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Hi guys! My Tramp arrived a few weeks ago and I'm finally on break for a week so I get to start working on it I made this as kind of a general questions thread to ask my noob questions and just to double check that what I'm doing is right. I'm making progress slowly but surely. My first question is about the indicator LED. Does the long or short lead get attached to the resistor? I'm sure I'll be back with more questions and pics. So thanks in advance

Either or! Since the LED is connected directly to an ac source (heaters) the polarity of the LED is of no consequence.
Having said that if you were to follow the schematic to a "T" you see Stephen has the resistor on the anode side (long lead). This is the usual side for the resistor on an LED. http://www.kpsec.freeuk.com/components/led.htm
Stew

thanks!

I'm back with more questions for you guys. I made some progress and I'm installing the transformers now. The layout says to tie off the brown/white wire coming from the OT. How should I do this? Also, should I twist together the brown/yellow and the brown wires? Looking ahead i see the instructions say not to attach the shielding on the shielded cable. Am I suppose to attach it at only one end then?

off to work on the board, thanks

For the tranny wires,,I put a small piece of heat-shrink over the tips to prevent shorting,then bundle the wires together with a tie-wrap and stow outta the way. The brown/yellow wires can be twisted for the short distance before they separate and go there own ways.
And yes..the shielded cable should only be grounded only at one end .

thanks man, i really appreciate it.


finished the board tonight

hi guys, back with more questions.


When powering up the amp for the first time, should I have a speaker plugged in? In the instructions it says to plug in a speaker after powering up twice, but couldn't that be damaging?

Also, when hooking up a speaker, what gauge wire do you guys use?

Thanks

No need for speakers if you power up the amp without tubes. When you start putting in the tubes it's probably a good idea to have the speakers connected.. you'll be able to hear if there is a problem... but really, with no audio going through the amp there's little chance of hurting anything. You definitely want them speakers hooked up when you crank er' and hit that almighty power cord!
I'm cheap so I use 14 gauge lamp cord for my short speaker wires.
Stew

Thanks stew.

So i finished up the wiring, checked it against the layout and plugged in. The tubes are lighting up, the LED indicator is on but there's no sound. There weren't any pops or smoke so I guess that's good. I'm hoping to get some guidance on what to check/ measure. Another set of eyes to check my wiring would be great too. The only camera I have is on my phone so here are some shots. If you guys need a picture of a specific section let me know. I'm hoping that someone will spot a stupid mistake and that will be the end of it. Thanks in advance.

pictures:

Time to do the required voltage checks. Remember there's some killer voltages present. Then you can compare the readings against the chart Stephen has provided.
One step a lot of guys miss is the links from turret to turret under the board .

Any tips for how measuring should be done? I'm not entirely sure where I should be putting the probes. sorry i'm new

Ok.. First off... BE CAREFUL!! there's 300+ volts in places inside there!!!
All DC voltages are measured with respect to ground. That means you put the negative lead of the voltmeter on a good ground/chassis connection. Then with ONE hand, carefully check the voltages on all pins of the tubes. Be careful not to short two pins together while doing this. If you look at the layout picture you will see voltages associated with various points in the amp.
The filament voltages are measured "across" the filament. This means one lead on one pin and the other on the other pin. NOT with respect to ground. So on the preamp tube (12ax7) you'd measure with a voltmeter set to AC volts on pins 4 and 9.
The old saying is keep one hand behind your back and the other on the plastic part of the meter lead Be careful Dude!

Thanks!

On the first 50uf cap I'm getting 436 VDC. Which I think is correct?
On the 33uf cap I'm getting around 416 VDC.
I'm getting around 345 VDC on the points with the two 220k resistors marked on the layout at 203 and 191.
I'm not getting anything at the joint with the 2k7 resistor, .047uf cap, and the 2uf electrolytic.
From pins 4 to 9 i'm getting 7 ACV.

whats the voltage on EACH of the 33uf caps? Can't see your wiring for V1. Doesn't look like it's drawing any current. Check the wiring for V1 carefully. If it looks ok change the tube in V1.

What's the voltage on pins 3 & 8 in V1?

I'm getting 440 on the first 33uf and 445 on the second with no tubes. I'll check with tubes and pins 3+8 in a few minutes...

...just turned it on again with tubes and i got a weird buzzing sound. No smoke or anything just sort of buzzing. i think from around the first 50uf cap? Not sure though.

here's the best picture i could get of my wiring on the socket. It looks right to me but you never know.

You didn't go and electrocute yourself did you?

not yet

I didn't check the pins. because of the buzzing. I didn't wanna ruin anything. I'll check them now...


ok buzzing has stopped.

430 on the first 33uf cap.
350 on the second.
2 on pin 3
1.85 on pin 8

at the joint with the 2k7 resistor, the .047uf cap and the electrolytic i'm getting 2.3 now.
No reading at the 750 5W where its supposed to be 29.

As i was typing this something sparked near the 6v6 socket..

Need clearer (non cell phone) pics.

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Yeah, sorry about the quality of the pics. I'm trying to get a hold of a camera. My phone has more MP than any camera I own... not sure if this helps but:

Not clear enough.
Need clear pics of the tube sockets and connections around the eyelet board.

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http://pdfelectronics.com