[AMRadio] 6BG6 ad

doxemf at aol.com doxemf at aol.com
Tue Feb 28 19:44:40 EST 2006

 -----Original Message-----
From: John Lyles <jtml at losalamos.com>

I wonder what the audiophools would think of using a 'Horizontal Sweep Tube' in 
a purist application? 

Guess that I have to put my 2 cents in on this one.
  Sweep tubes have long been used by the audio community for example the Futterman OTL amplifier, see the pdf schematic at:
  It used six 6LF6 sweep tubes and if you do a search on this amplifier you will see that it was controversial but became highly regarded.
  The 6AV5 was used in Bogens top line home HIFI stereo amp. I have one of these and it sounds great.
  Four 6GT5s were used in the Frazier/Precision G 101A 100 watt mono amp and this is another outstanding amplifier as well. I have several.
  The 6CD6 has also been used.
   There are many sweep tubes that can be used for audio amplifier tubes as long as the lower screen grid voltage is considered. 
  A power amplifier tube is just that regardless of the application. As long as the proper parameters are observed in the circuit design.
  Some of the early low power Ham transmitters used 6L6 metal tubes as did early audio amps.
  What the seller of these 6BG6's has to say is quite possible since with the downsizing of the tube industry a lot of tubes that still had Military stock use were made with whatever current tooling was still
available so if the 7581/7027 components were still available the only change the mfg had to make was to the plate connection.  An original 6BG6 cannot have the screen grid at 450 volts without meltdown.
The Military used these tubes as high voltage regulators and for CRT sweep I believe.
  BTW, the 807 is the origin of the entire 6L6 family of beam pentodes.
Bill  KB3DKS/1


More information about the AMRadio mailing list

This page last updated 18 Dec 2017.