceramique 2). Been listening for a few hours, definitely a fun project and likely has a lot of potential. There are a few questions I had on it.
1. U2 on this amp gets pretty dang warm. This is what makes 5V on the amp? Sorry for my ignorance, I'm no electronics guru, just read the diagram am guessing that's it's job. Anywho, I put a small heatsink on this, as well as U3 (which stays cool). I doubt there is any harm in this, but is this worth doing? Ease of mind, if anything?
2. With the stock heatsink, the fan turned on after 5 minutes or so. I kept the fan plugged in for testing to the side and, with the Zalman on it, I have yet to see it turn on after about an hour of play. Curious, anybody know what temp the fan is supposed to turn on at? Also, multimeter says only 9v at the + prong on J2 fan connector, with grounding directly to the COM from the PSU. Grounding to the - prong on J2, I get around 1v. Not sure why that would be, but I can feel and here the fan sounding like a hard drive, clicking away. Just no movement. Hoping I didn't hurt something when I swapped, as the fan simply never turns on properly.
3. My board came with 2 completely different set of tank caps. The side closest to the power input is the same I have seen in all pics, but the right side say "nichican, 330MF, UG 50V, H0645". It may be a mental thing, but it bugs me to think that each channel has different caps (or, at least, labels on the top). With that, I was debating between adding tank caps and replacing. Should this be more motive to replace rather than add to?
4. The input sensitivity switches (SW1) completely mute the sound when all switches are off. It seems the older version did not do this, as it was recommended to turn these all off in prior documentation here on the forum. What is recommended here? I ended up buying a bunch of 1W 22K resistors with my order, just in case I wanted to play with anything. Are these worth changing, or are there better options?
I think that completes my questioning. I have plenty of plans for this amp and lots of experimenting to do. I'm hoping this amp can really help me learn electronics better, especially with the diagram available and plenty of great help from this forum. Sorry if this is long winded at all.
I attached a pic of my current setup. Don't lol too hard at my shoebox enclosure... It's only temp until I decide how I want to build it.
Hey gang,
First post. Been doing PLENTY of reading/research on here and the net before attempting this project. I just got myself one of these amps (AA-AB32181 to be exact). Powered with the S-145-24 MW amp (28v). I have put the infamous blue Zalman heatsink on it already (with Arctic Silver Ceramique 2). Been listening for a few hours, definitely a fun project and likely has a lot of potential. There are a few questions I had on it.
1. U2 on this amp gets pretty dang warm. This is what makes 5V on the amp? Sorry for my ignorance, I'm no electronics guru, just read the diagram am guessing that's it's job. Anywho, I put a small heatsink on this, as well as U3 (which stays cool). I doubt there is any harm in this, but is this worth doing? Ease of mind, if anything?
2. With the stock heatsink, the fan turned on after 5 minutes or so. I kept the fan plugged in for testing to the side and, with the Zalman on it, I have yet to see it turn on after about an hour of play. Curious, anybody know what temp the fan is supposed to turn on at? Also, multimeter says only 9v at the + prong on J2 fan connector, with grounding directly to the COM from the PSU. Grounding to the - prong on J2, I get around 1v. Not sure why that would be, but I can feel and here the fan sounding like a hard drive, clicking away. Just no movement. Hoping I didn't hurt something when I swapped, as the fan simply never turns on properly.
3. My board came with 2 completely different set of tank caps. The side closest to the power input is the same I have seen in all pics, but the right side say "nichican, 330MF, UG 50V, H0645". It may be a mental thing, but it bugs me to think that each channel has different caps (or, at least, labels on the top
). With that, I was debating between adding tank caps and replacing. Should this be more motive to replace rather than add to?4. The input sensitivity switches (SW1) completely mute the sound when all switches are off. It seems the older version did not do this, as it was recommended to turn these all off in prior documentation here on the forum. What is recommended here? I ended up buying a bunch of 1W 22K resistors with my order, just in case I wanted to play with anything. Are these worth changing, or are there better options?
I think that completes my questioning. I have plenty of plans for this amp and lots of experimenting to do. I'm hoping this amp can really help me learn electronics better, especially with the diagram available and plenty of great help from this forum. Sorry if this is long winded at all.
