New to tubes

[AlexiLaiho]

Hi, would like to change my preamp tube in my Blackstar HT-5, so the stock is the 12BH7 Sovtek tube, can I put in a 12AX7 tube? Is retubing easy? Just switch off(how long) , Open back, remove casing and slowly remove tube am I right? How much am I looking at for a JJ or Tung Sol tube and is there any recommendations? My amp is producing alot of feedback and static, would a tube change solve this?

 

[AlexiLaiho]

bumpmmmmmmmmmmmmmmmmmmm

 

[Dongara]

Sorry to hear that no one replied to your mail.

From the Vintage Valve Museum:

The 12BH7 double triode is pin compatible with the ECC81, ECC82 and ECC83 series from Mullard but has slightly different characteristics. Brimar do not give an intended use but the construction is compatible with audio through to low VHF use.

The ECC83 is the 12AX7 tube. You can change the 12BH7 over to that if you wish, but the tone of the amp will change.

Drop by Martin Speaker Repair (or electronics, I'm not sure) and look at the tubes they have there. They may have the 12BH7, but I know they will have the 12AX7. Look for the spiral element tubes (JJ 12AX7s or Sovtek 12AX7LPS) as these will be lower noise.

To change them over, just turn of the amp, wait an hour for the tubes to cool down, then remove the tubes and replace them with the new ones.

Hope it helps.

cheers,

Mark.

 

[Schon]

try this link..

http://www.eurotubes.com/

they r always helpful..