I'm Building an Amp with a 6X5GT PS. It has 114v at Pins 3 & 5, which is Right, and it's a CLCRC Supply...But it has -.8v at Pin 8...I've tried 3 other Rectifiers, but they all show -.8v at Pin 8....Are my Pin-Outs Wrong??...The Heaters Glow, so at least they're Pinned Right???...
We need a schematic as we don't know the specific amp you have built.
_____________________________________________________Rick....
_____________________________________________________Rick....
between pin 8 and where exactly? If Pin 8 is at -0.8v, and your other test point is connected to the signal ground elsewhere in the circuit, the voltmeter is telling you you have a resistance between the rectifier cathode and the signal ground...
Your pin outs are correct. Pin 8 is the cathode and you should have around +150VDC unloaded with respect to DC return/ground. Either all 3 tubes have an open cathode connection, which is unlikely, or your tube socket isn't making a connection at pin 8. Check that very carefully.
Is this a full wave with a center tapped transformer?
Is this a full wave with a center tapped transformer?
Last edited:
ok - so now you have a 0.8v drop (or difference) between the AC safety earth and the DC signal earth. Is there a resistor or diode in that path? Or have you direct-connected the two earths?
. What hollowstate said...
would a dead short to earth on Pin 8 do this too? ie load the rectifier so that voltage was pulled close to zero?
Oh Well, Live and Learn...It would seem that I've totally Screwed the Poodle on this project...I tried to do the Back to Back 12.6v CT RS Transformer Trick..But I only have 114v between Pins 3 & 5.....Nothing between either of those and Ground...It really looks Nice & Glows Pretty though...
oooookay, think I may have it. Is the output of your second transformer centre-tapped? ie are there THREE wires from the secondary, or two...
Just add a pair of 1N4007s or other SS rectifiers to make a full-wave bridge. If your transformer has no center-tap, that's your only choice.
yep - what Tom said. Look for a diagram of a hybrid rectifier using a tube and two semiconductor diodes.
Bas...You Are The Man!!! All it took was 2 Little Diodes to Ground and now I have 134.7V B+...ThankYou! ThankYou!...And, I Now also have a Working 6DJ8 Phono Amp...
I have a Thread on this Amp that I'll update after Spinning some Vinyl Today..
I have a Thread on this Amp that I'll update after Spinning some Vinyl Today..
- Status
- Not open for further replies.