2. misc-audio
  3. 157071-3347

Mitchum or Blackburn for the Mullard 6922?

Do Mitchum production and Blackburn production sound different in the Mullard 6922? I believe I once read somewhere that Mitchum made tubes for the military, whereas Blackbutn did not, so, presumably, with better materials and/or tighter tolerances or testing. 
pmboyd

Showing 3 responses by petg60

petg60
1,486 posts
 
Hi,
i believe all E88CC/6922/CV2492/CV2493 were made at Mitcham factory (code R). Blackburn (code B) made ECC88, though having the Master facility as well. I never traced a Blackburn made E88CC even to back 1961 made ones, if ever made at that factory is very rare and prior 1960.
Mitcham ones after 70 have different construction and sound different.
petg60
1,486 posts
 
Hi,
codes?
petg60
1,486 posts
 
HI,
Thanks,
Branded IEC Mullard?
B5H3 is only the manufacturing date and plant, should have more digits for type of tube before those.
Are these numbers etched or same lettering as Mullard?
I have seen such tubes on eBay and they are Mullard made ones but not sure if rebranded or not.


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