Orange AD200 MKIII preamp tubes

Hi,

I would like to access (and maybe change) the preamp tubes (2 x 12ax7 and 1 x 12at7) of my newly acquired 2011 AD200 MKIII. I gave it a try by unscrewing the back panel. I cannot access to preamp tubes since the power tubes (4 x 6550) block the way.

Simple question: can I safely remove the power tubes and replace them afterward without any particular precaution?

Or is it another way (that I can't figure out by myself) to access the preamp tubes without touching the power tubes?

Thanks in advance

 

Thank you very much Mark!

I had in mind some NOS Telefunken too (or 5751 Tung-Sol) for the 12ax7s and RCA or Mazda for the 12at7. But definitely something clearer with more top.

 

Thanks for the tip Mr. Foxen. I don't have the head with me right now, but I guessed that the screws are in the feet of the head, right?

 

I followed your advice. Screws were in the plastic feet. Four screws, chassis out. Pretty easy. Thanks again for the advice.

 

Don't know yet. I am still waiting for the new tubes: 2 12ax7 Philips-Miniwatt (Bugle Boy) and 1 12at7 RCA black plates. I will let you know

 

After few weeks of use, I would say that the sound is clearer and more articulated. Now maybe there is no objective difference and I am completely projecting the kind of difference I was expecting by putting in the 12AX7 Phillips Miniwatts and the 12AT7 RCA.