Hi Bear,
I was checked it.
Using regulated PSU as source = 12.3 Volt DC
TDA2050 pin 5 = 5.9 Volt
TDA2050 pin 3 = -5.7 -5.8
And feel tight bass from mycMoy preamp (using NE5532P).
And the TDA2050 is just little warm for 4 hour playing
In my opinion, the two best ways to use a single output transformer to make a power supply for an amp are:
1. Try to determine if the single output transformer is made from a dual-secondary transformer with paralleled secondaries. This is surprisingly common; I'd guess at least half the transformers I have salvaged are made this way. The two lead wires from the transformer will disappear under some varnish-saturated paper where they are connected to the (stiff, solid copper) windings. Carefully cut away that paper (in a way that you can reverse the surgery later) and see if each lead is soldered to one or two copper windings. If two, then jackpot! You have a dual-secondary transformer. A little surgery will separate them, then you can connect them in series instead of parallel to get a center-tapped trafo.
2. Use a BTL - Bridge Tied Load - configuration with two amps. This way, there is no speaker current flowing into "ground", it goes rail-to-rail not rail-to-ground. That means that you can very effectively use a single supply along with a relatively weak phantom ground (via voltage divider) for the input side. The usual bridged amp considerations apply like doubling of load current (halving the effective load impedance), etc.
1. Try to determine if the single output transformer is made from a dual-secondary transformer with paralleled secondaries. This is surprisingly common; I'd guess at least half the transformers I have salvaged are made this way. The two lead wires from the transformer will disappear under some varnish-saturated paper where they are connected to the (stiff, solid copper) windings. Carefully cut away that paper (in a way that you can reverse the surgery later) and see if each lead is soldered to one or two copper windings. If two, then jackpot! You have a dual-secondary transformer. A little surgery will separate them, then you can connect them in series instead of parallel to get a center-tapped trafo.
2. Use a BTL - Bridge Tied Load - configuration with two amps. This way, there is no speaker current flowing into "ground", it goes rail-to-rail not rail-to-ground. That means that you can very effectively use a single supply along with a relatively weak phantom ground (via voltage divider) for the input side. The usual bridged amp considerations apply like doubling of load current (halving the effective load impedance), etc.
Hi Bear,
One more question. How about to paralleled the opamp to produce more current ? It could be ?
Regards.
For moderate current into the center, here is a possibilty:
http://www.diyaudio.com/forums/powe...ngle-secondary-transformer-4.html#post2681284
http://www.diyaudio.com/forums/powe...ngle-secondary-transformer-4.html#post2681284
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