New TMB w/reverb Build

[JMPGuitars]

You're connecting ground to your input jack, not your output jack. This is from the image you sent me

No. I'm not. That pic is from a couple days ago. Then, yes I did, but you directed me to use the ground on the output jack today, which I did for everyone of those last screenshots

Ok, cool. Measure the resistance of the resistor on the input jack. It should be 1M.

[foreverstrung]

Measure the resistance of the resistor on the input jack. It should be 1M.

Yes. 1.003 M resistance

[JMPGuitars]

Ok then. I have no idea what you've got going on at your input jack that you can't probe there. It looks like it's grounded out. But if you probe at V1P2, it looks normal, correct? V2P2 is the only one that really looks normal.

Hit your Measure button and get us some info on there. RMS, pk to pk, etc.

[foreverstrung]

It looks like it's grounded out. But if you probe at V1P2, it looks normal, correct?

No. It does not look good. It looks the same as directly at the input jack.

V2P2 is the only one that really looks normal.

Yes. That is correct

I have no idea what you've got going on at your input jack that you can't probe there. It looks like it's grounded out.

Agreed. IDK what's up with this input jack. I've redone it now totally 3 times. All new components everytime. This appears to be biggest hurdle for me getting this thing dialed in.

Hit your Measure button and get us some info on there. RMS, pk to pk, etc.

Please clarify what your asking me here. I understand hitting the measure and getting a screen shot. Just what of please.

[JMPGuitars]

Agreed. IDK what's up with this input jack. I've redone it now totally 3 times. All new components everytime. This appears to be biggest hurdle for me getting this thing dialed in.

Post a photo of your input jack from multiple angles. Remove it from the chassis first so it can be seen clearly. Then reinstall it, and take some photos where it can be seen, hopefully also with the wire to ground.

I doubt this input jack thing is related to your reverb thing, but we'll see what happens as we move through the circuit.

Also make sure all your pots are tightly fastened to the chassis.

[foreverstrung]

IMG_0763.jpg

IMG_0764.jpg

IMG_0765.jpg

IMG_0767.jpg

IMG_0768.jpg

IMG_0770 Small.jpeg

IMG_0771 Small.jpeg

[foreverstrung]

That's about as good as I can get these pics. Open to suggestions for better pic taking and posting

Hit your Measure button and get us some info on there. RMS, pk to pk, etc.

Please clarify what your asking me here. I understand hitting the measure and getting a screen shot. What and where would you like me to get screen shots with measurements?
Thx

[foreverstrung]

These pics might be better. Shows ground wires in the background

pic1.jpeg

pic2.jpeg

IMG_0770.jpeg

[JMPGuitars]

That's about as good as I can get these pics. Open to suggestions for better pic taking and posting

Hit your Measure button and get us some info on there. RMS, pk to pk, etc.

Please clarify what your asking me here. I understand hitting the measure and getting a screen shot. What and where would you like me to get screen shots with measurements?
Thx

You press the Print button to make screenshots. The Measure button adds information to the screen. To a look at this clip for an example of what I mean: https://youtu.be/HI7DGjgl2tw?t=103

When you press the Measure button, select the following (and make sure you're selecting it for your active channel): Pk-Pk, Ampl, RMS, Mean. If trying by my description doesn't work, please refer to the instruction manual.

Try removing V1, and probing at the jack again. Make sure the signal generator is active. Try 300mA amplitude on the generator. The amp doesn't need to be on for this jack test.

Thanks,
Josh

[foreverstrung]

You press the Print button to make screenshots. The Measure button adds information to the screen. To a look at this clip for an example of what I mean: https://youtu.be/HI7DGjgl2tw?t=103

Yes. I understand this. My question is, where am I "probing" when I hit the measure button?

When you press the Measure button, select the following (and make sure you're selecting it for your active channel): Pk-Pk, Ampl, RMS, Mean. If trying by my description doesn't work, please refer to the instruction manual.

