M Fowler wrote:That would be a good idea to build the 212 cabinet out of select void free pine and try some different speakers. Mix the speakers up they don't need to be the same brand/model. The speaker baffle board should be plywood though.
Mark
Hello and thanks for responding. Also for the info. I will assume that the baffle board is the wood that you bolt the speakers to. I have to do a bit of research for sure. As for the tubes, I purchased what had been suggested by the BillM site. As for purchasing them, I don't know enough about them to make a knowledgeable choice. Although there is come idea that I might be able to experiment with a 12AY7 tube in my V1, whatever that means.
Glenn
brentm wrote:On the Blues Junior I worked on for a friend, I replaced the tubes with exactly what BillM recommended (eventually). JJ EL84s and Groove Tubes 12ax7s. I tried inserting one of my old stock tubes in V1 and it ended up making some ghost notes appear some time later. At first I thought it was the speaker, but quickly swapped the tube with the Groove Tube 12ax7 and it disappeared. I think my old tube was going microphonic...
You might pop the back cover off and just visually inspect the power supply filter caps. Although the leaky caps seem to be limited to the 2003-2004 Blues Juniors, it'd be worth taking a peek and it's only a few screws to remove to pop that back cover off. http://billmaudio.com/wp/?page_id=267
The earlier link on tubes has a great subjective review of the tubes tested in a BJR. Of the modifications BillM has developed, the bias control is probably the one I would do on the Blues Junior.
Howdy and another thank you!
The tubes were discolored and I ordered and just installed JJEL84s and Sovtek 12AX7WAs. What a giant difference. Sounds greatly better. While in there I took the time to look at the Caps for any sign of damage and they seemed pristine. Great heads up!! That and the fact that I changed the caps and pots in the guitar has made it fun to play again. I checked on the BillM site and as he predicted the volume/loss of frequencies was unaffected. If I can get the gumpshun I may do the mods he suggested, possibly along with a new speaker or build a speaker box 2X12. I keep hearing raves about the cannabis rex. Ah so many choices and so little cash............. I do appreciate your and all the members help!
Glenn
If you know how to, check the bias or take the amp to somebody who can do it. Every Blues Jr. that I have serviced over the last 10 years has been biased waaaayyy too hot. Those are cooking them el84's. Biasing the amp right makes really big difference in those amps imho. Use a hemp cone speaker to tame those sometimes ear piercing highs, if you find it too overwhelming at the treble register.
It does not have adjustable bias supply stock, but it is really simple task to add one to it. Speaker change and proper biasing makes those amps a real bang for the buck.
-T
Dingleberry wrote:If you know how to, check the bias or take the amp to somebody who can do it. Every Blues Jr. that I have serviced over the last 10 years has been biased waaaayyy too hot. Those are cooking them el84's. Biasing the amp right makes really big difference in those amps imho. Use a hemp cone speaker to tame those sometimes ear piercing highs, if you find it too overwhelming at the treble register.
It does not have adjustable bias supply stock, but it is really simple task to add one to it. Speaker change and proper biasing makes those amps a real bang for the buck.
-T
Big +1 on that, and brentm's suggestion to add the BillM bias mod. Not difficult and absolutely essential!
Dingleberry wrote:If you know how to, check the bias or take the amp to somebody who can do it. Every Blues Jr. that I have serviced over the last 10 years has been biased waaaayyy too hot. Those are cooking them el84's. Biasing the amp right makes really big difference in those amps imho. Use a hemp cone speaker to tame those sometimes ear piercing highs, if you find it too overwhelming at the treble register.
It does not have adjustable bias supply stock, but it is really simple task to add one to it. Speaker change and proper biasing makes those amps a real bang for the buck.
-T
Hello and thanks for your reply. I have read about that and the modification.
Funny my tubes lasted decades {:-))! I may do it and some other modifications, but for the immediate future I am going to see how I like I like this one. I am not an aficionado, so I know I didn't like the way it sounded. This sounds much better, but I'd like to get more used to it.
I started checking some youtube eminence speakers. The swamp thing was suggested by BillM, the cannabis rex of course gets many raves, and I also listened to the Texas Specials. None except the TS and the Swamp thing were a/b, that I've found so far. I appreciate your time and information!
Glenn
Dingleberry wrote:If you know how to, check the bias or take the amp to somebody who can do it. Every Blues Jr. that I have serviced over the last 10 years has been biased waaaayyy too hot. Those are cooking them el84's. Biasing the amp right makes really big difference in those amps imho. Use a hemp cone speaker to tame those sometimes ear piercing highs, if you find it too overwhelming at the treble register.
It does not have adjustable bias supply stock, but it is really simple task to add one to it. Speaker change and proper biasing makes those amps a real bang for the buck.
