I love the 5e3. Just not mine! Please help.

[JohnRose81]

Here is a video of the amp being played -

[JohnRose81]

You're so smart. Wall outlet on the bottom wouldn't spit a reading. Just bounced around. Top one gave me 123 ac volts. Plugged amp in that one, now I get 123 ac volts through the fuse. Do that's nice. Still have medium volume and little bass. I should make a video.

[g1]

Where did you put your probes when you checked the wall outlet?
Try this: black probe to round pin, red probe to small slot, should read 120VAC. Then black probe to round pin, red probe to larger slot, should read around 0VAC. If you get other readings, the problem is in the house wiring, not the amp.

[JohnRose81]

I checked the wall outlet and it's 120. So it must be my grounds. I may have messed up on my grounds. I wanted it to be secure since I'm afraid of shocking myself. So I put ring wire connectors at the ends of my grounds. I then drilled holes in my chassis and bolted down those wires with screws made for grounding. Some I doubled up per drilled hole. So there are two wires going to a hole. I also may not have put the ring wire connectors on correctly. You can see the pics (should be visible).

[g1]

Wired for 2 prong and not 3? And the 70v AC to the fuse isn't correct? And what's the difference between 2 and 3 prong wiring. I did it just like the schematic that's posted at the top.

From the pictures and the schematic, you are wired for 3 prong. So either your AC cord is bad, or your house wiring does not have the 3rd prong safety ground connected.
With the amp unplugged, measure resistance from the round pin on the AC plug to chassis. If it measures around 0 ohms, the amp is good and the problem is in your house wiring.
This is a bit of a sidetrack issue here, it does not affect the sound problem with the amp, it only explains why you are measuring 70V on the fuse holder instead of 120V. It is strictly a safety issue. If the AC cord measures ok, the house wiring issue is something to talk to an electrician about.

[potatofarmer]

Have you verified the input jacks are wired correctly? Check post #14 in this thread: http://music-electronics-forum.com/t12667/#post99573

Usually a good suspect when one channel isn't working.

[JohnRose81]

[JohnRose81]

Wired for 2 prong and not 3? And the 70v AC to the fuse isn't correct? And what's the difference between 2 and 3 prong wiring. I did it just like the schematic that's posted at the top. Hmm, I'll have to find a 3 prong schematic. Here are some pics...

[g1]

Chuck: post #39 has the new readings with good meter and tubes installed.
JohnRose81: The weird reading on the fuse holder seems to be what eschertron described, your outlet is not properly grounded, or 2 prong wiring rather than 3 prong. So that is not a fault of the amp.

Edit: the power tubes seem to be running quite hot, which should probably be corrected, but I don't think it would account for a huge volume drop.

[Chuck H]

With only the rectifier tube in your voltage should be higher. But how much higher??? Not 210 with tubes in and, what, 430 without? You certainly have some wiring errors. Can you post a few detailed photos of the build? We need to see the wiring details of every circuit. If we can read component values that's even better.

[JohnRose81]

Maybe the fuse is wired backwards or the speaker is. Maybe too many grounds. Maybe not a good ground. Maybe I didn't solder the volume pot well enough to itself. Not sure. Double checked all. Seems good. Maybe I can Skype one of y'all.

[JohnRose81]

The schematic is towards the top of this thread. And yes. Maybe 1/3 volume and reduced bass. Normal channel volume pot is scratchy and cuts off as I roll the volume up and down.

[eschertron]

ALSO!!!! The 5 & 6 pins on the 6V6's is MV NOT V!

Ah! Makes sense now So the pins 5 of the 6V6's are reading in the millivolt scale? That's good!

I'll find a 5E3 schem and look at the PI stage, that's where I suspect the trouble lies. There's been so much about the meter you were using in this thread, it might be of use to review the original situation... please expand on the low volume and lack of bass. Is that the main complaint?

[JohnRose81]

Im not seeing my response post, so here it is again.

All of these readings are DC (the V with the ... under it) EXCEPT for the fuse, light, and black/white wire. I just retested using just DC again, and the numbers are the same. What would you like for me to AC (V~ icon)?

ALSO!!!! The 5 & 6 pins on the 6V6's is MV NOT V!

[eschertron]

I'm glad you have a new meter to use, I think this is getting somewhere now.

Are you on a DC-only scale? That's OK, but important info. I see zero (or thereabouts) on pins 4/5 and 9 of the preamp tubes. If they're working (and they are!), they'd have 6.3vac across the heaters. Or about 3.15vac from the pins to ground.

The 12AY7 looks normal. After that it starts to get weird. The 12AX7 side A (pins 1, 2, 3) shows 1.5v (about right) on the cathode but 2v on the grid. The grid of a properly-operating tube should *never* by more positive than the cathode. Excessive tube current and "red-plating" will occur. Maybe the 2v is an AC signal and there's some parasitic oscillations? This hypothesis, of course, conflicts with the guess above that you're on a DC-only scale. Oh, well.
The other side of the 12AX7 (side B) is probably a cathodyne phase inverter (correct me, please) and while the voltage between the grid and cathode is 'safe' by the above definition, the grid being THAT negative with respect to the cathode is effectively not conducting. Here's a spot to start looking at component values and voltages for the problem (take voltage readings on both sides of each component and mark it on the print). You will be able to find bad components or bad solder joints this way. And...

The plate and cathode voltages for both 6V6's look ballpark, but the grids (pin 5) are both off. If there was actually 120vdc on the grid of one of your power tubes, there would be smoke and noise and generally, mayhem. Re-measure these using both a DC scale and an AC scale if you can manually set them (usually there's a button that allows you to override the auto-select). Good voltages here will help narrow down the focus to the PI section.

last observation: the 70v to ground for the fuse (and from your previous posts, white and black power wires) tells me that your house wiring DOES NOT have the neutral and ground bonded in the distribution panel. Not too much of a thing, but be aware that with devices that only switch on the L1 side of the power wires you will have 70vac live in your device (to ground) even with it switched off. Probably not enough to send you to the hospital, but it'll sure give a tingle! Not to mention that anything over 40v is legally considered too dangerous to work on live without protective gear.