Diy integrated amplifier with tda7294

I constructed this amplifier for a friend with a low to mid budge, but the result was astonishing.

The mosfet chip power opamp gives about 50 watts rms into 8-ohms and about 83 watts rms into a 4-ohm load.

Capacitors are fairly standard (lelon electrolytics) and (BC low level audio), also the preamp is an old kit from c&a with acceptable sound quality due to the opamps used which are 2 pairs of ne-5532.

I admit that I overdid it with the power supply 400 watt toroid transformer and 94.000 mF total reservoir capacitors!!!

Overall it sounds powerful with acceptable distortion levels.

Note: The led VU-meter is not my design but from what i can see, it uses a UAA-180 chip.

Category:

Science & Technology

Tags:

• diy audio
• chip amplifier

[samjurai]

Hey there, nice work! ..do you think you could help me out? I'm looking for an incredibly simple circuit for the NE5532P ..my requirement is: it take's the right and left audio from a playstation and outputs it to two little speakers. do you think you could point me in the right direction? I'm having dificuilty finding a circuit for the NE5532 ..Thanks!

[pkanalog77]

@samjurai

Hello and thank you for commenting.

Can you tell me the resistance of the speakers ?

Note that NE5532 opamp drives loads with resistance until approx. 600 ohms bellow this it distorts badly.

Also for this purpose you could use a TDA-2030 chip which is a small power amp about 5-7 watt rms at 8 ohm load.

Philip.

[Henzzman]

@pkanalog77 Big question,if you dont mind answering.When running two separate tda7294 channels on common heatsink and they get their power from the same power supply,is it neccesary to use insulation between the chip and the heatsink? Also,the heatsink isnt electrically connected to anything.

[pkanalog77]

Dear Henzzman

The case of the TDA-7294 is electrically connected to the negative power supply of the amplifier (-ve), so yes the insulation is necessary otherwise it just won't work at all. (It will blow fuses and possibly destroy the chip... )

Also i do have grounded the entire sub-chassis and the heatsink together with it.

Thank you for your comment.

Philip.

[Henzzman]

@pkanalog77 Thanks for the answer.Btw what kind of voltage are you feeding into your amp,my ps gives +-40V when not under load,thats just after the filter caps,which are 15k each,the voltage should be just enough not to blow the chip i hope.Or do you think its too much for the chip to handle.

[pkanalog77]

@Henzzman

The maximum voltage for the TDA-7294 is about +-40V, so you will be fine.

However can only drive 8 ohm speaker loads with that voltage because otherwise you will exceed the maximum thermal power dissipation of the chip.

For safe driving of 4 ohm speaker loads the maximum DC voltage for the TDA-7294 is +-31V and this is the voltage that i use all the time including here.

Philip.

[TechLaine]

how the heck did u make that led system ,i really want to see how :/

[iirmantass3]

@pkanalog77 I want to ask, you, where do you got building plans? Because I want to try building it this summer.

[xSlavic]

HEY PEOPLE,nice work TRY LM3886 the best ,ill post a video when i will finish building mine

[xSlavic]

@pkanalog77

i use it with 32ohm headphones and it works and well,watch my video

[Henzzman]

@pkanalog77 Damn,i hoped that the chip's transistors could handle 4 ohm,but what the hell,tda7294,2N3055 and MJ2955 will drive it,because i want to use all the voltage and not to remove windings from my transformer.

[samjurai]

@pkanalog77

Hello, thanks for your reply.

The speakers are these ones: ebay (dot)  com /2-X-Super-Power-Loud-Dome-Spe­aker-Tweeter-Car-Auto-/2705670­74076

they're just little tweeters about 5cm diameter I think.

trying to keep power consumption low, so it's nothing very extreme. I will be using it in a portable handheld Nintendo64 I'm building :)