| No. | Mixers, Meters etc. |
Description | Flags |
| 30 | Stage and Recording Mixer |
Able to be built in modular form, allowing as many (or few) channels as desired. Includes effects sends, channel and master inserts, and 3-band EQ with tuneable mid. This is the most ambitious project so far, in terms of overall complexity - not for the faint of heart ! |
2000
 |
| 35 | Direct Injection (DI) Box |
An essential companion for the mixer for stage or recording work. Includes high and low level inputs. Two different versions to choose from - passive, or active 48V phantom / battery | 2005 |
| 50 | Mic Circuit Tester |
This simple project was inspired by a reader, who needed a small oscillator to check mic circuits during sound setup. It is fixed frequency (tuned to A-440), and provides from 0 to 100mV into a typical microphone input. | 2000 |
| 55 | PPM and VU Meter |
A versatile and useful VU meter circuit, that can also operate as a Peak Programme Meter (PPM). See the average and peak output level from an amplifier or preamp. Can also be used with any mixer. |
2006 |
| 60 | LED VU Meter |
Nothing even remotely special about this LED VU meter, but it is a useful project nonetheless. Includes a simple rectifier circuit to allow full wave detection, and is suitable for line or speaker levels. | Feb 08
 |
94
| Universal Preamp/ Mixer
|
A small preamp and mixer, able to be expanded into 4 stereo input channels. Mic or phono preamps can be added to the front end to make a small and versatile home recording mixer. Includes tone controls.
| Dec 05
|
94A
| Universal Preamp/ Mixer
|
Alternative wiring scheme to get more inputs from a single board. Includes tone controls.
| 05 Dec
|
96
| Phantom Feed Supply
|
Extremely low ripple and noise were the design goals, and this supply is extraordinarily quiet. Using a simple discrete regulator means no hard-to-get high voltage regulators, and it uses a readily available power transformer as well. Also features a phantom power microphone feed, and a technique to match supply resistors | Dec 05
|
128
| VU Meter Bridge
|
Build a stereo analogue VU meter to monitor recording or live PA mix levels. Uses the P87A PCB and is compatible with balanced and unbalanced systems. | Jan 10
|
129
| Matrix Mixer
|
Now you can build a matrix mixer to suit your exact requirements. Uses the P94 Universal Preamp/Mixer PCB. | Apr 10
|
135
| Phase Correlation Meter
|
More of an experimental circuit than anything else, it should help anyone trying to build a phase meter.  24 Mar 2011 | Mar 11 |
136
| Real-Time Analyser
|
This hardware based real-time audio analyser is a contributed project, based on the multiple feedback bandpass filter described in Project 63 20 May 2011 | May 11 |
Last Major Update: 20 Mar 2002 - modified page layout./ 05 Dec 06 - added P94A./ 23 Feb - Updated P60
