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Guitars Etc. / Fender Blues Junior Amp Resurrection
« on: August 07, 2016, 04:39:56 PM »
I had been wanting to pick up a small tube amp for guitar for some time now, and I came across a non-functional Blues Junior on Craigslist back in June. It was in minty condition cosmetically, but it had "blew a fuse" according to the owner. I took my chances, made him an offer and brought it home.
Upon tearing into it, it looked like one of the power tubes may have failed and smoked the corresponding screen resistor.
I cleaned up and fixed that mess, installed a new set of JJ tubes, and it fired right up!
Since these are pretty popular units to modify, I did some research and decided to make some of the common improvements while I still had it partially disassembled:
- Replaced the cheap PCB-mounted input jack with a Switchcraft
- Replaced the cheap PCB-mounted "fat" switch pushbutton with a toggle
- These are fixed-biased kinda hot from the factory, and so I added a trimmer to provide adjustable bias... and set it up to be a little gentler on the power tubes
- Upgraded the caps in the tone stack, and implemented the "Twin mod" on the midrange pot for a greater range of adjustment
- Replaced/upgraded the power supply filter caps
- Added a 3-position progressive Carling power switch that provides for a "standby" setting in the middle position (nice to mute the amp)
- Grabbed an amber jewel lamp for it just for grins (haven't installed that yet)
I ran that way for a couple of weeks, and during that time got a promotional email from Antique Electronic Supply advertising a 10% off sale in July. Figured that offered a good excuse to grab an upgraded driver and reverb tank for it!
That MOD tank made a vast improvement in the sound and sensitivity of the reverb, and the C-Rex driver really tightened up the low end. It sounds great for a cheapie amp! I'm happy with the results, especially considering I'm in it <$300 after all is said and done
Upon tearing into it, it looked like one of the power tubes may have failed and smoked the corresponding screen resistor.
I cleaned up and fixed that mess, installed a new set of JJ tubes, and it fired right up!
Since these are pretty popular units to modify, I did some research and decided to make some of the common improvements while I still had it partially disassembled:
- Replaced the cheap PCB-mounted input jack with a Switchcraft
- Replaced the cheap PCB-mounted "fat" switch pushbutton with a toggle
- These are fixed-biased kinda hot from the factory, and so I added a trimmer to provide adjustable bias... and set it up to be a little gentler on the power tubes
- Upgraded the caps in the tone stack, and implemented the "Twin mod" on the midrange pot for a greater range of adjustment
- Replaced/upgraded the power supply filter caps
- Added a 3-position progressive Carling power switch that provides for a "standby" setting in the middle position (nice to mute the amp)
- Grabbed an amber jewel lamp for it just for grins (haven't installed that yet)
I ran that way for a couple of weeks, and during that time got a promotional email from Antique Electronic Supply advertising a 10% off sale in July. Figured that offered a good excuse to grab an upgraded driver and reverb tank for it!
That MOD tank made a vast improvement in the sound and sensitivity of the reverb, and the C-Rex driver really tightened up the low end. It sounds great for a cheapie amp! I'm happy with the results, especially considering I'm in it <$300 after all is said and done