Hello vappo, Thanks for the question. The tube numbering depends on which way you are looking at the amp. They are all in a row and they are numbered 1 thru 6. Numbers 5 and 6 are the larger power tubes. Right now I have a 12AY7 in the number 2 spot. This is just to lower he lead and crunch gains - relative to the clean gain. This substitution does not affect the clean signal path. If you normally have the gain control all the way up (or nearly so) then this mod won’t work for you. To me, this amp has gain to spare. By this substitution I can get a little grit on the clean channel and still get hot, but controllable lead sounds. For more variation JJ makes special ECC832 and ECC 823 tubes that have one hi gain and one lo gain section in each. I have one of each but I went back to the 12AY7. I have one fairly low output guitar and if I’m using that I will usually have the gain all the way up, or nearly so. With other guitars I usually have the gain at 3 O’clock. It is a GREAT amp. Good luck. fred
This was done with a stock Ernie Ball Silhouette Special plugged straight into the amp input with a little DDL in the FX loop, played into an EVH 4-12...mic'd only with the ipod internal microphone.
Sorry, now I see the full comment...it's pretty easy, but kind of delicate...disconnect power (and the mains cable of course). Remove the 2 screws on the back to take off the rear grille. Remove the 4 chassis screws from the top and CAREFULLY slide the chassis out of the box. Then just swap the 2nd preamp tube for a 12AY7. The hardest part is not banging a tube when you slide the amp out. Not difficult - just don't get careless. It comes out very neatly as one unit.
Thanks. As a follow up I’d like to add that I believe that it is probably safest to use a tube with a reasonably high plate resistance. I don’t know as much as I’d like to about tubes, and I didn’t think about this at the time. But I believe (anyone feel free to correct me, please), that a lower plate resistance will mean more power dissipated in the plate resistor. At one point i tried (and mentioned in the video using a 12AU7 (plate resistance of 6.2K ohms, gain of 17/17). After all these years I’ve settled on a 12AY7 (plate resistance ~23K ohms. A gain of 40/40. (12ax7 has a plate resistance of ~62K ohms with a gain of 100/100 for reference). I tried a 5751 for a while (plate resistance of ~58K ohms and a gain of 70/70) but I didn’t want/need the extra gain and (for some reason?) the 12AY7 seemed to sound a little sweeter (?). (Hopefully it’s not peculiar to that particular tube.) Anyway - thanks for watching.
Nice, I put a NOS Rogers 7025A in the V1 or V2 position (can't remember now) and it sounds great. Does beautiful cleans, Thick Marshallish Crunch and a very good punchy Soldano kind of Distortion.
…So sorry. I’m just seeing this now. Since this posting I’ve had a stroke (not quite as terrible as it sounds). But recovery and therapy sucks. I should have seen this. Glad this worked for you. Cheap and easy “fix”….and easily “undoable”! Are you still using the Thunder 50?
JLed425 I would suggest the 12AY7. Some other low gain tubes (like 12AU7 or 12AT7) have much lower plate resistances...not sure how much of a problem that would be, long term...I'm looking into it...
Hey Fred! Thanks very much for the info my friend! Gonna dig in this weekend! Loving this amps gain, but just a tad to much for my playing style....Sooooooo, gotta cut it down some! Sounds like your pre-amp tube swap out will do the trick. I have tried similar things like this back in the day on older Peavey Classic 50's. Thanks again for a great video, and additional comments. Be well.......
I own a Thunder 50 Head as well! I bought mine used a few months ago and haven't changed tubes yet. Should I be worried about biasing my head before replacing the tubes? I'm thinking yes, but I've also heard that I shouldn't over think it and they are meant to be changed multiple times before a complete bias is needed. Thanks for the cool vid!
Haunted Smores Thanks. Since trying a 12ay7, I found that JJ makes a couple of custom tubes. An ECC832 and ECC823. One section is high gain and the other section is lower gain. I’ve been using the ecc823 lately. They both give a strong lead overdrive. The difference is how much distortion there is on the crunch mode. The ecc823 gives you a mellower crunch sound. Thanks for watching.
Haunted Smores I don’t worry about touching the bias unless I’m changing power tubes. Though it’s probably a good idea to check it every year or more, depending on how much you play it.
Hi, My current choice of tubes is all normal - except I've been using a JJ tubes ECC823 in the second position lately. It gives me a little grit on cleans, respectable crunch (not a metal crunch by any stretch), and still a hot lead tone. I end up using the preamp gain between 3:00 and all the way up, depending on guitar pickups.
I have a question. I didn't really understand which tube I have to remove to get this incredible better sound. i have the same opinion as you. I want to get a bit more of that british sound. Would you explain if I look at the amp from the back what do I have to do? Thank you for your response.
Yes - thanks for the question. It's so simple really. It's just swapping a 12AY7 for the #2 12AX7A (counting them as 1,2,3,4, power tube 1, power tube 2, in a row).
@@freddigirolamo7761 just to make sure i got this right (thinking of buying one right now): i have to change the order of the internal tubes? swichting the positions of power tube 1 and 2? do they get counted from left to right?
Hello vappo,
Thanks for the question. The tube numbering depends on which way you are looking at the amp. They are all in a row and they are numbered 1 thru 6. Numbers 5 and 6 are the larger power tubes. Right now I have a 12AY7 in the number 2 spot. This is just to lower he lead and crunch gains - relative to the clean gain. This substitution does not affect the clean signal path.