At every one of the 7 screenshots/points I posted earlier or just the input jack?

[foreverstrung]

OK. So here's a couple scope screenshots. Both have the V1 tube removed. Probe ground is on the output jack busbar/ground. (not input jack). The amp is off. I set the audio generator to 300mV. (I switched to #1 port, probe is set to 10x, not 1x)

SDS00029.png

Here is the measurement page

SDS00030.png

Should I post screenshots of the measurements of all the points we've gone through tonight?

[JMPGuitars]

OK. So here's a couple scope screenshots. Both have the V1 tube removed. Probe ground is on the output jack busbar/ground. (not input jack). The amp is off. I set the audio generator to 300mV. (I switched to #1 port, probe is set to 10x, not 1x)
SDS00029.png
Here is the measurement page
SDS00030.png
Should I post screenshots of the measurements of all the points we've gone through tonight?

No, let's focus on the jack first. Also, change your Measure settings so it shows just the ones I mentioned at the bottom. You need to hit the back button after pressing autoset for it to show everything correctly.

I wonder if there's something wonky with your shielded input wire. Try raising it off the chassis, and see if that changes anything. If not, disconnect it from the terminal strip, and connect the probe to it while floating.

[foreverstrung]

OK. Power is still off. V1 is still removed. Probe is in the exact same points. Audio gen is set just as it was, so is the scope, but I'm not even getting close to the same reading on the scope

SDS00033.png

I specifically chose PK-PK, Ampl, Mean and RMS in the measurement page. This scope reading as I just described above is wonky, active. I took 2 screenshots of the measurements as they were changing quickly as this reading was active

SDS00031.png

SDS00032.png

I hope I'm being thorough. I'm doing my best to post the info as I get it as accurately as possible. I don't want to waste anyones time.
I moved the shielding wire. No change. I disconnected the terminal strip with no change at all.

[JMPGuitars]

Post high resolution photos of your build. Also post photos of your testing setup with the amp off, but the scope and signal generator active. Post a photo of the signal generator screen as well.

[foreverstrung]

OK, so here's a pic of the signal generator. Plugged into and on channel 2

today1.jpg

This is the wave pattern on the scope

today2.jpg

And then this is the set up. Probe ground is on input jack busbar ground. Probe itself is on the input jack. (I get the exact wave pattern at the shielded wire @ the terminal strip, (Connected and disconnected from chassis. Same both ways). In the background we can see the AWG and scope.

today3.jpg

[foreverstrung]

So I had to step away for a couple days and let this stuff go. Settle down a bit. So I'm going to "ease" back into it.
One thing to note, the input jack appears to have grounded out on the chassis and this caused a ground loop which was throwing my scope off.
I'm going to go through now and the next day or 2 and meticulously clean up everything and run it through again.
Temporarily removing the FX stuff so that I've got better access to everything.

ground loop.png

[foreverstrung]

Back on page 14 of this thread Josh, you've got screenshots of an amp on your bench. One of the screenshots is of "PI P1 (anode)". Where exactly is this for me to probe on my build? I assumed it was the phase inverter, V4, pin 1. I'd like to get this cleared up as this is just one side of that tube and is at about 225v.
I've cleaned up much of this amp and tho my scope readings aren't as clean as the ones you've posted, I'm happy with them up to the point noted above. I'm happy because the sine waves are relatively clean and I'm keeping the 1 kHz signal
The points I've probed are. AWG, Input, V2P2, .047-56, Treble P2, Volume P2. (up to here, everything is good except for some background noise. I'll post pics of screen shots when I get past the next/last 2 positions).....So the PI P2 anode I need clarification and last, but no way the least is the output. I'm getting a poor reading and not nearly enough juice going out to move the speaker. I went through and checked all my voltages and there all still spot on.
I've got a few more areas I'd like to clean up before testing with the scope again.
So another quest for advice.
I've got a solder sucker and it does ok when I'd like to clean up a joint to resolder, but the wick braid is probably better right? Either way, once I remove the old solder, any recommendations to prep before applying new solder?
TIA