-T
Big +1 on that, and brentm's suggestion to add the BillM bias mod. Not difficult and absolutely essential!
Howdy,
Is the change done more for reliability or for sound modification, from your experience. It seems to accomplish both.
Thanks
Glenn
Dingleberry wrote:If you know how to, check the bias or take the amp to somebody who can do it. Every Blues Jr. that I have serviced over the last 10 years has been biased waaaayyy too hot. Those are cooking them el84's. Biasing the amp right makes really big difference in those amps imho. Use a hemp cone speaker to tame those sometimes ear piercing highs, if you find it too overwhelming at the treble register.
It does not have adjustable bias supply stock, but it is really simple task to add one to it. Speaker change and proper biasing makes those amps a real bang for the buck.
-T
Big +1 on that, and brentm's suggestion to add the BillM bias mod. Not difficult and absolutely essential!
Howdy,
Is the change done more for reliability or for sound modification, from your experience. It seems to accomplish both.
Thanks
Glenn
As Dingleberry noted, the factory set bias on the output tubes cooks them badly. That shortens the life of the EL84 output tubes. In my estimation (and there seems to be a consensus on this) it also makes the tone harsh. The BillM bias mod allows the tubes to be properly biased, prolonging tube life and and I think makes the amp sound better.
I did all of the BillM Blues Jr mods, including transformer swaps, and am pleased with the results.
From what I've heard they do make a much more pleasing amplifier out of it and also make it more durable. Possibly I will indulge myself eventually. Although I was thinking of a speaker first or maybe a 2X12 with the stock and some other speaker first. Don't know but appreciate the experienced advice. I also like those little boutique amplifiers sounds.
Thanks again
Glenn
glennc717 wrote:Howdy and another thank you!
The tubes were discolored and I ordered and just installed JJEL84s and Sovtek 12AX7WAs. What a giant difference. Sounds greatly better. While in there I took the time to look at the Caps for any sign of damage and they seemed pristine. Great heads up!! That and the fact that I changed the caps and pots in the guitar has made it fun to play again. I checked on the BillM site and as he predicted the volume/loss of frequencies was unaffected. If I can get the gumpshun I may do the mods he suggested, possibly along with a new speaker or build a speaker box 2X12. I keep hearing raves about the cannabis rex. Ah so many choices and so little cash............. I do appreciate your and all the members help!
Glenn
That big of a difference huh? Glad it helped. Did you say it helped the bedroom level dynamics that you were looking for or do you still need to do some changes?
On the bias mod. You can simply keep replacing the output tubes as needed. I'm not sure how much life the hot bias is cooking off of them, but I'm sure its measurable. And I don't think the mods really add to the resale value of your amplifier. If anything, I think the mods would detract from the resale value unless done by BillM himself. But they're fun to do!!!
glennc717 wrote:Howdy and another thank you!
The tubes were discolored and I ordered and just installed JJEL84s and Sovtek 12AX7WAs. What a giant difference. Sounds greatly better. While in there I took the time to look at the Caps for any sign of damage and they seemed pristine. Great heads up!! That and the fact that I changed the caps and pots in the guitar has made it fun to play again. I checked on the BillM site and as he predicted the volume/loss of frequencies was unaffected. If I can get the gumpshun I may do the mods he suggested, possibly along with a new speaker or build a speaker box 2X12. I keep hearing raves about the cannabis rex. Ah so many choices and so little cash............. I do appreciate your and all the members help!
Glenn
That big of a difference huh? Glad it helped. Did you say it helped the bedroom level dynamics that you were looking for or do you still need to do some changes?
On the bias mod. You can simply keep replacing the output tubes as needed. I'm not sure how much life the hot bias is cooking off of them, but I'm sure its measurable. And I don't think the mods really add to the resale value of your amplifier. If anything, I think the mods would detract from the resale value unless done by BillM himself. But they're fun to do!!!
Hey Brent,
Yes a wonderful difference. Along with the caps and pots in the guitar it sounds at least now, fabulous. Although it did not cure the low volume problem, I have found with fiddling that I can adjust the volume of the guitar and up the master on the amp and attain a good frequency range at a reasonable volume. Other than my abilities to mod, I have a feeling that I don't wish to permanently alter a greenboard original amp. Whatever resale value it has will be due to originality and it being American made, IMHO. Now if I had the money to get a new tweed, I'd be more likely to dive in. But at this moment I am exploring the range of sound I can get. I have never been much of an amplifier varying sound kinda guy. I am lucky to have found a sight that has a large quantity of setting for various sounds and have used or messed with them, not gaining any knowledge. Plus the list is 99% set up for fenders. Thank you and again and thanks for the checking of the caps!
You da man!
Glenn
