LOMARK AP2 MN3005 Circuit
There were two major revisions of the original Aqua Puss and this pedal is representative of the second revision (AP-2). The LOMARK name comes from the “LOMARK” sticker that is placed on the original MkI AP-2 Aqua Puss that John Mayer famously used throughout the John Mayer Trio (2005), Continuum, and Where the Light Is tours. Inside you will find the same circuitry as the original, including the coveted MN3005 bucket-brigade delay chip that arguably gives this circuit the mojo that differentiates it from the Mk2 and Mk3.
The Tone Geek Touch
The only thing I have changed in the circuit is the taper of the MIX potentiometer. For those who are emulating John Mayer’s subtle slapback, the logarithmic taper of the mix pot will allow you to fine-tune the delay a lot better compared to the touchy nature of the original linear taper. Because of the taper difference, you will need to increase the mix knob more than John’s real Aqua Puss if you look at his pedalboard pictures. You can also dial in the slapback tone using your ears by listening to “Out of My Mind” on the John Mayer Trio album. Another player that is known for using the AP-2 version of the Aqua Puss is Brad Paisely (last picture above).
When designing the layout, I wanted to re-use some of the design principles of my SMD Valve Screamer (TS10).
Improved power supply
Solid polymer power capacitors - Extremely long service life (20+ years at room temperature)
Additional DC smoothing capacitors
Hammond 125B size enclosure
Lock washers on the jacks
High quality 3PDT stomp switch
Military specification (MIL-SPEC), aerospace grade, 600V rated, irradiated cross-linked Ethylene TetraFluoroEthylene (ETFE) thin wall insulation, 22 AWG with 19 / 34 stranded tinned copper hookup wire. Conforms to Mil-Spec MIL-W-22759/16-22.
Calibration
I calibrated the internal trim pots to the exact specifications of two 1997 Aqua Pusses that I had access to. This really just means the maximum delay time is extended beyond the 300ms specification of the MN3005. The lower the clock frequency, the lower the quality of the sampling of the original signal and the result is a "darker" repeat tone after going through the filter and compandor network. The MK2 and MK3 Aqua Pusses that I've measured seem to be around 7.2kHz clock frequency when the delay is maxed out. The Mk1 measured 6.21kHz @ 9.21VDC from the power supply.
I will be selling these pedals as I build them in my shop with additional plans to release the circuit boards (with complimenting BOMs) for those who want to build their own just as I am doing with the TS10.
VIDEO DEMO COMING SOON
