Project Gallery: Zen Variation 4

I would like to share some pictures of my Zen v4. I started this project more than a year ago by self-learning AutoCAD. I laid down the chassis design in digital form after visits to Home Depot, Lowes, ThermaFlo (Internet), several local hardware shops and even NAPA auto parts. 

The dimensions of the chassis are 15.5"x26"x9.5" (WxDxH) -staying close to the Golden Ratio for aesthetic reasons. With the Zen v4 engine, it weighed in at 60 pounds. 

The beveled front panel, made of two ¾" thick oak boards, of course got its inspiration from your XA series. The curved faceplate is a declaration that with your help and inspiration the DIY audio world is not flat. The growth rings of oak look nice too and I bet (excluding the farm) I own the bragging rights (in all audio world?) for the thickest faceplate at 2 inches! 

Between the curved front panel and the ½" thick aluminum that serves as additional heatsink and as carry-around-the-house finger grips are blue/ red/ green LEDs. Blue is for normal operation and red and green (combining to produce orange light) is for standby/nightlight keeping the 90,000uF/ch power station fully charged. The 23.5" long heatsinks are from ThermaFlo, with thermal specs of 1.44 C/W/3". With 2A of bias per channel…it gets so hot at about 37 degC above ambient temp after 2 hours of rollicking musical fun. This tells us the rating of the heatsinks should be 2.89 C/W/3". The temp was checked using my dependable meat thermometer (no undercooked meats yet). The Zen checked in at medium rare 145 degF. 

The design is a dual mono up to the 120VAC inputs. The changes I made to the circuit include biasing the input buffer at about 33mA and the regulated voltage zener reference stack is at 50V. The unregulated voltage came in at 53V unloaded. With the Zv4 circuit in it drops to 49V. Regulated voltage output is a steady 45V. The measured ripple at the speaker outputs is about 1mV on both channels. 

The beveled back panel is equipped with 1" coupling nuts and 2" round-head bolts. These allow it to also stand on its back in party mode. I haven't tried it but I guess the heatsinks will dissipate heat better vertically. The legs of the amp in the Zen position are ½"x1.5" steel chrome lug nuts, I got from NAPA, usually reserved for light truck wheels. 

Popping the hood shows the legs extending to the top panel via threaded rods. The four rods are tipped with coupling nuts where the oak top panel sits and fastened with ½"x1" cap hex bolts. The big cap hex bolts add nicely to the overall look…this is from watching American Chopper and Monster Garage. My concern though is with the amp running hot the top panel might warp. I won't fret much if it warps like the sides of Rushmore. I'll just say it was inspired ;). 

A Zen logo in what I think is in its simplest form sits nicely on the front panel. The chassis's wood is finished with several coats of Watco Teak oil and Minwax Golden Oak. 

The sound amazes me in its tonal balance across the audio band. The bass is clean with just the right weight on my PSBs. The treble is clean and crisp. Eric Clapton, John Lee Hooker, Taj Mahal, Diana Krall, Ron Carter and his bass, Mark Knopfler, Men at Work never sounded so good. And they're all lining up to play again and again in my family room. With the Zen engine under my hood…I have created a musical instrument with the legendary Nelson Pass. Thank you so much.

Regards, Allan Flores aka Blues on DIYAudio.com

afdflores@msn.com