TDA729X paralel/bridge project

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Hi! I'm newbie here from Hungary. I would like to talk about TDA7293 or 7294S. I like to build paralel/bridge amp with these chips, but I'm not sure which the best one. If somebody tested, please tell me about. Which one have the best sound, best stability, how much the max output power, how much the max +-Vs. On the datasheet why no 22uF capacitor serial with 680 ohm resistor when bridged (on pin #2)? Can I connect stabilized 24V to the pin #5 (via resistor) for clipping led? :confused:
 
Now I have a plan for this idea:

http://rentahost.net/stratofan/pdf/Schematic_TDA_Br_Par.PDF

I would like to use pin5 of 7293 (clip detector). Is my plan is good on schematic with 24V and 4.7K resistors? Not exactly clear how do I mean "RL=10Kohm to 5V" about clip detector on the datasheet of 7293 (page 3).

Another question, on the datasheet of 7294S the - + inputs of slave IC vired to the 0V (page 10), but on the datasheet of 7293 vired these inputs to the -Vs (page 10). I think the 7294S datasheet is better for parallel...

If somebody think how better, please tell me! :cannotbe:
 
I'm not sure about output power yet. I think with four 7293 I gan get about 350-400W/channel. Marshall Mode Four is same config for 350W. On bridge, the ST datasheet said 150W on 8 Ohm +-25Vs, and 170W on 16 Ohm +-35Vs. I think I can do double power with parallel mode on half speaker impedance.
 
Yes, I heard same. If true what I heard, max three devices can be connected to parallel (one of them master, two slaves). But the speaker impedance must be lower if I want to get more power in parallel mode.

Somebody else have opinion about the schamatic? I looking for schamatic of PWM fan speed controller depending on the heat of heatshink.
 
It's not PWM but it works fine (I tried). I hope it helps u... All diodes 1N4004.

Note: diodes have to attached to the same heatsink with output transistors/ics...
 

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PARTS

U1: LM324N quad op-amp
U2: 78L12 12 volt regulator
Q1: IRF521 N channel MosFet
D1: 1N4004 silicon diode
LED1 Red LED
C1: 0.01uF ceramic disc capacitor, 25V
C2-C5: 0.1uF ceramic disk capacitor, 50V
R1-R4: 100K 1/4W resistor
R5: 47K 1/4W resistor
R6-R7: 3.9K 1/4W resistor
R8: 2.7K 1/4W resistor
VR1: 10K linear potentiometer
F1: 3 Amp, 28V DC fast blow fuse
S1: toggle switch, 5 Amps

for the pwm circuit...
 
Yeah..it could really be TDA7293s. Marshall only allow 8 or 16 Ohm speakers for this amp. This could be another hint.

Hehe, now they got a really cheap power amp. I wonder why the amp is so expensive :) Well, I guess it took them some time to tweak the circuit...TDA7293 don't seem to be the most stable devices.

But I wonder how they get 350W out of 4 chips.
 
Now I have a very simple diy poweramp with stereo bridged 7294 and working very well, I like it. Very simple circuit. Now I have about 150W with +-25Vs on 8 Ohm. The price is really interesting :hot:

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


this is the reason why I want to try birdged/parallel version with 7293 on +-50Vs 4 ohm :devilr: .

Why do you think it's not stable enought?
 
hi,

me and my friend have came out with a pcb that can have up to 3 TDA7293 in parrallel. This board is inverting configuration. I use slow startup for the mute/stby according to the datasheet (the 2 caps and small resistors at the lower left side)

The 6 big caps are the psu caps for the 3 ICs. the big white resistors are optional, we put there just in case the IC didnt feed equal current. so far we tested the ICs do feed equal current, so it means that the datasheet is correct. I design the input cap to be optional as well. Signal resistors are very close to the master IC

my friend have tested 1 board and he says it works very well, with 0mv offset. he sortof lost the 2nd board i pass him at a shopping center :smash: i'm on budget now so wun be doing mine till a long time later... :p
 

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