Linear power supply? I mean it's going to take a good amount of time for the bank to discharge after shut down, and meaninglessly excessive capacity, but pretty harmless. (Caveats of power limiting start up acknowledged)
As you rightly say, startup current will be a problem. To counter that I am going to use a soft start circuit.
But I have read in Class A forums that they use 100000 uf per channel, doesn't it help?
My understanding of class A is that they need better filtering than either class D or A/B. I am using 30K uf just because. I feel like 15K uf would probably be plenty enough.
One it's fairly simple to figure out how much the rails will sag under such load, especially if one takes a conservative assumption that you don't get any help from the transformer supplying current. Two the low frequency psrr is liable to be very good (can't remember if there's a plot in the datasheet, but you're down where there's a ton of loop gain). Three, are you actually pushing these amps so hard as to truly load down the rails? Pro sound maybe, home, not likely at all.
Was the amp SE classA where the active element/pass transistor was acting as a shunt? If so the capacitance requirement is decreased very substantially as in such a case the amp draws a constant current under all signal conditions.
What I did was to connect a DMM to the supply lines of my 3251 amp and playing it at moderate volume.
The digits were moving all the time, and variation was more when drums sounded. I dont remember the reading, but I can redo the experiment anytime.
The digits were moving all the time, and variation was more when drums sounded. I dont remember the reading, but I can redo the experiment anytime.
Anyone tried a Cap Multiplier with the TPA3255?
I am planning on building thehttp://www.diyaudio.com/forums/solid-state/297921-jumas-easy-peasy-capacitance-multiplier-28.html#post5215388 to try with my TPA3255 boards
I am planning on building thehttp://www.diyaudio.com/forums/solid-state/297921-jumas-easy-peasy-capacitance-multiplier-28.html#post5215388 to try with my TPA3255 boards
good afternoon. did anyone have a problem with sibilants? TPA3255 300W +300W DC50V 3900UF/100V*2 Channel Digital Power Amplifier Board | eBay
Interesting question!
I only have the 3e-audio board and it has no sibilance if anyone wondered. I used to get that with some of the cheaper tpa3116 boards before mods.
I only have the 3e-audio board and it has no sibilance if anyone wondered. I used to get that with some of the cheaper tpa3116 boards before mods.
It'd really be better to actually get a trace, as that is hardly a robust test. And far more important, are you seeing scads of distortion from PSU modulation? If not, and I'm going to assume not, this is digging around trying to invent a problem that isn't there.