Have you tried this yet? Your thoughts?
After reading your post this morning, I gave it a try. I compared a Tung-Sol 12AX7 (which is what I had in there) to a JJ 12DW7.
Very significant difference in
tone. I left everything dialed the same on amp and guitar & simply switched tubes and played the same "jazz" chording and then blues single note and double stop riffs.
I had the reverb pot set to "6" & then tried it around "7.5 to 8".
I don't hear much difference in the amount of reverb. About the same springy boingy sound with both. However, the 12AX7 adds some unpleasant "hash" harsh echo in the verb that the 12DW7 doesn't add. The 12AX7 makes the spring in the reverb tank sort of rattle on top of the higher notes. The more you dial up the reverb pot the more noticeable and even unpleasant in tone it becomes.
The harshness is maybe 80% eliminated with the 12DW7. The 12DW7 has the same springy boing sound but without the harsh rattle artifacts that the 12AX7 has. And the tone is
clearer and cleaner sounding to my ears. It gives the overall chording and single/double notes a smoother clearer tone, IMO. The 12DW7 may not be verbing the lower notes as much as the 12AX7 seems to add a little "mush/fuzz" to the lower notes?
I tried it with just the clean channel and then the OD channel engaged. See schematic below. The 12AX7 really had noticeable harshness on the clean channel when the reverb pot was around 7.5.
Please note that I am using a .003 into the dwell instead of the typical 500p to .001 that I usually use. This could be a factor in the 12AX7 having the harshness? OR ……… maybe the 12AX7 triode is overdriving the send signal too much adding harshness?
I am leaving the 12DW7 in there. I only tried one guitar with this using a semi-hollow body Tele (no f-holes) with H-S-H pickups.
Thanks for the suggestion! I think it is a worthwhile improvement. I would not anticipate getting more reverb with the 12DW7 but getting a smoother and cleaner sounding reverb with the 12DW7.
However, in some ways I can get more reverb with the 12DW7 because I can turn up the reverb pot higher and not have the unpleasant harsh echo riding on the reverb/notes. So because I can turn the reverb up higher and still have it sound good, perhaps one could say the 12DW7 allows more reverb to be used even though it doesn't seem to produce more reverb?
With respect, Tubenit