TPA3116D2 has an "over current trip point" of 7.5A (typical). When you divide the supply voltage with the speaker impedance, you should arrive at these 7.5A (or less). 20V (supply) divided by 2.7Ohm leaves a current of 7.4A. So, keep the supply voltage below or at 20V. The chokes I guess can handle 7.5A.
The TDA7498E has more power and better specifications (THD) than the TPA3116. That does not mean you will notice the difference, in particular in your car.
May I be indiscreet and ask what kind of car you drive (a reply is not mandatory but anything can beat my KIA)? Can the generator supply that much extra current?
The TDA7498E has more power and better specifications (THD) than the TPA3116. That does not mean you will notice the difference, in particular in your car.
May I be indiscreet and ask what kind of car you drive (a reply is not mandatory but anything can beat my KIA)? Can the generator supply that much extra current?
Tripath (who made the TA2020) is/was known for making really well sounding class T amplifiers (modified class D). I have a couple (boards) and they sound great. Even the small TA2020 and TA2024 had a very good reputation. Unfortunately, Tripath vent bankrupt in 2007. No new developments have appeared from Cirrus Logic who took over the company. A pity.
Hey again,maybe I should use it without the stepup then,only alternator voltage to be safe. No secret,my car is a Peugeot 406svdt stationwagon 2002. I have never been in to car stereo before but got a experience with chipamps,read the little story I wrote before. When I bought this car a year ago it lacked bass,I mean it really di NOT have any bass below 50-60 Hz and it was horrible. I am not a bassfreak,never listen to hip hop,but likes to hear what the bassplayer does,not only the guitar and drummer. I like a balanced but a little punch and warmer sound,I have tube preamp in my hifimat home..That's what the little Lepai sounded like;a small tubeamp..
Yes,its a shame. My little workhorse has been active 4years at work in a not good enviroment,I am a car mecaniac,worked 18years with Peugeot and Mercedes,last 7years with Mazda and Hyundai(Kia's twinbrother/siste)
And the little Lepai has even driven my carsub but cut at high volume,could play louder with 2 ohm in series with each voicecoil. So it's a really workhorse,I love the little one
P406 is a good car,the best they made. Low fuel consumption,good to drive,few and cheap problems. I had a sedan before and it didn't had that lack of bass,that's why this started.
you are joking right? Powerdraw is max 1/4 with heavy compressed music and in this case very bass heavy music; he will really have to push it to use 20W continuous, or 1/3 of a headlight. Class A/B car heaters are a different story.
No need for the step up converter; amps will be powerful enough and will be more efficient and stay cooler (live longer) at 13V. You will get about 2x30W @1%THD and 2x25W@<0,1%THD, and that's probably more clean power then the current amp can supply or the driver will like before distorting.
If you like to play very loud add a ~40Hz high pass filter so no power is wasted on frequencies to low to play and to reduce driver excursion, so it will take more volts/power before distorting.
The Lepai 2020+ with 3A power-supply, super crappy plug adapter, nice case and great sound for €22 also got me hooked and is still working fine.
My car is a 2001 Twingo 16V which I hardly drive and when I put the 2 subs in the back, it is almost full and serious overkill. In a living room they are fine for a party.
// I'm still in love with the looks of the P406 coupe, but my current car is way more economical, easy to park and spacious enough even for my 206cm or to move a washing machine or bike in the back.
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Removed chokes
Here is the chokes removed..I can't see why both positive could not be connected together and both negative together when j1,j2,j3 and j4 are soldered and set up for mono. Then the chokes will be parallell coupled 2 and 2. Under the print the left input says btl. Both negative are tied together before the chokes,same with positive. This must be the right way to use it in mono? Or am I missing something?
Here is the chokes removed..I can't see why both positive could not be connected together and both negative together when j1,j2,j3 and j4 are soldered and set up for mono. Then the chokes will be parallell coupled 2 and 2. Under the print the left input says btl. Both negative are tied together before the chokes,same with positive. This must be the right way to use it in mono? Or am I missing something?
Attachments
My concern is, If you use a single stereo channel with a 4Ohm load, giving more power than you intend to use in PBTL-mode, a single choke and a single filter capacitor is seen as the optimum by the designers. If you put the chokes in parallel and the filter capacitors in parallel, you get half the inductance and double the capacitance. The filter will be more heavy for the amplifier to drive, while your load may be above the 4Ohm (two voice-coils in series) or a little less if you use only one voice-coil. I am not certain if the designers have foreseen (and accounted for) the use of the output filters in parallel. But, they have decided for the single filter as best for 4Ohm.
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The situation is that the designer (if competent) decides for an output filter according to the maximum load current, the carrier frequency, the load impedance (for damping), the choke losses and the current capability of the chip.
NXP, a competent company, recommends 10uH/1.5uF for 4Ohm, 15uH/1uF for 6Ohm and 22uH/680nF for 8Ohm. If you decide to halve the inductance and double the inductance, you may deviate from the best values.
As a personal experience, when I have been using too heavy class D output filters, the treble had a tendency of producing a whistling sound.
Texas Instruments Class-D LC Filter Designer
LCFILTER-CALC-TOOL Class-D LC Filter Designer | TI.com
LCFILTER-CALC-TOOL Class-D LC Filter Designer | TI.com
Hello again,I found this page http://www.ti.com/lit/an/slaa701a/slaa701a.pdf
Much technical info but output filter has major influence in the higher frequencies,not in the bass,am I right? So it's not critical for bassamplifiers used 100Hz and lower? So maybe it's not so critical if the output caps and inductors is parallelled in the TDA7498e used in PBTL-mode? And maybe it's okay used with 3ohm or higher impedances,such as coils in series in my subwoofer; 2x2,7 ohm=5,4ohm? I use the sub under 80Hz
The question is: would it be bad for the amp with parallelled left and right output in PBTL mono-mode,could it kill the amp? Or is it just sound quality issues?
Much technical info but output filter has major influence in the higher frequencies,not in the bass,am I right? So it's not critical for bassamplifiers used 100Hz and lower? So maybe it's not so critical if the output caps and inductors is parallelled in the TDA7498e used in PBTL-mode? And maybe it's okay used with 3ohm or higher impedances,such as coils in series in my subwoofer; 2x2,7 ohm=5,4ohm? I use the sub under 80Hz
The question is: would it be bad for the amp with parallelled left and right output in PBTL mono-mode,could it kill the amp? Or is it just sound quality issues?
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You are a very experienced car enthusiast so I will translate the question into the car world:
Does it matter that I use old engine oil if I only drive slowly with the car in a low gear?
Back to amplifier electronics: The class D amplifier will keep on switching between the rails at a frequency of 300-400KHz (the carrier frequency), disregarding if you only use it for up to a couple of hundred Hertz. The output filter has to be adapted to that intrinsic switching at more hundred kiloHertz. If you put too heavy a filter on the output, you may have noise and excessive chip-heating even if you do not use the amplifier at all. You will circulate higher currents to a more heavy filter. It is not a matter of the cut-off frequency that should remain about the same with half the inductance and double the capacitance.
Your TDA7498E chip is not likely to be damaged if you try with parallel filters. The chip has over-current protection functionality.
With my car-comparison above, would you use old engine oil if you may get away with it?