12XXX Build 05/2010

[vanhalen5150]

Great strat78, hopefully here in the next few months we can swap spec idea's concerning these 12xxx builds (at least Vanhalen5150, you and me, or anyone else) I wonder how consistant the sound is gonna be from kit to kit, what speakers are being used, tubes, etc.

Vanhalen5150, what is that red looking solder ? Your build looks nice, sure wish I was that far along on mine.

It's just a red sharpie. I checked all my soldering joints for continuity with a multimeter. If they check out, I color them red. I fiqure may as well know if they work before turning the thing on.

Plus it looks pretty.

At this point I have 47.5 hours in. Most is thinking about how to do something the first time. This ain't lego. Taking your time is the key factor.

[vh junkie]

OK, I'll bite! Is that a sniffable cork laying there next to the board?

[vh junkie]

Oh, and I like the way the red looks on the joints, but once the modding bug bites you I would worry about contaminating the solder joints. Another problem with modding is that it is hard to keep things clean. Excess flux tends too build up... things get messy... doesn't look nearly as pretty... I ended up not really caring about being to neat in modding. Will clean things up when I get where I'm going.

As long as the solder joints are shiny they are generally good. You guys that are just starting out, when soldering always try to get iron touching the turret and all wires/leads when heating... don't want things at different temperatures. Let the solder flow towards the heat, don't put it right on the heat at first. Those cool looking rounded tops on the joints happen by tapping the iron at the end as you apply the last of the solder.

Keep in mind that things that are connected to larger pieces of metal (chassis, etc) will take longer to heat and may deform the wire insulation. Consider soldering lugs to wires before attaching the lugs to the chassis.

30 watt iron seems to work for me. While I have only built two kits, I did spend lots of years soldering as a tech.

Good luck, and check all your voltages before putting the tubes in!

[vanhalen5150]

OK, I'll bite! Is that a sniffable cork laying there next to the board?

Good eye Junkie.

Yeah, I checked on the sharpie on the soldering joints as well with a Navy electrical tech. He was sure it wouldn't affect the joints themselves, and I always remove all solder with braid and a solder sucker before adding anything new. It's tough to know exactly how much solder to use with the turrets

what's the best way to clean off the board? Oddly enough, it's easy to see the soldering flux in the close high res pics.

[vanhalen5150]

And, for soldering the bus ground to the back of the pots, higher wattage gun? My iron took forever to heat those man hole covers up.

[vh junkie]

what's the best way to clean off the board? Oddly enough, it's easy to see the soldering flux in the close high res pics.

Yes, and as you do mods you'll get more flux and things will start to look messy.

Really should clean the solder joints and the board with a flux remover. Leaving flux on the joints can cause them to corrode. Some folks use alcohol with a small brush or cotton swab, but that may leave white residue. Chemtronics make an aerosol, with a little brush on the end of the delivery nozzle, called Flux-Off that supposedly requires no cleanup.

What ever you try, probably should do some tests in an inconspicuous area to be sure it doesn't discolor the red swirl board.

And, for soldering the bus ground to the back of the pots, higher wattage gun? My iron took forever to heat those man hole covers up.

I use an iron that switches between 15 and 30 watts. 30 watts is enough for most things here.

Guys, may want to consider using SDMs alternate grounding scheme:
http://home.comcast.net/~jbjdav26/1959/ ... ubbers.JPG
This has buss wire above the pots instead of soldered to the back. This makes it easier to do mods that require replacing the pots with dual or switched pots required for some mods.

[vanhalen5150]

Now you tell me!

Actually I saw that and think its easier and makes more sense to begin with.

[vanhalen5150]

Done. Just need to add fuses. Any comments anyone? Do I need to ground the other side of the inputs even though they are grounded on the other side/top of chasis?

Thanks for the PM on the preamp heater wires Vhjunkie, I moved them a bit as senn from the previous pics. Feel free to elaborate Junkie. If I need to add longer wires, no problem. Whats another hour or so at this point.

[vanhalen5150]

101 VAC on the bias diode. Supposed to be 90 VAC.

DC current on V5-V7 pins 2 and 7 is 3.1 DC

AC is all over the place.

[axeman]

Fire it up. I have my tone stack at 56k/250pf I might change it to day to hear what it sounds like.

[vh junkie]

Voltages may be a little high without the load from the tubes. How are the other voltages? Look at the chart with the 100 w instructions. Are the fuses FastBLO (like what George would give you?)? ARe they holding up?

Important to remember that some voltages are DC and some are AC in the chart but it is not really clear. Let us know what you have on the pins.

[vh junkie]

The heaters are AC(6.3) the plates on the preamp tubes should be like 285v DC. The screens(yellow) and the plates(one of two colors depending on which side) should be about 500 DC). Will be higher without tubes.

[vanhalen5150]

Voltages may be a little high without the load from the tubes. How are the other voltages? Look at the chart with the 100 w instructions. Are the fuses FastBLO (like what George would give you?)? ARe they holding up?

Important to remember that some voltages are DC and some are AC in the chart but it is not really clear. Let us know what you have on the pins.

Yup, just going get a new tester. Wierd because V1 pin 1 shows no voltage, but unplug and bleed from V1,pin 1 it shows 154v and then disapates to 0.

Hmmm....

[vh junkie]

Are you talking about the first preamp tube? Do you have the low volt switch?

[vanhalen5150]

Are you talking about the first preamp tube? Do you have the low volt switch?

Yes , the voltage is fluxing. With the AC readings.

I'll check the tube sockets . Tubes were tight. Didn't seem to go in very easily