I attached a pic of my current setup. Don't lol too hard at my shoebox enclosure...
It's only temp until I decide how I want to build it.Attachments
Last edited:
You are right here, it is the 5V regulator. Don't know if the heatsink is needed, but it won't harm to put a heatsink on
cooler is always better.the problem with the fan(controller) here is that it is PWM controlled, and not very well done... the PWM controll starts at a specific temperature, but not on a duty cycle high enough for the fan to start turning, this is probably what you are hearing....
don't know if it really matters, the audio purists here will surely tell you to remove them3. My board came with 2 completely different set of tank caps. The side closest to the power input is the same I have seen in all pics, but the right side say "nichican, 330MF, UG 50V, H0645". It may be a mental thing, but it bugs me to think that each channel has different caps (or, at least, labels on the top
and get bigger better pricier good brand ones instead. better options?
look at the pic,
firstly remove the transient voltage suppressors (black ones),
secondly remove the input caps on my board C18/C19 and C24/C26,
and add some good quality caps on the place I marked before the board.
look at my previous post for an example of good input caps
I noticed a dramatic improvement of sound
(I think mainly because of the voltage suppressors)Attachments
help in 4&7 recipe please
hi boys,
i modded;
passive heat sink to a half Pentium4 that gives 38 Celsius degree in 33.5V
removed D1, D2 and shorted
replaced the input caps and removed the diodes
replaced the tank caps to 3* Pannys FM 1000uf 50V
put the Zoble 0.47uF mkp10 and 12R 1W
replaced the 10mH coils to 4.7mH Wurth
replaced all output caps (6 tot) to 0.47uF mkp4 as sugested in the middle of thread
the result is more clarity and punch compare to unmodded. but some blurring the sound stage! and emphasis on upper midds as well!!! which is not comfortable in long term listening.
now looking for the reason i saw this simulation #952 that showes the curve. has that up-going end to do with my consideration?
soldering back the original caps (0.68 and 0.22uF) will solve the problem? appreciate any help thanks.
hi boys,
i modded;
passive heat sink to a half Pentium4 that gives 38 Celsius degree in 33.5V
removed D1, D2 and shorted
replaced the input caps and removed the diodes
replaced the tank caps to 3* Pannys FM 1000uf 50V
put the Zoble 0.47uF mkp10 and 12R 1W
replaced the 10mH coils to 4.7mH Wurth
replaced all output caps (6 tot) to 0.47uF mkp4 as sugested in the middle of thread
the result is more clarity and punch compare to unmodded. but some blurring the sound stage! and emphasis on upper midds as well!!! which is not comfortable in long term listening.
now looking for the reason i saw this simulation #952 that showes the curve. has that up-going end to do with my consideration?
soldering back the original caps (0.68 and 0.22uF) will solve the problem? appreciate any help thanks.
Last edited:
done with the mods
Well i have to re-evaluate here. I will give it 8/10. This board will work very well paired with a valve pre-amp (with ecc88cc tubes). It becomes musical, dynamic & with strong bass notes also. The only downside is a slight emphasis to the mid to high frequencies. But you can use speakers with a slight roll-off tweeter behavior. Well done here for sure-electronics but i would prefer the hifimediy T2 amp because you don't need to do any mods, it performs the same and even better without touching anything. So 8/10 for the sure (but man way to many mods) 9/10 for the hifimediy T2 (no mods, which will get a 10/10 with just changing the input caps with better quality ones).
Vassilis
Well i have to re-evaluate here. I will give it 8/10. This board will work very well paired with a valve pre-amp (with ecc88cc tubes). It becomes musical, dynamic & with strong bass notes also. The only downside is a slight emphasis to the mid to high frequencies. But you can use speakers with a slight roll-off tweeter behavior. Well done here for sure-electronics but i would prefer the hifimediy T2 amp because you don't need to do any mods, it performs the same and even better without touching anything. So 8/10 for the sure (but man way to many mods) 9/10 for the hifimediy T2 (no mods, which will get a 10/10 with just changing the input caps with better quality ones).
Vassilis
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.