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Hi guys,

I have finished my TC15 (red board) build and i have two questions about the master volume and cut wiring.

1. Currently the cut control only seems to be active when the master volume is out of the circuit, is this correct? i've check it
over serval times and it is per the layout. Is it possible to have the cut active with both the master volume in and out?

2. Is i'd like to reverse the switch action so that the pulling the switch out removes the master volume and the switch down engages it.

Thanks!
Ben

1. Cut works with and without the MV engaged. Refer to the layout again?

2. Reverse the outside side connections.

If your switch has 6 pins like

1 2
3 4
5 6

and the MV uses pins 2 and 4. Move the wire from pin 2 to pin 6. Done!

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Yeah, wire reveral happens but it should work as kurtlives says.

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

Hi Guys,

Thanks for the help!

I have attached a photo of my master volume build and the layout i'm following. In this arrangement the cut does not work with the master volume engaged (pot pulled). it does work with with out (pot down).

Am i making a obvious mistake here? i've checked it over and over looks correct to me!

I'm not looking at my build right now but going from memory.

MV uses pins 2 and 4 if I recall. So if your switch is layed out like this:

1 2
3 4
5 6

You have pins 1 and 2 bridged.

I could be completely off base here, but I don't have pins 1 & 2 connected together and the MV works fine.

Hope that helps and good luck!

Yes, I have pins 1 & 2 bridged, it looks like it's mean to be that way on they layout. You recon it should just be pin 2?

Looks fine

Have you confirmed no broken wires with a DMM set to continuity test function? While at I'd verify the switch is working and the pots measure ok.

Bridging pins 1 and 2 won't make a difference.

Try reflowing your joints, especially that bridge between 1 and 2. I suspect your switch may be bad though.

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I haven't played with it much but I think my cut is working with MV on or off and I don't have 1 and 2 bridged.
Please note, I am at work and can't verify.

EDIT: I just read Kurtlives follow up post.....I would definately be listening to him! I'm a newcomer to the amp building world and most of this is Greek to me! But I am learning!

pins 1 & 2 aren't bridged, but as kurtlives says, it wont matter.

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

Thanks, so much guys.

I have re flowed the solder on all the joints and they are all getting continuity. The cut control is still not working with the master volume engaged. Broken switch?

Just throwing things at the wall but the first thing I'd do is just unmount the pots from the chassis and check without the pots touching chassis. Next I'd take that blue jumper and get it hooked to where the orange wire from the switch part of the pot attaches right at the pot terminal. That would make a temporary switch bypass (as if knob MV was engaged all the time) to see if it is switch.

I'm not sure if it matters if the yellow and blue going to the 220k resistors makes a difference which ones they go to but it wouldn't take much to switch the yellow and blue wires at the pots around just to see. Someone jump in if this is bad!

I don't know how to check the cap jumping from MV to Cut pot but basically there is the two wires going to the board to isolate the circuit. Other than that the whole Master circuit contains a 250K Liner cut pot, a 1M MV pot, a switch and a cap. If I knew how to test the cap I could probably figure out how to test each component individually as my chassis is still open on the bench and everything works fine!

If you want to, you can disconnect all leads from the switch and check continuity . There are two sets of poles so if one set is for some reason bad, use the other side. Look at the schematic and you'll see how this is designed to work and see if you can sort it out for the schematic as well. Sometimes that sorts out a wiring problem you overlook.
The cut is just across C9 and C19 and tied to the switch for convenience only.

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

Thanks again for all your help guys!

I've tried everything, i've ordered a new pot as it just seems to be faulty.

Thanks!

Does anyone know of a supplier in the UK to obtain a 1m audio pot with pull switch? I have been looking at looking and can't fine one. Or in Europe for the states?

Thanks
Ben

Try a guitar pot.
Can't see that a switch is faulty, and there a two poles to try, so one is a back-up! You can try it too.

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

Hi Stephen,

I don't quite understand your last post. Could you explain again?

I have tried making swapping the pot action over to see if the pot is faulty. wired as the layout, master volume pot in the down position (no MV in the signal) cut control works fine. Pot up (MV in circuit) cut control doesn't work) . I swapped the pots action over. Pot in down position (MV in circuit) cut control doesn't work. Pot in up position (MV out of circuit) cut control works.

I'm really stumped on this. Can some one help me with this? BTW I have reflowed all joints.

Thanks,
Ben

Ok, let me take a look at this. Go back to the schematic, the cut is always in the circuit. It is across C9 and C19. So, just to make it work, check that the wires from those two .022uf caps go direct to the cut pot. Trace the circuit from there.

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

Thanks Stephen,

OK I have followed you instructions. All appears to be connected correctly. See Pics.

C9 is connected to pin 3 of the cut pot.
C19 is bridged across pins 1 & 3 before connecting to the pin 2 of the MV

Pin 1 of MV is also connected to pin 6 of the MV switch because i wanted to reverse the switch action (cut problem either way).

Any ideas?

Anyone?

The only thing I can think of is maybe one of the wires is broken internally.
Can you use a DMM and check the wires using the continuity function?

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