Anybody know if the 274b and 5R4 are viable replacements for the 5u4 in the Melody AN845?
A useful response must came from a Melody AN845 owner that have tested all these tubes, seems a rare event.
You have to compare the tube data sheet here:
http://www.mif.pg.gda.pl/homepages/frank/vs.htmlIf you Google you will find various specs from this amp:
http://www.cattylink.com/AN845.htmlMELODY AODIXUN AN845 VACUUM TUBE INTEGRATED AMPLIFIER
GENERAL:
AODIXUN is the premium line series developed by MELODY
Ultimate high end Class A vacuum tube amplifier from Melody
Anodised aluminum chassis with piano lacquered wooden side benches
Massive custom built transformers made from Japan imported materials
Net weight of AN845 over 42kg
Point to point hand wiring production
Ultra expensive high end parts: Mcap Supreme silver oil capacitors
Nichicon Gold, Solen Gold Label capacitors
Mundorf M-RESIST supreme resistors
Silver plated contact exchange mechanism for line input selection
Remote control for volume setting
5AR4 rectifying tube, NOS 6EM7 x 2 in preamplifier session
Gold plated CMC ceramic tube sockets, gold plated rca inputs
Nickel and gold plated WBT standard speaker out terminals
Terrific 845 authority with the silky mellow direct heated triode sound
RCA and XLR balanced inputs with shortest signal paths
Detachable power cord system (IEC)
TECHNICAL:
Rated Output Power: 22W x 2 RMS Class A
Frequency Response: 20Hz to 30Khz
Distortion THD: <1% (1Khz)
S/N Ratio: 88db
Input Impedance: 100Kohms
Input Sensitivity: 480mV
Output Load Impedance: 4 and 8 ohms
Tube Complement: 2 x 845,
2 x 6EM7,
1 x 5AR4 (5U4)
Remote Control: yes
Dimensions (mm, WHD) : 450 x 260 x 440