• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6V6 line preamp

very nice George,

and as Salas said, the comparison with the 26 line will be very interesting ....

mine is still in my main system and sounds wonderful,
at sometime I tried tube rectification, kept it for a couple of days but didnt see any audible difference, so back to ss ....

I was thinkng at easter time to spend some time to enclose it in a nice wooden box and use a better pot, but maybe I have to try choke load first ...
 
Fukushima?
Vgeorge, I want th elow down on your Speakers. I have some Altec 416's and 288's sitting here waiting on boxes. I was going to put the 416's in a large Ml-TWQT, showing pretty flat response down to 35, with nic slow taper. I am afraid I dont have the rrom for true bass horns like yours. The 18's look like they are from AE.
 
Last edited:
diyAudio Chief Moderator
Joined 2002
Paid Member
Salas & George:
Are those big white R for the CCS setting really required? Isn't the Pd quite low for 0.45A? Or did you chose them mainly because easily available in low ohm values?

In my build where they are standing near the bottom cover and the 317 sink they get hot and I did not trust 2W. In George's that the box has height and the 317s dissipate at an angle on a large plate maybe 2W they would suffice. After long time some of my tubes tended to give more heater emission and I adjusted them to 20Ω//3.3Ω finally. So even my happier tubes don't overheat. Thermals and voltages are to be checked and adjusted if necessary in individual builds of course. Even another LM317 brand can have a bit different Vref etc.