audio equipment design and manufacture - jens jungkurth and john klett



NonLinearAudio products

FlexiGuy (FG500) - Mic/Line/Instrument Preamplifier:


The Flexiguy microphone/line/direct inject (D.I.) preamplifier offers up detailed and flexible tone, useful and controlled harmonic contribution and a somewhat "tape-like" dynamic response.

Useful Every Day

FG500 product page

FG500 pdf "cutsheet"

CurvOmatic (FT501) - Resonant LP / HP Filter Set with Bax Tone Tipper:

Ft501 CurvOmatic

The CurvOmatic module is a versatile set of high and low pass variable resonance sweep filters combined with a very sweet sounding version of Peter J. Baxandall's classic 1950 tone control circuit.

Used in combination, the resonant filters and Spectral Tone Tipper provide a surprising amount of tone carving and shaping capability that is unlike anything you can get from standard equalizers and cutoff filters.

Unusually Curvy

FT501 product page

FT501 curve plots

FT501 pdf "cutsheet"

Blenda (PLP502) - Parallel Loop Processor:


Blenda enables classic parallel processing in a "500" module. Blenda provides selectable level-shifted and impedance-adjusted loop interface modes to match to pedals, synth and hi-fi devices. Three loop modes accommodate balanced or unbalanced signals, matching the operating level and impedance to a variety of different equipment, including effects pedals and electronic instruments, as well as traditional outboard gear.

Blenda provides the functionality and signal path of a premium analog studio mixer and adds optimization of level and impedance of the effects insert loop to match to pedals, synth and hi-fi devices... a feature that no studio console we know of incorporates.

"it's da BOM NOM!" ... blend-O-matic null-O-matic

PLP502 product page

PLP502 pdf "cutsheet"

CandyBuss (CB2a) - stereo mix buss retrofit card:



The CandyBuss is a stereo mix-bus retrofit card that can be installed in many "virtual earth" summing consoles (which is most all analog mixing consoles designed since the mid-late 1970's). CandyBuss needs to be installed by a qualified tech... it is NOT plug and play.

The virtual earth summing input to the card should tap directly on to the console mix summing buss, preferrably directly from the motherboard. The console's own summing amplifiers have to be defeated and the CandyBuss mix output substituted for monitoring and control purposes.

The card has has two discrete virtual earth summing amplifiers, stereo transformer isolated insert sends (which are multed) and two stereo return ports that can selected as insert A or B. The insert bypass leaves the send active while sending the summed mix directly to the fade, bypassing the insert circuitry. Discrete post-mix-fader amplifiers drive transformer-balanced outputs. Buffered auxiliary outputs send signal to the console master modules for monitoring.

This is absolutely a TECH Geekery item...
e can install one of these in your console or we can kit one up for your tech to install.

eQueTee (EQT503) - 4-band console equalizer with sweep filters:


YES this is a bit of a tease and no one will see these until Spring

YES... the photo is a little... sketchy... the EQT is not yet in production but, if one were to ask what might be the next "500" module from us, at least numerically, the answer would be a "console" EQ. We need to fill 64 EQ slots in a console we are putting together and this is it (…and no, nonlinearaudio is not a console company, we're just building a console for someone who wanted one). We have EQT prototypes in hand and are massaging them, plying them with fine wine… generally having a good time.



inquiries or requests - send email to

About's not about making another rendition or clone of a common "classic". It's about making truly useful creative analog audio hardware tools with purpose.

NonLinearAudio is the outgrowth of creative technical audio design concepts and efforts from Jens Jungkurth (Eisen Audio, LLC) and John Klett (Tech Mecca, Inc.).

NonLinearAudio staff is comprised of audio engineers, who use their ears as well as math and measurement, while consulting other seasoned recording engineers producers and musicians for end-user feedback.

NonLinearAudio products are designed and assembled in New York City, U.S.A., using high quality, carefully selected, domestically-produced materials wherever possible and practical.


all site content copyright nonlinearaudio llc, jens jungkurth and/or john klett 2011-2014