I changed input caps with Vishay MKT1813 2,2uF, removed input resistors/caps, and changed output coils to Vishay toroidals 4,7uH.
Caps:
Vishay - MKT 1813 - Metallized Polyester Film Capacitor MKT Axial Type
Coils:
Vishay - Inductors - TJ3-HT - Toroid, High Current, High Temperature, Radial Leaded
I can't say I hear any difference from before, might be a bit better sounding overall.
Caps:
Vishay - MKT 1813 - Metallized Polyester Film Capacitor MKT Axial Type
Coils:
Vishay - Inductors - TJ3-HT - Toroid, High Current, High Temperature, Radial Leaded
I can't say I hear any difference from before, might be a bit better sounding overall.
I tried to run without a fan, but the heatsink gets too hot. I don't think making it 30% bigger would decrease temp enough to run passive, especially if placed in a box. Anyone tried to take out EMI with filtering?
I see there is an improved board with different heatsink and fan. Anyone tried it? What is the improvement?
I see there is an improved board with different heatsink and fan. Anyone tried it? What is the improvement?
Tuning the filter
Copied from another thread where the poster finds the sound too bright with 10mH coils (even though I am using 3.5mH).
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That is the problem with the Class D amps that have the filter outside the feedback loop. The frequency response is very load dependent at the top. I would try a 12mH coils and if it it still too bright keep increasing until the sound is just on the edge to maintain as much ripple and loss (good for the sound even if it is inefficient) as possible. You can then add a Zobel to tame the last of the edginess. (R and C in series, the whole in parallel between the speaker terminals). Start with .47uf and 10 pieces of 70 ohm 1/4 watt resistors twisted together in parallel to make 7 ohms. Measure and listen as you cut one resistor at a time to raise the value until you get just enough peak remaining to bring out the detail but not so much that it still sounds too bright. Probably around 10-15 ohms. Once you get an idea of the value, you can replace the parallel resistor mess with something nicer in a 5 or 10 watt resistor. It is a hassle to do this and the results are only good for one particular speaker but it is worth it in order to get the best resolution from the Tripath chips. I am sure you will find that a text book filter with no peak will sound veiled so measure AND listen as you go.
.
Copied from another thread where the poster finds the sound too bright with 10mH coils (even though I am using 3.5mH).
.
That is the problem with the Class D amps that have the filter outside the feedback loop. The frequency response is very load dependent at the top. I would try a 12mH coils and if it it still too bright keep increasing until the sound is just on the edge to maintain as much ripple and loss (good for the sound even if it is inefficient) as possible. You can then add a Zobel to tame the last of the edginess. (R and C in series, the whole in parallel between the speaker terminals). Start with .47uf and 10 pieces of 70 ohm 1/4 watt resistors twisted together in parallel to make 7 ohms. Measure and listen as you cut one resistor at a time to raise the value until you get just enough peak remaining to bring out the detail but not so much that it still sounds too bright. Probably around 10-15 ohms. Once you get an idea of the value, you can replace the parallel resistor mess with something nicer in a 5 or 10 watt resistor. It is a hassle to do this and the results are only good for one particular speaker but it is worth it in order to get the best resolution from the Tripath chips. I am sure you will find that a text book filter with no peak will sound veiled so measure AND listen as you go.
.
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SMPS that have a third Safety Earth/PE pin should always be connected to PE ! Since they are equipped with a net filter to avoid emission of RFI they need to get rid of this via the PE pin. Of course the primary goal is safety when live AC wiring touches the metal case of the SMPS. When PE is not connected half of the net voltage will be at the case of the SMPS because of the used net filter !! Not safe, not good. So please connect the PE pin to PE for correct functioning of the SMPS and you and your families safety.
On the subject of connecting signal GND to PE (which is a popular subject the last days it seems): I would never connect signal GND to PE directly as pollution from PE will creep into the audiocircuits which has no benefits. On the contrary. It is better to connect signal GND with 10 to 100 Ohm to the metal chassis case (which must be connected to PE). I only recently learnt that Mr. Pass uses a CL60 thermistor or NTC ( 10 Ohm at 25 degrees celsius) for this which seems a simple and elegant solution for this. Look at page 2 and 3 how to connect it.
http://passdiy.com/pdf/balzenpre.pdf
Problem with directly connecting signal GND to PE is that "ground loops" are unavoidable. Just think of the coax antenna cabling of the FM tuner of which the braid is connected to PE => loop !
On the subject of connecting signal GND to PE (which is a popular subject the last days it seems): I would never connect signal GND to PE directly as pollution from PE will creep into the audiocircuits which has no benefits. On the contrary. It is better to connect signal GND with 10 to 100 Ohm to the metal chassis case (which must be connected to PE). I only recently learnt that Mr. Pass uses a CL60 thermistor or NTC ( 10 Ohm at 25 degrees celsius) for this which seems a simple and elegant solution for this. Look at page 2 and 3 how to connect it.
http://passdiy.com/pdf/balzenpre.pdf
Problem with directly connecting signal GND to PE is that "ground loops" are unavoidable. Just think of the coax antenna cabling of the FM tuner of which the braid is connected to PE => loop !
