I built a DI using the preamp of an ampeg B15N. It uses a single 6SL7 tube with a volume control, followed by a bass/treble stack. I wanted to keep the design simple by using only one tube, so I followed this with a high voltage mosfet follower to drive a transformer for a DI out. The output transformer is a cinemag, and sounds very nice. The tube is an old unbranded russian 6SL7. I am using DC heaters for noise reduction, and a B+ just north of 300 volts. I made the PCB and faceplate myself, and of course, put it all together.
The volume control starts getting some good grunt right around 2 o'clock, and when maxed out, can sound pretty mean. I'm very happy with this build. Hopefully I'll get around to uploading some audio later on (actually I cut my left index finger building this thing, so it's difficult to play right now). For now, here are some pics:
**edit**
Here are the sound clips that I posted later on in the thread. The first two are with the unlabeled russian tube.
The volume control starts getting some good grunt right around 2 o'clock, and when maxed out, can sound pretty mean. I'm very happy with this build. Hopefully I'll get around to uploading some audio later on (actually I cut my left index finger building this thing, so it's difficult to play right now). For now, here are some pics:
**edit**
Here are the sound clips that I posted later on in the thread. The first two are with the unlabeled russian tube.
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