for switching one side to negative to make a non-bridgeable amp into a bridgeable one by inverting the phase of one channel
I was thinking of using two transformers and one one transformer reversing the output wiring that goes into the amplifier (line level signal or slightly higher like from headphone jack from computer) some kind of 1 to 1 signal transfer transformer if possible so theres not too much sound quality/volume degradation.
is this a bad idea?(explosively bad?) or something maybe nobody has thought of yet and might work?
so i would split the negative into two seperate negatives via separate transformers then reverse wiring one of the outputs of the transformers to get the signal reversed on one channel so i can hook a speaker to both positive outputs on the amplifier?
i'm not sure where this should be posted. in amplifiers or construction? tried my best.
I was thinking of using two transformers and one one transformer reversing the output wiring that goes into the amplifier (line level signal or slightly higher like from headphone jack from computer) some kind of 1 to 1 signal transfer transformer if possible so theres not too much sound quality/volume degradation.
is this a bad idea?(explosively bad?) or something maybe nobody has thought of yet and might work?
so i would split the negative into two seperate negatives via separate transformers then reverse wiring one of the outputs of the transformers to get the signal reversed on one channel so i can hook a speaker to both positive outputs on the amplifier?
i'm not sure where this should be posted. in amplifiers or construction? tried my best.
The transformer scheme to create an inverted polarity for amplifier input will work. However, you still need to verify if the amplifier outputs are suitable. The negative terminals need to be common to each other, or if not they need the capability to be connected together with no issues.
Dave.
Dave.
sounds interesting.... I have tested and both negatives seem to output sound to both left and right speakers equally. (as in. both negatives will give power to left and right speaker whichever negative you put the wire to) Does that mean they're "joined" and unsuitable for this kind of job?
Yeah, that probably means your okay, but I would still test with an ohmeter to confirm. Sometimes amplifier negative terminals are not tied directly to ground but via low-ohm resistors to ground. So, you might have a few ohms between adjacent black terminals and the practical experiment your performed would appear successful, but you still don't have an optimum bridging configuration.
Also, the standard caveats apply when bridging channels. Each channel now sees one half the impedance load it would have otherwise.......which may or may not be a problem.
Dave.
Also, the standard caveats apply when bridging channels. Each channel now sees one half the impedance load it would have otherwise.......which may or may not be a problem.
Dave.
That's a LOT more complicated than just two transformers. I don't have access to any of the parts for that... Only the transformers I got.
Is there some way i can still do it simply with two transformers? without any circuit's or extra power? My amplifier is a 40 watt 2 channel stereo player with CD selector cassette player ect. can probably guess what kind of amplifier is in it just by guessing.
It's RCA inputs (2 channel input 2 channel output) it has a working Radio too which is neat. it's probably ancient or something but what can you get from a dumpster dive? lol
Is there some way i can still do it simply with two transformers? without any circuit's or extra power? My amplifier is a 40 watt 2 channel stereo player with CD selector cassette player ect. can probably guess what kind of amplifier is in it just by guessing.
It's RCA inputs (2 channel input 2 channel output) it has a working Radio too which is neat. it's probably ancient or something but what can you get from a dumpster dive? lol
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It is not as complicated as it looks. The parts are common and extremely cheap, hence my suggestion. You could get everything you need to build a circuit like this at Radio Shack, and on a PCB, it's a little nothing of a thing probably the size of a silver dollar, not counting the power supply if you have to add one. Adding the power supply will be as simple as finding a suitable DC voltage in the unit and adding two regulator ICs and possibly some capacitors if there isn't already a supply you can use. Unless you have a tube amp there probably is.
Remember that all you are really looking at is the area in green, and this is a diagram so it is simplified. The actual circuit will use one eight-pinned IC in place of the big triangles.
I just left some area around that example so you could see where the inputs and outputs go for reference. I would obviously find a design specific to your application but this is an excellent example circuit. I believe an op-amp to be the best way to do this quickly and easily while keeping your amp and wallet happy. You could even build this as an outboard module to use with almost any amplifier.
I just left some area around that example so you could see where the inputs and outputs go for reference. I would obviously find a design specific to your application but this is an excellent example circuit. I believe an op-amp to be the best way to do this quickly and easily while keeping your amp and wallet happy. You could even build this as an outboard module to use with almost any amplifier.
