SAME THING TO ME !
This is exactly what i was thinking & what i experienced. T2 warmth in the mids masks some details that extend to the highs too. For example, sure shows a lot of detail with high frequencies & T2 lacks a lot of this information. I reduced t2 input caps from 3.3uf to 2uf. Mids are better but highs are the same. There is a bad quality 0.1uf paralleled to the (+)-(-) of the outputs which is not mentioned on the hifimediy schematics. I will put an mkp1837 in its place (i ordered some). Another thing which is not good in terms of sound (but it protects) are the protection relays. I have a moded Audiolab 8000p power amp which had crap quality output relays. When i changed them with Japanese made ones, the sound was great. I opened the crappy ones and their contact were almost melted - so good quality relays is an issue on t2 & the affect high frequencies sounding crisp & clear. So if i can get the "sure" extension in high frequencies, then T2 will be one of the greatest inexpensive class-d amp out there. The 10000uf cap on t2 gives it better control with bass lines. Believe me "sure" is out of competition here.
jyoung070848 --> lets improve both amps. As i said to you, trial & error will lead to our best results.
Vassilis
This is exactly what i was thinking & what i experienced. T2 warmth in the mids masks some details that extend to the highs too. For example, sure shows a lot of detail with high frequencies & T2 lacks a lot of this information. I reduced t2 input caps from 3.3uf to 2uf. Mids are better but highs are the same. There is a bad quality 0.1uf paralleled to the (+)-(-) of the outputs which is not mentioned on the hifimediy schematics. I will put an mkp1837 in its place (i ordered some). Another thing which is not good in terms of sound (but it protects) are the protection relays. I have a moded Audiolab 8000p power amp which had crap quality output relays. When i changed them with Japanese made ones, the sound was great. I opened the crappy ones and their contact were almost melted - so good quality relays is an issue on t2 & the affect high frequencies sounding crisp & clear. So if i can get the "sure" extension in high frequencies, then T2 will be one of the greatest inexpensive class-d amp out there. The 10000uf cap on t2 gives it better control with bass lines. Believe me "sure" is out of competition here.
jyoung070848 --> lets improve both amps. As i said to you, trial & error will lead to our best results.
Vassilis
Has anyone tried the new 2x100watt with the bigger fan and new layout? I have tried the old 2x50watt TK2050 sure and it sounded good out of box.
Also, you two (vmed and jyuong) change the output coils?
Adding a low ESR cap like a pana FM on the power rails helps a lot on mine with the bass. Changing the input cap does too.
I haven't gotten around to changing the input filter yet and matching the amp with the load it sees.
Since the Hifimediy went up from 37usd to +50usd the new Sure looks promising.
I don't know if they made a seperat fan circuit on the new one. I remember that people complained that the fan motor was feeding noise into the amp on the old one.
Also, you two (vmed and jyuong) change the output coils?
Adding a low ESR cap like a pana FM on the power rails helps a lot on mine with the bass. Changing the input cap does too.
I haven't gotten around to changing the input filter yet and matching the amp with the load it sees.
Since the Hifimediy went up from 37usd to +50usd the new Sure looks promising.
I don't know if they made a seperat fan circuit on the new one. I remember that people complained that the fan motor was feeding noise into the amp on the old one.
If you have 8 Ohms speakers just go for 0.22uF output cap and zobel cap.
I got 11uH self wound shielded bobbin inductors and by putting this onboard I did set the mids free, got more clarity, soundstage and the lows are much better. Next try with air cored litz .
Added 400uF Nichicon PL-U's to the +5V lines of tc2000 and tp2050 also, worth of doing but a pain to do because I have the 4x100 board.
[]'s
I got 11uH self wound shielded bobbin inductors and by putting this onboard I did set the mids free, got more clarity, soundstage and the lows are much better. Next try with air cored litz .
Added 400uF Nichicon PL-U's to the +5V lines of tc2000 and tp2050 also, worth of doing but a pain to do because I have the 4x100 board.
