You have dual secondaries, dual rectifiers.
In the only working way to re-order the batteries in a two cell flashlight, you can likewise re-order those bridge rectifiers. See if the imbalance relocates or changes.
EDIT:
That procedure wouldn't help a stereo amp that has only one channel of imbalance. Are both channels the same or is there one different than the other?
In the only working way to re-order the batteries in a two cell flashlight, you can likewise re-order those bridge rectifiers. See if the imbalance relocates or changes.
EDIT:
That procedure wouldn't help a stereo amp that has only one channel of imbalance. Are both channels the same or is there one different than the other?
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I have tried swapping bridges,,but still it goes.It is just the same for both amps.And I have measure when amp is poweredd,,there is min imbalance like .1 v,,,,Does 11mv dc offset cause the probs ?..Anyway it doesnt affect the sound.
The led in ? is the negative terminal.
What if i connect the anode to the gnd and 10k resistor from cathode to the negative terminal.In my,your connection it is the opposite.
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Yay! So, wiring it exactly like the power supply schematic works fine?
I have lost track of how many features are in that supply (it is low parts count design so there's a lot of functions not obvious on first glance) and the many reasons for them. Unlike the majority of dual secondaries supplies, it has only one solid (very solid) central ground. There was a good reason for this but I did not remember it. I think you found out though. Thanks!
I have lost track of how many features are in that supply (it is low parts count design so there's a lot of functions not obvious on first glance) and the many reasons for them. Unlike the majority of dual secondaries supplies, it has only one solid (very solid) central ground. There was a good reason for this but I did not remember it. I think you found out though. Thanks!
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Very solid power supply.I was connecting the opposite terminals of the bridges like Carlos ,,like a bit lengthy wire.But When I connected exactly like you ,,it was just doing fine.thanks again.
http://img256.imageshack.us/img256/1341/ampli7293schma2.jpg
I have use this schematic from Francis Ibre for point to point, just reverse the négative rail diode
I have use this schematic from Francis Ibre for point to point, just reverse the négative rail diode
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The idea is fantastic, but the reliability is hit or miss. On that schematic, it reduces reliability because we shouldn't voltage drop the V- pin, which is substrate. If that is lower voltage than PWV- the chip's internal diode may be overloaded, corrupt, crack, and set the chip and speaker on fire. Voltage drop the substrate = worse than a short circuit. SO, on that schematic, it is probably necessary to parallel that V- diode with a sturdy resistor, which can give you that desired slight isolation effect without the dangerous voltage drop. Must not voltage drop the substrate. I'm not sure what resistor value to Add parallel to that V- diode for guaranteeing that the predrive section never actually experiences a voltage drop. Perhaps 0.47R.
No problem with the V+ diode.
Other part of that schematic, the 33k, diode, and 10u on the mute circuit are useless if you don't need to switch the mute on and off. It is simpler just to use the 10k by itself, if you don't intend to attach switches.
No problem with the V+ diode.
Other part of that schematic, the 33k, diode, and 10u on the mute circuit are useless if you don't need to switch the mute on and off. It is simpler just to use the 10k by itself, if you don't intend to attach switches.
A gainclone TDA,,, isnt that having a 50x gain.I have a couple of schematic where bootstrap cap is 100uf.I like this.
Sorry, I don't have any power supply designs made for using bad caps, so just simply replace any defective parts.
But I do have some questions:
Did you add adjustable snubbers to the secondaries like we discussed previously?
Do you have alloy transformer hookup cables from transformer to bridge rectifier?
Do you have the bridge rectifiers on the power supply board, per the schematic?
How much voltage discrepancy in the DC power?
But I do have some questions:
Did you add adjustable snubbers to the secondaries like we discussed previously?
Do you have alloy transformer hookup cables from transformer to bridge rectifier?
Do you have the bridge rectifiers on the power supply board, per the schematic?
How much voltage discrepancy in the DC power?
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hey mr daniel!
i´m building a 7293 in bridge config.,
as by the 7294 bridge mode, but using your
rc values; my question is: the resistor from
IC1 out to IC2 neg in, should be 60k too?
the transformer is a 25-0-25 125VA
and 4700uFx4 any comments?
thanks for your postings and your time
and attention.
martinnez martin
uruapan michoacan
forgot to say its going to replace burnt amp
and ps board from an amplified speaker.
i´m building a 7293 in bridge config.,
as by the 7294 bridge mode, but using your
rc values; my question is: the resistor from
IC1 out to IC2 neg in, should be 60k too?
the transformer is a 25-0-25 125VA
and 4700uFx4 any comments?
thanks for your postings and your time
and attention.
martinnez martin
uruapan michoacan
forgot to say its going to replace burnt amp
and ps board from an amplified speaker.
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Hi Martin,
However, you could have a look at the OP275 datasheet, find +15v and -15v regulators, and then try a high quality bridge adapter:
Yes, a "bridge resistor" is same value as your feedback resistors. The simple bridge method works okay for making a guitar amplifier.
However, you could have a look at the OP275 datasheet, find +15v and -15v regulators, and then try a high quality bridge adapter:
I'm currently building a power supply that could help this. I was almost done, but the soldering iron quit working.
thanks!
i have a little doubt: my xfrmer is from another amplified spkr,
25-0-25 i have dual bridge rectifiers and 4x4700uf. it was used
with single rectifier and 15000 x2 caps to feed 2 lm3886 bridge
for lo freq and another 3886 for hi freq.
Since i want to use fullrange amp for 8 ohms spkr wpassive xover,
what doyou recomend with that ps?
Its 25-0-25 125va dual rect and 4x4700...
My doubt is about what would fit better either single or bridge
3886 or 7293; any sugestions?
thank you very much
for your reply
martin martinnez
uruapan michoacan
i have a little doubt: my xfrmer is from another amplified spkr,
25-0-25 i have dual bridge rectifiers and 4x4700uf. it was used
with single rectifier and 15000 x2 caps to feed 2 lm3886 bridge
for lo freq and another 3886 for hi freq.
Since i want to use fullrange amp for 8 ohms spkr wpassive xover,
what doyou recomend with that ps?
Its 25-0-25 125va dual rect and 4x4700...
My doubt is about what would fit better either single or bridge
3886 or 7293; any sugestions?
thank you very much
for your reply
martin martinnez
uruapan michoacan
ic substitution?
can use ne5532 more easily available here, or another choice?
so that way of bridgin with the feedback res its not so good?
Then i have to use opamp brdge adapter?
this speaker has integrated mic line pre,eq and usb-card mp3player
then i can use gain 29x?
i´ll change my res and caps for feedback
can use ne5532 more easily available here, or another choice?
so that way of bridgin with the feedback res its not so good?
Then i have to use opamp brdge adapter?
this speaker has integrated mic line pre,eq and usb-card mp3player
then i can use gain 29x?
i´ll change my res and caps for feedback
See also Rod Elliot's site, and alternative schematic with TL072. Bridging Adapter For Power Amps