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I dont have my own money to spend or even a way to get to radioshack. lol its a long ways away and it's too hot outside to ride my bike. I'd get heatstroke. and my parents car isn't working very well and last time i was at radioshack there wasn't any capacitors.
the only other way to do this would be to use Audacity and invert one of the channels of the song i want to listen to and put speaker wires positive to positive on the amplifier speaker outputs... dont really feel like doing that for every song i want to hear lol thats just silly.
the only other way to do this would be to use Audacity and invert one of the channels of the song i want to listen to and put speaker wires positive to positive on the amplifier speaker outputs... dont really feel like doing that for every song i want to hear lol thats just silly.
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Then I would enjoy your amplifier as a stereo unit. Keep in mind transformers are impedance matching devices and you may cause problems using them in the way you are describing. I would not recommend it unless you are personally sure it will work for your application.
The transformer method is ideal for trying out your bridged configuration.
You could have it hooked up real fast. Forget the suggestions that require unneeded tools, parts, supplies and complexity.
You could have it hooked up real fast. Forget the suggestions that require unneeded tools, parts, supplies and complexity.
If you have a problem with my suggestion you can address it directly. I would like to hear it.
Again, regard my warning about transformers.
Art is correct. The xformer scheme is an easy hook up with no extra circuitry to build or power. Realflow sounds like a young fella who is just getting his feet wet with limited parts access and funds and is game for some simple experimentation. Putting a couple of transformers together and learning about polarity reversal and bridging is a nice little project and one that he already has all the parts for.
Transformers are not going to cause any (serious) problems/issues in this application. Nothing's going to go up in smoke and he's not going to damage anything if they're not hooked up correctly the first time. 🙂
Dave.
Transformers are not going to cause any (serious) problems/issues in this application. Nothing's going to go up in smoke and he's not going to damage anything if they're not hooked up correctly the first time. 🙂
Dave.
It would however help to know more about the transformers. If they are 1:1 absolutely no harm will be done. That is why I have cautioned against this solution.
I understand the limited parts access but I don't think it is a bad suggestion and it is still relatively simple. Not a bad idea to keep in mind for down the road, maybe. One IC and some caps/resistors, possibly two regulators. All very easy to implement with many plans and how-to tutorials online. It would be an excellent beginners project- shame about the limited access to parts. If I were in better financial shape myself, I would just send them to him since I have all of the necessary components laying around on my desk at present. Then again, my desk is as much of a bench as it is a desk these days 😛
The joys of being a broke student.
Best of luck with your project, OP. Post some information about the transformers if you have it.
Bridging will increase the SPL by 3dB. Remember: a subjective doubling of audio volume requires ~10 dB. Silly...?
You do not seem to have access to normal quality parts, and even good transformers distort, degrade the phase and frequency response, etc, etc
Why would you jettison the (relatively) high quality stereo for something that will in the end be only marginally louder, but significantly worse in terms of quality?
Well, "de gustibus non est disputandum" so let's concentrate on the issue: why use two transformers, when one is already capable of phase inversion (and signal degradation, of course)
You must be kidding.
1) all realflow needs is 1 50 cent Op Amp and 2 5 cent resistors per channel.
Hecan feed them from the already existing preamp supply and does not even need to make a PCB, it can easily be built dead bug style.
2) where in h*ll did you get 2 audio grade transformers?
I would love to hear your "story".
Because that Radio Shack which "does not sell capacitors" will even less have such transformers ... which if available and good quality will cost upwards of $50 ... each.
3) and you *still* have to mount them, avoid hum pickup, etc.
Of course, this is just another classic post by realflow who seems to have lots of free time and finds it fun posting this kind of stuff, always posing as a poor clueless kid .
Just as a free sample, the post where he claims he connected a 2W speaker, pulled from a TV, straight to 120V wall voltage and it survived
He's famous for posting impossible / unbelievable stuff and making Forum members try to answer:
http://www.diyaudio.com/forums/full...cketed-2-watt-speaker-survives-undamaged.html
A typical answer to his posts is:
For the full show, just browse:
http://www.diyaudio.com/forums/search.php?searchid=7985271
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