183 Build Report

[Structo]

Each power tube has a 1 ohm resistor from the cathode to ground.

The tip jack that you plug your meter into is connected to the socket pins (1& 8 for EL34)

To check the bias you set your meter to read DC volts and plug your black probe into the black jack and the red probe into each red jack to see how much current each tube is pulling.

The 1 ohm resistor converts the current to volts using Ohm's law:
E/R = I and since R = 1, then what ever voltage you measure is the same number as the current is since whatever you divide by one is that number itself.

Most of these amps have one bias pot so you can't adjust the tubes individually, but you can check to see how closely they are biased to each other.

On my amp I installed two bias pots so I can adjust each half of the output.

[UltraHookedOnPhonix]

I'm just crying - what a build!
Totally brilliant pics too.
You set that bar so high, buddy, we've all gotta try a bit harder now.
Well done mate

Thanks Rob! I have to commend you on the really nice 86 special cab you recently made. I can’t woodwork for #$%&!

This is one of the nicest builds I have ever seen. The pictures are excellent. Thank you for posting them. You obiously spent hours sourcing and planning this build, and it shows.
I am currently building my own 183, and I will use this build as my standard. I hope mine comes out looking half as good as this one.
It seems a shame to put it in a cabinet where it can't be seen.
I have two questions:
What make is the cube shaped cap on the board? It would be C19 (1uF tant.) on the 183 schematic in the presence circuit.
Where are you sourcing your suede? My 3-year-old son is adamant that I cover my amp in burnt orange suede.

Thank you OneWithNot! It took me a fraction of the time compared to my first Bluesmaster build. The first one is quite a pain but then it gets easier.
That cap is made by Panasonic, Mouser part#: 667-ECQ-V1H105JL.
Interesting you should mention burnt orange suede. That’s the exact color I’ve ordered from Jelle. I really have no clue as to where his cab guy find that stuff.

Hey UHOP-
What can you tell me about the multiple bias test points, I'm trying to do test points and a 50 watt switch and can't wrap my head around it. If you could give me some insights into how you test with the multiple points it might make some connection in my brain on how I can lay it all out. Are you just dividing the current for each tube?
Just a really beautiful build you have there. I used to love looking at the insides of my hiwatts, but now that I know more about circuit constants, component selection and lead dress, form follows function and there really is beauty there.
I see trainwrecks as a haiku and Dumbles as a great historical novel, the amp you built is like a Joseph Campbell book that analyzes other works but becomes a great work in it's own right.
-ER

Tom beat me to it. Thanks for the explanation Tom!

I’m deeply humbled by your generous compliments! I have to say that the Joseph Campbell one hit me in the stomach like a sledgehammer. I am somewhat of a Campbell-ite. What an extraordinary man! The foremost comparative mythologist in my view. I was introduced to him like many others thru the six-part PBS documentary with Bill Moyers entitled, “The Power of Myth”.

[OneWithNot]

Thanks for the info on that capacitor, UHOP! I've seen caps like that in several builds so far, and couldn't figure out what it was.

And thank you for the info on the suede. Some people are reluctant to share their sources.

So how do I get in touch with Jelle?

When I mentioned to my son that I was considering covering the cabinet in Tolex, he burst into tears.

"No Tolex, Daddy! It's SUEDE! Burnt! Orange! Suede!"

(We had several bedtime discussions on which amp to build, and what it would look like.)

So you see, my hands are tied.

For that matter, how do I get in touch with Funkaliciousgroove?

I remember from the Dumbleator thread you said you got the transformer for it from him.
I sent him a PM, but maybe he doesn't check them often.

I might be a little late to the party on that one.

[boldaslove6789]

Funkaliciousgroove is Brandon @ Bludotone amps. He used to sell kits, chassis,
and trafo's but doesn't anymore.

[Joost]

Man I just keep looking at your pics. Very educational. Do you happen to have pics of a 124 build of the same quality, clarity and detail? That would be extremely helpful! Thanks!!!

[amplifiednation]

I can get high quality suede if you need some let me know.

[martin manning]

Man I just keep looking at your pics. Very educational. Do you happen to have pics of a 124 build of the same quality, clarity and detail? That would be extremely helpful! Thanks!!!

This is basically a #124, with a few small changes, and the modern power supply, of course: https://tubeamparchive.com/viewtopic.ph ... highlight=
More photos on page 3. The #124 layout in the files section will show up the differences, but it depends on your goal... Is it the circuit or an exact replica? Personally, I think the evolved layout and power supply are very worth-while improvements.

[jelle]

Ultra,

Can I mess with you one one second?! The Rock /jazz switch is wired different....

Great build, looks flawless.

[CHIP]

Ultra,
Are those NTE metal films in the preamp?
I decided to go with the RN 65's on the plates in mine, but debated over which to go with.

Your photo taking skills are also exceptional. Those photo's are soothing to the eyes, just as a finely tuned Dumble is pleasing to the ears.

[UltraHookedOnPhonix]

Man I just keep looking at your pics. Very educational. Do you happen to have pics of a 124 build of the same quality, clarity and detail? That would be extremely helpful! Thanks!!!

No, sorry I don’t. I hate to be a Mr. Smarty Pants but the pictures of the original 124 aren’t so bad:
http://www.roblivesey.com/dumble/

Ultra,
Can I mess with you one one second?! The Rock /jazz switch is wired different....
Great build, looks flawless.

Very perceptive of you, I enjoys me a good messin’!!
I remember drawing the standard way of doing the R/J switch vs. 183 and came to the conclusion that they were electrically the same thing. Did I miss something? I’d hate to miss out on the kind of tone that would open up a stargate or something…

Ultra,
Are those NTE metal films in the preamp?
I decided to go with the RN 65's on the plates in mine, but debated over which to go with.
Your photo taking skills are also exceptional. Those photo's are soothing to the eyes, just as a finely tuned Dumble is pleasing to the ears.

Thanks CHIP! Personally, I always enjoyed a good gut shot or two, it tells you so much!
Yes, some of the resistors in the preamp are NTE’s “HW” series of 1/2W, 2% flameproof resistors (rated at 350V). 183 looks like it has the HWs for the 220K plates but not for the 150K (KOA?).

[Joost]

Man I just keep looking at your pics. Very educational. Do you happen to have pics of a 124 build of the same quality, clarity and detail? That would be extremely helpful! Thanks!!!

No, sorry I don’t. I hate to be a Mr. Smarty Pants but the pictures of the original 124 aren’t so bad:
http://www.roblivesey.com/dumble/

Yeah, I have those two, but not to knock mr Dumble, I like your build and photos better. They are much easier to analyse

[Drumslinger]

Thank you very much! Did you get started on your loop build yet?

UHOP,

Yes, just about done with it. I'll try to get some pics up this week.

[UltraHookedOnPhonix]

Thank you very much! Did you get started on your loop build yet?

UHOP,

Yes, just about done with it. I'll try to get some pics up this week.

radical!

[UltraHookedOnPhonix]

Here's some new shots of my 183. Cab couresy of Jelle Welagen of Welagen Amps. Simply amazing! Please excuse the small wooden particles caught in the suede. I haven't had time to clean it after I drilled chassis mounting holes in the cab.

[IMG703]http://i205.photobucket.com/albums/bb17 ... suede1.jpg[/img]

[IMG768]http://i205.photobucket.com/albums/bb17 ... suede2.jpg[/img]

[IMG741]http://i205.photobucket.com/albums/bb17 ... suede3.jpg[/img]

[Structo]

Whoa!

Now that is orange!

Looks great and is well built no doubt.