Reposted from Cayin HA-3A thread:
I have to report that my thoughts on the 300b tubes as a radical decision to eliminate the brightness seem to be true. Yesterday I turned on my HA-300mk2 for the first time (stock RCA rectifiers, Linlai Elite 6SN7, PSVANE Acme 300b — these tubes are neutral sounding). Initially I’ve listened it as a speaker amp — wasn’t impressed by the sound until it warmed up (it’s cold outside, travel took a long time).
After a half an hour I said “wow”. But speakers aside, when I switched to headphones (HE1000SE, stock 4XLR cable), I’ve noticed my familiar tracks sounded too warm for my taste. Maybe I just got used to HA-3A presentation, it’s a pentode in ultralinear mode amplifier, as far as I know. Direct Heated Triode is quite different.
Switching to another source (iDAP6, no upsampling) made things better.
My new digital source is Shanling ET3 with upsampling to 192kHz, highly recommend for the thin sounding recordings.
I have to report that my thoughts on the 300b tubes as a radical decision to eliminate the brightness seem to be true. Yesterday I turned on my HA-300mk2 for the first time (stock RCA rectifiers, Linlai Elite 6SN7, PSVANE Acme 300b — these tubes are neutral sounding). Initially I’ve listened it as a speaker amp — wasn’t impressed by the sound until it warmed up (it’s cold outside, travel took a long time).
After a half an hour I said “wow”. But speakers aside, when I switched to headphones (HE1000SE, stock 4XLR cable), I’ve noticed my familiar tracks sounded too warm for my taste. Maybe I just got used to HA-3A presentation, it’s a pentode in ultralinear mode amplifier, as far as I know. Direct Heated Triode is quite different.
Switching to another source (iDAP6, no upsampling) made things better.
My new digital source is Shanling ET3 with upsampling to 192kHz, highly recommend for the thin sounding recordings.

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