Reviewer Hugh Odom
Manufacturer Ruby Tubes
Model STR 7025 pre-amp tube
Price $10.00

Dimensions exact replacement for 12AX7 or 7025 pre-amp tube
As the owner of a Tube Works "Blue Tube" (see reviews), I noticed over time that it was very difficult to get a warm bass sound without tipping over into hard distortion. The Blue Tube uses a single 12AX7 tube (Chinese made) and I began to wonder if changing the tube would significantly improve its tone.

After researching on the web, I found several recommendations for the Ruby STR7025 for bass pre-amps. The STR7025 is a straight replacement for a 12AX7 made specially for Ruby in China. Unfortunately, they are now out of production, but they are still readily available.

The Blue Tube came factory equipped with an inexpensive run-of-the-mill Chinese 12AX7. I had already replaced it with a Fender 12AT7 and replaced that with a Mojo 12AX7. None of these tubes significantly changed the tone of the unit.

I installed the STR7025 and noticed an immediate difference in tone. This tube greatly increased the usable warmth of my Blue Tube and I would highly recommend it for any bass amp or pre-amp which uses a 12AX7.

Construction 100%
Usefulness 100%
Value 100%
Overall 100%
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