If you normally have the gain control all the way up (or nearly so) then this mod won’t work for you. To me, this amp has gain to spare. By this substitution I can get a little grit on the clean channel and still get hot, but controllable lead sounds.
For more variation JJ makes special ECC832 and ECC 823 tubes that have one hi gain and one lo gain section in each. I have one of each but I went back to the 12AY7.
I have one fairly low output guitar and if I’m using that I will usually have the gain all the way up, or nearly so. With other guitars I usually have the gain at 3 O’clock. It is a GREAT amp. Good luck.
fred
Thanks, I really appreciate that. It's all about chasing "that" tone.
This was done with a stock Ernie Ball Silhouette Special plugged straight into the amp input with a little DDL in the FX loop, played into an EVH 4-12...mic'd only with the ipod internal microphone.
Sorry, now I see the full comment...it's pretty easy, but kind of delicate...disconnect power (and the mains cable of course). Remove the 2 screws on the back to take off the rear grille. Remove the 4 chassis screws from the top and CAREFULLY slide the chassis out of the box. Then just swap the 2nd preamp tube for a 12AY7. The hardest part is not banging a tube when you slide the amp out. Not difficult - just don't get careless. It comes out very neatly as one unit.
+FRED DIGIROLAMO Thank you. I`ve order a 12AY7 tube. So we`ll see the difference.
Thanks Fred, very helpful
Thanks. As a follow up I’d like to add that I believe that it is probably safest to use a tube with a reasonably high plate resistance. I don’t know as much as I’d like to about tubes, and I didn’t think about this at the time. But I believe (anyone feel free to correct me, please), that a lower plate resistance will mean more power dissipated in the plate resistor. At one point i tried (and mentioned in the video using a 12AU7 (plate resistance of 6.2K ohms, gain of 17/17). After all these years I’ve settled on a 12AY7 (plate resistance ~23K ohms. A gain of 40/40. (12ax7 has a plate resistance of ~62K ohms with a gain of 100/100 for reference). I tried a 5751 for a while (plate resistance of ~58K ohms and a gain of 70/70) but I didn’t want/need the extra gain and (for some reason?) the 12AY7 seemed to sound a little sweeter (?). (Hopefully it’s not peculiar to that particular tube.) Anyway - thanks for watching.
Nice, I put a NOS Rogers 7025A in the V1 or V2 position (can't remember now) and it sounds great. Does beautiful cleans, Thick Marshallish Crunch and a very good punchy Soldano kind of Distortion.
…So sorry. I’m just seeing this now. Since this posting I’ve had a stroke (not quite as terrible as it sounds). But recovery and therapy sucks. I should have seen this. Glad this worked for you. Cheap and easy “fix”….and easily “undoable”! Are you still using the Thunder 50?
Many thanks, excellent video!
WOW! Sorry I didn't see your response until now. Thanks for watching.
Great Video Fred....Think I'll try this.
JLed425 I would suggest the 12AY7. Some other low gain tubes (like 12AU7 or 12AT7) have much lower plate resistances...not sure how much of a problem that would be, long term...I'm looking into it...
Hey Fred! Thanks very much for the info my friend! Gonna dig in this weekend! Loving this amps gain, but just a tad to much for my playing style....Sooooooo, gotta cut it down some! Sounds like your pre-amp tube swap out will do the trick. I have tried similar things like this back in the day on older Peavey Classic 50's. Thanks again for a great video, and additional comments. Be well.......
I own a Thunder 50 Head as well! I bought mine used a few months ago and haven't changed tubes yet. Should I be worried about biasing my head before replacing the tubes? I'm thinking yes, but I've also heard that I shouldn't over think it and they are meant to be changed multiple times before a complete bias is needed. Thanks for the cool vid!
Haunted Smores Thanks. Since trying a 12ay7, I found that JJ makes a couple of custom tubes. An ECC832 and ECC823. One section is high gain and the other section is lower gain. I’ve been using the ecc823 lately. They both give a strong lead overdrive. The difference is how much distortion there is on the crunch mode. The ecc823 gives you a mellower crunch sound. Thanks for watching.
Haunted Smores I don’t worry about touching the bias unless I’m changing power tubes. Though it’s probably a good idea to check it every year or more, depending on how much you play it.
Hi, My current choice of tubes is all normal - except I've been using a JJ tubes ECC823 in the second position lately. It gives me a little grit on cleans, respectable crunch (not a metal crunch by any stretch), and still a hot lead tone. I end up using the preamp gain between 3:00 and all the way up, depending on guitar pickups.
sorry for all the mistakes - I should have warmed up...live and learn...
still better than most... Im going to try this now
I have a question.
I didn't really understand which tube I have to remove to get this incredible better sound.
i have the same opinion as you. I want to get a bit more of that british sound.
Would you explain if I look at the amp from the back what do I have to do?
Thank you for your response.
Yes - thanks for the question. It's so simple really. It's just swapping a 12AY7 for the #2 12AX7A (counting them as 1,2,3,4, power tube 1, power tube 2, in a row).
@@freddigirolamo7761 just to make sure i got this right (thinking of buying one right now): i have to change the order of the internal tubes? swichting the positions of power tube 1 and 2? do they get counted from left to right?