Stereo Parallel Blender, Dual Loop

Stereo Pedal Blender, Parallel, two loops
Stereo Parallel Blender capable of handling higher line level signals.
This is an all analog Stereo Parallel Blender that offers two independent loops and a Dry blend and is able to handle signals varying from instrument level up to higher line level (~24Vpp max).

All jacks are TRS. The device is compatible with mono signals as well.

Brief function explanation:
  • The signal is taken from the INPUT and is split into three separate signals.
  • One is send to Loop-A (SND-A), the other to Loop-B (SND-B) while the third is the DRY signal.
  • The signal from the Loop-Return (RTN-A, RTN-B) is then fed back to the circuit: first to the Phase Select section, then to the Volume section.
  • The two Loop-Return signals are then mixed together with the DRY signal and sent to the OUTPUT.
Footswitches A, B turn the respective loop ON/OFF
Tails switches are for both Loops allow you to choose if the footswitches A, B will mute the SEND or the RETURN for each loop.
Phase reverse switches are available for both Loops.
Ground lift switches have been added on both Loops that may come in handy if you experience ground hum. They both lift the ground on the return jacks.
▹ The footswitch in the right corner completely bypasses the circuit (true bypass).

For a schematic representation of the signal flow check the flow chart below
two loop stereo blender flow chart

The device is also compatible with MONO signals. If you want the mono signal to expand in stereo and appear in both L & R channels in the output you'll just have to use a TS 1/4" to TRS 1/4" Adaptor like the on shown in the image below, which actually ties the TIP of the TS to both the Tip and the Ring of the TRS.
TS to TRS adpator
 
NOTE: if you plug a TS jack at the input the mono signal will only appear on the Left (L) channel of the Stereo Output.


---- Technical specifications: ----
▹ True Bypass (via analog IC switches, requires power)
▹ Supply Voltage required: 9V DC (center negative) [Do not exceed recommended voltage!]
The use of a regulated/stabilized power supply that can provide at least 200mA is advised. 
▹ Current draw: 195mA ▹ Internal voltage doubler provides the necessary Dual Rail voltage, for maximum headroom.
▹ Input signal level: up to ~24Vpp
▹ Input impedance: 10MΩ
▹ Output impedance: 100Ω
▹ RETURN input impedance: 5MΩ
▹ SEND output impedance: 100Ω
Flat response on the whole span of the audio frequency spectrum.
▹ Max Gain: +6dB(V) (applied on the return signals and the dry signal as well) ▹ Weight: 0.700kg (aprox.)
▹ Enclosure dimensions:  188 x 120 x 39 mm (7.40 x 4.72 x 1.53 in)