Let's build an amp! Greg's journey to electrocution

[JD01]

That looks amazing, Greg.

[Minerman]

Wow Greg, that looks great...You're very organized & I appreciate all the explanations, along with the labels with the masking tape dude...Very nice...


There's something I just can't quite get my head around though, the faceplate & knobs on that thing look very strange for an amp of yours...I'm so used to seeing the gold faceplate & knobs, it's gonna take some time for me to get used to it...

Super job man, I'm actually excited & wanna hear that thing man...

[Greg_L]

Thing of beauty buddy boy.

That looks amazing, Greg.

Wow Greg, that looks great...You're very organized & I appreciate all the explanations, along with the labels with the masking tape dude...Very nice...


There's something I just can't quite get my head around though, the faceplate & knobs on that thing look very strange for an amp of yours...I'm so used to seeing the gold faceplate & knobs, it's gonna take some time for me to get used to it...

Super job man, I'm actually excited & wanna hear that thing man...

Thank you guys. Yeah it looks not bad. Let's hope it works. I'll take ugly and sounding great over pretty and non working. Lol.


And with that said....I just soldered my last wire (I think. I hope).

Wired up the front of the chassis this afternoon. Smoking pots....






And here it is.....complete gut shot. Everything from input jack to speaker jack, connected.



I've visually inspected every single solder joint on this thing. It all looks good. I'm gonna take a few hours off and go back over it with the schematic to double-check and make sure all the wires are going to where they need to go.

Maybe tonight, probably tomorrow, it gets the juice. I have a checklist/procedure to fire it up to check voltages before tubes go in and sound hopefully gets made.

[WhiskeyJack]

MAn thats pretty good dude. Have you kept a log of your hours? how much time spent on each step / section/ process etc?

Were the pots actually smoking?

[Greg_L]

MAn thats pretty good dude. Have you kept a log of your hours? how much time spent on each step / section/ process etc?

Were the pots actually smoking?

No no and no.

I think about a couple hours each day for about two weeks. Maybe 30-40 hours. A lot of it was spent sitting there drooling trying to figure things out. An experienced builder could probably build this thing in a few days.

But I aint done. I hope I am, but I'm not too confident that it will just be perfect right off the bat.

[Greg_L]

The aftermath....



Getting ready to test....

[Minerman]

Very, very impressive Greg...If that thing sounds anything like it looks, it's gonna be killer man...I gotta say I'm really impressed by how organized you are & your meticulous attention to everything involved, not just the amp/build, but just everything...You've clearly had a game plan & it looks to me like a winner...

I've said this before, but I'm pretty excited to hear it man, & I know you are too...


Gonna throw this in the hat too, I dunno how much knowledge you have about the inner workings of amps (way more than me), but I think you might have some luck doing a little work for folks man...Maybe do some mods or something similar (kinda like the guy at the Marshall forum who's adding gain stages to amps for people)...Just a thought dude...

Very, very impressive Greg, I'm actually floored by how good your work looks, especially for your first build...

[Greg_L]

Very, very impressive Greg...If that thing sounds anything like it looks, it's gonna be killer man...I gotta say I'm really impressed by how organized you are & your meticulous attention to everything involved, not just the amp/build, but just everything...You've clearly had a game plan & it looks to me like a winner...

I've said this before, but I'm pretty excited to hear it man, & I know you are too...


Gonna throw this in the hat too, I dunno how much knowledge you have about the inner workings of amps (way more than me), but I think you might have some luck doing a little work for folks man...Maybe do some mods or something similar (kinda like the guy at the Marshall forum who's adding gain stages to amps for people)...Just a thought dude...

Very, very impressive Greg, I'm actually floored by how good your work looks, especially for your first build...

Thanks a lot miner, but unfortunately....

Fail.

I started my testing tonight. It started out pretty good. Good heater voltage, pilot light lights up, with no tubes things were looking good. Then I installed the rectifier, brought up the voltage in increments on the variac, then POP! At 70 volts AC it blew the two A node filter caps. Literally blew them up! Lol. Pop, smoke, greasy internal capacitor guts everywhere.

Oh well, back to the drawing board.

