Post by matt@IAA on Jan 21, 2019 9:03:22 GMT -6
Hi guys,
I saw a lot of folks talking about wanting to do wet/dry blend on the forum over the past few days. I had some downtime traveling for work and drew up a simple two channel mixer.
Features:
- Two balanced inputs
- Header for unbalanced inputs after the input amps
- Passive mix between wet/dry with a constant power fader
- Mixing is accomplished by an active combining amplifier (VE summing)
- Inputs can be done with either THAT1246 or 2520 footprint DOAs
- Output can be done by either a single DOA using a 2503 footprint output transformer or a NE5534 with a THAT1646 output
The idea was to give as much implementation flexibility as possible. For example, you could use this to grab an input (balanced) and mix it with one internal unbalanced signal, or mix two unbalanced signals bypassing the two input amplifiers altogether. You could use two of these, take the fader points on both and wire them to a two deck pot or switch for stereo.
The output is set up to be switchable using a 3PDT switch. So you could also bring the signal in with a color option on the output (5534 into 1646 or DOA and transformer out). The inputs are either / or but the output is completely separate. You can also omit the switch and make it one way or the other using jumpers.
The footprint came out to be 3.1" x 5.6". You could easily stuff a couple of these in a 1RU. It could be significantly smaller if I omitted the DOAs or moved the transformer off of the board - if you wanted to trade flexibility for space to try to retrofit this into an existing unit.
Comments? Feedback? Any interest?
Preliminary layout:
I saw a lot of folks talking about wanting to do wet/dry blend on the forum over the past few days. I had some downtime traveling for work and drew up a simple two channel mixer.
Features:
- Two balanced inputs
- Header for unbalanced inputs after the input amps
- Passive mix between wet/dry with a constant power fader
- Mixing is accomplished by an active combining amplifier (VE summing)
- Inputs can be done with either THAT1246 or 2520 footprint DOAs
- Output can be done by either a single DOA using a 2503 footprint output transformer or a NE5534 with a THAT1646 output
The idea was to give as much implementation flexibility as possible. For example, you could use this to grab an input (balanced) and mix it with one internal unbalanced signal, or mix two unbalanced signals bypassing the two input amplifiers altogether. You could use two of these, take the fader points on both and wire them to a two deck pot or switch for stereo.
The output is set up to be switchable using a 3PDT switch. So you could also bring the signal in with a color option on the output (5534 into 1646 or DOA and transformer out). The inputs are either / or but the output is completely separate. You can also omit the switch and make it one way or the other using jumpers.
The footprint came out to be 3.1" x 5.6". You could easily stuff a couple of these in a 1RU. It could be significantly smaller if I omitted the DOAs or moved the transformer off of the board - if you wanted to trade flexibility for space to try to retrofit this into an existing unit.
Comments? Feedback? Any interest?
Preliminary layout:
