What is spec with 4ohms speakers?
One of speaker will be 4 phmsX2 subwoofer. I wonder it will be (100W+)x2 or not.
Unfortunately this amplifier is not rated for a 4 ohm load, only as low as 6 will be safe.
Date published: 2013-06-10
Can I use 2ch for one subwoofer?
I am getting Bravox PXW12D-4 12" DVC Subwoofer 4 Ohm Per Coil.So I thought I could feed 1ch per a coil. Would it work?
Yes you can use one channel on each coil of a DVC woofer.
Date published: 2014-08-12
Can I build a distribution amplifier to use with the 6x100W TDA7498 Class-D Amplifier Board?
I have already asked this Q. a couple of months ago, and thanks to those how replied, but so far I did not get anywhere. I got couple of factory made distribution amplifiers – with 9 and 24 stereo outs, but due to my space limitation (the whole think is going to be located in a kitchen cabinet, which is only 16 inches wide), I could not use them. I can disassemble one of them, take out the board and use it but for number of reasons I prefer to build my own, if possible.Here is my original Q: I have total 9 pairs of speakers and planning to buy 3 of these amplifiers - (6 X 100W Class D Audio Amplifiers TDA7498), It is going to be 3 pairs of speakers for each amp. How can I connect all three amplifiers to one sours of signal (or music)? Do I need something else in between of my preamp and the power amps? ThanksI did some digging on the Internet and found an audio distribution amplifier’s schematic TL084. It has one in and three outs. The following is the comments of the original 3 channel distribution amplifier:The three channel output distribution amplifier uses a single TL084. The first stage is capacitively coupled with a 1.0 μF electrolytic capacitor. The inputs are at 1/2 VCC rail or 4.5 V. This makes it possible to use a single 9 V supply. A voltage gain of 10 (1 M ohm/100 k ohm) is obtained in the first stage, and the other three stages are connected as unity-gain voltage followers. Each output stage independently drives an amplifier through the 50 μF output capacitor to the 5.1 k ohm load resistor. The response is flat from 10 Hz to 30 kHz.Here is my Q: Since a TL084 has four separate independent operational amplifiers can I add to the original schematic two more TL084s (or another eight secondary stages) to extend the number of outs from three to eleven?The music signal comes out of CD, Radio, TV or computer. Then goes through 1.0 μF electrolytic capacitor to the first stage. Then the original schematic splits to three secondary stages but I want to add another eight secondary stages and split it to total of 11 (eleven) secondary stages. For stereo signal I would need two of this schematics. Can someone tell if it is going to work or not? Thanks.
What you're proposing should work fine. You could have virtually unlimited outputs without having any problems. The 1st-stage TL084 (the one with the gain of 10 V/V) would be completely capable of that, and the audio source that you use would have no effect on the outcome.However, one thing you should change in the schematic is the gain. A gain of 10 V/V is very high (it is 20 dB), and will cause all sorts of problems: the 1st-stage op-amp might oscillate out of control with certain audio inputs, playing anything at moderate to high volumes on your source will cause the audio signal to clip in the op-amps, the volume control that you use will be touchy, and it will create a lot of noise. I'd suggest setting the gain to something much lower than 10 V/V. You can change the gain by changing the value of the 1 Mohm resistor: gain = 1 + R/100k, where R is the value of the resistor that is currently 1 Mohm. I would suggest not making R less than about 20 k (ie, a gain of 1.2), and not more than 200 k (ie, a gain of 3), unless for some reason you really need a lot of gain.Another note: the TL084 is generally considered to be a budget op-amp. Not everyone will notice it, but its audio output quality isn't really the greatest. For a step up in performance (and a slight step up in price), I'd suggest the NE5532, a mid-quality op-amp that lots of people usually recommend. There are of course even better op-amps out there, but not many people will notice the difference between them and the NE5532, especially if anything else in the stereo is not of the utmost premium quality.
Date published: 2013-03-20
How much static noise on the outputs is to be expected?
I got the amp all hooked up and got sound out of it, but before I started to experiment with it I noticed there was a good amount of static noise coming from all 5 speakers (only using 5 ch). So I power down everything, disconnect the source and power back up, still there. Power supply? So I replace the PS with 3 batteries I had around. Still there. It doesn't knock you over, but in a quiet room, the volume down, it sounds like one of those white noise machines. Am I wrong in thinking if I have nothing connected to the input RCAs I should get near silence out? Anyway to clean it up? I was actually hoping it was PS noise, but you can't get much cleaner than 3 large batteries.
Possible original hook-up problems caused some damage. Once damage happens the effect cam continue after the cause is cleared. Contact PE for help and/or replacement.
Date published: 2013-03-05
How can I connect three amplifiers to one sours of signal (or music)? I mean the 6 X 100W Class D Audio Amplifiers TDA7498
I have total 9 pairs of speakers and planning to buy 3 of this amplifiers - (6 X 100W Class D Audio Amplifiers TDA7498), It is going to be 3 pairs of speakers for each amp. How can I connect all three amplifiers to one sours of signal (or music)? Do I need something else in between of my preamp and the power amps? Thanks
You need something to split a stereo signal into 9 stereo signals. This can be achieved with a number of products. Depending on the impedance of your source and the type of connector what equipment you need varies. The input impedance of these amps is 48kOhm minimum.Sorry, I think we need more info to make a recommendation for you.
