Author Topic: 12AX-7 dimension (Read 158 times)

pierreyves · « **on:** July 04, 2010, 03:06:46 AM »

Hi everybody, could you confirm if this tube is well for F1-X?
http://www.jj-electronic.sk//pdf/ECC%20803%20.pdf
best regards

bassclef29 · « **Reply #1 on:** July 09, 2010, 02:40:19 PM »

Pierre-Yves,

I have a JJ ECC83 in my F1-X. Recently, looking for a higher-gain tube, I made an inquiry to a reputable company called Eurotubes (http://eurotubes.com/).

They recommended the JJ ECC803 and assured me it would fit within the same metal sleeve as the ECC83. But I do not have personal experience with the tube, so I cannot be certain.

Hope this helps.
--Joe in San Diego, California, USA

xlrogue6 · « **Reply #2 on:** July 09, 2010, 02:57:35 PM »

JJ ECC83s are one of the smaller diameter current production 12AX7/7025/ECC83 tubes. Electro Harmonics, TungSols, and Mullard reissues will probably be too large to fit inside the shield on an F1-X. Just tried all of these in a 70's Marshall with small diameter shield bases and the JJs were the only ones that fit. I highly recommend getting the Ruby tested 12AX7HG+, which is Ruby's nomenclature for the highest gain/lowest microphonics JJs out of the large batches they get.

pierreyves · « **Reply #3 on:** July 10, 2010, 12:15:31 AM »

But they are ECC 803, not ECC83 ? Possible to compare size of your tubes ? Sorry, I don't have pied ? coulisse:
http://www.temps-et-mesures.com/img/p/218-274-thickbox.jpg
Thank's

rraymond · « **Reply #4 on:** July 10, 2010, 02:00:39 PM »

How about some data sheets for JJ tubes:

ECC803:
http://www.mif.pg.gda.pl/homepages/frank/sheets/163/e/ECC803.pdf

ECC83S:
http://www.mif.pg.gda.pl/homepages/frank/sheets/163/e/ECC83S.pdf

Hope this helps!