New TMB w/reverb Build

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Re: New TMB w/reverb Build

Post by JMPGuitars »

I have a 36W prototype of a Tremolo TMB Xtra on my bench, so I used that for the following comparison. All tests are with the probe ground connected to the output jack ground wire.

Scope direct to AWG:
SDS2504X Plus_PNG_1.png
Input jack (004):
SDS2504X Plus_PNG_2.png
V2P2 (005):
SDS2504X Plus_PNG_3.png
.0047 to 56k and 220uF in tone stack (007):
SDS2504X Plus_PNG_4.png
Treble P2 / Volume P1 (009):
SDS2504X Plus_PNG_5.png
Volume P2 (008):
SDS2504X Plus_PNG_6.png
PI P1 (anode):
SDS2504X Plus_PNG_7.png
Output jack:
SDS2504X Plus_PNG_8.png
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Re: New TMB w/reverb Build

Post by JMPGuitars »

foreverstrung wrote:
Fri 01/06/23 2:10 pm
Also, set your bandwidth limit on the channel you are using to 20M.
How do I do this?
Thx
Anything to do with adjusting a channel, you click the channel button, and look at the options that pop up on the screen. Bandwidth should be one of them. It probably says "BW Limit" - set that to 20M.
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Re: New TMB w/reverb Build

Post by foreverstrung »

IDK what "probe direct to AWG is". Please advise.
I set BW to 20M max
With my MM and amp still off, input jack securely in place, I get 72 ohms resistance at the input jack tip.
I've got the ground on the probe always to the output jack ground bar onl
The following screenshots have all the knobs up to 50% except for Reverb which is at 0
Input
SDS00022.png
V2P2
SDS00023.png
0047 to 56k/220uF @ TS
SDS00024.png
Treb P2/Vol P1
SDS00025.png
Vol P2
SDS00026.png
PI(V4) P1
SDS00027.png
Output
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Re: New TMB w/reverb Build

Post by JMPGuitars »

foreverstrung wrote:
Fri 01/06/23 3:18 pm
IDK what "probe direct to AWG is". Please advise.
I set BW to 20M max
With my MM and amp still off, input jack securely in place, I get 72 ohms resistance at the input jack tip.
I've got the ground on the probe always to the output jack ground bar onl
The following screenshots have all the knobs up to 50% except for Reverb which is at 0
AWG = Arbitrary Waveform Generator. The Signal Generator.

You're connecting ground to your input jack, not your output jack. This is from the image you sent me:
your-input-jack.jpg
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Re: New TMB w/reverb Build

Post by foreverstrung »

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
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Re: New TMB w/reverb Build

Post by JMPGuitars »

foreverstrung wrote:
Fri 01/06/23 4:55 pm
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.
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Re: New TMB w/reverb Build

Post by foreverstrung »

Measure the resistance of the resistor on the input jack. It should be 1M.
Yes. 1.003 M resistance
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Re: New TMB w/reverb Build

Post by 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.
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Re: New TMB w/reverb Build

Post by 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.
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Re: New TMB w/reverb Build

Post by JMPGuitars »

foreverstrung wrote:
Fri 01/06/23 6:56 pm
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.
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Re: New TMB w/reverb Build

Post by foreverstrung »

IMG_0763.jpg
IMG_0764.jpg
IMG_0765.jpg
IMG_0767.jpg
IMG_0768.jpg
IMG_0770 Small.jpeg
IMG_0771 Small.jpeg
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Re: New TMB w/reverb Build

Post by 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
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Re: New TMB w/reverb Build

Post by foreverstrung »

These pics might be better. Shows ground wires in the background
pic1.jpeg
pic2.jpeg
IMG_0770.jpeg
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Re: New TMB w/reverb Build

Post by JMPGuitars »

foreverstrung wrote:
Fri 01/06/23 7:21 pm
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
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Re: New TMB w/reverb Build

Post by 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?
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