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		2000Z28M6
New member
I knew I had a set of Ruby 12AX7 preamp tubes somewhere and I found them today! 
I'm wondering 2 things what brand are the stock MPA Gold tubes?
And would it be a good idea trying out the Ruby's on the MPA?
Thanks guys,
GN
				
			I'm wondering 2 things what brand are the stock MPA Gold tubes?
And would it be a good idea trying out the Ruby's on the MPA?
Thanks guys,
GN
 
 
		 
 
		