5F6-a Bassman not working..

[silat]

It is a  universal choke I got from  Weber . I thought it was weird too because usually you have only two back wires. But this choke has black and white wires... I bought one just in case for a 6L6 But I did not put it in yet.

[Willabe]

Some chokes have 2 different colored fly leads, I think some hammonds are made that way.

1 is the start and the other is the finish of the choke wind.

I think it's like with a coupling cap where the outside foil (finish) of the cap gets hooked up to the lowest Z side or to ground and acts as a shield. 

[plexi50]

We can get this amp working tonight after a few questions here.

[plexi50]

Ok i understand now. Now i want you to unplug the amp and lets do a continuity check first from the other side of the 4.7k and over to the 100k/82k PI junction. Continuity?

I am looking for a problem before or at the 10K PS resistor feeding V2 pin #6

[HotBluePlates]

V1 Pin 8 pin3   V2 Pin 8  pin 3   V3 Pin8  pin 3
     1.4    1.4         358    2.1          53     53

V2 Pin #8 358 volts dc?

You have a resistor mounted on the socket for V2, running (I assume) from pin 6 to pin 1, and pin 6 is connected to power supply voltage. This resistor should be 100kΩ (Brown-Black-Yellow); measure its resistance. I think you have a 10kΩ (Brown-Black-Orange) or 1kΩ (Brown-Black-Red) in there instead.

That would cause the stage gain before the cathode follower to be very low.

[silat]

It seems I have continuity from the 4.7K to the 10K but not over to the 100k

[jojokeo]

you know what to do, get 'er done!

[silat]

 it is Brown black yellow silver  100kOhm

[silat]

So what do you think continuity problem somewhere? Possibly from the 10k over?

[Willabe]

it is Brown black yellow silver  100kOhm

Don't go by just the colors, double check to confirm by measuring it.

[silat]

I have got continuity over from the 10k over to the 6 Pin on V2

[silat]

it is Brown black yellow silver  100kOhm

Don't go by just the colors, double check to confirm by measuring it.

I confirmed it with my meter.

[HotBluePlates]

What's the resistance you measure from V2 pin 8 to ground? Use your power supply filter cap negative terminal as your ground point for this measurement.

I'm asking because you have essentially the full B+ at the cathode of one section of V2 (and across the cathode follower load resistor, which appears to be pin 8 in your amp), and too-high voltage on the plate of the other section of V2 (which appears to be pin 1 in your amp). The V2 pin 3 voltage with V2 installed looks reasonably correct. So for there to be too-high plate voltage at pin 1 means too little voltage drop across the plate load resistor on V2 pin 1; that happens with either too-low current through that tube section (ruled out by the good cathode voltage reading) or a too-small plate load resistor.

Find and fix your error with V2 and you'll be closer to the amp working.

[Willabe]

I confirmed it with my meter.

On a lot of the newly made R's the colors can vary a lot and are not easy to read. The old R's seem to have had deeper, more clearly readable colors. 

[silat]

What's the resistance you measure from V2 pin 8 to ground? Use your power supply filter cap negative terminal as your ground point for this measurement.

I'm asking because you have essentially the full B+ at the cathode of one section of V2 (and across the cathode follower load resistor, which appears to be pin 8 in your amp), and too-high voltage on the plate of the other section of V2 (which appears to be pin 1 in your amp). The V2 pin 3 voltage with V2 installed looks reasonably correct. So for there to be too-high plate voltage at pin 1 means too little voltage drop across the plate load resistor on V2 pin 1; that happens with either too-low current through that tube section (ruled out by the good cathode voltage reading) or a too-small plate load resistor.

Find and fix your error with V2 and you'll be closer to the amp working.

360 PIN 8 to ground    pin 1 60  I am at a loss. I am going to my grand-daughters B-Day  party so I will be out for awhile.

I will check back later and get right back looking for the problem. I changed somethings on my input jacks and no longer have any sound. I also changed  one of the pots that was supposed to be 1 M as it was 10K no I have nothing.

[jojokeo]

This is a pretty simple circuit and build so it'll get resolved eventually and is a good learning situation for you silat. However you photos are a bit too close up to get an idea of things in better perspective. Plus things like the photo below also don't help much cause we can't see where things are going very easily...? You really need to be sure on all of the part's values you are using before installing them in the future. It's good practice to always measure resistors & capacitors ahead of time. Believe it or not, you'll have a few experiences where you or the part is not always correct. I also double check all voltages and heater contacts at all sockets before installing components (where applicable) because I've found what looks like a great good solder job actually had a bad heater connection one time that was verified by my meter. A simple re-touch up of the joint saved me time & frustration later on. It's just called doing your due diligence aka "a stich in time..."

[plexi50]

Like others have said do not go strictly by the color code on your resistors. Use your meter to verify their values.
Be certain that you have your power supply capacitors going to  each section of the amp as in the schematic.
You do essentially almost have the entire B+ voltage on V2 pin 8.
Re-check each power supply filter caps grounds and perspective B+ connection points.

[plexi50]

What is the plate voltage on V1 PIN 1 & PIN 6?

[silat]

What is the plate voltage on V1 PIN 1 & PIN 6?

