r343
100+ Head-Fier
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- Nov 29, 2016
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You can probably remove background hum with gain reducer like IFI IE Match, also use lowest impedance setting on HA-A1 to further reduce hum.Guys, has anyone managed to completely get rid of the noise floor of the HA-1A MK2? So far I’ve reduced the initially strong hiss to practically nonexistent, but there’s still a quiet low hum left. Nothing to worry about but can’t help but to think it may be just as solvable as the hiss issue, with the right treatment. I noticed a few posts throughout this tread the amp being referred to the amp as “dead silent” but I couldn’t tell if it was meant literally or as in “pretty quiet for a tube amp of this price range”. Any actually dead silent HA-1A MK2 out there? Your feedback is much appreciated.
If you connect HA-A1 to USB DAC it will most likely cause ground loop because amp has build in PSU and connection to amp is unbalanced RCA.
Ground loops makes you hear PC mouse movements, gpu and other unwanted noises trough headphones.
Ground loop is different than humming sound with the amp.
to get rid of ground loop you can
- connect DAC with SPDIF input from PC to get rid of USB noise
or
- connect RCA outputs of HA-A1 to other device
or
- Attach RCA ground loop isolator between DAC and RCA cables to HA-A1. This one i do not recommend because it will worsen audio quality and is audible.
I've had HA-A1 MK2 and Feliks Echo Mk2.
Feliks Echo Mk2 was dead silent without hum even with sensitive Focal Utopia and Fostex TH900 but hum aside i think HA-A1 Mk2 had more robust sound.
*edit*
If you physically "knock" amp with finger and get ringing like noise trough headphones you have faulty tube, fully working tubes don't exhibit any noises even when amp is touched.
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