New Build - Express

[Ian444]

The pin placement is to limit the number of selectable positions. Put the pin in a spot so you only get 3 positions if you want just 4, 8 and 16 ohm selections for example. Then use your meter to check continuity between the upper pins and lower pins at each position, and draw up a diagram of how the switch works. Have a couple of beers while your at it, and crank the music up, to increase your patience level, that's how I would go about it.

[Picker]

Okay, I got the Impedance selector worked out. It looks like the one in the Build guide is set up in 4 sections. The one I have is three. I think I can use the main group and either of the other two.

From what I gather, I really only need to use one. The jumpers etc are just for redundancy. Since it has them why not use them?

Anyway, I have it connected now... On to the next mystery.

[Picker]

Thought I'd post some of my challenges.

Things are progressing very slowly. Each new stage presents a new problem and I have to stop... think... examine... think... read... proceed with one step... stop..

The first thing I built was a bulb limiter. I didn't take any pictures of that yet, but it came out nice. I tested it on my Champ and it worked fine.

Next, I didn't have an amp cradle and was low on funds after purchasing the parts for the amp, so I had to improvise. I did have a 2x4 left over from finishing my basement so here's my amp cradle on the cheap,

[IMG:800:531]http://i54.photobucket.com/albums/g94/r ... C_0460.jpg[/img]

Later I added the bumper to prevent it from sliding off (excuse the mess in the background).

[IMG:800:531]http://i54.photobucket.com/albums/g94/r ... C_0465.jpg[/img]

[Picker]

The next two challenges were the Turret Board and the Grounding bus on the PEC pots.

After reading several posts, I found out it was really hard to solder to the stainless steel pots so I would have to find another solution. I contacted RJ (who I bought most of the parts from) and he sent me a set of the little tabs that you bend around the side of the pot to make the connection. The problem I ran into was that after bending them around the side the holes in the tabs were about 1 or 2 mm short of where I could run the copper through the holes. I experimented with bending the copper different ways to feed it through the holes, but it wasn't working. Instead, I ended up resting the bar on top of the tabs and using some of the clipped ends of the caps to make a jumper tying the hole to the bar.

[IMG:800:531]http://i54.photobucket.com/albums/g94/r ... C_0572.jpg[/img]

[Picker]

Finally, the PEC pots are larger and so I ran into a couple of size issues. First, the chassis was drilled for a smaller shaft size so I had to drill out the holes to fit the larger pot. At RJ's suggestion, I purchased a "Step bit" to enlarge the holes. This was the scary part. I was afraid of drilling the chassis, since I had to get it right the first time. If I messed up I couldn't "un-drill" the holes.

The step bit worked great. With my new found confidence I even added holes for the tabs on the pot instead of breaking them off (though I did break off one of them instead).

The next issue was that because of the larger size, there is no room at the top of the chassis to fit the wires as described in the build guide. You cannot get the right angels for the wires because basically, there is room for one wire width before you meet the chassis. Instead, I ended up bending the tabs a bit so that I could run the wires parallel to eachother so I didn't have to cross the wires.

[IMG:800:531]http://i54.photobucket.com/albums/g94/r ... C_0571.jpg[/img]

[Picker]

The last thing I was struggling with was the turret board. This was mostly just inexperience. Every build and amp that I worked on previously had used eyelets which is what I was used to. With the Turrets, I was trying to decide the best way to use them. My first thought was to use the holes in the turrets. They are small however, and will not fit more than one or two leads (maybe 3 for small resistors). I assembled the board, but found soldering difficult. It was hard to tell if the solder was flowing down into the turret (which is what I wanted) or if was just bubbling over the top.

I ended up over heating a couple and scorched the board a bit in one place.

[IMG:800:531]http://i54.photobucket.com/albums/g94/r ... C_0573.jpg[/img]

Next time, I may not use the holes at all and just have everything go around the turret instead, but I think I have good connections so far.

That's it so far. I'm going to try to finish up wiring the Pots and then start in on the power supply.

[angelodp]

You might consider using nylock nuts throughout as they do provide a solid lock for mounting.

A

[ChrisM]

Three or four leads should fit inside the turret. Then solder the top of the turret and get a nice smooth surface. Looking at your pics your trying to fill the entire volume inside the turret with solder, no good, your using too much solder.

For wires you can run them underneath the board and into the turret. Or I prefer rapping them around the turret with a mechanical connection then solder. This way they are easier to service later, if need be.

[Picker]

Thanks Chris,

Yes, originally I was trying to fill the turret. It did not look like it would take as much as it did. Anyway... live an learn. I finally reached the conclusion you posted, so will not be doing that anymore.

[surfsup]

Three or four leads should fit inside the turret.

I realize I am new here but this was a sore point for me, the turrets. I even used Watts "double turrets" which advertise "holds 2-4 leads depending on size", got a new drill for them, etc specifically for the larger hole.

On my rail caps, one lead was all that went in there.
The most I got in there was 3 and this was the big turret with the bigger hole. (I used both)

On a smaller standard turret unless you are putting in leads for 1/2W resistors, which are very small, I just don't see how 3-4 leads will fit in there.

[M Fowler]

I wrap the caps around the bottom of the turret and depending on how many wires or resistors that need to go into a turret I decide ahead of time if I am going to use the center of the turret for wire leads or use it for components.

It's a toss up some times, I use the turret center for wire and other times I wrap the wire leads around the top of the turrets.

Also some resistors are too short for many boards and certainly would not be able to wrap around the turret so they go in the holes.

Mark

[Colossal]

resistors, which are very small, I just don't see how 3-4 leads will fit in there.

I use the typical Keystone double turrets with the 0.078" ID hole. For places where I need to have 3-4 components meet at one junction (such as the center of the phase inverter in a typical layout), I drill out the hole with a #33 bit, about 1/2 way down. Works great; plenty of room even with higher wattage components with fatter leads.

[NickC]

^^^ That is a GREAT idea. Thanks for sharing!

[surfsup]

Yea I thought about drilling it out but I needed to drill through to the other side and I figured there wasn't enough material to bore it out larger or it wouldn't mount to the board. I was using the doubleturrets for the Solens on the x10 and didn't have enough room for the underboard ground/B+ runs using 18g with just that one lead in it. With 20g solid I could barely get it in but I got it. I use 1W resistors everywhere, the couple bucks over the whole amp is justified (to me). The leads are definitely thicker over 1/2W Rs.

[angelodp]

Colossal, so when you drill it out it does not spin the turret.

A

Necessity is the M....