[liv_rong]

Damn man! That sucks! You’ll figure it out quickly I’m sure.

[Greg_L]

Damn man! That sucks! You’ll figure it out quickly I’m sure.

I might already have.



This kit uses a "copper cap". It is a solid state rectifier that plugs into the standard tube rectifier socket. Okay...

...so the layout shows the rectifier heater wires connected to that tube socket to be used with the copper cap.
...the schematic says in micro print "do not use 5 vac heater wires with copper cap".

WTF. I'm getting conflicting information.

So I know for sure I need two new 16uf filter caps because they literally blew up. I might be able to get those locally tomorrow. Then I'll have a decision to make.

1) Do I try it again with fresh caps, my existing copper cap, and remove those 5 vac wires per the schematic...which just happens to contradict the layout?
2) Put the new fresh caps in, leave the 5 vac heater wires, and use a real rectifier tube...which will have to be ordered?

I think I'll try option 1 since I already have the copper cap and will just need to get new filter caps and remove two wires. That's the easier option.

[SweetDan]

Watching this thread has been awesome! I just read through this morning's post, and felt real anticipation. Then read next about the thing blowing up. Big old bummer! Who'da thought watching some other guy do all the work would be such an emotional roller coaster?!

WTF. I'm getting conflicting information.

Before deciding on the fix, would a call to the Weber people do any good?

[Greg_L]

Before deciding on the fix, would a call to the Weber people do any good?

Maybe. But none of it matters until I get new caps. So this thing is on hold for a minute. I'm gonna go back over my filter cap wiring and try it again when the parts get here.

[Greg_L]

Fuuuuck. No matter how neat and organized I try to be....I got one very fundamental basic thing wrong very early in the build.

The fucking tube rectifier socket is 180 degrees out of whack.

So no matter if it's a tube rectifier or a solid state tube replacement rectifier, the wrong pins are getting the wrong voltages and there you go.


I know how this happened too. I know I had it installed correctly at first. I counted the pins from the keyway and off you go. But shortly after that I removed that tube socket to mess with these spacer things to see what they do or if I even needed them. I decided not to use the spacer and reinstalled the tube socket....backwards. It can only go two ways. I put it back in the wrong way. Stupid Greg. And this was before the wiring....like literally day one...so it's been wrong this whole time and I never caught it.


So, never mind the conflicting schematic and layout information and/or the copper cap needing heater wires or not needing heater wires. None of that even matters if the fucking tube socket is in backwards.

[muttley]

Unlucky mate, at least it didnt blow a random fuse. Much harder to troubleshoot..

I'm sure you will nail it down soon.

[Greg_L]

Unlucky mate, at least it didnt blow a random fuse. Much harder to troubleshoot..

I'm sure you will nail it down soon.

I already have! Well, I've figured out the first problem. There's no telling what's waiting for me on down the line!

[muttley]

If its any consolation many years ago I put a truss rod in upside down because I wasnt paying attention. Didnt spot it until I had strung it up and was setting up...

[Greg_L]

If its any consolation many years ago I put a truss rod in upside down because I wasnt paying attention. Didnt spot it until I had strung it up and was setting up...

Lol. Yeah. I knew I'd hit speed bumps and it wouldn't work right off the bat. But this is just dumb. Lol.

[einstein magoo]

Don't beat yourself up. Shit happens. It will all come out in the wash. Notice you had a speaker hooked up in one of the earlier shots. I think it's important to have that load on there when you do fire up again and do your testing. Not telling you anything you don't already know. How hard is it going to be to get to that tube socket now with the wiring in place?

[Greg_L]

Don't beat yourself up. Shit happens. It will all come out in the wash. Notice you had a speaker hooked up in one of the earlier shots. I think it's important to have that load on there when you do fire up again and do your testing. Not telling you anything you don't already know. How hard is it going to be to get to that tube socket now with the wiring in place?

If I had to do a tube socket wrong, this would be the one to do it on. It'll be an easy fix. Four unobstructed wires and flip the socket around. No big deal.

[Bubba]

This gave me a wry grin. All those fiddly little components and it has to be the fuck-off massive one you get wrong! Type of thing I'd do.

At least it only blew a couple of caps.