Date published: 2013-03-18
Can I parallel bridge 2 of the channels?
No, the amplifier chips are already bridged as far as they can go.Since you are asking if you can bridge only 2 of the channels, it stands to reason that you may be looking to get more power to a subwoofer. If this is indeed the case you could use two separate channels to power separate voice coils on a dual voice coil subwoofer.
Date published: 2013-02-22
How to lower the THD
The specs show a lower wattage with lower THD. How does one lower the wattage when working on a project? Is this literally using a lower volume or using a lower VDC rated power supply? I want to run 8 ohm speakers at the lowest THD possible but not sure how.
I am sorry about the confusion, the higher the output, the higher the distortion is. To keep the distortion down, just use it at a lower volume.
Date published: 2013-02-22
Could i add a circuit breaker...
To the audio outputs to protect the speakers and the amp from over driving and, if so, what speaker circuit breaker would be suited for 8 Ohm loads on each channel, I know this is kind of a stupid question since the minimum recommended impedance for this board is 6 Ohms, but, I tend to drive my systems up the wall with overly loud bass. I'd probably easily overdrive the amp, even on 8 Ohm loads. My bet it to use the 100w circuit breaker(260-820) I mean it's unlikely id sustain 100w+ with this board on 8 Ohm loads, but it's just a precautionary idea.
It is unlikely you are going to damage your speakers if they are rated to handle 100 watts at 8 ohms as this board is only rated to put out 80 watts at 8 ohms... UNLESS you are feeding them a clipped signal.You get a clipped signal from driving cheap under-powered amps too hard, which it sounds like you have every intention of doing here : )This circuit breaker, and indeed all that I have encountered are too slow to protect your speakers from clipping as they need a sustained signal over the rated power. From the description:"Thermally opens when power level reaches 200% of rated hold current for 5 seconds. Power levels ratings are estimated and given for a 8 ohm load."So, in short, this will not protect your speakers.If you really want to enjoy your "overly loud bass" without destroying equipment you need to invest in a better amp and some speakers that have accurate power ratings.
Date published: 2013-02-22
Can I use the Sure rotary encoder volume control with this amp?
The model AA-AA11117 Rotary Encoder + Volume Control Board works for some models of amp boards; would it work for this one? (I suspect that I might need 3 since the volume control seems to be for a pair of channels)
Unfortunately no, this amplifier will not work with those encoders.
Date published: 2012-11-27
So... where is the mystery power supply?
From what I am reading, and forgive me for being new at this, there is no 36VDC 18A regulated power supply here at PE.The 24VDC 14.6A 350W is not enough juice.The 48VDC 12.5A 600W is too much juice.I tried to find one that was 36VCD AND 18A online and found one- for almost $300.What's the solution here? Settling for less than 100WPC? I just don't have the electrical knowlege to field this myself and am just getting into the DIY audio. But I really want to build an amp and even though I will not start with this one, I do have plans for it in the future. I am just lost on the power supply situation.
If you are unable to build a power supply then purchase is your option. The lower power will allow the amp to work well, but not at full rated output. With the power supply below you should be able to obtain 65 to 80 watts. Remember demand from each amp will vary as input changes.For use in a small room system it will perform well.
Date published: 2012-11-27
What happen if I don't need to use one of the 6 channels?
I have a 5.1 home theater system and and the power board just burns up. Can that board help me?
If this is a home-theater-in-a-box style system, this will likely still require 6 channels, because the amp is in the system for the sub as well. I don't know how your system is or how it's wired, but if you can attain RCA preouts for all channels, this may suit your issue *IF* the preamp and decoding circuitry is okay. (That's a big IF, and you may just be better off buying a new receiver/system.) If you have a vid-player that has all channels of preouts decoded for analog connection, this could also work, but you'll still require a level adjustment method, not unlike a preamp.Just speculating here- but it is minutely possible this could resolve your issues. Of course- you'll still require the power supply as well, as the amp you have is likely run at a different voltage supply level.
Date published: 2012-10-19
How would this run on 14v in a automobile?
I have an upgraded electrical with HO alternator and Odyssey (dry cell) battery that easily runs 14v and was hoping to get 6 channels at perhaps 50w X 6 to drive an active 3-way setup. Would this amp work in such a setup? I was hoping to tap into the factory fuse panel (20amp fuse) in order to avoid wiring a wire directly to the battery. (avoid firewall)I can mount the amp anywhere inside the cabin and add additional fans if need be. Please advise.
