V1b conection?

[Oddvar R]

Hi. I have V1b(?) point that I am a bit uncertain of where it's going? It says "vol(ume?)" above it, but which?

[pompeiisneaks]

That is connected to the volume output, on the front panel. if you look at the volume pot there's also a V1-2 meaning v1 pin 2. (grid) it's what takes the output from teh tone stack and sends it off to V1a (btw you're calling V1a V1b. Look at the picture, pins 1,2,3 are v1a, 6,7,8 are V1b. (in this layout anyway.)

~Phil

[Oddvar R]

So, is it going directly from the 220k resistor to the volumepot, the pot to the right on the pic, or the volume to the left? (Sorry for being a bit ignorant her.)

[pompeiisneaks]

No it goes to the center pin, the left pin is ground. It's for shunting some portion of the volume to ground instead of letting it go off to that next stage.

i.e. Input signal goes into V1b, through the tone stack, etc, into the volume pot top, (right pin) and then the volume pot provides a voltage divider that sends some signal to earth and some to the next stage via that wire you connect to pin V1-2 or V1a grid.

You've circled the left pin.

~Phil

[pompeiisneaks]

Like this:

volume.png

~Phil

[talbany]

If you look at the "input volume" pot on the layout. The input of the pot is called the top (right pin). It comes off the Treble pot which basically acts as a mixer pot for the tone stack. It mixes the treble frequencies with the bass frequencies and then sends it off to the volume pot via the wiper. The output of the Vol pot Wiper (middle lug) sends the signal off (from the stack) to be amplified again to recover the gain lost in the stack to the grid of "V1B. This is called the tone stack recovery stage.The bottom of the Vol pot (left lug) is grounded so as you turn the pot (wiper) . The closer the wiper gets to ground (less resistance) the more signal gets shunt to ground until it's finally shorted 0 grounding out the V1B's grid killing your signal
Be Careful!
Tony

[Oddvar R]

Thanks a lot for this. I must admit this build is a difficult one for me. I juggle between two different layouts, and they are not entirely the same ones.

[Guitarman18]

Thanks a lot for this. I must admit this build is a difficult one for me. I juggle between two different layouts, and they are not entirely the same ones.

I'd definitely recommend working with the schematic in conjunction with the layout. That way you can get confirmation of any queries you have about the layout. But more importantly, when you have finished your build and you want to recheck everything, it's a great idea to use a highlighter on the schematic to trace out every single connection and component to 'proof read' your build.

Cheers,

Paul.

[norburybrook]

Thanks a lot for this. I must admit this build is a difficult one for me. I juggle between two different layouts, and they are not entirely the same ones.

Oddvar,

May i take it from your recent posts you're fairly new to this? I recognize some of your type of question

The layouts are very good and with the help here you can build an ODS if you follow basic safety and can make a decent solder joint

I'll mention a couple of things that have given me issues on the first builds I've done.

1: RELAYS.....some relays are polarized.... don't use these if you can help it
2: Anodized chassis and ground connections. Make sure you remove anodizing on ground points, including chassis grounding jacks.
3: Check, measure components before fitting, things can be faulty or mislabeled from the factory/distributor.

have fun and be safe.



M

[talbany]

Thanks a lot for this. I must admit this build is a difficult one for me. I juggle between two different layouts, and they are not entirely the same ones.

Here is generally a good order I give newbies or those with no real background in electronics wanting to get into building tube amps confidently.
1 5E3 Deluxe or a Trainwreck like Express. Seriously.
2Jtm45/Bassman
3.AB63 circuit. reverb/Trem
4 Overdrive Special
5.SSS without the follower
Now I know some here will say I didn't go this route and built one right away
So to those I say OK great but where would you be without the help of this forum
If you have people here helping you along the way did you really do it all yourself?
No you didn't Start simple and work your way up!
I am ready for the flames

Tony

[norburybrook]

Thanks a lot for this. I must admit this build is a difficult one for me. I juggle between two different layouts, and they are not entirely the same ones.

Here is generally a good order I give newbies or those with no real background in electronics wanting to get into building tube amps confidently.
1 5E3 Deluxe or a Trainwreck like Express. Seriously.
2Jtm45/Bassman
3.AB63 circuit. reverb/Trem
4 Overdrive Special
5.SSS without the follower
Now I know some here will say I didn't go this route and built one right away
So to those I say OK great but where would you be without the help of this forum
If you have people here helping you along the way did you really do it all yourself?
No you didn't Start simple and work your way up!
I am ready for the flames

Tony

good advice.

My order was similar to tony but I missed a step.

1: Single ended 5w amp
2: JTM 45
3: Overdrive special.....many of them, with much help from the forum
4: Trainwreck, which after the ODS was a walk in the park

M

[talbany]

Thanks a lot for this. I must admit this build is a difficult one for me. I juggle between two different layouts, and they are not entirely the same ones.

Here is generally a good order I give newbies or those with no real background in electronics wanting to get into building tube amps confidently.
1 5E3 Deluxe or a Trainwreck like Express. Seriously.
2Jtm45/Bassman
3.AB63 circuit. reverb/Trem
4 Overdrive Special
5.SSS without the follower
Now I know some here will say I didn't go this route and built one right away
So to those I say OK great but where would you be without the help of this forum
If you have people here helping you along the way did you really do it all yourself?
No you didn't Start simple and work your way up!
I am ready for the flames

Tony

good advice.

My order was similar to tony but I missed a step.

1: Single ended 5w amp
2: JTM 45
3: Overdrive special.....many of them, with much help from the forum
4: Trainwreck, which after the ODS was a walk in the park

M

So Marcus? Now which one did you enjoy the most? Mine were the 5E3's I had a blast building those amps early on (still do). The ODS were more fun later after I had built a few

Tony

[pompeiisneaks]

I started with a Hoffman AC30, and it was a pretty challenging build for me as a first build. I did get it working though!.

I then tried to repair a Vox AC100CPH that turned out to be utter garbage, and the power transformer (unbeknownst to me) was dead. I gutted it, rebuilt a Vox AC100/2 in it, got it working for long enough to demo it on video and then the PT blew things up. I moved on to:

Fender 5F6A Bassman
Gibson EH-185
Fender Champ
Vox AC30/4
Trainwreck Liverpool (reusing the parts from that first Hoffman Vox AC30)
Tweedle Dee Deluxe
ODS #124
Sluckey's Marshall Dual (that also used that same accursed PT that I finally chucked thanks to help realizing it WAS that damned PT)

I feel like I'm missing one somewhere, but yeah, that's somewhat the gist of it. 10 amps I've built. I still feel like a complete neophyte though

~Phil

[Oddvar R]

Hi, appreciate the advice. Totally spot on that forums like this is of great help. Helped me a heap of a lot. But I guess that's one of the points with having a forum in the first place?

My build record, with a big help from different forums:
Bassman 5F6A
Fender Pro jr
Fender 5E3 (two)
Fender Blues Jr.
Marshall 18w (two)
Marshall 2204
Marshall Plexi
Vox AC30
Soldano Slo
Fender Bandmaster AB763
Dumble ODS (nearly finished. Took me 6 months so far.)

The reason I build is because I am searching for a sound, not to be a electrician. I must admit that I don't understand all aspects of amp building, but as long as there are good layouts, and respect for voltage, it's doable, isn't it?

[pompeiisneaks]

It is, but being able to easily read the schematic, look a the layout, and understand what's going on will greatly help your building. I still find tons of things I don't understand, and have to figure out/learn etc.

I think the original question has been answered, the thread just got derailed a bit.

~Phil