Jeff Zahos

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Setup/Equipment

• TASCAM DA 38 Digital Tape Recorder (44.1kHz, 16bit)
• Mixed in Cubase, using MOTU 896 interface
• Hamptone HVTP2 tube preamp, (2) MXL 2001 (large capsule cardioid condenser) (Overhead ORTF placement)
• ART Tube MP preamp, Heil PR40 on bass drum

Process/Issues/Evaluation:

This session was particularly interesting for several reasons.  The multiple-percussion setup of this piece resembles a drumset in that it’s main elements are kick drum, snare drum, tom-toms and cymbals, with bongos, and various woodblocks and cowbells added.  In planning, I vacillated between close mic’ing the various instruments or groups of instruments and using a stereo ORTF mic’ing/bass drum or spaced overhead pair/bass drum setup. After some brief experimentation, I decided to use an overhead ORTF pair and bass drum mic, for several reasons.

With the spaced overhead pair setup, the non-cymbal voices were noticably “deeper” in the stereo field than the cymbal, causing an timbral and volume imbalance.  The ORTF pair achieved a more “realistic” environment, that is, the impression of being in a small room full of instruments being hit, and not a “fabricated” acoustic space (which would have occured in a dry, close mic’ing situation).

In the end, I was pleased with this recording.  I avoided the main personal objection I have to many studio concert percussion recordings;  many times, the sounds are more like drum sounds you’d hear on a pop or rock record, unlike the piece would sound in performance.  While these are aesthetic preferences, I currently feel that the ‘acoustic’ approach is closer to the spirit of most concert percussion pieces.  In most cases, the pieces were written for live, acoustic performance and recordings I make of them should reflect that aesthetic intent as much as possible.  There were edits made in this example, no reverb was added.

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Setup/Equipment

• TASCAM DA 38 Digital Tape Recorder (44.1kHz, 16bit)

• PreSonus Firepod (onboard preamps, analog outputs), (2) MXL 2001 (large capsule cardioid condenser) (ORTF Configuration)

• ART Tube MP preamp, MXL 604 (small capsule omnidiretional condenser)
• Edited in Cubase

Process/Issues/Evaluation:

Solo marimba in a large concert hall (2,100 seats).  The instrument was noisy, however beginning around 00:14 seconds, what sounds like distortion does appear.  A particular frequency range **(name it)** was problematic, most likely to the mic amplifier circuit.  Because the session was gratis (and during a specified time slot), I did not stop the performance to try to troubleshoot the situation.

There is no reverb added, or editing/crossfading in this example

Last year, my friend James brought up the idea of building woodblocks specifically for Iannis Xenakis’s Rebonds.  Here’s what we came up with:

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That’s my friend from Truman State University, Scott Quade performing on a set we made.  Scott, like many others at the school, is a fantastic percussionist.

Anyway, James had some sketches of a set of blocks which belonged to a former teacher.  Along with this, Kolberg makes “Power Blocks”, which are often used for the piece.  There is a great video of percussionist Pedro Carniero playing Rebonds B.  Carniero’s blocks are cool, but of course I’m partial to “XenakibloX”!

…next up will be designing and building a mounting system for the blocks.

I play in a couple bands based in Champaign, IL.  One of them – definitely the most domestic-aquatic themed one – is called  Backyard Shark.  I love playing with Ed, Tony and Tommy B – we’ve been together for several years now, which not many bands that have members in 3 cities (4 from Aug. ‘08-May’09) can say.  We have a lot of fun, and we like to think our audiences do, too!  Check us out at:

• Facebook! A book with pictures of our Shark-face
• MySpace! OurSpace
• Flickr! Awesome pics, mostly taken by the awesome Taylor “Hawkins, drummer from the Foo Fighters” Thornton
• Purevolume! LOUD!
• Twitter! Does this have something to do with texting?  I don’t text – I don’t have anything to do with this one…

SHARKIFY!

Sound Samples:

• Open – No Muffling

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• Muffled – One Moon Gel

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This is a vibraphone “rescue” project I completed for a local musician. The instrument was given to him by a friend in derelict condition, and only had the bars (the part that is struck by mallets), the damper bar and the frame intact. It did not include a pedal to operate the damper, or, more importantly, resonators.  Because it was given to him by a friend, the instrument has special sentimental value, and it is affectionately called the “Red Vibes”.

MAIN IMPROVEMENTS/FEATURES:

Damper System

Damper Bar – New felt on damper bar

Pedal- Completely new, wide damper pedal for easy access while playing through whole range of instrument.

Resonators

Dimensions – 1/4 wavelength one-end-open, one-end-closed (half open) aluminum tubes, 1 3/4″ outer diameter (equal to the bar width).

Tunable – Tube stops made with aluminum discs with rubber o-ring as a seal (similar to a piston in a combustion engine). Each tube stop has a 1/4″ hex bolt through it, allowing each resonator to be tuned individually with a hex wrench.

End Correction – Gap between bar and tube provides end correction for 1/2 open tube resonators. This ensures the vibrating bar is at the anti-node of the wave, which is slightly (about 1/2″) outside the open end of the tube.

Finish- I investigated several finish options, (anodizing, lacquer, etc.), but decided a “brushed” finish would be best (least expensive and cool looking).

Bars (keys)

I cleaned the keys (along with cleaning and lubricating other existing metal parts) using Scotch-Brite, steel wool and acetone.

THE PROJECT

Design

I designed a pedal mechanism which would mate to the existing damper bar hardware and that would be easy to remove and reassemble at performances. I had it machined from aluminum at Wagner Machine Co. in Champaign, IL (they were in Urbana, IL at the time). This was the easy part…

Because the resonators are part of the sound-producing system of this instrument, designing and building them was particularly challenging. They needed to work with the existing frame and be easy to assemble/disassemble, in addition to making the instrument sound better.

The operating principle of resonators in keyboard instruments is that when a vibrating bar is situated near the end of a tube of equal fundamental frequency (f₀₎, the column of air in the tube will vibrate sympathetically. Because the bar and tube resonate sympathetically at f₀, but have different resonances at the harmonics (f_n), f₀ is amplified more than the higher harmonics. This means that the loudness of f₀ is greater than the loudness of f_n, making the instrument sound less “bright” or more “mellow”. There may be matching of higher harmonics between the resonator and bar, along with the vibraphone, but the main amplification is at f₀. This is the signature sound of the vibraphone, and what I sought to achieve in my design.

Fabrication and Assembly

As mentioned above, the damper pedal was machined at Wagner Machine Co.:

Note that significant mass has been removed from the pedal to keep the action lighter.

Wagner was also the site of drilling the holes for the resonator tubes and rails. The tubes were cut using a plumbing pipe cutter. The brushed finish was achieved using sandpaper, steel wool and Scotch-Brite with the tube spinning on a metal lathe. The tubes are attached to the rails by round head hex bolts and nylon-insert lock nuts.

U-Channel aluminum was used for the endpiece on each resonator set. The original instrument included a small metal bracket with a raised knob in the middle. The U-Channel endpiece has a hole into which the knob fits, holding the resonators in place.

The curve of the resonators made smoother after the “rough” photo above was taken.  The curve was made more smooth.

The vibes on a sunny fall day before being returned to their owner!