Audio research Corp. LS5 Preamp??
Specs say the preamp uses ten 6922 tubes.....
http://www.arcdb.ws/LS5/LS5.html
Though the tube pin out for the 12BH7 and the 6922 are the same, I do not believe the two tubes are interchangeable.....
http://www.drtube.com/tubedata.htm
The circuitry for the preamp was built around the 6922 tube characteristics. The preamp should sound best using 6922 tubes or tubes from the same family, 6922/E88CC,7308/E188CC.
Using the 12BH7 could cause the filament winding of the power transformer to fail due to overload.
12BH7 heater current is 0.6 amp @ 6.3V.
6922 heater current is 0.3 amp @ 6.3V.
Specs say the preamp uses ten 6922 tubes.....
http://www.arcdb.ws/LS5/LS5.html
Though the tube pin out for the 12BH7 and the 6922 are the same, I do not believe the two tubes are interchangeable.....
http://www.drtube.com/tubedata.htm
The circuitry for the preamp was built around the 6922 tube characteristics. The preamp should sound best using 6922 tubes or tubes from the same family, 6922/E88CC,7308/E188CC.
Using the 12BH7 could cause the filament winding of the power transformer to fail due to overload.
12BH7 heater current is 0.6 amp @ 6.3V.
6922 heater current is 0.3 amp @ 6.3V.