[JMPGuitars]

Back on page 14 of this thread Josh, you've got screenshots of an amp on your bench. One of the screenshots is of "PI P1 (anode)". Where exactly is this for me to probe on my build? I assumed it was the phase inverter, V4, pin 1. I'd like to get this cleared up as this is just one side of that tube and is at about 225v.
I've cleaned up much of this amp and tho my scope readings aren't as clean as the ones you've posted, I'm happy with them up to the point noted above. I'm happy because the sine waves are relatively clean and I'm keeping the 1 kHz signal
The points I've probed are. AWG, Input, V2P2, .047-56, Treble P2, Volume P2. (up to here, everything is good except for some background noise. I'll post pics of screen shots when I get past the next/last 2 positions).....So the PI P2 anode I need clarification and last, but no way the least is the output. I'm getting a poor reading and not nearly enough juice going out to move the speaker. I went through and checked all my voltages and there all still spot on.
I've got a few more areas I'd like to clean up before testing with the scope again.
So another quest for advice.
I've got a solder sucker and it does ok when I'd like to clean up a joint to resolder, but the wick braid is probably better right? Either way, once I remove the old solder, any recommendations to prep before applying new solder?
TIA

Correct, PI P1 is V4 Pin 1. You said both P1 and P2, P1 is plate (anode) P2 is grid. Scope P1 of V4. That's the main signal path. P6 of V4 is the signal that will come from the reverb, but scoping reverb is goofy anyway, because it's reverb.

Try setting your bandwidth limit to 20M (channel button, look for options). If you haven't already done that, then it might reduce the noise.

I use the desoldering gun on my soldering station. I don't have the patience for the other stuff. If it's a good braid, it might work better. To clean stuff, desolder as well as possible, and then use a coarse brush to try and clean further. You can use a tiny amount of solder to clean as well, but that's tricky.

I'm glad to hear you're making progress!

[foreverstrung]

So hopefully this thread ends with a happy ending. LOL. I really got tired of dickin around and not getting anywhere with the idiosyncrasies I was finding with the scope. At one time the amp was putting out good sound but I had the reverb not performing. At all. The more I dicked with it, the better it did NOT get. Just seemed like more obsticles.So I've upgraded many of my tools and enough parts for the next build, and then just pretty much took this thing apart. De-wired and de-soldered the heaters and pots and all wires to the PCB board. Now I'm putting it all back together. I watched all the soldering videos recommended, again, plus many more, from the same outfit, that don't really apply.
One thing I did diff is that the reverb rca jacks I had installed with a washer on each side of the chassis as the predrilled holes were way too big for the rca jacks themselves. To get rid of any potential/probable continuity issues, I drilled 2 hole just next to these at the right diameter that rca jacks anchor directly on the chassis itself. Figured it can't hurt.
I'm also doing my best to get better solder connections.
Anyways, that's where I'm at with this build right now. I'm looking fwd to building the cabinet as I've got all the components, but I just can't go there till this amp is kickin.

[JMPGuitars]

One thing I did diff is that the reverb rca jacks I had installed with a washer on each side of the chassis as the predrilled holes were way too big for the rca jacks themselves. To get rid of any potential/probable continuity issues, I drilled 2 hole just next to these at the right diameter that rca jacks anchor directly on the chassis itself. Figured it can't hurt.
I'm also doing my best to get better solder connections.
Anyways, that's where I'm at with this build right now. I'm looking fwd to building the cabinet as I've got all the components, but I just can't go there till this amp is kickin.

Hmmm, I sent you Switchcraft RCA jacks thinking they'd be easier to solder. These are the ones I normally use: https://www.amplifiedparts.com/products ... old-plated - but if you get those, make sure they're tight and you use some kind of loctite. The solder cups are a little tricky at first, so get extras if you go that route.