TDA7297 Parallel mode

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Folsom

TDA7297 Parallel mode
« on: 12 Apr 2014, 02:50 am »
Alright, for anyone who wants to monoblock these guys.

Here's a few drawing showing how to connect the inputs and speaker outs.

First the input. Choose right or left to hook up your signal, and use an insulated piece of wire to connect the pins shown in this picture to avoid contact with others. You can remove the input caps for whichever channel you are not using. It's good to do if you want to run parallel. The less inductance from tracing the better. To the point where you can cut the tracing on the "dead" input you're not using, right before the chip, and just keep the jumper wire in place like drawn in the picture.




Next up you can do the same thing to the speaker output. Use an insulated wire, so it doesn't touch anything it shouldn't. If you're uncomfortable with doing it pin to pin on the chip, you can do it by connecting the two via a jumper wire from one terminal/terminal pin to the other. You can even just connect both positives at the binding post. The chip pin to chip pin will offer the least inductance. You can also cut the "dead" output tracings near the chip, if you did the chip pin to chip pin jumper wire.





elb

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Re: TDA7297 Parallel mode
« Reply #1 on: 12 Apr 2014, 03:47 am »
Hi Salis,
thank you for that.

A generous gift for the non technical people like me.

Best regards.

Davey

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Re: TDA7297 Parallel mode
« Reply #2 on: 12 Apr 2014, 11:07 am »
Equal current sharing with that configuration?

Dave.

Folsom

Re: TDA7297 Parallel mode
« Reply #3 on: 12 Apr 2014, 10:23 pm »
I think you got the idea, you just increase current. Gain doesn't change. The question I don't know, is if it sounds better. I haven't done it since I've been playing with TPA3116 amps atm.

Davey

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Re: TDA7297 Parallel mode
« Reply #4 on: 12 Apr 2014, 10:56 pm »
Yeah, I understand the concept.  I'm asking you if the internals will share current equally without adding a series resistance to each output.

Cheers,

Dave.

G Georgopoulos

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Re: TDA7297 Parallel mode
« Reply #5 on: 13 Apr 2014, 12:51 am »
I think you got the idea, you just increase current. Gain doesn't change. The question I don't know, is if it sounds better. I haven't done it since I've been playing with TPA3116 amps atm.

Hi Salis

you increase current for lower ohms loads,
 if one amp can drive the load of a speaker
there's no need to increase current...
please note Vout and load determine the current
required...

cheers

Davey

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Re: TDA7297 Parallel mode
« Reply #6 on: 13 Apr 2014, 01:36 am »
Assuming the load is the same, paralleling two channels will halve the current required from each section......IF they share equally.  (There's no current "increase" here.)

On many of these chip-amps just jumpering the two outputs together won't guarantee a 50/50 current sharing split.  I was wondering what the output Z is on these chips.  If significant enough then maybe a simple jumpering would work.

Cheers,

Dave.

G Georgopoulos

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Re: TDA7297 Parallel mode
« Reply #7 on: 13 Apr 2014, 02:45 am »
The question I don't know, is if it sounds better. I haven't done it since I've been playing with TPA3116 amps atm.

yes it will sound better, if there is the required current,rather than lack of it...

G Georgopoulos

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Re: TDA7297 Parallel mode
« Reply #8 on: 14 Apr 2014, 04:21 am »
hi again...

as for current sharing most chips have internal  resistors for thermal run down
these also perform the function of current sharing espesialy in bjt chips

sorry i stoped your thread with my posts,keep experimenting!!!...

cheers

Davey

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Re: TDA7297 Parallel mode
« Reply #9 on: 15 Apr 2014, 01:36 am »
I'm not sure Salis even understood the question I was asking.  :)

Regardless, how it sounds is not really pertinent until it's confirmed the current-sharing works as expected.  Only then it would be appropriate for subjective evaluation.

Cheers,

Dave.