m808a valve preamplifier
Some of The Features Of The M808A At A Glance!
Custom Manufactured Bakelite VU Meters With Traditional Ballistics
Custom Hand Wound Input and Output Audio TransformersNew Matched Valves For Each Unit ManufacturedCustom Manufactured GR Style Bakelite Knobs
Channel Strips With MIC IN, LINE IN/OUT, DI, and Inserts
Active True Bypass FILTER Section Featuring Useful Filter Freq.
Modular Design Throughout The Unit
Switchcraft & Neutrik Audio Connectors
Metal Film Resistors + Foil & Film Audio Grade Capacitors ThroughoutHermetically Sealed Input & Output Transformers in MuMetal Shielding Cans
High Gain & Exceptional Flat Frequency Response 10Hz-25kHzOptional M808APB Accessory Patchbay for Dual-Channel Units.
Custom Designed And Manufactured Bakelite VU Meters With Traditional Ballistics
Custom Designed Hand Wound Input & Output Transformers Hermetically Potted in MuMetal Casing
Class A Operation Throughout The Signal Chain
Up to 80dB Of Gain
Channel Strip Design With MIC IN, LINE IN/OUT, DI, And Effect Inserts
Low Noise Design Topology
Custom Manufactured GR Style Bakelite Knobs From Original Moulds
New Old Stock Matched Valves For Each Unit Manufactured
Switchcraft® & Neutrik® Audio Connectors
Active True Bypassable FILTER Section Featuring 4 Useful HPF & LPF Filter Frequencies of 50Hz, 150Hz, 5kHz, 2kHz @ −6 dB per octave (−20 dB per decade) Butterworth 1st order.
Premium Grade 6350 ★★★★★ Output Tube
Metal Film Resistors, Foil & Film Capacitors, Rubycon® & NIPPON Chemi-Con® Elcos Throughout The Unit
All Through-hole Components And No SMDs
Japanese Made TOCOS® Sealed Potentiometers
Carling Toggle Switches
Modular PCB Design Throughout The Unit
4mm Thick Carbon Steel Face Plates & Power Coating on all Panels
Fully Regulated Solid-State Power Supply With Soft Start & Short Circuit Protection On All Nodes
High-Quality Sealed Japanese Relays With Gold Contacts For All Localized Signal Switching
Individual Anti Pop Soft Start & Stop Phantom Power Switching & Indicator Lamp Per Channel
Buffered & Isolated VU Meter Driver Circuit With Selectable +4dB Or +8dB Scale Range
Saturation THD Indicator Of The Input EF86 Valve
86V to 260VAC Global Line Operation
Accessory M808APB Patchbay Available For All I/Os On Front Panel
Key features:
MIC IN Input Impedance: (2KΩ) Actual. Accepts Microphones ranging from 33Ω -600Ω
MIC IN (Pentode Mode) Maximum Gain: Approximately 80dB @ 150Ω Source Impedance
MIC IN (Pentode Mode) Frequency Response: 10 Hz to 25 kHz ± 1dB @ 150Ω Source Impedance
MIC IN (Triode Mode) Maximum Gain: Approximately 70dB @ 150Ω Source Impedance
MIC IN (Triode Mode) Frequency Response: 10 Hz to 20 kHz ± 1dB @ 150Ω Source Impedance
LINE OUT Impedance: 600Ω or 150Ω @ +4dB Output
INSERTS (SEND) Output Impedance: 250Ω
INSERTS (Receive) Input Impedance: 100KΩ
DI/INSTRUMENT Input Impedance: 1MΩ
Signal to Noise Ratio: (Triode): -96.5dB below 13.44dBv @ 1% THD. 22Hz-22kHz, No weighting
Signal to Noise Ratio: (Pentode ): -82.4dB below 13.48dBv @ 1% THD. 22Hz-22kHz, No weighting
Maximum Output Level for 1% THD: +16.1dBu into 10K Load
THD + Noise at +4dBu: 0.06% 2nd Harmonic Dominant. (0.02% A-Weighted)
Crosstalk: -80dB Between Channels @ 1kHz
Power Requirements: 86V to 260VAC 50-60Hz For Global Line Operation.
specifications:
Documentation:
Operation & Maintenance
M808A Quick Guide
M808A MIC Gain Staging
We ship every M808A dual-channel preamplifier with gain-matched premium grade 6350 tubes. Information about the 6350 premium-type output tube and its characteristics can be found below.
Output tube characteristics:
Premium Grade 6350 ★★★★★ Output Tube
6350 Specifications:
Amplification Factor Mu μ: 18
Plate Impedance: 3900Ω
Transconductance: 4600 μMhos
Lower output Impedance than ECC82
Higher headroom than the ECC82 tube