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Just saw this in another thread :
http://www.diyaudio.com/forums/diya...ponent-grounding-interconnection.html?garpg=2
It had this comment which I have seen in amps from the seventies/eighties (I think in Onkyo Amps):
There are more ways to Rome. It is important to build things safe and at the same time "RF/audio clean".
http://www.diyaudio.com/forums/diya...ponent-grounding-interconnection.html?garpg=2
It had this comment which I have seen in amps from the seventies/eighties (I think in Onkyo Amps):
There are more ways to Rome. It is important to build things safe and at the same time "RF/audio clean".
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filter caps
I haven't had a chance to compare the stock filter caps to the Dayton foil yet because up until now, I have always removed the stock caps to gain access for the removal of the stock coils.
Many thanks, Scott,
I have forgotten to ask, regarding your schematics from the post #14 in another thread (New TK2050 board) - is the Zobel filter absolutely necessary?
I have already installed 4,7uH Wurth XXL coils, stock C1 and C2 are .68uF and stock Zobel filter values are 10R/1uF.
Contrary to the others the overall sound is a bit dark which I do not like.
What could I expect if I add a differential cap across the speaker outs?
Thanks, Baki
Zobel empty
I think you will find that the stock pads for the zobel are empty. I have never listened to the stock caps with modded coils so I don't know how much the sound will change if you change caps.
Sorry for the confusion, my mistake
I am using the 2 channel version with passive cooling and zobel is implemented.
So, it is worth to try it without zobel, with just an lc filter (and differential cap). Or not?
That's my last question, I promise
Thanks, Baki
Attachments
try it
Removing the Zobel should brighten the sound by allowing the big ultrasonic peak from the small coils to develop more fully.Sorry for the confusion, my mistake
I am using the 2 channel version with passive cooling and zobel is implemented.
So, it is worth to try it without zobel, with just an lc filter (and differential cap). Or not?
That's my last question, I promise
Thanks, Baki
Hi,I hope you're hearing improvements from your cap swap. It feels so good when you make an amp sound better and you know you did it yourself! I'm not putting down those who send their amps off to others to do the upgrading, but I find it very rewarding to know I made it happen with my own hands, especially when things go wrong and I have to scramble to fix my mistakes and make things right.
16AWG should be plenty. It looks smaller to me in the picture. Of course, some people think more is always better, so if you come across some 0000 welding cable, it'll make great power lines
I've replaced my output coils with 10uH coils I bought from board member Arjen Holder. He makes them for his MkIII TA2020 boards. They're very nice toroids rated at 3 amps and wound on the MicroMetal type 2 cores that Tripath recommends. They're small enough to fit on the TK2050 board and they're inexpensive:
I upgraded the input caps at the same time I installed the coils, so I don't know for sure what part of the improvement was the caps and what was the coils. But the total improvement is significant, much more open, detailed, and balanced. The mids are slightly too forward, but my highs are finally present.
The parts are still burning in and I haven't changed the output caps or added a Zobel or changed the input and feedback resistors yet, so I expect things to get better still. But I love what I'm hearing so far.
I'm also waiting for a fan to arrive so I can play it louder!
-dr_vega
Are those choke coils heating up?
I have bought similar ones from ebay but they are burning hot and I wonder if those ones from Arjen are burning hot or you can touch them?
Can you supply the link for Arjen's choke coils please?
Regards
I hope you're hearing improvements from your cap swap. It feels so good when you make an amp sound better and you know you did it yourself! I'm not putting down those who send their amps off to others to do the upgrading, but I find it very rewarding to know I made it happen with my own hands, especially when things go wrong and I have to scramble to fix my mistakes and make things right.
16AWG should be plenty. It looks smaller to me in the picture. Of course, some people think more is always better, so if you come across some 0000 welding cable, it'll make great power lines
I've replaced my output coils with 10uH coils I bought from board member Arjen Holder. He makes them for his MkIII TA2020 boards. They're very nice toroids rated at 3 amps and wound on the MicroMetal type 2 cores that Tripath recommends. They're small enough to fit on the TK2050 board and they're inexpensive:
I upgraded the input caps at the same time I installed the coils, so I don't know for sure what part of the improvement was the caps and what was the coils. But the total improvement is significant, much more open, detailed, and balanced. The mids are slightly too forward, but my highs are finally present.
The parts are still burning in and I haven't changed the output caps or added a Zobel or changed the input and feedback resistors yet, so I expect things to get better still. But I love what I'm hearing so far.
I'm also waiting for a fan to arrive so I can play it louder!
-dr_vega
So would those choke coils from Arjen (I guess he is from ebay) are recommended for upgrade????
Are they burning hot? Do they heat too much?
thank you
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