Author |
Message |
hydrargyrum
Advanced Member Username: hydrargyrum
Post Number: 327 Registered: 3-2004
| Posted on Saturday, April 26, 2008 - 3:46 am: | |
Its time to retube my Fender pro-reverb again, and I recently had been reading that there are a number of tubes that can be substituted for 12AX7's to give a reduced gain, forcing the poweramp to work a bit harder. Does anyone have any experience with this? Additionally, if someone could point me towards a good source for tubes, it would be much appreciated. |
lembic76450
Intermediate Member Username: lembic76450
Post Number: 129 Registered: 5-2002
| Posted on Saturday, April 26, 2008 - 6:28 am: | |
Kevin, I recently replaced my F-2B tubes with tubes from Eurotubes (www.eurotubes.com). They have a good video on biasing a Fender amp,it kind of removes the mystery. Prices are good and shipping was fast. It's a good site for info and I found them very helpful on the phone. |
hydrargyrum
Advanced Member Username: hydrargyrum
Post Number: 328 Registered: 3-2004
| Posted on Saturday, April 26, 2008 - 10:38 am: | |
Thanks a lot. I've bought tubes from this guy before, but for the life of me could not remember his name (or site). I'll almost certainly buy from him, unless someone cares to step in and recommend some incredibly great deal. |
crobbins
Intermediate Member Username: crobbins
Post Number: 128 Registered: 6-2004
| Posted on Saturday, April 26, 2008 - 11:40 am: | |
I buy tubes for my Mesa Boogie amps from the Mesa Boogie site. Otherwise I take my amps to our tube amp guru, Robert Dixon, and he retubes them with whatever he uses.... http://mesa.stores.yahoo.net/mesboogtub.html |
jbybj
Intermediate Member Username: jbybj
Post Number: 159 Registered: 6-2006
| Posted on Saturday, April 26, 2008 - 12:56 pm: | |
I have made happy purchases from both these places. https://www.boiaudioworks.com/ http://www.tubedepot.com/powertubes.html good luck, JBY |
gtrguy
Intermediate Member Username: gtrguy
Post Number: 131 Registered: 9-2004
| Posted on Monday, April 28, 2008 - 11:04 am: | |
Pretty hard to beat Eurotubes (plus it's close for me). They sound good in a Fender. I wouldn't bother with anything other than 12AX7 in your amp. The best way to make it work harder is to turn it up! Mesa tubes are good but cost more and don't sound any better. Electro-harmonix (sp?) high end 12AX7s sound great in V1 position. I don't like Ruby or Sovtek. NOS stuff is OK, like RCA, etc. Again way overpriced. Mullard 'holy grail' stuff is supposed to sound great, but I don't know personally. IMHO, the single best thing for a Fender Pro would be a better speaker. I stuck some Mesa C90s in my twin and now it sound GOOD! Keep the stock ones for resale time. Bye, Dave |
lbpesq
Senior Member Username: lbpesq
Post Number: 3059 Registered: 7-2004
| Posted on Monday, April 28, 2008 - 12:31 pm: | |
I've had a blackface Pro Reverb for many years. My friend, from whom I obtained it, long ago swapped out the original fender (Jensens?) for JBLs. It sounds fantastic. Bill, tgo |
hydrargyrum
Advanced Member Username: hydrargyrum
Post Number: 332 Registered: 3-2004
| Posted on Monday, April 28, 2008 - 1:32 pm: | |
Yeah, for some time I have imagined that I would try to swap out the guts into a figured hardwood cabinet with some tone-tubbies, but alas, it always seems like some other piece of gear has tempted me more. |
dfung60
Advanced Member Username: dfung60
Post Number: 326 Registered: 5-2002
| Posted on Monday, April 28, 2008 - 2:25 pm: | |
The 12AU7 is a lower gain tube that is otherwise pin compatible with a 12AX7, but I don't think that will do you want. If you make that substitution, then you'll have lower output because the preamp circuit isn't driving the power amp circuit as hard. You make this change if you want more clean headroom. The 12AU7 is often used in the section of the amp between the preamp front end and the power amp section or in front of a reverb tank. At these points in the amp, the signal level is a little higher and you don't want to introduce distortion. If you put a 12AX7 in place of a 12AU7, then you'll increase the output level and that WILL drive your power amp harder. David Fung |
hydrargyrum
Advanced Member Username: hydrargyrum
Post Number: 333 Registered: 3-2004
| Posted on Monday, April 28, 2008 - 2:51 pm: | |
Thanks for the illumnination David. The explanations I had heard were that by reducing the gain in the preamp, one had to force the poweramp to work harder to produce the same volume, thereby forcing it to "breathe" differently. I wasn't necessarily looking for more gain from my, amp, as much I was in exploring different tonal options. Frankly though, the amp has never really lacked for clean headroom. |
pace
Advanced Member Username: pace
Post Number: 374 Registered: 4-2004
| Posted on Monday, April 28, 2008 - 4:16 pm: | |
I might still have a bunch of old 12au7's lying around if you want to try them out Kev.... shoot me an email.... -Mike |
crobbins
Intermediate Member Username: crobbins
Post Number: 129 Registered: 6-2004
| Posted on Monday, April 28, 2008 - 8:38 pm: | |
I use a Pro-Reverb, and a Boogie amp. the fender has Tone Tubby speakers, and the Boogie a JBL.. |