Marantz PMD 620MKII The PMD 620 Basic rebuilds the PMD 620 mic preamp with a very low noise, high slew rate op amp that dramatically enhances detail and clarity while lowering noise and audible distortions. This upgrade also increases the mic input gain by 6dB in order to record lower signal levels without using the ALC circuit. All features remain intact. The PMD 620 Concert rebuilds the PMD 620 mic preamp with a low noise, very low distortion and high slew rate op amp that dramatically enhances detail and clarity while lowering noise and audible distortions. This upgrade also improves the line input circuit. The built in mics are removed to maximize microphone input quality, all other features remain intact. The PMD 620 Super rebuilds the PMD 620 mic preamp with a very low noise, low distortion and high slew rate op amp that dramatically enhances detail and clarity while lowering noise and audible distortions. This upgrade also improves the line input circuit and increases the mic input gain by 6dB in order to record lower signal levels without using the ALC circuit. The built in mics and plug n power are removed to maximize microphone input quality, all other features remain intact. Marantz PMD 661MKII 24 bit recorder The Marantz PMD 661MKII Concert MOD upgrade rebuilds the microphone preamp using high speed, low noise and very low distortion op amps that dramatically improve fine detail and clarity. The result is a very detailed, open 3D soundstage. Ideal for recording all types of music where transparency is needed. The Marantz PMD 661MKII Warm MOD upgrade rebuilds the microphone preamp using high speed, low noise and very low distortion op amps that dramatically improve fine detail and clarity. The result is a very detailed, open 3D soundstage with a warmer tone than the Concert MOD plus a more expansive soundstage. Ideal for recording all types of music when a warm tone is needed. The Marantz PMD 661MKII Super MOD upgrade rebuilds the microphone preamp using very high speed, very low noise and super low distortion op amps that dramatically improve low level detail and clarity. Input PCB capacitors are also upgraded. Super low THD+N op amps allow for a very wide SFDR even with signal levels down 50dB. This preserves the signal quality of the highest grade microphones when recording soft signals, like voice, un amplified music, nature sounds and FX. The Marantz PMD 661MKII FET MOD upgrade rebuilds the XLR inputs using very high speed, very low noise and low distortion FET op amps that dramatically improve low level detail and clarity. Very low THD+N op amps allow for a very wide SFDR even with signal levels down 50dB. The warmth of the FET microphone preamp allows for a more natural vocal tone when using highly directional mics, like a shotgun mic. The very low noise is perfect when recording soft signals, like voice, un amplified music, nature sounds and FX. Our first choice for use with dynamic interview microphones. The FET upgrade also produces an impressive 3D stereo image, ideal for stereo nature recording ! Edirol R44 4 Channel Recorder         Edirol R44 records 4 channels of uncompressed audio Edirol R44 Concert upgrade rebuilds the mic preamps using high speed, low noise and very low distortion op amps that dramatically improve fine detail and clarity. Components are selected by ear to optimize detail and imaging for recording music. Improvements are also made to reduce the audible digital noise that contaminates the analog signal path with noise generated by the display. Edirol R44 Super upgrade rebuilds the mic preamps using high speed, very low noise and low distortion op amps that improve intelligibility and low level detail. Components are selected by ear to optimize detail and imaging for ENG, Acoustic Music or Ambient recordings with Ambisonics or Schoeps Surround mics. Improvements are also made to reduce the audible digital noise that contaminates the analog signal path with noise generated by the display, essential for high gain applications. Imagine yourself surrounded by sweet, relaxing sounds ! The Schoeps Double M-S microphone system & the Edirol R4 Ambient Digital Recorder in the North Carolina Mountains Learn about the Schoeps DMS system E-Mail Support is available 5 days a week, please send an E-Mail to Doug Oade for Sales info or support for gear purchased from Oade Brothers Audio.