TDA7297. Figure 3 in the pdf.
http://www.radiotechnika.hu/images/TDA7297.pdf
SG

Awesome! Is a tda2005 any good? I'm looking for a good price point as well as power. Also does it have to 2 speakers(which is nice) but can it mono out for double power?

 

Awesome! Is a tda2005 any good?

From the spec sheet at 18 volts and 4 ohm: 10 watts per channel stereo, 20 watts bridged.
SG

 

The TDA2005 can be bridged and produces about 13W into a 4 ohms speaker at low distortion when its power supply is a 13.2V lead-acid battery or a little more power if powered from four Lithium cells in series. Then it would be a powered mono speaker for a job site.

The TDA2005 can produce about 4.5W per channel into 4 ohm speakers in stereo at low distortion when powered as above. then it can be used around the house.

Digikey has some stock of one version of TDA2005 but say another version is obsolete. Newark has only a few in stock but say more are coming in November. ST Micro says it is active. It sounds like its production might stop soon.

 

That I can say is true.

Many "stereos" have the speakers so close together that it sounds like mono.
When one stereo speaker points here and the other speaker points there then people hear only half of what is playing.
Two speakers pointing in the same direction produce twice the power but sound only a little louder than one speaker.

Many "stereos" have the speakers so close together that it sounds like mono.
When one stereo speaker points here and the other speaker points there then people hear only half of what is playing.
Two speakers pointing in the same direction produce twice the power but sound only a little louder than one speaker.

That I can say is true. Can't deny human hearing! I would humbly as sir; what ic would you recommend for my watt and voltage requirements? I've essentially given up on just transistor circuits. I know ics are easier to circuit work and more powerful. Honestly not many plain bjt circuit's can give me what I need with just batteries so I must expand my horizon's so to speak. Hate to be a quitter but the best men admit losing the game.

From the spec sheet at 18 volts and 4 ohm: 10 watts per channel stereo, 20 watts bridged.
SG

That would be nice but as I told audio guru I've given up on a just bjt circuits. I just can't seem to make them work for me using batteries; the voltage requirements far exceed the logical amount of batteries I need to power it for the size I desire. Like putting a V12 in a golfcart. Impossible and why would you anyways?.. I'd like to find an affordable and easy to use ics meant for audio amps. Hate to be a quitter but I know I've lost this battle. Damn good at a lot of things but circuitry isn't one of em.

From the spec sheet at 18 volts and 4 ohm: 10 watts per channel stereo, 20 watts bridged.
SG

I assume at 18volts though? So 12 would be, and guessing here, 12 watts? That would be great either way. Forgive my dumbassness on all of this. I am trying to learn and I shall. Once I have something I can use and be happy with then I can devote my time to strictly learning.

The TDA2005 can be bridged and produces about 13W into a 4 ohms speaker at low distortion when its power supply is a 13.2V lead-acid battery or a little more power if powered from four Lithium cells in series. Then it would be a powered mono speaker for a job site.

The TDA2005 can produce about 4.5W per channel into 4 ohm speakers in stereo at low distortion when powered as above. then it can be used around the house.

Digikey has some stock of one version of TDA2005 but say another version is obsolete. Newark has only a few in stock but say more are coming in November. ST Micro says it is active. It sounds like its production might stop soon.

That will do but if there is another more available version or better ic feel free to tell me. It absolutely doesn't have to be a tda2005. Just seen a lot about it from simple Google results. Any easy or cheap ic will do really. I'm very open to trying any. I just threw it in as a topic of discussion.

 

That will do but if there is another more available version or better ic feel free to tell me.

See Post #177.
SG

 

See Post #177.
SG

I see that. Somewhat expensive I think. Maybe not for hardcore guys like yall but for me that's a bit much. I'll probably still get a few though.

Alrighty my friends I just got and tried my oscilloscope. ...results are disappointing. Crazy distortion on my plain a class. If I'm using it right. I assume if the wave hits the top or bottom and flat lines that's distortion correct? Or clipping? Distortion in the middle it flat lines and clipping if it top or bottoms out I think..

