post #3229 gives you an example how you can calculate maximum power needed, in my opinion for 1 channel.
speakerprotection board mostly take AC in, many small transformers are offered on ebay, don't forget this amp is BTL.
Thanks! Something like this might be the better option
100W 18V 5.6A
Thanks! Silly, I was not even paying attention that spk.protec. boards need AC12V
However, I see that not many bother about these boards, and just run amplifiers without one, as chip itself has DC protection anyway. The only issue is that POP while switching ON/OFF, that is not even issue if volume pot of the preamp for exp. is turned down. Or am I missing something more here
Is on/off pop reduced too? does your preamp come with XLR too? sometimes I feel every connection part on top chipside is more sensative to noise, but could be psychologicalthe groundplane is a shield though
BTW thank you for "glare" translation. To me outputfilter or powersupply caps sounds more likely for the cause. Did you open the little box already? I suppose the battery of elco's is for powersupply, but near inductors the photo also shows 2 smaller elcos, are they for powersupply decoupling too, they seem too far away
My Audio Research LS7 line stage does not have balanced XLR outputs, just single ended RCA outputs. The slight on/off pop I had sounds a little louder than before I increased the capacitance from 1uF to 3.3uF on the inputs. I thought it would be diminished, but that is not the case.
In modding this unit and other TPA31xx amps, I have found the following:
- I don't think there will ever be a consensus on what power supply works best. I've tried a modified SMPS and obtained decent results. I have not tried batteries. I am quite pleased with my upgraded Astron RS-12A regulated linear power supply, but I didn't spend a whole lot of money on this either since I found a mint condition unit on Craigslist for $20. With these really efficient amps, the power supply is the foundation of the amp. Garbage in = garbage out.
- Installing the 330uF/25V Panasonic SEPF OSCON caps on the power supply decoupling positions and 220nF/250V TDK X7R ceramic caps on the bootstrap positions made the greatest overall improvement in sound quality. If that's all I did, I would be pleased with the results.
- Installing the 10uH Coilcraft SER2915L-103LQ inductors made further refinements to the amp making it more transparent. It was a very nice improvement that was worth the effort. For an easier modification, installing the Bourns 2100 inductors might be better with similar sound quality results. I guess I just like the funky appearance of the Coilcraft inductors.
- Increasing the input AC coupling capacitance from 1uF to 3.3uF has improved bass response, but reading how most people use these amps, it may not be necessary if you have speakers that roll off the bass anyway.
You could be correct that the output filter or power supply caps could be contributing to the heightened upper midrange on the SMSL SA-36A Pro TPA3118 amp. As I played it more, it did smooth out a bit, but that pop noise on powering the unit off with the volume turned down was pretty loud. I'll continue to work with it. I haven't opened up the amp enclosure yet, because I wanted to make sure it operated properly before breaking the foil tape seal on the case. I think once that tape is broken, the warranty is voided.
If you don't have tpa amp in 20dB gain mode you can shortly mute the amp and it will play in 20dB gainmode till power has been taken off. This changes the inputfilter, so you can hear if increasing the inputcaps is audible for bass on your speakers. From standard 26dB gain it is like doubling the inputcaps value? You can also check that way if it is worth the effort of removing the one 100K resistor (from standard 26dB gain), yes with only one 20k resistor tpa ampboard also selects 20dB gain, you don't need to replace that one for 5k6
Thanks for all your efforts and enlightenment!
I still don't understand - did you get rid of annoying POP in speakers, after all these improvements or not quite? And why you didn't try to implement some of those speaker protection boards yet?
On a side note, about the expenses, I know from my experience of modding tube amp/preamps that expenses could go out of control easily, if 'hi end' parts are entering the game. From your great modifications of (YJ) Blue/Black 2.0 Board I see that for those inductors you have spent perhaps more than for the board itself? The cheapest I found on eBay would cost me some $40USD , and that alone is more than double price of the board itself, which I paid $17. Not sure if I'll go that path anyway. But again, your modified device looks astonishing, and could bet sounds great!
Increasing the input capacitance from 1uF to 3.3uF did not eliminate or reduce the pop I hear on turn-off (I don't hear anything when I turn the amp's power supply on). In fact, it got just a little bit louder, but it is not a serious concern of mine. Eventually, I'll work on eliminating it.
The 10uH Coilcraft SER2915L-103LQ inductors cost me about $15 plus $8 shipping in the U.S. I consider that a very reasonable cost for what they did for the amp. My YJ blue amp cost about $26 including shipping from Hong Kong. If anything, I spent more money on speaker binding posts, RCA connectors and the DC power connector, but with connectors being the weakest link in a circuit, I am willing to pay for good connectors.
I think potentially a very good deal is something like SMSL's SA-36A Pro TPA3118 amp. With more play time, the amp opened up and started sounding pretty smoother. My big concern is the loud turn-off thump. It may have something to do with all those electrolytic caps. I have to open it up and see what can be done to reduce that problem. My Klipsch Forte II speakers are 98dB sensitive, so that pop noise can be annoying.
The 10uH Coilcraft SER2915L-103LQ inductors cost me about $15 plus $8 shipping in the U.S. I consider that a very reasonable cost for what they did for the amp. My YJ blue amp cost about $26 including shipping from Hong Kong. If anything, I spent more money on speaker binding posts, RCA connectors and the DC power connector, but with connectors being the weakest link in a circuit, I am willing to pay for good connectors.
I think potentially a very good deal is something like SMSL's SA-36A Pro TPA3118 amp. With more play time, the amp opened up and started sounding pretty smoother. My big concern is the loud turn-off thump. It may have something to do with all those electrolytic caps. I have to open it up and see what can be done to reduce that problem. My Klipsch Forte II speakers are 98dB sensitive, so that pop noise can be annoying.
