Weber 6O100 kit build

[M Fowler]

Weber 6O100 kit

Ordered with high headroom OT.

Right from the start I did not like this kit, over crowded board being the filter caps hung off plus some how run balance resistors with the caps.

I built my own boards and just designed as I built. Not as loud as I thought it would be wimpy transformers maybe.

Mark

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[xtian]

Nice work, as usual, Mark. And thanks for the review. Can you show the original circuit board? And what are the chassis dimensions?

[Kagliostro]

COOL

K

[M Fowler]

I will post more information later but here is the original board some one put shorter caps on that actually fit.

zmjle9.jpg

wpt100sch.JPG

wot100hhrsch.JPG

[M Fowler]

The chassis data.

6o100.pdf

Since these photos were taken I've added the knobs and changed the V1 cathode resistors to 820R and bypass caps to 330uf for improvement to bass.

I changed the bias resistor to 470R to get the bias range I needed and 15k to ground off 10kL bias pot. Running EL34's not KT66 because this is amp was built for my Brother-in-law for Native American Bass thumping on the res. He loves the orange cabinet for this.

I need to take all the voltages yet and make voltage chart which I will post.

More data and photos to come.

Mark

[telentubes]

Your board layout is way cleaner

[M Fowler]

Not sure what the voltages should be for this amp but I am posting what I measured.

Having some weird noise if you increase the MV over noon affected by presence pot NFB circuit. Deep pulsing bass sound. I will reverse the OT primary wires first.

6O100xlsx.xls

6o100_schem.jpg

[gldtp99]

Nice job on the new boards !!

I got a Weber kit from the 'bay years ago (a Plexi 50 type kit)---- somebody had tried to build it and messed it up, then gave up and sold it cheap.
I gutted it and built a 2204 circuit into it with a new 2204 turret board----- I used the orig iron and it sounded ok but nothing to write home about.
I still believe that the Weber iron was the limiting factor in that amp project.

Years ago I built a Vintage Orange type head (based on my real 1974 Orange OR80) into a Hiwatt type chassis/head cab----- I used a Twin Reverb type PT and an Edcor 100 watt OT (w/4.2k primary).
The guy that finally bought it from me used it to gig locally for several years----- last I heard he moved out of Texas to Colorado------ here's a quick vid of his band------ the amp is the black Hiwatt-looking head sitting on top of the Mesa 4x12 on the left hand side:

https://www.youtube.com/watch?v=X99ws9-8FoM

[M Fowler]

I enjoyed the video the amp comes alive.

So many of the Weber amps are ruined in my opinion solely because of those terrible boards they provide in their kits and components are questionable.

I started buying some kits because $575 for complete kit was great price and the chassis/cabinets are built well but not worth the headache.

[csjoyner]

I’m currently finished a build on a 6O100 with my brother and am currently having issues. When we first turned it on the amp squealed and we did get a guitar sound. After about 2 minutes the squeal stopped but the amp stopped making any noise at all. We get pops and crackles when probing tube posts. Also the amp will crackle when turning the bias all the way up. I’m including pics of the amp. We used the original Weber board. I grounded everything to the same screw so one side is a little cluttered. I also included voltage readings on the tubes too. Ignore the typed numbers, we just used the chart for convenience. The letters next to the numbers represent noise we heard while probing. Any help is welcome. We are new at this and learning. Thanks.

Scottie

[csjoyner]

Sorry, my voltage readings did not post. Remember, ignore the typed numbers. Thanks.

Scottie

[thetragichero]

just looking at the power tube measurements either you measured the wrong pins or the pins are wired wrong. pin 6 shouldn't be connected to anything. pins 1 and 8 should be right around 0v. pins 2 and 7 are your heaters and there should be ~6.3vac between them

[csjoyner]

There is nothing written on 1 and 8 because they measure 0. They are just grounded. According to the weber wire layout the B from the power at the choke goes there. The heaters were 6.02v so those are good. The numbers are listed below the tube labels. Thanks.
https://www.tedweber.com/media/kits/6o100_layout.jpg

Scottie

[csjoyner]

After further research it looks like the layout is just using the 6 post on the power tubes as a solder point to hold components as the tube does not use that point. I forgot about that when checking voltages. Is there something else I’m missing?

[martin manning]

Pin 6 is commonly used as a tie point on power tube sockets for mounting screen resistors, since there is no internal connection on 6V6, 6L6, EL34, and KT66 etc. tubes. Your measurement is showing the screen supply voltage, so it's useful. Since pin 4 (screen) voltage is the same, it looks like there is no screen current flowing. I don't know why that would be.

The squeal you heard is oscillation, which is often caused by the output transformer primary leads being swapped. In your case the blue and brown color coded OT leads look to be in the right places, or at least they match the layout. Messy wiring can cause that too. I'd also be worried that the squeal stopped because something has failed.

I think I would consider taking a step back and cleaning things up in the power section, basically redo it. You want it to look more like Mark's photo at the top of this page https://ampgarage.com/forum/viewtopic.p ... 03#p379403

Perhaps this build should start a new thread? Maybe the mod's can snip and relocate it.