TDA7294 + Power Transistors AMP (TDA7293 to come also)

Right that all does sound Perfect too me =)

I was thinking of just bridging a plain pair of TDA7294's for these transformers for 100 rms 200 max

Im 100% going to pay the little extra to get that power =)

I have 2 of these transformers lieing around

Perfect power for my Midtops =)
 
Thanks for this thread!

I made a PCB for the class H application of the TDA7294 including a batch of custom wound 2x15/2x30V 300VA transformers in the mid 90's.
It never worked properly, one blew up and fried the subwoofer it was in :mad:

I recently got rid of most transformers and bought some Chinese PCB's to finally use my TDA7294 chips, and only now I find this simple solution :eek::smash: The intended power of what I was aiming for, but a much simpler design :D

I'll reserve one chip and one transformer for this amp! Then I can finally finish my active sub after 15+ years :yes:

Edit: I bought one chinese BTL stereo board (4 chips), so if calculating correctly with 1kW of single output 48VAC transformers lying around, I should get over 2x400Wrms@4ohms (too little transformerpower, but won't be using it all to often...). Plenty for my 350Wrms Aliantes that I want to convert for homeuse...
 
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TDA7294-IRFP240/IRFP9240 Audio Amplifier schematics!?

Hi guys!
Very interesting audio amplifier with TDA7294 and BIPOLAR transistors 2SC5200/2SC1943. But I want to making this amplifier with MOSFET transistors IRFP240/IRF9240 and IC = TDA7294, because I want to ask how to make a schematics (circuit)?!
Thanks for your help and cheers!:cheers:
 
With the bases of the output devices tied together, this is class B, however being inside the NF loop, the outputs are fed a "corrective" signal to make the crossover point linear. I'm going to build this and have fun with the oscilloscope. I still wonder how clean the output is at very low levels. Should be an interesting experiment.
 
With the bases of the output devices tied together, this is class B, however being inside the NF loop, the outputs are fed a "corrective" signal to make the crossover point linear. I'm going to build this and have fun with the oscilloscope. I still wonder how clean the output is at very low levels. Should be an interesting experiment.
Johnr66 I agree with you that experiment and make some measurements for this amplifier. But I consider that this schematic would look like amplifiers with output MOSFETs irfp240/irfp9240?
Cheers!
 
The voltage is limited due to the TDA7293's limitations--see the datasheet. The transformer can be va 1.5x watts (from 500va to 750 va for 500 watt amplifier). Current handling may take about 4 pairs of output devices per each chip.

The current of TDA7293 can also be boosted with a multi-parallel arrangement using the slave pin http://www.ebay.com/sch/i.html?_nkw=7+parallel+tda7293&_sacat=0&_odkw=7xparallel+tda7293&_osacat=0
The parallel fets give you a more powerful parallel amplifier without ballast resistor losses.
 
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Hello ...i m a newbie here...n intrested to build thir amp.. But the only problem are the power transistors. I cannot get these from my nearby shop. Can i use differnt transistors? If i can ,can u tell me which is it...? May be smthhng like irfp9xxx...,?
 
I did this audio amp and worked great!

I just discovered this page and the info of this amp with two out put transistors that I decided to make it. I did it and worked great. In has great power and quality sound! I have some pics and they are here.I did the board and I added a preamp. I have not tested the preamp just the amp. and I very satisfied with the power and sound. MUY BUENO.

This is the classic TDA7294 AMP with LOTS more Power then normal, this is with using Power Transistors at the output stage, it is a simple Addon to make, it just requires a SYNC resistor and the feedback to be moved to the output after the Power Transistors.
So to make this AMP you can just start with the TDA7294 with one change, just need to "move" the feedback so you can connect it to the Output after the Power Transistors, in all the AMPS i have made with the TDA7294 the 6.8Ohm has been spot on when using the 2SC5200 & 2SA1943, if you use other transistors you may need to experiment with another value for the SYNC resistor.
Things to do when SYNC it is to listen to it, things to listen to are from very low volume (FROM a clean source) and go slowely up in volume, the POINT here is that it should just get louder like a normal amplifier would, if the SYNC is off then a normal thing will be that at audio peaks (like drums & bass) it will sound like someone is kicking your speakers because the Transistors kick in at a wrong volume then the amp is playing, believe me you will hear it, this needs to be corrected by changing the resistor else you will have an amp that only sounds good at very low volume and medium to high volume.

Component list: (1x AMP)
1x 680 (680R) Resistor
1x 10K Resistor
3x 22K Resistor
1x 6.8 (6R8) 5W Resistor
2x 0.15 (0R15) 5W Resistor
2x 10uF 50V Capacitor
2x 22uF 50V Capacitor
1x 1uF 63V MKT/BiPolar Capacitor
1x TDA7294 Chip AMP
1x 2SA1943 PNP Transistor
1x 2SC5200 NPN Transistor

Schematic:
An externally hosted image should be here but it was not working when we last tested it.

NOTE: 6.8Ohm resistor is a 5W

Hole Print "Design": (Would like to make proper boards...)
An externally hosted image should be here but it was not working when we last tested it.


Pictures:
An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


STATS:
Output Power: well lets just say that speakers that where 250/500W 2Ohm (RMS/MAX) where played to the max with NO DISTORTION AT ALL
I will call the output at 400W+ (MAX) and this is based on that the TDA itself adds ONLY 20-40W (because of the much higher driving Ohm), but the 5200/1943 are some GOOD POWERFULL transistors and going through the datasheet it will deliver peeks over 600W (short pulse pr Transistor), they supply 100W but this is FULL DC and there are no audio tracks to my knowledge that has that kind of "sound"
Driving Impedance: i have been using it for 2-8Ohm speakers, the lowest i have driven was 1.3Ohm but as with all AMPS if you know your Transistors you know how many watts you can pull out, this AMP will drive what ever you hook it up to, JUST one thing, when i was using my 1.3Ohm set it did introduce some "noise" (sounded like 80' AMP hiss), and at this point the SYNC resistor properly needs to be changed, i did not do this, i took the lazy way out and put some 1.8Ohm POWER Resistors in line with the speakers instead.

I have been using this AMP for +3 years, it is good for driving 2-8Ohm speakers with current config (6.8Ohm RES & 5200/1943)
The only thing i can really say is BUILD it, you will not be disappointed i can guaranty that, as long as you follow the "guide" it will be fine, i will how ever RECOMMEND that you use the same components (5200/1943) then you should not go wrong and it will play beautiful the first time it is hooked up, and also with these components it is VERY cheap to make (depending on suppler), where i buy my components i can make 1 channel (All components) for about 15$, it is as always the POWER SUPPLY that is going to set the price back.


Link to the original Thread DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...) - maemo.org - Talk

Whats more to come, well more "stats", and the new AMP im building right now, it's the TDA7293 With Power Transistors x 4, for a nice POWERFULL BI-AMP system, but it can also be used as a 4.0 Surround AMP or a Bridged 2x 700W+, also more pictures etc.

This post will be updated again and again to meet questions and to add pictures, guides etc...[/QUOTE]
 

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Glad you like it juanj54c, was easy to make right?

Also an update, i have yet to complete the TDA7393..... i know it has been a loooong time since i posted but really been busy with lots of other projects and just moved so now everything is not where it should be...., can't say when im done, but the 7393 worked like 94 with the output transistors.

There are alot of future projects that have more attention right now, but someday ill update.

How else then juanj54c has made this amp?


dr_frost_dk out.
^^ google if you want a summery of other projects hehe :p