18Watt.com

I know it's a Fender thing, the cloth wire, but I liked the colors. It's not really cloth. It's go some sort of plastic insulation and you can't push it back. I like it because it stays exactly where you put it.

Those turrets are the worst.
I can't imagine ever using them again.

brought it home to test today and I forgot my fuse cap. You know how those things don't stay on without a fuse in them.

gkwallace wrote: ↑

Mon 11/25/24 11:26 pm

brought it home to test today and I forgot my fuse cap. You know how those things don't stay on without a fuse in them.

Bummer!

Bieworm wrote: ↑

Tue 11/26/24 2:44 am

gkwallace wrote: ↑

Mon 11/25/24 11:26 pm

brought it home to test today and I forgot my fuse cap. You know how those things don't stay on without a fuse in them.

Bummer!

New conundrum this morning. I only have 1A and 5A fuses at work. Can I use one of those for testing?
My thought is 1A might blow right away and the 5A would smoke my transformer if I wired something wrong.
I do have a variac to bring it up slow, if that helps.

You can try the 1A, but don't try the 5A. Maybe order some appropriate fuses.

JMPGuitars wrote: ↑

Tue 11/26/24 1:31 pm

You can try the 1A, but don't try the 5A. Maybe order some appropriate fuses.

I'm anxious to try it this afternoon. I have a little fuse socket with the correct fuses I am going to replace the big one with.

Cross your fingers!!!!

Smoked a resistor.
I can't believe I missed this. I put a 1/2w 220k resistor on the 32/32 can instead of a 1w. It was labeled 1w from mousers in the bag but I was in such a hurry I didn't notice it was wrong.

Would you expect a 1/2w in place of a 1w to instantly melt down or is it a sign of another issue?

Step 1: HIGHLIGHTER TEST. Always verify every value and connection with the schematic AND layout before proceeding.

yes, Obi Wan
I actually did find some discrepancies between the two and went with the higher voltage rating. This one I missed.

1W is the minimum in that position, and only if it's a good quality resistor. Some people prefer 2W there. YMMV.

I bought a few 1 watt and 2 watts next day aired.

I was wondering if leaving out the sag register made the situation worse.

The sag resistor doesn't matter. I don't usually use them unless requested.

That 220k resistor is what drains the caps when you shut off the amp. The resistor needs to be rated well enough for that to happen without what happened happening.

Paid for next day air, but it won't get here till after I leave work, bummer.
I found a spare 1w PRP resistor and stuck it in there. Nothing smoked!

Won't know if it works till I get home, left all my tubes there.

I have 419v DC after my rectifier diodes.
What the hell?

Are all the tubes installed?

If so:
Verify all tube connections.
Make sure none of the tubes died when whatever happened happened.

If not:
Install the tubes.

No tubes.
I forgot that dc converts AC voltage by 1.4 or 1.7 factor, forget which.
I was confused as to why the 290AC went to 420DC.

I don't have a load to put on it here at work so I have to wait to go home.

About 5 years ago you gave me a form to log voltages, where can I find that?

With modern wall voltages, and tubes installed, you'll probably see the 290 turn into 300 to 315. Zeners might be needed to lower your DC when you get that far.

Voltage charts are on the project pages: viewtopic.php?t=24430

Thanks,
Josh

Thanks buddy.
I thought you gave me a Link to blank web form or something one time. I could be wrong

JMPGuitars wrote: ↑

Wed 11/27/24 3:43 pm

With modern wall voltages, and tubes installed, you'll probably see the 290 turn into 300 to 315. Zeners might be needed to lower your DC when you get that far.

My voltages are pretty much in range now but I can't test any further.
I saw smoke.
I can't find where it's coming from.
I checked every solder connection and followed the entire circuit 1 point at a time, using a sharpie to mark them off.
No sound, some smoke.
When I first turned it on I put my finger on the end of the input cord tip and could hear a response, but it slowly faded away to just a low hum.

I haven't checked the under board wiring, yet but there is continuity where there should be.

I'm kinda at a loss.
1. pull the board up and look at the under-wiring.
2. Maybe damaged the 32/32 can with the short of the resistor on it (doubt it cause my voltages look close).
3.????

Hard to know what to do when you see smoke. Maybe let it smoke and look for signs of heat, dunno.

I would make some pics of the build in all possible angles and details. Looking at pics somehow shows irregularities that I didn’t notice/ overlooked while looking at the actual build.
Post them images here too, so we can help you.