mildmanofrock Posted June 11, 2010 Share Posted June 11, 2010 (edited) [attachment=51897:DSC01048.JPG] I've got a gig tonight and thought it would be a good idea to buy some nice new tubes from the lovely people at Watford Valves. I whipped out the old valves from my Ampeg SVT-6 Pro and didn't note which valves went where. Yes, I'm an idiot, I know. To cut a long story short, I need to put the original valves back in. There are four 12AX7 valves and two 12AU7 valves. I've hunted high and low for a schematic - called Panic Music, spoken to Watford Valves, and left a message with Loud Technologies and no ones entirely sure what goes where. Can anyone help??? I've attached a picture of the empty valve slots! Thank you folks!! Steve Edited June 11, 2010 by mildmanofrock Quote Link to comment Share on other sites More sharing options...
allighatt0r Posted June 11, 2010 Share Posted June 11, 2010 (edited) At a guess (completely uneducated mind you) I would say that the four 12AX7 valves go in the top four wholes of the picture, and the other 2 go in the erm... other two. Just makes sense to e as it looks like the lower two are on the preamp board and the upper four are on the poweramp board Don't take my word as gospel though! I'll try and find something to back up my guesses. EDIT: If you can decipher them, schematics are [url="http://basschat.co.uk/index.php?showtopic=20596"]on post 7 here[/url] Edited June 11, 2010 by allighatt0r Quote Link to comment Share on other sites More sharing options...
BottomEndian Posted June 11, 2010 Share Posted June 11, 2010 [quote name='allighatt0r' post='864452' date='Jun 11 2010, 03:55 PM']At a guess (completely uneducated mind you) I would say that the four 12AX7 valves go in the top four wholes of the picture, and the other 2 go in the erm... other two. Just makes sense to e as it looks like the lower two are on the preamp board and the upper four are on the poweramp board Don't take my word as gospel though! I'll try and find something to back up my guesses. EDIT: If you can decipher them, schematics are [url="http://basschat.co.uk/index.php?showtopic=20596"]on post 7 here[/url][/quote] Schematics seem to give*: J11 = 12AX7 J12 = 12AU7 J14 = 12AX7 J39 = 12AU7 J2 and J3 aren't specified, so presumably you can whack the two remaining 12AX7s down there. They're the preamp valves, so that kind of makes sense (half the fun of a valve preamp being the testing of different valves). [size=1]* Caveat: I can read a schematic, but I'm no engineer. I take no responsibility for anything, including my own life. [/size] Quote Link to comment Share on other sites More sharing options...
mildmanofrock Posted June 11, 2010 Author Share Posted June 11, 2010 [quote name='allighatt0r' post='864452' date='Jun 11 2010, 03:55 PM']At a guess (completely uneducated mind you) I would say that the four 12AX7 valves go in the top four wholes of the picture, and the other 2 go in the erm... other two. Just makes sense to e as it looks like the lower two are on the preamp board and the upper four are on the poweramp board Don't take my word as gospel though! I'll try and find something to back up my guesses. EDIT: If you can decipher them, schematics are [url="http://basschat.co.uk/index.php?showtopic=20596"]on post 7 here[/url][/quote] Thanks so much for taking the time to reply allighatt0r - I really appreciate it. I've had two independent sources confirm the correct placement now... it's 12AX7s in J11, J14 and the front two preamp slots... and 12AU7s in the J12 and J39 slots. My god, that was a close call. Cheers mate! Steve Quote Link to comment Share on other sites More sharing options...
mildmanofrock Posted June 11, 2010 Author Share Posted June 11, 2010 And BottomEndian - thank you sir for confirming what Phil from Audio Spares has told me... you are exactly right! Never again will I whip things out before writing down what they are. Brilliant stuff, thanks folks, this forum is bloody great. Cheers! Steve Quote Link to comment Share on other sites More sharing options...
Colledge Posted June 11, 2010 Share Posted June 11, 2010 glad to see you're all sorted. i don't get that amp though... its 2 12ax7s for the pre and 2 12ax7s and 212au7s as "driver tubes".... what is the difference between driver tubes and preamp tunes if their going into a solid state power section? Quote Link to comment Share on other sites More sharing options...
Stylon Pilson Posted June 11, 2010 Share Posted June 11, 2010 Also, what would the consequences have been if the valves were put back in the wrong slots? Fire risk, or just poor tone? S.P. Quote Link to comment Share on other sites More sharing options...
bassicinstinct Posted June 11, 2010 Share Posted June 11, 2010 [b]"Never again will I whip things out before writing down what they are."[/b] Sentence of the day at the very least!! I think we should all try to live our lives based on that principle. Quote Link to comment Share on other sites More sharing options...
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