Breath problem, ht5rh head.

[Sadja]

Good evening,
ht5rh head bought used, the output sound had more breath than notes! I changed the 2 tubes: JJ ecc83s and electro hamonix 12bh7.
There is always so much breath when: I mount the treble in clean and when I put a little gain in overdrive. Both are worse when I plug a jack (even without a guitar!).
it is almost unusable on my 12 "box and only low-medium sound with a headset.
Has someone already had this problem?
Thank you for your answers