Weber 5F6A build with no output

[Delmar Evans]

Hello to all. Im new to amp building and new to the forum. Have had great success building several 5E3's Tried my hand at a 5F6A bassman using a Weber layout. So far, no output. Have reviewed all wiring and components on the turret board. All appear good at this point. Have not checked any voltages as of yet, and am looking for some guidance. Any thoughts appreciated.

Regards,

Delmar

[martin manning]

Measure and record voltages on all tube pins and power supply nodes and post them.

[Delmar Evans]

With tubes in or out?

Regards

Delmar

[LOUDthud]

Test voltages with the tubes installed and a speaker connected. All the controls should be set midway. When you touch the meter probe to some pins you may hear a click or hum or maybe even a radio station. This generally means that the amp is basically working from that point back to the speaker.

Did you examine the input jacks to make sure that the jacks you used match the ones in the layout?

[martin manning]

Tubes in. You don't need to measure the rectifier tube pins if you have good DC voltage on the OT CT.

[Delmar Evans]

Thanks for the quick responses. I will
Check all voltages and reply tomorrow.
Getting late here. On the output jacks,
I used 4 RCA jacks. I will attach a photo
Have there been problems with these jacks?
Normally I would have not used these,
But I'm building the amp for a friend of
Mine.

Regards

Delmar

[Delmar Evans]

Oops , mis spoke on input jacks. Was
Thinking of speaker RCA jacks. Yes input
Jacks are shorting jacks

Regards

Delmar

[Delmar Evans]

Well I started taking some voltage readings. Seems like what I have so far does not look correct. I attached a spread sheet.. Any thoughts appreciated

Regards,

Delmar

[Delmar Evans]

Guess my attachment did not go do here
I'd s jpg

[Teleguy61]

There's no voltage on V2.
I'd say there's your problem, check wiring.
Looks like you are missing a connection from power node D to R24.

[ToneMerc]

There's no voltage on V2.
I'd say there's your problem, check wiring.
Looks like you are missing a connection from power node D to R24.

I agree that problem is at that node, I bet The jumper between the filter cap and the bottom of the 10K is missing.

TM

[Delmar Evans]

Yep. No jumper from 8 uf cap to
Pin 6 of V 2. I knew that v2 was
An issue but I was looking at it too
Hard! Actually looking but not
Seeing ! Thanks to all. Will discharge
And solder tomorrow. Too tired now.
Here is a pic of my invisible wire !

[ToneMerc]

Yep, no B+ feed to V2 would do it.

TM

[Delmar Evans]

Couldn't wait. Powered up V2. Pin 1
At 174 vdc pin 3 at 1.26 vdc. Pin 6 at 337 vdc
And pin 8 at 177vdc. Much better. However
No output at speaker. What is interesting
Is the output sounds like it is coming out
Of the chassis ! Like it's coming directly
From a tube it output transformer !

Regards

Delmar

[tubeswell]

So the chassis is microphonic? Could be a dodgy input jack tip switch not quite closing. Or could be bad lead dress picking up some stray EMF