Aretha MKII 6SL7 vs Joule Electra LA150 MkII
The LA150 MkII's output impedance is 400Ω against the Aretha MKII 6SL7's 625Ω. Both share class (A).
AI-generated product photo — not official manufacturer imagery.
Aretha MKII 6SL7
Erhard AudioAmplifiersTube AmplifiersPre-Amplifiers
Estimated price (community-sourced)
$1,200 - $1,950
Around — community and catalog average, updates slowly
About the Aretha MKII 6SL7
The Erhard Audio Aretha MKII 6SL7 is a hand-built, single-ended tube line preamplifier using four matched 6SL7 dual-triode tubes. It employs a classic cathode-follower output stage with a Baxandall bass-and-treble tone-control circuit. The tone controls are flat when centered and can be bypassed entirely when the optional Tone Defeat configuration is fitted. The unit features a regulated DC tube-filament supply, a redesigned high-voltage linear B+ supply, a custom toroidal power transformer, a precision 59-step attenuator, and selectable RCA line inputs and outputs. It can be configured for 120 V/60 Hz or 220–240 V/50 Hz operation. The manufacturer’s current website still lists the Aretha MKII and provides specifications, so it should not be classified as discontinued.
Specifications
Power Specifications
Amplification power output and characteristics
- Amplifier Class
- A
Analog Output
Analog signal output specifications
- Output Impedance
- 625Ω
Connectivity
Input and output connections
- Bluetooth
- No
- Wi-Fi
- No
- Ethernet
- No
Specifications are community-contributed and may not be accurate or complete. Verify all details with the manufacturer before making purchasing decisions. Terms & Conditions