Blair Chapman Custom Stereo Tube PreamplifierCustom built in 2014 by Blair Chapman. Unique one-of-a-kind stereo preamp based on 12SN7 tubes, which are sonically similar to, but less expensive than, 6SN7 tubes. The project was to build the best-sound-for-the-buck preamp. Mr. Chapman designed the preamp, chose the tubes, built it and tested it. Point-to-point wiring. The preamp has 3 switchable line inputs, as well as a partial “balance control” if fine channel balance adjustments need to be made. The preamp has upgraded volume and balance pots, and comes with a pair of vintage GE 12SN7s. Mr. Chapman said: “Front left switch (black) is the power. The knob on the left is the volume, the switch (silver) is the cutout switch for the knob between the tubes which allows you to adjust balance between the channels if needed. Up is engaged and down is out. The right knob is the input selector which is logical. It points up towards the input set you need. i.e. left is the left input from the front of the preamp.” “It has three inputs, and one set of outputs. I installed a higher grade conductive plastic pot which has much better tracking. There is a balance control between the tubes that you can use in case you buy mismatched tubes. Use o-rings to damp tall bottles. Most short bottle 12SN7s will not require any damping.” Beautiful wood enclosure. Due to DIY nature, rating condition at 8. See linked AA post re another Chapman preamp. Search internet for more info on Mr. Chapman's tubed creations. $22 to ship in US lower 48. FREE local pick-up in Chicago. Thanks for looking.
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