[]'s
I have a mystery (Vassilis, this may be related to your .1uF poor capacitor). I removed two tiny teardrop shaped devices from the Sure 4x YK2050 board that were labeled R4 and C4, that are between the output inductors and the speaker connection blocks. They look identical and both have 224 printed on them. I measured them and discovered they were both capacitors, 0.208uF, in series that comes out to about 0.1uF. Sure's schematic shows the two to be R4 = 10ohms and C4 = 0.22uF. This should be the zobel, and Sure's picture of the board shows an orange device and a blue device. It looks to me like they just dropped the resistor and replaced it with another 0.22uF capacitor, can that be right?
James
James
That's right. they did put those caps there instead of the zobel network. Just remove those and put there the zobel network. 10 Ohms 1 watt, 220uF 100v. The 0.1uF cap is probably the differential mode output cap. Not a big deal but this one is also missing in the sure boards.
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I have just tried the zobel I calculated for my speakers on the Sure. My speakers are R=4.6ohms, and L=0.057mH, the zobel is Rz=5.75ohms, and Cz=1.72uF. Very different from Sure's Rz=10ohms and Cz=0.22uF. I used Cz=1.0uF, and two 10ohms in parallel for Rz=5ohms. The results are better than I expected, and the sound is very nice. The zobel has reduced most of the peak in the highs.
Now on to the output filter. I unsoldered one lead of an output inductor to measure it. Unfortunately, I am working at the extreme low end of my meter. I got L=0.005mH, or 5uH, while Sure's schematic says it should be L=10uH. The inductors look awfully small for 10uH, but because of my meter, I can't be sure the inductor is wrong.
Has anyone else measured the inductors?
Now on to the output filter. I unsoldered one lead of an output inductor to measure it. Unfortunately, I am working at the extreme low end of my meter. I got L=0.005mH, or 5uH, while Sure's schematic says it should be L=10uH. The inductors look awfully small for 10uH, but because of my meter, I can't be sure the inductor is wrong.
Has anyone else measured the inductors?
OK, now that I have had some time to listen to several varieties of music, I have to take it back. The sound isn't nice, it is more glorious than I ever expected in my wildest dreams, and that is no exaggeration. I also decided I would try out my new Audio Research DAC7, Audiogon special, in place of my 20 year old AR DAC1. Before this round, the DAC7 had sounded edgy and lifeless in the highs, all the things I've always hated in solid state. When I bent down to make the swap I discovered that I already had the DAC7 in the system, I had changed and forgotten it. When I swapped to my DAC1 the sound became ever so slightly vague, though still very good. With the DAC7, all the edge was gone, the sound stage is huge, and the clarity at loud volumes is amazing.
This is the sound I have always wanted, and, I haven't yet changed the output filter to match my speakers, with the much better inductors recommended by trevmar in his web article Trevor Marshall - Class D Audio Amplifier Design - TDA7498 Output filters who knows what may happen. I chose the 33uH, ICE 1D17A Series (mailed today, here in two, I hope). They are too big to fit on the board so I will have to bring them just outside. It will only add a couple of inches to the path, and the inductors are shielded. I have some polystyrene caps on the way. They are supposed to be the lowest distortion types. If I parallel the 0.1uF caps, I can get to the value that matches my speakers, 0.39uF, and that will give a corner frequency of 62,755Hz, not bad.
This is the sound I have always wanted, and, I haven't yet changed the output filter to match my speakers, with the much better inductors recommended by trevmar in his web article Trevor Marshall - Class D Audio Amplifier Design - TDA7498 Output filters who knows what may happen. I chose the 33uH, ICE 1D17A Series (mailed today, here in two, I hope). They are too big to fit on the board so I will have to bring them just outside. It will only add a couple of inches to the path, and the inductors are shielded. I have some polystyrene caps on the way. They are supposed to be the lowest distortion types. If I parallel the 0.1uF caps, I can get to the value that matches my speakers, 0.39uF, and that will give a corner frequency of 62,755Hz, not bad.
