My first (guitar) amplifier

layt · 18th October 2005, 01:01 AM

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).

Robski666 · 18th October 2005, 01:32 AM

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

aletheian · 18th October 2005, 02:17 AM

Quote:

Originally posted by layt
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).

Hey man,
you should check out http://ax84.com/bbs/ for great info on guitar amp stuff.

Trout · 18th October 2005, 04:26 PM

Quote:

Originally posted by layt
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).

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

layt · 19th October 2005, 12:55 AM

hope they work this time!

layt · 19th October 2005, 01:00 AM

cant i attach multiple images to the same post??, ah well ill just do it this way

layt · 19th October 2005, 01:02 AM

last one

Cassiel · 19th October 2005, 08:26 AM

Hi layt,

The blues junior sounds quite nice, i would like to know what do you like about the Princeton that doesn't have the blues junior.

Thanks,

Al.

layt · 21st October 2005, 11:27 PM

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....

Cassiel · 22nd October 2005, 12:06 AM

Quote:

so im a bit biased....

Not really, it's not the first time i hear that... Actually this is the second time i hear, from someone who has had both amps, that the Princeton sounds better.
Just wanted to be sure, i was about to buy one.
Thanks for your reply.

Al.

18th October 2005, 01:01 AM	#1
layt diyAudio Member Join Date: Apr 2005 Location: Ballina	My first (guitar) amplifier 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).

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18th October 2005, 01:32 AM	#2
Robski666 diyAudio Member Join Date: Sep 2005	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

19th October 2005, 08:26 AM	#8
Cassiel diyAudio Member Join Date: Sep 2004 Location: Madrid	Hi layt, The blues junior sounds quite nice, i would like to know what do you like about the Princeton that doesn't have the blues junior. Thanks, Al.

21st October 2005, 11:27 PM	#9
layt diyAudio Member Join Date: Apr 2005 Location: Ballina	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....