But could I be certain that the hiss would disappear completely with a 5k pot? And what would happen to the sound experience if I went for a 5k solution pot? It's a lot of work for me to dismantle the active speakers so I don't wanna go for a 10k pot only to have to do it once again for a 5k.. The speakers have decent sensitivity and are used on my desk next to the computer screen, so ideally there should be no noise at all. This is no high end setup by any means so would a 5k work?
Being a bank holiday got a couple hours to start some modding. Replaced the DC caps with some 470uf 35V, and as I pulled off the heatsink a few nights ago to test temperature of IC, I yanked out the 1nf ceramic smd DC cap bypass and dropped in a 1nf 100V (not smd).
Have to say, just by listening the vocal range of frequencies jump forward 12inches. And not in a bad way. More spacial. Even standing off to the side of drivers, virtually 90degrees off axis the sound has exploded.
Wanted to add some 100nf replacements at same time but those I got were too massive to use. Gonna add PP 100nf next week. Probably some WIMA.
Have to say, just by listening the vocal range of frequencies jump forward 12inches. And not in a bad way. More spacial. Even standing off to the side of drivers, virtually 90degrees off axis the sound has exploded.
Wanted to add some 100nf replacements at same time but those I got were too massive to use. Gonna add PP 100nf next week. Probably some WIMA.
Hi,
I have not been active on here for a few years, but now fancy a little tinker. I ordered one of the black/blue boards today and I am starting to sort through all of my components to find out what I do and don't need to order. I have a couple of 3.3uf Ampohm polypropylene input capacitors and wondered if these will be suitable for this board?
http://www.farnell.com/datasheets/327360.pdf
Many thanks
Richard
I have not been active on here for a few years, but now fancy a little tinker. I ordered one of the black/blue boards today and I am starting to sort through all of my components to find out what I do and don't need to order. I have a couple of 3.3uf Ampohm polypropylene input capacitors and wondered if these will be suitable for this board?
http://www.farnell.com/datasheets/327360.pdf
Many thanks
Richard
this makes some sense to me, with no educated reason why it would, other than the harder it works the more it might lose fidelity... Though loudness is still wattage, regardless of changes to gain right?
anyway, back to the questions I was trying to get a hold on a few posts back, reducing gain increases input impedance. Wouldn't that increase the hiss, if it really is the low current input, by doing that?
I guess I'm having trouble believing that's the source of my hiss though. I should ground all my audio inputs and take a listen....
No, the rise of internal input impedance does not contribute to additional hiss.
It is a minor mod - just check it out!
Just for that reason I set my all TPA-amps to lowest gain available.
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Changed my gain down to 26dB and it definitely helped a lot. Less hiss, still the same thing with the volume knob but less of it and when the volume is up, it's not audible.
I also read the gain structure guy, informative. Thanks
On the impedance matching, I'm not sure if I get that. Surely you can't "match" impedance, since output are single digit or less ohms and inputs are in the kohm? Or is this back to the volpot resistance vs input impedance thing? I didnt quite get that either.
I also read the gain structure guy, informative. Thanks
On the impedance matching, I'm not sure if I get that. Surely you can't "match" impedance, since output are single digit or less ohms and inputs are in the kohm? Or is this back to the volpot resistance vs input impedance thing? I didnt quite get that either.
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-60.html#post3924399
and subsequent posts.
and subsequent posts.
If you mean which 1nf cap I am referring to, its the 1nf smd cap under the heatsink which is part of the DC power cap circuit going into pins 17/18/19. Cap C23 on the tpa3116 data sheet schematic.
I know everyone seems to think modern smd, minute technology is a god send, but personally I don't.
I replaced it with a larger leaded Panasonic 1nf ceramic with shortest legs I could manage to safely solder, the hiss halved, and the music became more spacial. I did replace at same time as changing the DC power caps to 470uf 35V, so can't be sure of the caps improvement on its own.
Hi, I bought this amp TPA3116 50W X2 Dual Channel Class D Digital Audio Amplifier Board 100W 8V 25V | eBay , and it came today. I tried to replace my old blue YJ board, but got no sound. Blue LED next to volume pot came to life for 2 seconds than died. Maybe I tigered some mute-protection mode somehow, by wrong +- conection to PS (laptop brick).
Any help, please?
Any help, please?
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Hello,
If you have another power supply of the proper DC voltage and amperage try that.
With the volume pot turned all the way down at first of course.
Other, smarter people will no doubt be able to tell you how to measure this board to see if it's functioning properly. Hope they chime in.
Good luck!
Mark
If you have another power supply of the proper DC voltage and amperage try that.
With the volume pot turned all the way down at first of course.
Other, smarter people will no doubt be able to tell you how to measure this board to see if it's functioning properly. Hope they chime in.
Good luck!
Mark