OK. (was the idea of the datasheet 3.3R/100nF RC to have that effect , but doesnt work?)
I'll have a look at the circuit you posted, see if it will fit in with my plan in that area of board.
WHAT VALUES?
Does the 750K resistor in your example circuit go where the Mute 100K resistor is? Or is it a seperate 2nd resistor?
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The 3R3+100nF is something different.
The 750k goes from MUTE to GND, with a schottky diode in parallel, cathode to MUTE, anode to GND. The cap is connected between GVDD and MUTE. I don't have a 100k there.
So, for the datasheet:
http://www.ti.com/lit/ds/slos708d/slos708d.pdf
Figure 37:
R14 is changed for the cap, and 750k + diode is extra to GND.
The 750k goes from MUTE to GND, with a schottky diode in parallel, cathode to MUTE, anode to GND. The cap is connected between GVDD and MUTE. I don't have a 100k there.
So, for the datasheet:
http://www.ti.com/lit/ds/slos708d/slos708d.pdf
Figure 37:
R14 is changed for the cap, and 750k + diode is extra to GND.
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Think I got it. R14 in figure 37 is the 100k between mute & ground on my board. So I replace this with 750k, with a parallel schottky.
I then bridge the 1uf cap across from the gvdd trace (before it hits resistor divider) to join mute at R14 750k. The mod doesn't go near SDz/faults trace!
If I were to replace the R14 with the cap, it wouldn't connect to gvdd.
Sorry, my fault. You're right, R14 is changed for 750k+diode, cap is extra between GVCC and MUTE.
If you can't find a schottky, a normal diode will do as well. (It additional clamps the negative discharge voltage/current from the cap when switching off. (Additional to the internal input protection diodes)
If you can't find a schottky, a normal diode will do as well. (It additional clamps the negative discharge voltage/current from the cap when switching off. (Additional to the internal input protection diodes)
Ok, got it. gonna have to look again at input cap plan because of cap gvdd to mute, but where theres a will theres a way.
i've also figured an easy enough way to config pin 17 avcc mod with resistor connecting to pvcc after 1nf cap decouple, and straightens out the "crossing" 1nf/100nf (personal preference). just waiting for copper trace to be delivered!
Should have asked.... diode values?
i see the batzfilm in wiki version is 40V 0.35A. is your version same?
mainly its the A i need clarification. V will be alright above pvcc.
cheers.
Anything from 50mA will do, even voltage ratings can be as low as 10V, absolutely not critical.
Ok. supplier I am ordering resistors from does shottkey diodes in range of your suggestion. I'll just add a handful to the order.
just got to narrow down which 1uf's to get, spec sheets up to eyeballs, and thats me done on aignal and power. just outputs to tackle!
😀
cheers for help.
The 1uf at the MUTE pin isnt critical. You may go for X5R or X7R 10V.
I would suggest Murata or Taiyo Yuden.
(In case you want it small smt)
I would suggest Murata or Taiyo Yuden.
(In case you want it small smt)
Is anyone using a 2.1 board (or even the 4.1!) and happy with it?
I understand they weren't particularly rated at first but I can't seem to search for '2.1'
I understand they weren't particularly rated at first but I can't seem to search for '2.1'
lol... that wasnt clear of me. i meant the 1uf for other places such as gvdd decouple etc. thia mod will just have to make do with same as cheaper and easier to buy in 10's for me.😱
That surprised me as the 3116 evm value is 16V for this gvdd/plimit to gnd.
Don't pay too much enthesis on the voltage anyhow, as long as minimum recommended or above.
So I'm going to skip the ready built 2.1 amp
Is there anything wrong with my plan below?
Use this board for the left and right
http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB
I'll also run the source to this low pass filter (This filter has a single ground for right and left source, is that a problem?)
http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB
Then I'll amplify the low pass filters mono output with the amp below set to PBTL and wire that to the sub
http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB
Is there anything wrong with my plan below?
Use this board for the left and right
http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB
I'll also run the source to this low pass filter (This filter has a single ground for right and left source, is that a problem?)
http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB
Then I'll amplify the low pass filters mono output with the amp below set to PBTL and wire that to the sub
http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB
Hi Audioje!
I'm using this 2.1 board every day from early 2014 without any issue. It sounds smooth, detailed, no hiss or sibilance, 330pf/10Ohm Bootstrap Snubber Mod highly recommended. And yes! I'm very happy with it!
http://www.ebay.com/itm/Class-D-TPA...724?pt=LH_DefaultDomain_0&hash=item5d43b3a71c
PS: Try it with a 12V car accu attached, and you'll not believe your ears...
Cheers
egra
Attachments
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Hi Audioje!
