Triple Rectifier: 7581a and 6L6GC.

[darkentity]

Made some research online, and it turns out that 7581a and 6L6GC are pretty much the same. Can someone confirm this? I have 4 of the 7581As and 2 new 6L6GCs. Can mix the two kinds? Is there any specific order that I have to put them in? I have a matched quad of 7581As and a deuce of 6L6GCs. Thanks.

 

[94Tremoverb]

7581As are essentially a higher-spec, ruggedized military 6L6. They will work fine in any 6L6 amp. Depending on what they are, they might even be exactly the same tube - late Philips/Sylvania 6L6GCs as used by Fender and Mesa in the early 80s appear identical to JAN/Philips-ECG 7581As.

If you're mixing the two kinds, put the 6L6GCs so that there is one in each half of the power tube set (left hand three, or right-hand three), and the other in the other half. It doesn't actually matter where within that, but it's conventional to put them in symetrically, eg the middle two or outer two tubes.