How hot does your 1k 25 watt resistor get?

[guilds100]

I just recieved my express kit and the board seems to be missing a few turrets, including one end of the 25 watt resistor. I know this handles alot of current so I asssume it heats up. I will have to connect the 25 watter to the first 9.1k using the lead of the 25w. How much space should i leave between the resistor and the board to disipate the heat?

[paulruby]

Why not get a few turrests? Or, at least... Get some #4 brass bolts and nuts, maybe 3/8" long to use as turrets. Put the bolts up through from the bottom, nut from the top and use the threaded part that comes through to wrap leads around. The brass will solder nicely. Or a few brass eyelets from a fabric store... Something...

[M Fowler]

Which Express kit did you get? Ceriatone or some one elses?

I have the Ceriatone if you need to compare, I also built my own Express Combo and in the process of another Express build using Allyn Meyer's chassis and his Pacific trannies and rjguitars perforated boards. Give me a shout if you need help.

The only thing noticably difference has been the bias pot arrangement between my suppliers.

Mark

[guilds100]

The boards are from rjguitars. Upon futher inspection, I found the board to be very much like the francesca which looks like it shares a turret for the 25w resistor and first 9.1k and lacks a turrest where the rectifying diodes come together.

[M Fowler]

I am attaching one of Joebob's board sets for reference. I can take a picture of my rjguitar board if you need one?

Mark

[M Fowler]

Here is my rjguitar board and as you can see I have yet to rewire the third leg of the bias pot.

Mark

[guilds100]

My board looks just like that minus the turret where the 4 diodes converge rectifiying the ac. I'll just solder a wire at that point and run it through the board and out for stability.

[M Fowler]

Robert sent me extra turrets incase I needed to change some things, I take it you did not get any extra or have any on hand?

It will sure work the way you described but if you want it to follow the original TW you should get a turret. I can send you one if you like no problem? Insert it in the hole and take a philips screw driver or location punch or something and lightly tap the bottom of the turret to flare out the bottom of the turret. Unless you already know how to do all this then I apoligize for the instructions.

Mark

[guilds100]

I have some turrets and a staking tool I bought a year ago but never used. I may try to get a turret in there but I've started to populate the board and dont want to disturb what has already been soldiered.

[M Fowler]

You can put a single turret in there without damage to the others or componets must exercise some restraint is all.

Or just wire it the way you said its about getting the amp done and built well that counts right, have fun.

Is this your first TW amp? What trannies and pots and other components did you decide to go with?

I like to hear what others are using it helps me decide with other amp builds and the quality of certain components based other builder's responses.

Oh I almost forgot your question about the 25w resistor. I have mine flat on the board and will use the perforation holes to pass my wire through for connection rather than under the 25w resistor as I have done in other builds. If you look at Ron Worley's Express build guide it discusses this.

Mark

[ontariomaximus]

To answer the OP's question, the 25W ain't gettin too hot. Consider the simple math. If each screen grid was pulling 40ma (they would have melted well before that point), that's 80ma, squared = .0064a, multiplied by 1k = 6.4 watts.

6.4w can be hot, but under normal loud playing you'd be looking at perhaps 3 watts of heat.

[guilds100]

This is my first trainwreck. I plan on using toneslut transformers, sprauge 716 caps, and cts pots (which I already had on hand). I toyed with the idea of adding some carbon comps in key places. From the clips I've heard, the amp is quite gainy and the noisy resitors may be just alittle too much so carbon film will have to do.

[M Fowler]

guilds100 watter,

Yeah it is a gainy amp for sure, tube swapping is common.

The only two places the original express used the CC was one on the power board and two for bleed resistors but I avoided them all together and used 1 watt throughout as well especially on the input jack to help lower the noise.

Can't go wrong with tonesluts tranny sets. The caps and pots to me are purely subjective to each builder. I will be fun to see another Express born soon, have fun.

Mark