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I double checked all my connections (obviously not too well). Here are the voltages from my tubes:

........................P1.... P2.... P3.... P4.... P5.... P6.... P7.... P8.... P9

V1 (12AX7)....... 136...........1.35................. 136...........1.35

V2 (12AX7)....... 92.6..........0.65................. 302...........95.5

V3 (12AX7)....... 245...........62.4..................257...........62.4

V4 (EL84)..........................6.4...........................356

V5 (EL84)..........................19.8..........................364

V6 (5AR4)..................................................................365

V7 (EF86)..........83.6..........1.52...................114..........1.52

Some of the voltages are waaaaaaaaaayyyyy off. Also, I gave it a little test run and found that I could barely get any clean on it at all and the notes have a decaying quality...almost a fizzle out.

Hopefully someone can give me an idea about where I went wrong. I'll review the wiring etc when I can see straight again. Pretty tired.

Which version do you have?

If you can, post some pictures of the wiring, it should help us try to figure things out.

I have the newest version of the TC15. I have EHX in the preamps and power section. JJ for the rectifier tube and Tungsol Gold for the EF86.

The EF86 Channel sounds ok but the volume crackles alot a la Zvex "crackle ok" which I've read could be the ?coupling cap? Also, the contour switch makes no audible difference at all. As if it's not even part of the circuit. I was confused as to how the contour switch was supposed to be hooked up. Tried to find some pictures but had no luck.

The regular channel sounds pretty good but not very clean at all. The cut knob doesn't do much either. I

My 18 Watt Plexi turned out amazing so I obviously screwed up somewhere along the line on this one.

I plan on giving it the once over again tomorrow, checking and testing connections etc. If that doesn't work I'll post photos.

I haven't built a TC (yet )

Make sure all of the caps have been discharged!

Then, get a clean copy of the layout and start going through it and compare it to your build.

At each point mark off the connection on the layout after you have verified it has been made correctly, this will help you go through the build and not miss anything.

Check the grounds and the polarity of the electrolytic caps, bad/missing solder joints, resistors in the wrong place (I've done this before ) and that you haven't connected anything to the tab on a tag strip that is connected to ground (done this too ).

If I remember right, there is a pretty detailed drawing on the contour switch on the latest layout in the "resources" forum.

Make sure there are no "whiskers" or stray wires or leads from components making connections where they shouldn't be, like on the tube sockets or the contour switch.

Let us know how things are going, check voltages without your tubes in, there should be a voltage chart showing what they should be without the tubes in so you don't lose a tube.

(Do you have a set of known good tubes? i.e. know they work in another amp, it's not unknown for new production tubes to be bad out of the box!)

As jcny suggested, pictures will help. Check all the grounds.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Here are some pics...

Update: resoldered the coupling cap and now the crackle on the volume pot is gone. EF86 channel sounds awesome now but still the contour switch does nothing at all. I checked the connections and everything seems to be ok. Will have to triple check.

The regular channel works fine as well. Cut knob works fine now too (went over some suspected cold solder joints and that seemed to have done the trick). Still not much clean head room - could that have something to do with the voltages on my tubes??? As I mentioned, they seem to be way off.

The other thing is the crunch munch switch - really loud pop every time it is engaged or disengaged. Also when the higher gain is engaged, the fizzing decay of notes returns.

Any help/suggestions would be appreciated. Thanks.

All those contour caps are soldered [bussed] together on the opposite side correct? I cant see. And the lead from the board (pin 6 EF86) connected to there?

You should be able to hear a difference - Fat - Thin.

You're going to get a bit of a pop when switching those In/Out as these make major changes to the circuitry.

There is something wrong in V2 for sure., those voltages are way off. Check the tube, check the components esp the ground to the cathode resistors. What is Pin 6 voltage?

Also, Pin 3 of the EL84 should be the same on both as they are tied together and both go to the cathode bias.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

SHOP TIPS: move all cords out of your way when you are maneuvering in your work space....

It sucks to be me right now....I went into my shop to check on Coco's suggestions and what did I do??? tripped on the speaker cabinet cord which was attached to the TC15 bare head which then yanked it off my desk and onto the concrete floor. Smashed the rectifier tube and one of the matched power tubes and one of the 12AX7's.

My next stop after signing off the Trinity forum is to logon to the Tubestore and make another purchase. Damn....

Oh man, sorry to have caused any pain.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

LOL! Thanks but no worries. I take full responsibility. It's a habit I have developed over a lifetime. I get so focused on the three or four things that I am doing at one time that I completely forget about neat and tidy work areas. I just want to get stuff done...and then stuff like this happens. No matter what I do to stay "organized" if you will, always goes by the wayside when I get into something. I used to get really pissed off when this kind of stuff happened but I deal with it much better now. Luckily I manage to get through more and more projects now without screwing up. Just not this time.

Just ordered new tubes...the saga will continue...

Still waiting for my new tubes. In the meantime I've been reviewing some of the wiring and noticed that on one drawing the 5VAC (yellow/white) from the transformer goes to pin 2 of the rectifier and the 0V (yellow) goes to pin 8. On another drawing the wires are reversed.

Just curious, which one is right? And does it really matter?

I had seen that as well. I went with the big layout option......it worked....
It may catch fire yet!!!!

It looks to me like there isn't much solder in a lot of those eyelets.

I resoldered a lot of those eyelets to fill them up. Gonna double check that as well.

One question I do have about the EF86 and contour switch...Does the wire from PIN6 go directly to the contour switch or through the circuit board. From the drawing, it looks like it goes through the circuit board but not through a circuit of any kind.

Just goes from the circuit board. No circuitry.

The heater 5V & 0V doesn't matter but I updated the TC15 hi voltage layout for consistency sake.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Got my new tubes. Installed them after correcting a connection on V2 (good call coco) as well as running a connection between pin 3 of V4 and V5.

Here are my new voltages...

HVAC 305/305

B+ 407 VDC (JJ)

........................P1.... P2.... P3.... P4.... P5.... P6.... P7.... P8.... P9

V1 (12AX7).......144...........1.25....................142...........1.26

V2 (12AX7).......159...........1.26....................260............160

V3 (12AX7).......225...........60.......................254...........61.3

V4 (EL84)..........................7.3..............................353

V5 (EL84)..........................7.3..............................352

V6 (5AR4).....................................................................362

V7 (EF86)..........82.7..........1.47...................112.............1.49


Sounds pretty awesome. Very loud. Scratchy volume pot on the EF86 channel has returned. Will have to check the continuity of the cap again. The contour switch still does not work. No audible difference in tone shaping.

I confirmed that PIN6 from EF86 does in fact go to the contour switch through the board as indicated on the diagram. No quite sure what to do here.

At least I'm making progress.

I could try taking a few pics again to show the connections.

Yes, if you can take a close up pic of the switch, it has to be simple. The contour does work!

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Yeah, I can assure you, the contour switch is noticeable. It's hard to see your caps in the picture. Can you post something from the other side or face on?

J.

PHOTOS - hot off the press...









I couldn't get great angles but hopefully these help with the diagnosis. I'm going to go over things AGAIN in an attempt to figure things out.

Coco: even without the Cut/Contours, this thing sounds awesome...