Because of dropbox and how this forum works i have added a new post with a copy of this post but with the pictures
Can be found here
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I was asked to post my home AMP from a fellow user on talk.maemo.org so here it is
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:
NOTE: 6.8Ohm resistor is a 5W
Hole Print "Design": (Would like to make proper boards...)
Pictures:
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 http://talk.maemo.org/showthread.php?t=74341
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...
Test Results on this AMP done by zanden30 and cmorariu can be found here and some pages forward.
EDIT: 2014.03 - Now also on facebook https://www.facebook.com/groups/760434413975466/
Can be found here
--------------------------------------------------------------------------------------------------------------------
I was asked to post my home AMP from a fellow user on talk.maemo.org so here it is
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 http://talk.maemo.org/showthread.php?t=74341
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...
Test Results on this AMP done by zanden30 and cmorariu can be found here and some pages forward.
EDIT: 2014.03 - Now also on facebook https://www.facebook.com/groups/760434413975466/
Last edited:
Very cool Project!
There have been a few discussions on whether or not some thing like this would work well.
Please post some more testing info when you have it available.
I am very interested in seeing some THD figures as well as driving loads in the 2 ohm or lower range.
I have been thinking about something like this possibly using something like 4 to 8 pairs of output devices.
Great Job !!!
jer
There have been a few discussions on whether or not some thing like this would work well.
Please post some more testing info when you have it available.
I am very interested in seeing some THD figures as well as driving loads in the 2 ohm or lower range.
I have been thinking about something like this possibly using something like 4 to 8 pairs of output devices.
Great Job !!!
jer
Very cool Project!
There have been a few discussions on whether or not some thing like this would work well.
Please post some more testing info when you have it available.
I am very interested in seeing some THD figures as well as driving loads in the 2 ohm or lower range.
I have been thinking about something like this possibly using something like 4 to 8 pairs of output devices.
Great Job !!!
jer
Thanks, well i can say in my XP (15+ years, 30+ DIY AMPS, DIY 100+ Speaker sets & 100+Normal Speaker sets) that this AMP is just awesome, unfortunately i don't have any equipment to test it to the full, but some info and will be added to post #1 along the way:
Output power (2Ohm) Beyond 400W, tested with speakers rated to 250/500 and they were played up to the limit WITHOUT ANY DISTORTION.
S/N is even better then stock (TDA7294), wear the speakers as headphones and you will barely hear any hiss (also no hum what so ever) and this is with speakers that have a SPL of 95+.
Just want to show a few pics of the "micro" prints for the new TDA7293, again TDA7293 so don't use these for reference if your making a TDA7294.
And yes those are SMD resistors, i could not find any 1% metal film resistors on wieser-electronic so i opted to make a "challenge" again
Also all the connections are not made yet when i took the pictures.
And yes those are SMD resistors, i could not find any 1% metal film resistors on wieser-electronic so i opted to make a "challenge" again
Also all the connections are not made yet when i took the 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.
First picture in Post #1, it is from my dropbox but should not give any problems, or do you mean that it is not like a normal schematic, then yes your right, but is should not be that hard to follow, numbers represent pin numbers on TDA7294.
Also try clicking on it if you mean it is not clear enough.
Also try clicking on it if you mean it is not clear enough.
Jamen hey så
Well that is of course something i have always wanted to do, but it always cost a sh*t load of money if you just want a few boards, but if users in this forum get interested in the AMP well then i would be a better ratio of $ pr board.
And it is as you can see a VERY simple board, just has that extra connection for the moved feedback.
Well that is of course something i have always wanted to do, but it always cost a sh*t load of money if you just want a few boards, but if users in this forum get interested in the AMP well then i would be a better ratio of $ pr board.
And it is as you can see a VERY simple board, just has that extra connection for the moved feedback.
400W+ into 2 ohms, from a single 5200/1943 pair? But that's like 14 amps rms, or 20 amps peak. Sure you've only got a +/-40 V supply (how many VA is the transformer?), but it still seems rather optimistic to me. Looking at SOA, I'd say this is pushing it a bit even at low temperatures. I'd rather use two pairs.
That transistor pair have 15Amps DC and 30Amps peak, hence no problem with that power handling level, also note that the TDA itself chips in (just a little bit but however it still helps), Power came (in that amp) from a 300VA Ring-Transformer, and it has power to spare when considering that i had 2x70,000uF.
And yes if you want even more power then it will help to use 2x 5200/1943 then you are looking a 1Ohm stable and power close to 1000W (not kidding here), and if you want even more use 2x TDA with dual Transistor Pairs and Bridge them, then you will be beyond 1500W 2Ohm
Again i have bridged the normal setup and was ripping a 700W woofer to MAX X-MAX and again with power to spare.
I cant w8 for my parts to arrive. Deffo building some of these =) ... and DR frost ... 1ohm 1000 watt? now thats power! Were in the circuit would u add the extra chips? would it be like one afta the other .. chained, or would there need to be stuff in between? cause i have the money to get more no problem =) also im going to have like 9 spare of each resistor, capacitor.. so adding more of them too? what do u recon ?
Well you basically add transistors and emitter resistors, something like this, BUT i cannot say if the 6.8Ohm resistor needs to be changed to adapt to this config.
Here is a Schematic i just remodeled to show the DUAL NPN&PNP setup
Again press picture to make it bigger (zoom)
EDIT: Gotta love Dropbox, if an error in the schematic is found i just have to change it locally and Dropbox (ubuntu) updates it and the changes are now done here 5 seconds later
Here is a Schematic i just remodeled to show the DUAL NPN&PNP setup
An externally hosted image should be here but it was not working when we last tested it.
Again press picture to make it bigger (zoom)
EDIT: Gotta love Dropbox, if an error in the schematic is found i just have to change it locally and Dropbox (ubuntu) updates it and the changes are now done here 5 seconds later
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Sweet looks tidy =) Im now looking at plans for the TDA chip amp part. How does this look ? http://circuitsmag.com/amplifier-circuits/tda7294-50w-power-audio-amplifier . they also have plans for power supplies , looks good =)
Theres also this one that is a little more detailed also shows how the PCB works so can be adpapted to perf board alsp its dosnt have the 2n7f mkt capacitor wich i cant seem to find (only cerramics)
TDA amplifier circuits
TDA amplifier circuits
Well you can go by those designs or just use mine, the components work just fine, if you go to the thread i stated in post #1, (talk.maemo.org) then you will see a prototype TDA7293 on a board i bought from ebay, i did have to make some connections on it but it now uses the components and schematic that i made.
All that needs to be taken into account is the FeedBack resistor has to be moved (22K Ohm) and the SYNC resistor needs to be between output and the TDA7294/3
All that needs to be taken into account is the FeedBack resistor has to be moved (22K Ohm) and the SYNC resistor needs to be between output and the TDA7294/3
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Ok im just .. lost now. I can find a picture were the TDA is visible ... but i cant see a schematic and because im very amature still ... i have no clue whats going on all of a sudden .. i only just noticed that the schematics i download of ya dont have instrustion on the TDA =/ ... i wouldent know were to move the feed back or ne thing .. i just assumed u had to attach the output to the input of the 2S board.
EDIT) Maybe i have found my confusion here but maybe not lol . on the main schimatic does the number like reprisent the TDA pins? or is that hole numbers? if so then i apologise for filling your thred! lol
EDIT) Maybe i have found my confusion here but maybe not lol . on the main schimatic does the number like reprisent the TDA pins? or is that hole numbers? if so then i apologise for filling your thred! lol
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