Hum is my number one bugaboo. I can not stand it .. Often when asking a seller if there is any hum in the unit and being really specific that Im referring to the amp itself they will respond with --oh, its very quiet from the speakers. thereupon now comes a lengthy explanation from me.
I have never held onto anything long that had hum. It often can be in the power supply design but also being directly coming from a transformer Ive been told that it is the plates vibrating. On new transformer in a new unit like the one you got I cant imagine -either p.s. design or cheap transformers .. Im not a tech so cant identify exactly but pass along my experience. I had a custom 2a3 SET built once and it had a hum and the builder used a recycled power transformer ---how old was that thing ? I sent it back,, and he didnt do a thing about it. I sold it. Really had good sound but the hum was so obvious it could be heard from 5 feet away even with music on low. Send it back to Had or at least complain. ruins the experience.
I had a 80's Sony STJ75 tuner that is well known how black the noise floor is but it had a hum ... Sent it to ASL Absolute Sound Labs and he actually had the transformer re-potted . fixed the hum.
I have never held onto anything long that had hum. It often can be in the power supply design but also being directly coming from a transformer Ive been told that it is the plates vibrating. On new transformer in a new unit like the one you got I cant imagine -either p.s. design or cheap transformers .. Im not a tech so cant identify exactly but pass along my experience. I had a custom 2a3 SET built once and it had a hum and the builder used a recycled power transformer ---how old was that thing ? I sent it back,, and he didnt do a thing about it. I sold it. Really had good sound but the hum was so obvious it could be heard from 5 feet away even with music on low. Send it back to Had or at least complain. ruins the experience.
I had a 80's Sony STJ75 tuner that is well known how black the noise floor is but it had a hum ... Sent it to ASL Absolute Sound Labs and he actually had the transformer re-potted . fixed the hum.