Supreme Tube Board for Blues Jr

We have upgraded the Fromel Tube PCB Mod for Blues Jr: See description below for details. With over 100 boards sold I made some slight revisions.

You cherish your Blues Jr, and now it's time to take it to new heights. The Fromel Tube PCB is the solution to maximize your amp's performance, regardless of its version, from Made in USA to the cathode biased IV.

Experience a profound improvement in tone, feel, and noise reduction with the new Tube PCB Mod. We've fine-tuned every detail to deliver excellent performance.

Mods from Stock:

A cathode follower driven tone stack creates a smooth, compressive vintage feel. The stock Blues Jr leaves one of the gain stages in V2 unused, we use this for the cathode follower. The tone stack loads the signal down a lot, the cathode follower helps recover that signal while adding some musical compression. 

Cathode biased for a touch responsive playing experience. Prior to the current version of the IV all Blues Jr’s were fixed bias and run hot if not modified. Changing from fixed to cathode bias solves all the bias issues for the amp and it sounds fantastic.

DC elevated heaters virtually eliminates heater hum, pushing the boundaries of silence. When we installed the first prototype, we were astonished by how quiet the amp was; I honestly don’t know why every amp maker does not do this to the heaters, it’s very simple and works incredibly well.

We've included a special mod to tame reverb noise because the amp was so quiet after the mods the reverb was irritatingly noisy even at 3, it’s a real easy mod, just clip one cap and we added it to the newest version of out our Supreme mod instructions and recommend it for all Blues Jr’s modded or not.

High-quality double-sided through-plated board sets for durability. The stock board is single sided and the PCB mounted plastic tube sockets are only secured by one pad and a bit brittle lead free solder. After a couple of tube changes the stress can crack these joints and this is one of the well known failure points on these amps.

These boards are double sided and plated through so the solder joint is very secure. All the traces on the PCB are the equivalent of 16 gauge wire. There is a ground plane to further reduce noise. Pre-soldered resistors, capacitors, and diodes make installation a bit quicker. I put all the instructions right on the PCB and there are detailed instructions with photos online.

The ribbon cables are replaced with individual pre-stripped leads. The kit also includes high quality ceramic sockets. 

Changes:
- All board mounted components are SMD. Why? I can get a much higher rated component for the same cost as through hole for the same cost, resulting in a higher quality product without raising the price.
- Added in rush protection for the cathode follower so any 12A*7 or similar pinout will not get hurt.
- Modified the hole sizes on the PCB for easier install of the leads.

Our recommended tube set for this board is 12AX7, for V1, 12DW7 for V2, and 12AT7 for V3. 12AX7's in all three spots works fine as well.

The tube board is a great improvement to any model Blues Jr with or without the Supreme mods for the main board.