That 'loud turn-off thump' really bothers me much. None of my 3 tube amplifiers have such issue, and not even little SMSL SAD-01.
Don't know how and will this power port with filter have any impact on this POP issue once I start to build my set-up, but its here to be used anyway.
Still need to choose a proper PSU that will not break my bank account
Attachments
Here are a few photos of my latest 3116. I have changed the input and power caps as recommended earlier in this thread. There is a 24V SMPS turned down to 22V under the amp. The amp is mounted on a piece of 1/4" plexi above the PS. I haven't wired up a pot yet. The one in the picture is just there to hold the knob in place.
Right now I am using a Weilang DAC with my MacBook for a source. It sounds very good with my CHR70 miniOnkens. Much better than the LM1875 amp I was using. The 1875 didn't have enough power for these drivers.
Hope you like it
Right now I am using a Weilang DAC with my MacBook for a source. It sounds very good with my CHR70 miniOnkens. Much better than the LM1875 amp I was using. The 1875 didn't have enough power for these drivers.
Hope you like it
Attachments
Interesting, I would have expected the 2 amps to have very similar output capability, possibly the LM1875 a little more plus having lower THD. Guess it depends what power supply you gave the LM1875. I have built LM1875 and LM3875 amps and never found them short of power with a good PS.
That 'loud turn-off thump' really bothers me much. None of my 3 tube amplifiers have such issue, and not even little SMSL SAD-01.
Don't know how and will this power port with filter have any impact on this POP issue once I start to build my set-up, but its here to be used anyway.
Still need to choose a proper PSU that will not break my bank account
Are you sure that the thump is not caused by the pre-amp. Try the power amp alone with a shorted input.
I have no such problem yet! My board is still on the road, I'm just collecting and commenting information from others who experience such issues so far.
As I said earlier, none of my tube amplifier with or without preamplifer (modified or unmodified) cause such 'thump', and not even t-amp SMLS that I use during the hottest summer time!
Very cool!Here are a few photos of my latest 3116. I have changed the input and power caps as recommended earlier in this thread. There is a 24V SMPS turned down to 22V under the amp. The amp is mounted on a piece of 1/4" plexi above the PS. I haven't wired up a pot yet. The one in the picture is just there to hold the knob in place.
Right now I am using a Weilang DAC with my MacBook for a source. It sounds very good with my CHR70 miniOnkens. Much better than the LM1875 amp I was using. The 1875 didn't have enough power for these drivers.
Hope you like it
What link? are you refering to my post and Arlen&Alice Trading Co.? http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-326.html#post3946205
If so, yes it looks they have many of those bargains and many pleased customers.
Wonderfull enclosures indeed prezden! Cone looks like paper to me. Current generation drivers MA are 8ohm plus, older ones 4ohm. For 8ohm+ comparing amp specs it would be surprising, but currentlimiting is mentioned for protection in LM sheet and not very clear to me when and how you could hear that. I do know that even the tpa3110 has less trouble driving some speakers then much stronger specced sta510A amp (10watt vs 100watt)
add yes arlen&alice
add yes arlen&alice
It isn't a power supply problem. I use a 24 + 24 toriod along with the regulator board from Chip Amp. For months I have been listening to it and always thought it lacked some power. The CHR70 are not known to be terribly sensitive.
For myself the difference is quite significant.
You are right, thats a good PS. I have never compared the 3116 to any of my chip amps so I take your word for it! How do you thing the sound quality compares?
Yep, I have some Alpair 7.3s in FH3 cabinets, same sensitivity as the CHR70. The 3116 drives them easily, that is till the drivers "hit the stops" which sounds rather nasty!
It's good to know that the TPA3116 can properly drive Mark Audio Alpair speakers. I heard a pair of the Alpair 12p bass reflex monitors at last Fall's Burning Amp Festival, and I was very impressed with how smooth they sounded driven by the low power Pass-designed Amp Camp Amp monoblocks.
I had a little time yesterday to open up my SMSL SA-36A Pro TPA3118 amp, and snapped a photo of the innards.
I took an inventory of some of the items, especially the caps:
Aside from the mild turn-on thump and the louder turn-off pop, this amp has the potential to sound really good, and it is a potentially great value at $50. It is a very quiet amp and it sounds a lot smoother than the first time I used it.
I'll need to study the layout and figure how I can overcome the turn-off pop noise. I am open to any ideas.
I had a little time yesterday to open up my SMSL SA-36A Pro TPA3118 amp, and snapped a photo of the innards.
I took an inventory of some of the items, especially the caps:
- 2x 47uF/35V organic polymer cap, 8mm dia
- 8x 470uF/25V Panasonic M electrolytic caps, 10mm dia
- 4x Pilkor 680nF/450V MKP LC filter caps
- 2x 3.3uF/250V Epcos MKT, 22.5mm LS
Aside from the mild turn-on thump and the louder turn-off pop, this amp has the potential to sound really good, and it is a potentially great value at $50. It is a very quiet amp and it sounds a lot smoother than the first time I used it.
I'll need to study the layout and figure how I can overcome the turn-off pop noise. I am open to any ideas.
The noise is present immediately after turning off the amplifier or a few seconds later?
In the second case, it may be useful to measure the voltage of the power supply, because I would suspect a problem during the transition below the minimum operating threshold (4.5V).
My 2 cents
If the noise is present immediately after turning off the amplifier, it is possible that power switch is sparking.
In such a case, I would try to disconnect the primary side of the power supply (leave the power switch ON, but unplug the amp from the wall) and if the noise has gone, a cap across the switch might help.
In such a case, I would try to disconnect the primary side of the power supply (leave the power switch ON, but unplug the amp from the wall) and if the noise has gone, a cap across the switch might help.