Input to the TMB documentation

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jhguitarlab
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Input to the TMB documentation

Post by jhguitarlab »

Stuff I think may help with the TMB documentation (after my night on the bench).
Regarding the various layout drawings of Richie’s TMB and the schematic that was original posted.

Norm’s layout.
The OT primary at V5 needs to be changed from pin 8 to pin 7.
If you wire it the way this is currently drawn the normal channel Vol knob will control the TMB channel volume. The TMB Vol knob will control the normal volume.
Conclusion: Reverse V1 pin 2 and pin 7 and it works.

Richie’s drawing showing of the TMB layout changes shows input I at pin 2 and input II at pin 7 this way and it works.

The schematic:
This shows V1 pin 2 and 7 wired as Norm’s layout is drawn but it also shows V1 pin 1 and 6 reversed to follow it. In effect the schematic also shows Richie/Norm’s V2 pins 2 and 7 reversed to follow this input assignment.
Conclusion: It’s hard to say the schematic is really wrong regarding this as both ways do work.
What does appear incorrect on the schematic is that V2 and V3 are mislabeled so the tube order would change. If these labels are switched “Bob’s Your Uncleâ€
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EBE
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Post by EBE »

I think the intent of the drawing I did was to keep the number of wires that cross to a minimum thus the change in V2/V3. I have corrected the OT feed to V5. I wish Richie would jump in and make a comment on some of the other value changes like the 470K to 220K. I have my board built for this one but I need a set of trannies to complete the build so I have not heard it yet.

JH,

I can redo my drawing to apply the changes you stated in your other thread and post if you like.

Norm
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jhguitarlab
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Post by jhguitarlab »

Thanks Norm. Actually just switching the inputs V1 2&7 will make it right. Your layout is easy to follow, mine has so much wiring and components included it gets pretty busy.
Not sure about the value changes - might be just a matter of tweaking to taste. Aside from my noise problem I think I do like the values I have but I'll have to get to know it for awhile to decide. It seems to have plenty of low end and nice thick mid/top. Can't wait to quiet it down.
JH
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jhguitarlab
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Post by jhguitarlab »

BTW Norm.
It looks like Richies mark up does have the 470k vs. the 220k (he sent it yesterday).
He has a 250pF treble cap and a 47k. You have a 220pF and a 56K, (I have a 500pF and a 56k). The rest looks like what you have.
Jersey-aaron changed some cathode bypass values with good results as a preference tweak from Richies.

We're throwing a lot of stuff at Richie so I think it's like drinking from a fire hose for him right now.

He always responds though.
Thanks Richie

JH
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EBE
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Post by EBE »

JH/Richie,

How about this one?
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