I just tried a little capacitor swapping figuring that the new clarity would reveal differences between capacitors. On the zobel, I had polypropylene capacitors so I decided to try some paper in oil I bought because of the craze some people have for them. The soundstage became a little vague and the highs a little fuzzy so back to the polypropylene. Then I moved to the input, I had paper in oil there because a previous test had favored them. So, I swapped them out for polys and the sound stage collapsed toward the center and the highs became fuzzy. What is this? I didn't think capacitors could make this much difference especially when the "bad" capacitor is supposed to have less distortion. The PIO went back in and the sound stage expanded back to an amazing size. I am now wondering if the RFI is feeding back to the poly capacitor causing cross-feed (but no one has mentioned that as a serious problem). The PIO is in a can that prevents feedback by either electrical or magnetic inference and the poly is larger than the caps the board came with, making it more of an antenna. I suppose one test I could try is to enclose the poly in a can and see if the problem lessens.
Hi,
Sure will not send me a new board, I have to give up my biamping project, at least with the Sure. They said this board is old and now no more sold.
Anyway, I'll compare a T1 STA510, stock but the input caps removed, with a MeanWell 36V, and a fully modded Sure TK2050 at 32V, same pot and input caps.
Sure will not send me a new board, I have to give up my biamping project, at least with the Sure. They said this board is old and now no more sold.
Anyway, I'll compare a T1 STA510, stock but the input caps removed, with a MeanWell 36V, and a fully modded Sure TK2050 at 32V, same pot and input caps.
coils
I got the coils today & i will install them on the sure amp.
I will post my results.
I got the coils today & i will install them on the sure amp.
I will post my results.
You are right Virpz, sorry.
Vassilis and Malefoda,
Since LC+zobel output filters are independent of the amp and its effect on the sound is entirely dependent on the user's speakers, I am going to start a new thread open to all boards called "Match Your Output Filter to Your Speakers - All Boards Welcome", I hope you will come and share your results. Anyone in this thread interested, regardless of board, please come.
James
Vassilis and Malefoda,
Since LC+zobel output filters are independent of the amp and its effect on the sound is entirely dependent on the user's speakers, I am going to start a new thread open to all boards called "Match Your Output Filter to Your Speakers - All Boards Welcome", I hope you will come and share your results. Anyone in this thread interested, regardless of board, please come.
James
I have purchased two of the 4 channel boards and started modding them slightly. I am aware that this thread is mend for the 2 channel boards but at the moment i'm soldering on them and got the idea of removing the input capacitors altogether. Posted this message in the other tread too but i admitt it, I am posting it twice to hopefully get an answer faster and since the same could be done to the 2 channel boards, I hope you'll forgive me.
Thing is, they'll be used as poweramps for a 8 channel dsp amp where the signal will be fed bij two minidsp boards wich already got pretty decent 470uF Nichicon Muse output capacitors. This gave me the idea that I probably could do without an extra set of input caps on the Sure boards and in this case, less is more right?
Annyone tried such a thing yet? Can't get less signal alteration from the caps then by removing them altogether i thought
.
Greetings, Reinder
Thing is, they'll be used as poweramps for a 8 channel dsp amp where the signal will be fed bij two minidsp boards wich already got pretty decent 470uF Nichicon Muse output capacitors. This gave me the idea that I probably could do without an extra set of input caps on the Sure boards and in this case, less is more right?
Annyone tried such a thing yet? Can't get less signal alteration from the caps then by removing them altogether i thought
.Greetings, Reinder
Sounds great. Thanks all. I was wondering if we should do a very easy mod PDF with the formulas to how to get the right values. There is many good advices in this thread but scattered all over. I can start making it if you will chip in .
If someone could provide me with a very high res picture of the board from top and bottom as a start that would be great (I don't have my sure board available atm.).
Regards
.If someone could provide me with a very high res picture of the board from top and bottom as a start that would be great (I don't have my sure board available atm.).
Regards
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