 

10 to 20 years ago there were many car radio amplifier ICs. Most were single bridged and two were needed for stereo. Quite a few ICs were dual bridged. But now most are not made any more, a few quad bridged are made. Maybe most car radios today are made cheaply in China using Chinese ICs? Therefore western amplifier ICs are not purchased or made anymore.

 

The wave form for my simple class a is very erratic. The wave form for my 3watt bt speaker is rather even. No clipping at all. That tells me a lot. I need to tinker and make my waveform smoother. This gadget will help me much I think.

 

Clipping is seen on a sinewave as a horizontal line at the top or bottom instead of the proper curve.
A class-A transistor can be conducting too little which causes the top of a sinewave to clip before the bottom clips.
If the bottom clips first then the transistor is conducting too much.
If both top and bottom clip equally then the biasing of the transistor is correct but the input level is too high.

Other distortion can be seen on a sinewave as the top or bottom being squashed.
Class-B causes a "step" at both sides in the middle of a sinewave.

 

10 to 20 years ago there were many car radio amplifier ICs. Most were single bridged and two were needed for stereo. Quite a few ICs were dual bridged. But now most are not made any more, a few quad bridged are made. Maybe most car radios today are made cheaply in China using Chinese ICs? Therefore western amplifier ICs are not purchased or made anymore.

Probably explains the difficulty in finding then like old school. I'm not that old but damn I love the old days. My tips are likely China. I know my lm386s are. Difficult to find true USA things. I will gladly do a "complex" circuit but if it isn't with or verified using my component's then I'm turned off of it. I have built many and tips just don't do it. I don't want to quit transistors. I love bjts. So difficult to be old school when the world is forcibly new.

Clipping is seen on a sinewave as a horizontal line at the top or bottom instead of the proper curve.
A class-A transistor can be conducting too little which causes the top of a sinewave to clip before the bottom clips.
If the bottom clips first then the transistor is conducting too much.
If both top and bottom clip equally then the biasing of the transistor is correct but the input level is too high.

Other distortion can be seen on a sinewave as the top or bottom being squashed.
Class-B causes a "step" at both sides in the middle of a sinewave.

Yes yes yes! It was clipping on both top and bottom! It stopped when I lowered my phones aux input. Very quiet yet very clean sound. An oscilloscope is what I needed. That is also bad to hear. Now I need a circuit that can handle both low and high input. Granted I could hear it just below clipping, it wasnt enough to hear for more than a few yards away. So good sir....should I stick with making a circuit of decency with my tips or should I give up and get a real ic?

 

If an amplifier sounds good just below clipping but is not loud enough then you need more power that can come from from a higher supply voltage, a lower speaker impedance or a bridged amplifier.

You can make a pretty good amplifier with TIP transistors at the output, mid-power transistors driving the TIPs as a compound pair and a few more low power transistors for lots of gain before feedback. Those things are inside a good amplifier IC.

EDIT: I forgot to say that when you saw the output of your amplifier clipping then it might have been the output of your phone that was clipping.

 

If an amplifier sounds good just below clipping but is not loud enough then you need more power that can come from from a higher supply voltage, a lower speaker impedance or a bridged amplifier.

You can make a pretty good amplifier with TIP transistors at the output, mid-power transistors driving the TIPs as a compound pair and a few more low power transistors for lots of gain before feedback. Those things are inside a good amplifier IC.

EDIT: I forgot to say that when you saw the output of your amplifier clipping then it might have been the output of your phone that was clipping.

Thank you. That's the info I needed. I knew I needed a more complex circuit but knowing the tips can final out and knowing how to order it is what I needed to know. My phones output is fine. But I figured it should be since it's an aux jack for headphones. I know it's my simple circuit causing the distortion. How do I find the gain of a transistor if it's data sheet doesn't specify?

