TSE B+

With the Edcor transformer I used, my B+ was on the high side for a #45 tube, which has a data sheet max of 300V, but Tubelab and others run it higher.  Seems like you can run up to around 320-330, and maybe a little higher than that.  I ran up to 350V while testing, but not for long periods of time.

I have a variac, which lets me vary the input voltage, so I can feed the amp any voltage from 0-160VAC.  It let me dial down the B+ so it was never too high.

Initially I tried a 10uf cap at C5.  C5 sets B+.  

I lowered C5 to 2uf.

With the GZ30, B+ is about 310V.

Found a Mullard CV2748 / GZ30 / 5Z4GT for a somewhat reasonable price.

GZ30 type tube has a higher voltage drop than the 5V4G but I've been using (and so more than a gz34).  Its drop is comparable to a 5y3.  But its a slow turn on tube.  I don't know why it doesn't get more love lol.

GZ30 is only rated for 350 volts and 125 mA, so maybe that's why, good for a 45 but low for other DHT's.