Cant figure this out - asking for help

[dogears]

Hi Mat,

That is a step in the right direction, but my voltages are no more than 10v apart. Also, use a 47pf snubber.

Lastly, you definately want .02uf grid couplers. That is what is in all the amps.

[mat]

Hi Mat,

That is a step in the right direction, but my voltages are no more than 10v apart. Also, use a 47pf snubber.

Lastly, you definately want .02uf grid couplers. That is what is in all the amps.

I wonder what might cause such a big difference on the voltages

47pF snubber going in. Aready have the .02 couplers in there. I'll check the voltages tomorrow with other tubes also.

If I have time tomorrow I'll make a clip to demostrate the sound problem.

[dogears]

Hey Mat,

How did your other 12AX7 tubes measure in there??

Hi Mat,

That is a step in the right direction, but my voltages are no more than 10v apart. Also, use a 47pf snubber.

Lastly, you definately want .02uf grid couplers. That is what is in all the amps.

I wonder what might cause such a big difference on the voltages

47pF snubber going in. Aready have the .02 couplers in there. I'll check the voltages tomorrow with other tubes also.

If I have time tomorrow I'll make a clip to demostrate the sound problem.

[heisthl]

look at the bottom of the tube socket carefully and make sure it grabs all the pins also look at the 2 heaters in the tube and make sure both are lit equally - you may have a problem with the 4,5 heater connection.

[mat]

look at the bottom of the tube socket carefully and make sure it grabs all the pins also look at the 2 heaters in the tube and make sure both are lit equally - you may have a problem with the 4,5 heater connection.

heisthl, thanks for the tip. I will check that and the new tube tomorrow (folks are sleeping).

[heisthl]

I was fighting this exact problem today and it was the tube socket(brand new chinese porcelain) THe symptoms were low plate voltage(219 and 231) high cathode voltage (47) no matter what tube I used. Heating the solder side of the pins while pressing down improved the readings somewhat. I also noticed noise when I tapped the tube. After I replaced the socket all was well. There were no visual clues.

[mat]

I was fighting this exact problem today and it was the tube socket(brand new chinese porcelain) THe symptoms were low plate voltage(219 and 231) high cathode voltage (47) no matter what tube I used. Heating the solder side of the pins while pressing down improved the readings somewhat. I also noticed noise when I tapped the tube. After I replaced the socket all was well. There were no visual clues.

I think I'll change the PI tube socket just to be sure. I didn't notice visually a problem. I have Russian nos sockets in my amp.

With JJECC83S on PI the plates gave 256,241. Is that good enough ?

The sound is somewhat better but as I mentioned earlier when striking the string at 'normal' pressure the sound is harsh.

I made this 11,5 minute long clip while tweaking the guitar volume, picking pressure, pu selector, OD switch. If someone listens it, feedback very welcome ! (Sorry for the clipping on clean section)

Recording settings:

Ibanez semihollow-Duncan '59s-amp(alesis microverb4 on d-lator loop)-Celestion 1265 Heritage-shure57-SM proaudio TB202 micpre-Audiophile2496-Cubase(no effects or proseccing)

Amp:
normal input
pre volume 12:00
bright off
mid off
Rock/Jazz =Rock
(treble 12:00)
(middle 12:00)
(bass 9:00)
drive 14:00
drive master 8:00 (loud!?)
clean master 8:30
presence 11:00
PAB on
D-lator send 11:00 (audio taper)
D-lator return 11:00 (audio taper)

The recorded sound is tad softer than the amp in person. The cabinet+speaker works great with my nonHRM.

The very long clip:

http://media.putfile.com/hrmnoodling