Hi all,
I’m looking around for a circuit diagram for a microphone preamp.
There are lots of designs around but I have some specific requirements:
Balanced input
Balanced output (if possible)
Variable gain adjustment (+- 40-60dB)
Pad switch (if possible)
Battery powered (single 9V or 2x 9V)
Primarily for use in live environments so studio type noise levels are not a must have.
Simple design that can be made on strip board.
(Possibility a small batch of PCB’s could be made overseas. I’d therefore need a layout in a compatible format)
Nice to have: A battery level LED: Bi-colour that indicates good/low.
Small overall footprint - similar to a large smart phone with a height of around 25mm/1"
Nice to have: low voltage phantom power
Searching around the web I’m a bit snow blinded by the designs but none seem to fit my spec.
Any pointers or thoughts would be welcome.
I’m looking around for a circuit diagram for a microphone preamp.
There are lots of designs around but I have some specific requirements:
Balanced input
Balanced output (if possible)
Variable gain adjustment (+- 40-60dB)
Pad switch (if possible)
Battery powered (single 9V or 2x 9V)
Primarily for use in live environments so studio type noise levels are not a must have.
Simple design that can be made on strip board.
(Possibility a small batch of PCB’s could be made overseas. I’d therefore need a layout in a compatible format)
Nice to have: A battery level LED: Bi-colour that indicates good/low.
Small overall footprint - similar to a large smart phone with a height of around 25mm/1"
Nice to have: low voltage phantom power
Searching around the web I’m a bit snow blinded by the designs but none seem to fit my spec.
Any pointers or thoughts would be welcome.
Ad797 Mic preamp Kit
This Russian design looks really nice but would require 4x 9V to be battery powered.
I already have a Canford battery powered preamp which takes the same 4x 9V and is the size of a house brick..
Ideally, I'm after a compact form factor that runs off 1 or 2 9v cells.
This Russian design looks really nice but would require 4x 9V to be battery powered.
I already have a Canford battery powered preamp which takes the same 4x 9V and is the size of a house brick..
Ideally, I'm after a compact form factor that runs off 1 or 2 9v cells.
If you select a TL072. use the + and - inputs, pins 3 & 2 with suitable feedback for a gain of 100 as the front end and the other half to vary the gain that you require.
Employ a TC7660 to produce the -9volt supply from the single PP3 battery.
I get about 200hours of use on one PP3 battery.
Employ a TC7660 to produce the -9volt supply from the single PP3 battery.
I get about 200hours of use on one PP3 battery.
Attachments
Thanks Jon for that.
I found this complete Preamp circuit utalising the TL072 on the EEV Blog forum. Would that circuit benefit from the TC7660 split rail supply?
TL072 - Microphone preamp (differential) - Page 1
I found this complete Preamp circuit utalising the TL072 on the EEV Blog forum. Would that circuit benefit from the TC7660 split rail supply?
TL072 - Microphone preamp (differential) - Page 1