V1  pin 1       pin6
    185        196

[plexi50]

Are you 100% certain you have the power supply capacitors and 10K resistor feeding V2 wired correctly?
Look again if you have to. There is no way you should have anything near 300VDC on the cathode pin 8 of V2.
You have to have the 10K resistor and power supply cap wired wrong. There's nothing else that would or could  be putting any voltage over 190VDC max on V2 cathode.

Are you certain you have the 100K resistor on V2 going to pin #1 #6 & #7?  Not #1 #6 & #8
Check again:

[silat]

I have looked it over and it looks right. I have to be missing something somewhere. I took a picture of the back of my board and it looks right.

[silat]

Are you 100% certain you have the power supply capacitors and 10K resistor feeding V2 wired correctly?
Look again if you have to. There is no way you should have anything near 300VDC on the cathode pin 8 of V2.
You have to have the 10K resistor and power supply cap wired wrong. There's nothing else that would or could  be putting any voltage over 190VDC max on V2 cathode.

Are you certain you have the 100K resistor on V2 going to pin #1 #6 & #7?  Not #1 #6 & #8
Check again:

It is going to 1- 6 and  7

[plexi50]

Well your gona hate the answer but your going to have to go through the amps part values and wiring as if you were building it all over again. Pull your rectifier tube and turn just the power switch on. Measure the (2) red leads soldered to the rectifier socket. Ground the black meter lead and touch each red wire at a time. What are your AC voltages for each red wire lead?

[silat]

393 VAC   385

[sluckey]

Just to be perfectly clear about that resistor on V2 socket... The resistor connects between pin 1 and pin 6. There is just a piece of wire between pin 1 and pin 7. It's common practice to just loop the resistor lead through pin 1 and double it back to terminate at pin 7.

[silat]

And that is just what had done   1-6-7

[jojokeo]

And that is just what had done   1-6-7

It doesn't look like it in the photo below? See photo and remarks. But again, your supplied photos aren't helping us much here. Please take a few better shots for us as this is tedious without your continued help in showing us your amp's interior better.

[silat]

Just to be perfectly clear about that resistor on V2 socket... The resistor connects between pin 1 and pin 6. There is just a piece of wire between pin 1 and pin 7. It's common practice to just loop the resistor lead through pin 1 and double it back to terminate at pin 7.

I had  it looped behind from 6 to 7 so I changed it 

[sluckey]

Just to be perfectly clear about that resistor on V2 socket... The resistor connects between pin 1 and pin 6. There is just a piece of wire between pin 1 and pin 7. It's common practice to just loop the resistor lead through pin 1 and double it back to terminate at pin 7.

I had  it looped behind from 6 to 7 so I changed it

Show us another picture that clearly shows exactly what V2 socket looks like now. We need to be able to clearly see what is connected to each pin. If the pic is too large to post here and you can't figure out how to get the file size down, then post it somewhere else and just post a link to the pic on the forum.

[silat]

I hope you can see this?

[silat]

Here is another.

[Willabe]

Do you have some wire ends going to the sockets center hub?

[silat]

Do you have some wire ends going to the sockets center hub?

No......

[plexi50]

Need pic's like this/ Looking down at the tube pin and socket. This is V2

[sluckey]

Need pic's like this/ Looking down at the tube pin and socket. This is V2

You switched triodes! That's really gonna be confusing.   

[silat]

I am sorry I do not have a good enough camera but here they are anyhow.

[silat]

One more.

[silat]

One more.

[shooter]

look at the pic, not sure if it's your issue now but it will be.
nib off the "tail" from the blue wire, clean out the solder splatter from the other circle

[plexi50]

Shooter your pic is looking mighty hungry! It doesn't eat amps does it? 

[plexi50]

Silat don't give up and get feeling bad. We all have had our share of going through similar issues.

[Willabe]

Yep.   

[silat]

I tell you I feel like giving up. But I appreciate everyone being positive for me.

[plexi50]

That's what make this forum so great! You have a lot of help and eventually the problem will be found. It makes you learn and understand what all the component do and there function. It takes a little time to grasp all of the possibilities.

Did you get your input jacks straightened out? Volume pot? What king of A/C DC meter are you using?

[Willabe]

You never said if you tried double checking your amp with our host Doug's method?

It works great, we've seen a number of guys who couldn't find what's wrong use Doug's method and find it.

Here's the link again if you haven't tried it;

http://el34world.com/Forum/index.php?topic=17701.0

[silat]

I am going to start tracing soon.(Using Doug's little handy dandy method) I am given myself a little break now for a few hours. so I  will be bothering you  all again soon enough when I begin again.

[plexi50]

If this helps this is the underside of my board wiring.

[silat]

Thank you Plexi!

[shooter]

It doesn't eat amps does it?

 
Don't think so, but I did give up on photography and moved on to oil paints!

that "tail" looks like a spark-gap waiting to fire though.

[plexi50]

Ok Silat lets get going on this.  Whats the latest news? I want to hear it working. I myself cant wait to hear what the problem was.
I have myself done some silly things in the past. And looking back you wont forget them once found. I used to expect the Fn worst. But 9 times out of 10 it usually turns out to be something so simple that it makes you feel dumb.

Keep going. No rest for the weary.