Lm 324 amplifier?
Hello i am trying to build a Lm324 Stereo preamp to go into my 100w tube amp, and i cannot find any schematics on 324's.
My idea was to have each channel occupy its own side of the chip, and having a switch to switch between 1 and 2 amp stages.
please help thank you.
My idea was to have each channel occupy its own side of the chip, and having a switch to switch between 1 and 2 amp stages.
please help thank you.
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Jun 4, 2011. 5:51 PMframistan
says:
The 741 op-amp is supposed to be used with a dual supply. The lm324 has the advantage that it requires only a single supply voltage to power it up. I have used the lm324 as a mic-preamp to with great success using this schematic of an LM1458 that has the same pin-outs. If you are not connecting it to a condenser mic, then just omit the 4.7k resistor near the mic and omit the mic also as shown in the schematic. The LM324 has 2 other amps in it on different pins that you could wire the same and get another channel (left and right).
You are correct, however a dual supply is only used to avoid having
to provide a split reference for those older op-amps,
as your two 10K resistors do for the LM1458 and
as the 18K / 22K does for the 741..
The LM1458 DC gain of 10 X 10 => 100 may be too much gain for the
synth audio signal application, causing rail distortion.
I think ski4... is smart enough, to act on the hint of using the LM324
in place of the 741...
A
to provide a split reference for those older op-amps,
as your two 10K resistors do for the LM1458 and
as the 18K / 22K does for the 741..
The LM1458 DC gain of 10 X 10 => 100 may be too much gain for the
synth audio signal application, causing rail distortion.
I think ski4... is smart enough, to act on the hint of using the LM324
in place of the 741...
A
You didn't specify the audio source ( Mike, tape, CD,radio ). A
Jun 3, 2011. 2:46 PMski4jesus (author)
says:
I am putting my synth through it into a 100w tube amp
Doesn't a synth have enough output to feed your big amp ?
Here is a pointer to a crystal pre-amp.
The crystal is a high level signal, probably like a synth
and a 741 like Steve said is a ¼ of a LM324.
Here is a pointer to a crystal pre-amp.
The crystal is a high level signal, probably like a synth
and a 741 like Steve said is a ¼ of a LM324.
Jun 4, 2011. 2:21 PMski4jesus (author)
says:
The synth allows it to play but in order for the speakers to play richly, i need a preamp. so yea.
I do understand.
When I was young, I found this rock canyon and started build a solid state
12V 50 Watt power amp to ring my ears in that geological amphitheater.
But we moved away and I never got the chance to fry my brain right :-D
If you build any preamp, keep the circuit small, and put it in a metal box
like an altoids tin. Ground the circuit to the tin where you bring in the 12VDC.
Start very low volume ( Don't Burst Your Spkrs ).
A
When I was young, I found this rock canyon and started build a solid state
12V 50 Watt power amp to ring my ears in that geological amphitheater.
But we moved away and I never got the chance to fry my brain right :-D
If you build any preamp, keep the circuit small, and put it in a metal box
like an altoids tin. Ground the circuit to the tin where you bring in the 12VDC.
Start very low volume ( Don't Burst Your Spkrs ).
A
The tricky part to building audio amplifiers, in my opinion, is that you want only want to amplify the AC part of the signal. The picture I have attached is from H+H's Art of Electronics, 2nd Ed. The circuit I drew a red box around is just one stage, using one op-amp.
This is one of my favorite op-amp circuits, and I've posted this picture here before.
Link to the full-res actually-readable version of this picture:
http://www.instructables.com/files/orig/FYQ/TPWU/GGMMR482/FYQTPWUGGMMR482.jpg
This is one of my favorite op-amp circuits, and I've posted this picture here before.
Link to the full-res actually-readable version of this picture:
http://www.instructables.com/files/orig/FYQ/TPWU/GGMMR482/FYQTPWUGGMMR482.jpg
I am guessing you already have a datasheet for the LM324. If you don't, you can find one here:
http://www.alldatasheet.com/
http://pdf1.alldatasheet.com/datasheet-pdf/view/53583/FAIRCHILD/LM324.html
http://www.alldatasheet.com/
http://pdf1.alldatasheet.com/datasheet-pdf/view/53583/FAIRCHILD/LM324.html
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