Express Problems Pictures

[ampmike]

Im on it Thanks Man,Ill report progress on Sun Morning,Mikey

[ampmike]

Ok,I took my time and got these results
No tubes in standby V1&V2&V3 Pins 1&6 22.75 average
V4 & V5 Pins 3 190 to 200
Both switches on no tubes V4 & V5 417dc
Filter caps Top ones about 21.50
Bottom ones 168 417 417
Hope Im ready for tubes,Wait to here from you guys,I will post new pics,Mikey Also Bias is -35

[ampgeek]

Hey Mike,
Leaving the tubes out, hit the standby switch to bring high voltage out to the rest of the circuit and report back on the tube pin readings.
Cheers,
Dave O.

[ampmike]

Hey Dave Thanx,Do you want the sames pins and sockets?
Preamps1&6 power pins 3 and 5 ect.? Mikey

[ampgeek]

My pleasure mate!

At the risk of appearing anal retentive, I suggest going here:

https://tubeamparchive.com/viewtopic.php?t=5691&start=0

Scroll down a couple of clicks and download/print out the Express Voltage Chart Excel file. Print out a couple of copies of the blank sheet and one of the already filled in sheet and study it will looking at your build. The idea being to recognize what you will be measuring and where you need to "probe" (VERY carefully!) to measure it.

Plug the amp (without tubes installed) into your light bulb limiter, hit the power switch, hit the standby switch and fill in, completely, one of the blank sheets.

Sure...there will be a handfull of zero values...but...the methodical "practice" of doing this is invaluable. Not to mention obtaining a nice, without-tube baseline data set that you can always refer to at a later date.

Not sure how best to share that data with us here. If you have a scanner, whip up a pdf or jpeg or gif or...other(?) scan of your hand collected data and post it in this thread. Or....save the Excel file that you downloaded as "Mikey's Express" and fill in a blank work sheet with your collected data and post the Excel file up here for review.

The really important thing is to provide all the good folks here with as complete a "picture" as possible of the amp voltages in one, easy to digest format. That will make troubleshooting/evaluation a breeze.

If, after that, all appears well...plug the tubes in and repeat the exact same process.

Good luck,
Dave O.

[PlinytheWelder]

Doing the voltage chart is how I found that I put a 470K resistor in the PI tail instead of a 470. Stuff like that is easy to do.......

[WhopperPlate]

The really important thing is to provide all the good folks here with as complete a "picture" as possible of the amp voltages in one, easy to digest format. That will make troubleshooting/evaluation a breeze.

+1, Just like I told you Mikey.

[Big Jim]

Good luck with your testing Mikey! Sounds like you are back on the right track!
Jim

[ampmike]

OK,Guys,Here we go,
Amp on standby on,
V1 p1=27.25 p2=.002 p3=000 p6=021.80 p7=0 p8=0 heaters=3.3
V2 pi=27.25 p2=.000 p3=0 p6=.002 p7=.002 p8= 0 heaters 3.3
V3 p1=25.33 p2=16.13 p3=.193 p6=26.47 p7= .247 p8= .201 heaters 3.3
V4 pi=0 p3=410 p4=413 p5=-35 p6=413 8=0 heaters 3.3
V5 p1=0 p3=4140 p4=412 p5=-35 p6=413 p8=0 heaters 3.3AC
The pos ends of the mallorys are the 20uf"s are 23.08
The pos ends of the 40uf"s are all about 406
As soon as I can get one of my kids up I will post new better pics,Thanx guys I really appreciate all your help and support ,Mikey

[ChrisM]

Looks like the dropping string is seriously messed up. Your plate voltages are super low.

[ampmike]

Hey Chris,Does it sound like I wired somthing wrong or I fried something,Mikey You know the longer I leave it on some of the voltages get higher,What could I recheck pin wise to see if it is any better,Thanx ManV2 p
Update,I just found a jumber missing .

[ampgeek]

Hey Mike,
Does "standby on" mean the amp is in standby mode?

If so, take it out of standby and check the same pins again.

If not, measure the voltage across the standby switch.

Cheers,
Dave O.

[ampgeek]

Ooops...If all of the 40 uf caps have ~400 V then the standby switch must be closed.

If all of the 20 uf are at low voltage then there is something up with the two 9.1K dropping resistors or the wiring to/from that network.

Measure voltage to ground at each end of each resistor and let us know what you get.

Dave O.

[ampmike]

Ok I measured with both switches ON,Does that help? Thanx Mikey

[ampmike]

I just found a problem the big cement resister does not have a lead to the last dropping resister,Thank Man Hey Dave now all the mallorys are hot,Up around the 400to 410,So you were right I missed a jumper to the big cement resister,OK this is getting exciting,We have found several mistakes today,You guys are awsome!! Mikey