Ive finally finished my first amplifier!, Its a Fender princeton 5F2 circuit and I love it!. Makes my new blues junior sound ordinary in comparison and also hisses and carries on alot less. Im using the speaker in the blues junior at the moment and it makes the amplifier rattle like ive never heard it before, im guessing the reverb tank and/or the springs holding the power tubes are to blame. The only real problem im having is the tone pot does nothing at all and im not sure why, could i have destroyed it somehow? It seems very loose and easy to turn compared to the volume. Its definitely wired up properly so something must be fried somewhere (im sure its the pot). Even without a tone control though its still great, thanks to everyone who answered my stupid questions and prevented me from frying power transformers, myself etc etc. My next project will be a 15watter with reverb (goodbye blues junior).
Hi Layt,
good on ya you one step ahead of me, all mine have been "sand state" so far! not knowing the circuit power it off! and use your meter and check the tone pot should get the nominal r value from the outside connections and the wiper the middle connection should act as a divider between either outside connection, varying as you rotate the pot.
another gotcher is the curve of the pot although this would usually be a case of nothing much changes untill you rotate the pot to either extreme. ie log vs lin.
rattle whats rattling?
Robert
good on ya you one step ahead of me, all mine have been "sand state" so far! not knowing the circuit power it off! and use your meter and check the tone pot should get the nominal r value from the outside connections and the wiper the middle connection should act as a divider between either outside connection, varying as you rotate the pot.
another gotcher is the curve of the pot although this would usually be a case of nothing much changes untill you rotate the pot to either extreme. ie log vs lin.
rattle whats rattling?
Robert
layt said:
Might not be a bad idea to just switch it to the 5F2-A setup. If the 250K pot is questionable. The 5F2-A uses a couple less parts and (2) 1 Meg pots.
5F2-A Schematic
I have been fighting my recent Fender Build a few days myself. I built the Champ AA-764 but used a PT strong enough for 3 of them LOL
Gene
PS, Thou Must Post Pics
The blues junior just doesnt have the bass like the little princeton (I can play with the tone controls all I like but it just cant come close), it has a much thinner sound and it doesnt respond to my playing as well either. Also the princeton has less background noise than the blues junior, even with no reverb whatsoever the junior carries on and hisses and makes a racket. Not that the junior sounds bad, I just prefer the sound of the princeton and I can crank it in the bedroom whenever I like and not bother my household quite as much. Its probably also that I built the princeton myself, so im a bit biased....
Having built Both the Princeton 5F2 and the Champ AA764 and actually having had a chance to side by side them subjectively.
The Princeton was a bit quieter than the Champ at full volume, But, I preferred the addition of the separate Bass/Treble controls. I found it difficult trying to deaden the bass without affecting the treble a bit which I was not pleased about. BOTH are in my opinion GREAT sounding amps. Both of those series of amps are so similar a blind fold test would be very tuff.
I have only had a chance to try 1 original Champ 5F1, And honestly, I think The Clones have a slight advantage, Perhaps better tolerance components, Perhaps My Tin Ear, But Either way, I would never spend in excess of $1000us for an original unless I owned a museum.
BTW,, Nice Build!
Gene
The Princeton was a bit quieter than the Champ at full volume, But, I preferred the addition of the separate Bass/Treble controls. I found it difficult trying to deaden the bass without affecting the treble a bit which I was not pleased about. BOTH are in my opinion GREAT sounding amps. Both of those series of amps are so similar a blind fold test would be very tuff.
I have only had a chance to try 1 original Champ 5F1, And honestly, I think The Clones have a slight advantage, Perhaps better tolerance components, Perhaps My Tin Ear, But Either way, I would never spend in excess of $1000us for an original unless I owned a museum.
BTW,, Nice Build!
Gene
Your blues jr. must be broken. They sound very good and the clean bass output far surpasses any of the SE 6v6 fenders. They do have design problems, though. PCB mounted tube sockets, jacks etc. Totally stupid. I've had to repair/replace/resolder mine probably 5 times. The reverb is opamp driven and can give some hiss depending on which revision it is. It should not hiss w/ reverb set to 0. FWIW, I've modded my BJr. a lot, but the basic character is still there and its a good sounding amp. Totally different sound than the blackface fender sound..more marshall-like.
I like the early SE 6v6 fenders , don't get me wrong. They just aren't that flexible. Not enough clean headroom for me. I gotta have on-board spring reverb. Not as tight sounding. Great output stage distortion though at reasonable volumes (still suprisingly loud though).
Congrats on the great looking build, btw. Glad you like the sound too.
-z
I like the early SE 6v6 fenders , don't get me wrong. They just aren't that flexible. Not enough clean headroom for me. I gotta have on-board spring reverb. Not as tight sounding. Great output stage distortion though at reasonable volumes (still suprisingly loud though).
Congrats on the great looking build, btw. Glad you like the sound too.
-z
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