voltages

[EBE]

Has anyone compared their voltages new layout vs old? I just finished a head last night and I have a couple of issuses so I wanted to run the voltages against the voltage table first.

Norm

[Plexi]

Everything should be the same..or ballpark figure depending on the tubes your useing. V3 will have the voltages swapped on the plates,but still should be about the same.. And maybe a slight change in V2 if you use the 47k over the 56K tail.. As in the preamp section etc.. tour resistor values, if they are out of tolerence a little bit will vary slightly on the voltages, more so in the cathode resistor..if your 820 resistor is off a bit,and reads around 1K ..the Plate voltage will go up some on that tube.

But thats about it.. A miswiring run under the board,wrong side hookup or things like that can happen.. just some things that might look for,if you get weird readings.. I just finished a Head.. all works fine squeals or nothing. And used the latest version. Just orderd the tolex for the head.
But finally had time to finish the amp part.

Richie

[EBE]

Well.... I ran the voltages when I got home from work and they look pretty good actually. The AC is 305 off the transformer and the DC is 334 off the rectifier. The voltages on the power tubes are a bit cooler 10.67, 321, 311. The voltage on Pin 1 and pin 6 are reversed on V3. Some of the voltages on V1 and V2 are a bit cooler but not much.

On this amp I ran the B+ on the top of the board with the long run pushed over and under the edge a bit. I used a flying bus wire between the board and pots that ties to a terminal strip by the PT. This makes the grounding pretty easy. Similiar to Richie's but I don't tie it to the chassis at all until it hits the terminal strip.

My sick father-in-law now lives with us so I couldn't fire it up for a real test until I got home today. The amp had a few crackles for a bit at first but then settled down and got pretty quiet.

Issues: The normal channel does not have volume control. Seems like it is turned up to ten, period, no matter what the volume setting. Kind of funny and cool but not practical so back to work on the debugging. Any quick tips on the volume???? Also, this amp seems to break up on the trem channel pretty quick with my Les Paul. My strat sounds better through the trem channel, Les Paul on the the normal.

Norm

[Plexi]

can you shoot us a pic?

"""The normal channel does not have volume control. """
Sounds like the Abnormal channel

Probably just a simple wiring mistake.. not much there on the vol and tone pots.

The voltages do seem just a bit low for the 18.. very slight.. Still should be fine. You might look it over, and see if something is wired wrong..
As you can look at the voltage chart that came off the old site.. they vary.
Can be from recto tube differences and tubes to resistor values off a bit.

Richie

[EBE]

I think I got it. I am missing the ground wire off the volume pot. I was so sure I checked everything. I used used Attilio's and Gabi's layout this time. Attillio's is missing a couple of ground wires. One of the missing grounds comes off of the volume pot. Another is off the 470K/57K tail resisitor. I caught the tail but missed the volume pot ground.

Norm

[Plexi]

Ahhhh your keen eye picked that up.. you are correct, Attillos is missing those.. Gabis looks correct..

Richie

[EBE]

Fixed!

Now I need to tolex the cabinet and make me a 2x12 for this one. I am going to try an eminence v12 combined with an eminence legend 125 for grins. I got both of them on the cheap and figured they would be worth a try.

Norm