The Q-MNR FX Loop Controller Kit, a member of London Power’s Q-system of switching kits, is the heart of London Power’s Q-MINI amp switching system. It is designed to provide complete control and bypassing of a series/mixing effects loop, synchronized with the channel selection of a 2-channel preamp. This amp configuration is the most popular form of 4-voice guitar amp. Relays are used to perform the audio switching.
Q-MNR is also the most sophisticated effects loop controller available. It accommodates series/mixing operation and can be used to select send/return levels for instrument or line devices.
Combining Q-MNR with Q-LATCH and three or four RLYs provides a complete switching solution for a 4-voice system, where the voices are: A, A+FX, B. B+FX. How these voices are grouped is up to the installer, and easily programmed by soldering diodes onto the PCB. Four diodes are supplied to satisfy the voices described – the most common application.
The preamp control portion of Q-MNR can easily be a single output, since mechanical relays provide an exclusive 1-of-2 choice switching between their non-powered and powered states. For many preamp configurations, this is sufficient. For greater versatility, Q-MNR provides two relay controls for symmetric relay functions. This means one relay group is ‘on’ while the other is ‘off’, allowing positive selection of features, as your application may require.
Effects loops can be simple or complex, transparent or tone-changing, series or mixing or switchable. To accommodate the best loops, like our own BFX, two relays are needed: one for the series/mix function and one for enabling the loop. Both functions interact when the loop is set for ‘series’ operation when active, but must then be bypassed when ‘off’. Q-MNR handles this with ease and can be used just for loop control if that is really the issue of your switching application.
When Q-MNR is used solely to control an effects loop, the RLY1 and RLY2 outputs can be used to control ‘send’ and ‘return’ levels and gain, for optimization of the loop signal-to-noise for instrument level and line level devices. This capability greatly expands the possibilities for stand-alone effects loop controllers.
LEDs indicate the preamp status with separate LEDs for Ch.A and Ch.B. A LED also indicates when the ‘series’ mode is selected, and a fourth LED shows when the FX loop is active. Any or all of these LEDs can be on the front panel. In a system where Q-LATCH is mounted remotely in a foot switch, then Q-MNR’s LEDs are welcome on the amp front panel.
A plus or minus 12Vdc supply can be used.
PCB construction makes assembly quick and easy.
PCB size: 3.7 x 1.5″ (94 x 38mm)
For more information:
– see our page, About Our Switching Kits
– download our informative PDF: London Power Switching Kits Selection & Application (135 kB, 22 pages)