Posted by Tnuctipun [ 64.12.116.14 ] on February 15, 2005 at 14:10:31:

In Reply to: Thanks , Doug ! :-) posted by Damir on February 15, 2005 at 13:17:01:

If you don't need as much gain as the 5687 delivers( u=~16 ), the 12B4 is my next option. It takes a second 9-pin socket, and ought to have 6 or 7, instead of 2 LED's to bias. That's about *IT*.

The heaters will take ~25% more curent, at 0.6 amp instead of 0.45 amp of the 5687. Both will run at 12.6 V.

I offer this as an alternative to the gymnastics a lot of ForePlay owners go through getting a reasonable amount of volume knob sensitivity. We're not stuck with 12AU7's so there is no need to act like it at the design table.

Putting in a second socket later oughtn't to be too difficult. Take out the valves before drilling more holes. Reserve a bit of real estate with a Sharpie....
regards,
Douglas

Replies:

• Re: the 12B4 option... - Damir 14:30:48 02/15/05 (6)
  • Oh...yes! - Tnuctipun 15:10:04 02/15/05 (5)
    • Re: Oh...yes! - manualblock 15:28:24 02/15/05 (4)
      • Re: Oh...yes! - Tnuctipun 15:35:40 02/15/05 (3)
        • Re: Oh...yes! - manualblock 16:33:13 02/15/05 (2)
          • Re: Oh...yes! - Damir 17:17:19 02/15/05 (1)
            • Re: Oh...yes! - manualblock 19:01:03 02/15/05 (0)