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Hi from Barcelona, Spain.
First of all sorry for my bad english.
A week ago, or so I recieved a TC15 kit and started mounting and soldering. After some initial problems (I changed the 2,2k and the 220k resistors) my voltage measurements are not so bad as initially:

_________1____2____3___4___5___6___7___8___9
V1............121.............1,20..................120.........1,20
V2............160.............1,05..................249..........163
V3............226............58,6...................58,6.........58,6
V4...............................7,13...........................340
V5...............................7,13...........................340
V6........................................................................350
V7.............53.............1,70....................84.........1,70

But I have one question:
before I detected this resistors change, the capacitors were loaded since about 20 hours later. I think this is normal. But now they unload inmediately to 8-9 volts.
I´ve checked everything and cables are ok. There is no comunication between positive side of the capacitors and ground. And I´m still alive, so no cable touches the chassis.
I´ve allways heard that these capacitos keep loaded during hours.
So, what is wrong?
I´ve plugged the guitar in, and channel 2 has sound and channel 1 has a "rithmic" hum. But that´s another story I will look when this capacitors thing is solved.

Thanks very much

Dani

I believe what you are asking is:

Is it unusual for the capacitors to discharge quickly after the amp is turned off?

I hope others with more experience will help on this, but I have found that this is normal.

If I turn the main power switch off and immediately strum the guitar strings, then turn off the standby, I have found that this will discharge the capacitors so I can work on the amp.

Of course you MUST CHECK that the capacitors are completely discharged in a SAFE MANNER before working on the amp.

I hope that this helps

Welcome to the forum. Glad you got the voltages in line now.

The capacitors have a load on them now where before they were simply charged with no way to discharge through a working amp. As jcny said, if you turn off the power only [i.e. not use the stand-by] they will discharge quite quickly otherwise they will take a little longer in a built amp. This technique is explained in the manual as well.

Do be very careful when working on an amp that recently had live voltage on it.

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

Hi
I allways turn first the standby off, then the power. I knew turning the power off some seconds before the standby discharges the capacitors. Even so the capacitors discharge inmediately when turning the stanby off, then the power. That´s why I´m worried. When the amp is working, the capacitors have the high voltage they are expected to have.
Could the capacitors be damaged? How can I check if they are?


Dani

Hi
Today I have tested the amp with a 2 x Celestion V30 cab and some guitars. Chanel 2 sounds terrific. No noises at all, no scatchings and a wonderfull tone. I liked specially the telecaster on it.
But there is one things I will have to check and don´t know how:
Chanel 1 has only a hum, or hiss ( don´t know the difference). There is something like a ground noise that ritmically comes and goes. A guitar plugged in is not to hear. This noise dissapears when the channel volume is turned down. I suppose this makes it easier to detect where the problem is, but I don´t know what checkings to do. I have changed the EF86 and it´s not the tube. Can I dissolder the contour pot and conecti the volume pot directly to the EF86? So I could discard it´s one of those components atached to the contour pot. Don´t know what other things I can do.

Thanks

Dani

P.D.: I have to suppose these instant unloading capacitors are not a problem.

Dani, check you have connectivity from the input to tube.
Recheck your wiring at the EF86 channel.
You can bypass the contour pot with a jumper and test.
Post a picture if you can of that end of the amp and we can look it over.

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

What about the capacitors, unloading so fast. Should I be worried?

Thanks

Dani

Can you also send or post a picture of the power supply end and the EF86 end.

If the caps are discharging instantly (less than 1-2 seconds) when you turn the power off after standby, there may be a hi resistance leak from B+ to ground. To check, turn the amp off and measure the resistance from B+ terminal to ground.

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

Hi
I found comunication from inputs to ground, so I changed the cables that came from inputs to EF86 and finally there is sound in chanel 1. With a bit of ground hum and contour doesn´t work, but I think I´ll be able to work it out.
Here are some picture. If someone finds something strange with these capacitors.
[img][img]http://i157.photobucket.com/albums/t77/BuenaventuraDurruti/TC-154.jpg[/img][/img]
[img][img]http://i157.photobucket.com/albums/t77/BuenaventuraDurruti/TC-152.jpg[/img][/img]
[img][img]http://i157.photobucket.com/albums/t77/BuenaventuraDurruti/TC-153.jpg[/img][/img]
[img][img]http://i157.photobucket.com/albums/t77/BuenaventuraDurruti/TC-151.jpg[/img][/img]

Woo Hoo!!!

What is the resistance from the B+ to ground? It looks OK from what I can see quickly but the nuts are pretty close to the B+. You might want to reverse the nuts and put them on the outside of the chassis and the heads inside the chassis.

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

Hi Stephen.
The tester shows nothing from B+ to ground. Like there´s no comunication at all.

Dani

That's EXACTLY what you want. So, I think you are good to go. Just sort out the contour now.

For any hum, is it only when your guitar is plugged in or not?

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

Hi
I´ve sent a cable directly frompin 3 in the chanel 1 volume pot, to the EF86. The hum presists. This happens even with no guitar plugged in.
I´ve cahnged the audio cable that goes to the volume pot from the board and nothing changes.
Here are some pictures from that area:


[img][img]http://i157.photobucket.com/albums/t77/BuenaventuraDurruti/1.jpg[/img][/img]
[img][img]http://i157.photobucket.com/albums/t77/BuenaventuraDurruti/2.jpg[/img][/img]
[img][img]http://i157.photobucket.com/albums/t77/BuenaventuraDurruti/3.jpg[/img][/img]

It looks like it's wired OK. Try touching up the connections with some heat an a wee bit of solder just to be sure they are well connected.

Also, clean around your parts as there looks to be some splatter.

Double check all the ground connections are made well icluding the one from the two input jacks.

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

Sorry to butt in, I would also check for a short in each coax between signal and ground. Looks like a bit too much heat on the heatshrink tubing...

Joe G

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Some assembly required,
Brain sold separately...

Hi
Here are some measurements from the board. There are some measures in the layout, in small white circles. In the next list I wil write that number, ithat appears in the layout, first, and my reading, in that point, next.
184-215, 253-298, 262-307, 197-250, 601-7 (!!), 200-220, 202-225, 34-23, 50-60, 34-23, 132-163, 1,3-1,04, 110-122, 1,2-1,18, 1,5-1,76,
56-57, 260-305, 90-77.
Let´s see if this could help somehow.
I´ll check the chanel 1 later today.

One little thing more. My contour and impedance switches have, both, 11 positions. I don´t care in the contour switch but in the impedance selector I do. If there was a little mistake and switch to position 4 the amp wouldn´t have speaker conection. To avoid this can I put a jumper from, say, pin 1 to pins 4 to 12? That way the amp would never be without speaker resistance in case of mistake.

Thanks

Dani

In the manual, it tells you how to set the switch to a 3 position switch using the tang washer. See Page 39?

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

I see that high voltage 601 (!!), on my printout. OOPS where did that come from?? Missing decimal I guess.

Should be around 6 - 8 so your voltage is fine.

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

Hi
After some problems, resolved, in channel 1, finally the TC-15 is working and I could try it in a 2x12 (V30) cabinet (by the moment).
Sound is absolutely great. I love both chanels. Specially in the clean range. But dirty, at high volumes, also very nice.
Thank you Stephen for the amp and, specially, for your patience.
Now I´ll build the housing. I´ll post the pictures when posible. Probably in some weeks. I´ll be father TOMORROW. So I guess I won´t have much time in the coming weeks, or months, or years!

Thanks again

Dani

Congratulations on being a Dad! and Good job on Ch. 1.

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