| T O P I C R E V I E W |
| VoidKeeper |
Posted - Oct 30 2010 : 5:07:56 PM
Hi, I recently built the Audio Mixer posted on this website and it is quite good, I made a few changes like the capacitor at the input that created a high-pass filter which would cause a bit of bass to roll off.
Anyways, the volume that is coming out is a bit low, not THAT much, it's ok, but I notice the difference and I have to turn the volume up a notch, I would like to add some kind of pre-amp inside the mixer, I was wondering if anyone could recommend some kind of schematic or something in special? |
| 6 L A T E S T R E P L I E S (Newest First) |
| VoidKeeper |
Posted - Oct 31 2010 : 06:52:12 AM
Awesome, I'll get right on it =P |
| audioguru |
Posted - Oct 30 2010 : 11:01:12 PM
The NE5532 and the TL071 and TL072 all sound the same: perfect. |
| VoidKeeper |
Posted - Oct 30 2010 : 7:49:52 PM
I got an NE5532P here, but I might take a look at the TL072, since I built this thing with separate channels for Left and Right. I guess I'll test them both out and see which sounds better, although the TL072 does consume less current, that would probably be a plus. |
| audioguru |
Posted - Oct 30 2010 : 7:34:17 PM
You must design the opamp circuit correctly so it is an inverting mixer not just an adding buffer like the FET was.
You should use an audio opamp like a TL071, not a lousy old 741 opamp. |
| VoidKeeper |
Posted - Oct 30 2010 : 7:26:24 PM
So all I need to do is change the FET and everything after it with an inverting op-amp?
I think I got an op-amp lying around, just need to check what resistor values to use to get little to no gain, I want to keep the sound quality as intact as possible. |
| audioguru |
Posted - Oct 30 2010 : 5:51:54 PM
The FET audio mixer circuit is extremely simple so instead of gain, it has loss. The loss increases each time another input is added.
If you need a mixer that has no loss or that has gain then an inverting opamp should be used instead of the FET-follower. |
