Changing the Tubes/Output Transformer of Valve Junior

[moota]

Hi Folks,

I don't have experience in this.

If I just want to swap out both the stock 12ax7 and el84 and use say JJ tubes. Is it just as straight forward as just swapping them or do I still have to do things like biasing?

Are they just "drop-in" replacements?

Is this also true in the case of output transformers? (other than the fact that you may have to drill holes to physically accomodate the OT)

I'm definitely not equipped to do anything that require changing caps/resistors, anything that require soldering at all. Pl PM me some reliable sources that can help me with this.

Thanks,
Louis

 

[Dongara]

Hi Louis,

Changing out the preamp (12AX7) and power tube (EL84) are both straightforward and can be done without any need for rebiasing as all these tubes in this amp are self-biasing.

The output transformer is a single ended one (only one output tube) and can be changed to another equivalent single ended one, just by removing the original and replacing it with an upgraded one.

I'm not living in Singapore so am not able to help you with the work, but it is straightforward for anyone who can do soldering.

cheers,

Mark.