I'm using this 2.1 board every day from early 2014 without any issue. It sounds smooth, detailed, no hiss or sibilance, 330pf/10Ohm Bootstrap Snubber Mod highly recommended. And yes! I'm very happy with it!
PS: Try it with a 12V car accu attached, and you'll not believe your ears...
Cheers
egra
Thanks Egra
I believe that model doesn't have a low pass filter
How did you tune your sub?
16V is a common value for caps, thats why. If you have a look into the specs right from the beginning, you'll see the voltages for GVDD etc.
They state to have 1uF at given voltage. But because the commonly known dc-bias of class-2 ceramics, you have to make sure to meet that requirement.
Depending on the dc-bias of your choosen cap, you may run in trouble because i.e. some 16V rated caps will have -40% at 7.5V while others only have -20% and are rated just 10V.
Thats why i recommend Murata or TY, as they offer "good" dc-bias vs. capacitance vs. case-size.
Ceramic Capacitors FAQ | Murata Manufacturing Co., Ltd.
So, for class-2 ceramics, you will always make sure to have your capacitance at your desired voltage. This also is somewhat dependet on the case size.
So, sometimes you'll end up with with 6.3V/10V/16V/25V even if you only need some 3V..
http://www.maximintegrated.com/en/app-notes/index.mvp/id/5527
Links stripped and not working.
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Some info on 2.1 low pass filter from another forum:
"I have one of the YJ 2.1 amps. I have been listening to it and testing it for about a month. I like it pretty well, but couldn't resist modifying it.
Stock form:
Left and right RCA inputs go direct to the two main channels through a 50k volume control and two 1uf caps in series (oddly one is film, the other is ceramic). The 'trible' control is just a high cut shelf filter with no boost (not even constant corner frequency), and I didn't find it very useful. The bass channel gets the sum of L+R after the volume control, then passes through a 72Hz -12dB/octave Salen-Key active filter, then a bass level control, before going to a buffer/inverter that allow it to get up to 100W rms into a 2 ohm (50W into a 4 ohm) subwoofer load.
In stock form, the distortion performance is reasonable (~.06%), but the low frequency rolloff is somewhat high at about 30 Hz.
It sounded pretty good to me until I made measurements and realized what I was missing at the bottom.
Microsurgery:
I replaced 6 small surface mount resistors and two SM capacitors with higher values to improve the low frequency response (noise is a non issue). Now it is about -1dB at 20Hz instead of -4dB to -6dB at 30Hz. It was decent before; it is really nice now.
I also cut three traces on the board, and rewired the 'trible' pot into the Salen Key filter, so now I have variable low pass frequency from 35 Hz to 1400Hz. The other mod I did was add a closed circuit 3.5mm stereo jack to the back panel above RCAs between the low pass and the bass level control so that I can use either the internal crossover when nothing is plugged into the jack, or use the full range direct input to the sub and use my miniDSP for high pass to the mains and low pass to the sub."
I'm using Clarion car LS set. 4" widerange satellite speakers and 12" sub. The satellite speakers are in an open baffle cabinet.
Cheers
egra
"I have one of the YJ 2.1 amps. I have been listening to it and testing it for about a month. I like it pretty well, but couldn't resist modifying it.
Stock form:
Left and right RCA inputs go direct to the two main channels through a 50k volume control and two 1uf caps in series (oddly one is film, the other is ceramic). The 'trible' control is just a high cut shelf filter with no boost (not even constant corner frequency), and I didn't find it very useful. The bass channel gets the sum of L+R after the volume control, then passes through a 72Hz -12dB/octave Salen-Key active filter, then a bass level control, before going to a buffer/inverter that allow it to get up to 100W rms into a 2 ohm (50W into a 4 ohm) subwoofer load.
In stock form, the distortion performance is reasonable (~.06%), but the low frequency rolloff is somewhat high at about 30 Hz.
It sounded pretty good to me until I made measurements and realized what I was missing at the bottom.
Microsurgery:
I replaced 6 small surface mount resistors and two SM capacitors with higher values to improve the low frequency response (noise is a non issue). Now it is about -1dB at 20Hz instead of -4dB to -6dB at 30Hz. It was decent before; it is really nice now.
I also cut three traces on the board, and rewired the 'trible' pot into the Salen Key filter, so now I have variable low pass frequency from 35 Hz to 1400Hz. The other mod I did was add a closed circuit 3.5mm stereo jack to the back panel above RCAs between the low pass and the bass level control so that I can use either the internal crossover when nothing is plugged into the jack, or use the full range direct input to the sub and use my miniDSP for high pass to the mains and low pass to the sub."
I'm using Clarion car LS set. 4" widerange satellite speakers and 12" sub. The satellite speakers are in an open baffle cabinet.
Cheers
egra