peavey delta blues ?

[fretboard12]

hello everyone, im new to the forums and i have a few questions that im not quite sure of and would appreciate your advice.

i bought a used delta blues amp the amp sounds nice no real trouble as of yet. and was wondering,

1. does tubes have a manufacture date on them?

2. the preamp tubes do not glow as bright as the power amp tube's.

3. there is a static sound like a radio not tuned to a station not loud though has to be turned up really loud to be very noticeable i thought this might be normal.

4. does this type of amp need matched power tubes because it is fixed bias or is it just suggested

the preamp tubes are 12xa-lps sovtek with the numbers 99 11 at the bottom thinking this might mean Nov 99 if so those are some long lasting tubes.

i am new to owning a tube amp but have done some searching before asking these qestions. so these questions maybe very noob type questions

thx for your reply's fret.

[pecorporation]

Noise like that I'd suspect as a tube problem 1st and solder errors 2nd.

Lightly tap the tubes one at a time with a chop stick to see if any make noise or static or excessive microphonic ringing.

Loose ground or solder on the input jack can cause some static noise as well.