14 Volts * 20 Amps = 280 Watts. That equals 46.66 Watts per channel, not taking into account the efficiency of the amp, which it claims is 90%. So that would work out to be 42 Watts per channel, absolute maximum. It will work, the question is how well. I suspect you will run into a lot of clipping and start blowing fuses when you crank it up much. You will also need to devise a clever way to attach a very hefty power wire to that 20 Amp fuse. I would suggest at least a 12 gauge wire, preferably 10 gauge if you do it. The safe and proper way would be to run a 10 gauge wire from the battery with a 20 Amp inline fuse.I can't say this is ideal for auto use, but I know a lot of people have used these amps for such. One thing to pay attention to is that this amp is not intended to drive 4 ohm speakers (as most auto speakers are rated). You should only use 6 or 8 ohm speakers with this .Good luck, be safe, and have fun!
Date published: 2012-07-04
Why couldn't you use the 48VDC 600w Power Supply (#320-317) ?
The 320-317 power supply outputs 43 to 56 Volts DC output, this amplifier requires 14 to 39 volts DC.It may work but I wouldn't recommend it as the amp may be damaged by the excess voltage.
Date published: 2012-05-17
Chassis for this Board
Does Parts Express carry a box that would fit this board? Does anyone else know of place that I could get a box of the correct form-factor?
Unfortunately, we do not currently carry cases specifically for these amplifier boards. We do have a selection of project boxes that would accommodate the boards, but drilling for various connections and/or fitting additional components would be required.
Date published: 2012-05-07
Can I run 3 of these amps from a single power supply? If so, what specs? And, do you have any recommendations?
I need to run 3 (count 'em, three) of these amps for a theatrical-type, self-contained, amusement-ride-esque project. While three independent power supplies is not entirely out of the question, a single power supply just feels more-logical and the "right" thing to do. But, if the cost of a single supply (am I looking for 54 Amperes?) far-exceeds the cost of three independent supplies, then three it is. Many thanks!
I think you will find (I have looked at this but not in the past month) that 3 individual PS's is best. This also gives you redundancy if one fails (you can run 2 amps on one PS for brief periods). The very high amperage switching supply you would need for 3 of these boards would be VERY expensive--it is because the high amp supplies are special items, whereas the smaller PS's are a commodity and also much less expensive to construct.Though you will not get full rated output from the amp board (I doubt you will need it unless your application requires thermonuclear level sound), the 24V 350W Meanwell supply from Parts Express should drive this board adequately. However, if you need more drive, there are similar industrial grade PS's that supply up to 36 VDC at 400W ratings, for about 1.5x the cost. Once you get above 400W, the price per supply appears to vary with the 1.5 or so power of the rating (i.e. not quite the square of the ratio of power to 400W but close).
Date published: 2012-05-09
Would you be able to run this amp off of two of the 24V 350W power supplies?
Yeah, I should think so. Just wire them in parallel to get the full possibility of 700 watts @24 volts.
Date published: 2012-09-12
i was wondering if i could run 3 channels at 4 ohm and the other 3 at 8 ohm?
Yes, you can do that. All 6 channels are completely independent of each other, and they can all handle either 4 or 8 ohm loads.
Date published: 2012-02-16
TDA7498 vs TK2050
I was going to get x3 of the Sure TK2050s to run a MTM so each driver had it's own amp. But after seeing this (even tho I just odered my 2x100 kit, ggrrrr). I assume the output quality is nearly the same? Anyone have hands on experience with this?
There are several differences between the TDA7498 amp board and the TKO2050 amp board.The TDA7498 has 6 speaker outputs rated at 100 watts each at 6 ohm. sufficient for a 5.1 home theater sound system. The TKO2050 only has 4 speaker outputs rated at 100 watts each @ 4 ohms.Each board requires a slightly different power supply, the TDA7498 has a different frequency responce specification, however I believe the difference is minimal considerering the speakers most likely used.Parts Express has the complete product info sheet and specs posted on the website if you would like to review them in detail. Depending on your need for either 4 or 6 speakers, I would compare them as very similar in performance.Good Luck
Date published: 2012-05-09
14 to 39VDC @ 6 x 100W
Hi,I was planning on a 5.1 DIY for speaker system. So, this device came into the, "hey this just might work" list.It says here that the 14 to 39 VDC at 6 x 100W so that is 600W. Meaning, you would require more than 600W input to get the full output?Is the 24VCD 350W the only Power supply available in Parts express? Are there alternatives to get 600W supply with 36-39VCD?
A better way if it fits your usage, would be to get a medium size 12V gel-cel battery. Then you keep it charged with a 15VDC 1 A wall wart or some such. This can be made to be portable, too!I keep a car battery at my bench for testing and development of my projects, to run high-power amps. Then design in gel-cel which are smaller and portable. They last about a day at full power. AND you can keep them charged using a 10W [12v/1A] solar panel! Free NRG!
Date published: 2013-07-06
I need a 5.1 amp to mount with my htpc.
I have 2 unused rails from the pc power supply at 12v 18a each. would 12v be enough to power this amp? Driving 4ohm 5 inch 2-way speakers, volume is not a concern but quality is.Thanks,Peter
You wouldn't have enough voltage 12VDC, to run the amp. You would neeed a step up transformer to get it up to 24VDC or you can connect two transformers that are 12VDC in series to get 24VDC.
Date published: 2012-12-30