 

I will gladly do a "complex" circuit but if it isn't with or verified using my component's then I'm turned off of it

So does this mean you are back to trying transistors? Forget trying to build anything from parts made in China. If you want quality components order from Digikey or Mouser. Yeah there're more expensive but that's the cost of doing business.

I don't want to quit transistors. I love bjts. So difficult to be old school when the world is forcibly new.

The "Lil Tiger" amp I posted is from 1967, definately old school but it works just as good today as it did back then. I made the changes for it to operate on the parts you have on hand. I have personally breadboarded the circuit and verified operation.
Here's a link to the original article in Popular Electronics.
SG
http://www.swtpc.com/mholley/PopularElectronics/Dec1967/PE_Dec1967.htm

 

So does this mean you are back to trying transistors? Forget trying to build anything from parts made in China. If you want quality components order from Digikey or Mouser. Yeah there're more expensive but that's the cost of doing business.


The "Lil Tiger" amp I posted is from 1967, definately old school but it works just as good today as it did back then. I made the changes for it to operate on the parts you have on hand. I have personally breadboarded the circuit and verified operation.
Here's a link to the original article in Popular Electronics.
SG
http://www.swtpc.com/mholley/PopularElectronics/Dec1967/PE_Dec1967.htm

I'll certainly try it out when I get off work. I haven't entirely given up on transistors. Just the idea of getting the power I'm wanting. Suppose I been to greedy about that. Need to lower my standards I believe is what I mean to say.

 

How do I find the gain of a transistor if it's data sheet doesn't specify?

The datasheet of every western transistor shows the minimum, typical and sometimes maximum DC current gain at various DC currents called hFE. The voltage gain is determined by the circuit.
The minimum DC current gain of a TIP41 and TIP42 at a DC current of 3A is 15 and its maximum is 75.
3A peak is 18W RMS into 4 ohms. If the transistors have the minimum gain of 15 then the driver transistors must produce peaks of 3A/15= 200mA.​

 

The datasheet of every western transistor shows the minimum, typical and sometimes maximum DC current gain at various DC currents called hFE. The voltage gain is determined by the circuit.
The minimum DC current gain of a TIP41 and TIP42 at a DC current of 3A is 15 and its maximum is 75.
3A peak is 18W RMS into 4 ohms. If the transistors have the minimum gain of 15 then the driver transistors must produce peaks of 3A/15= 200mA.​

To clarify for me, the output of my driver stage must be 200mA? Supposing my input is 3A where would I check to see,if it's even possible, what my amperage is and/or how do I allow the circuit to pull or use that current. The batteries are 6volt at 7AH.

 

You obviously weren't paying attention. I explained this in post #104.

Where and how did you determine that your input was 3A?

 

I think he means that his 13.2V battery (two lead-acid 6V batteries in series) can supply 3A. But the max amplifier peak output current will not be 3A, it will be about (13.2V - 3V)/2= 5.1V peak/4 ohms speaker= 1.28A and the max output power will be (1.28A x 0.707) squared x 4 ohms= 3.6W RMS. The amplifier will heat with 1.4W. If he bridges two of these amplifiers then the peak output current will be 1.28 x 2= 2.56A and the output power will be about 12.6W. The amplifier will heat with 5W.

The average power from the amplifier will be about (3.6W + 1.4W)= 5W x 0.1= 0.5W if the amplifier is not bridged and is playing music so it is almost clipping. Then the average battery current will be about 120mA (a guess). A 7Ah battery charge will last 7/0.12= 58.3 hours.

Calculate how long the battery charge will last yourself when the amplifier is bridged.

 

You obviously weren't paying attention. I explained this in post #104.

Where and how did you determine that your input was 3A?

It was a hypothetical. It is not 3A or not in a working circuit. I asked that regarding the TIP transistor power. If it was to be 3A

 

You obviously weren't paying attention. I explained this in post #104.

Where and how did you determine that your input was 3A?

I just read it and I understand. Haven't noticed all of the postings. I don't get alerts for every response and usually none if to many replies come in at once. I'll have to reread the entire thread.