low B+ voltage on a fresh 5f1 build

[mort]

I'm getting squealing when the volume is raised even with no input, and with input sound is made but is very undesirable choppy output.


Here are my voltages:

V1
1. 130.3
3. .9
6. 143.1
8. .9

V2
3. 416
4. 223
5. .55
8. 19.6

V3
343 AC in, 423DC out

In place of the 10K resistor at the first B+ node I used an 11K 2W. That shouldn't make that much of a voltage drop. Do I more likely have a bad resistor or could something else be going on here?

this is a straight forward 5f1 build except for the 11Kr
http://3.bp.blogspot.com/_BYIkYo9cnn..._5f1_schem.gif


The layout is a little non-standard but I don't see where any problems could come from it...

[loudthud]

Chances are you need to reverse either the Primary or Secondary wires to the Output Transformer. On the Primary side one is usually Red and the Other Blue. If one has been cut too short, you can reverse the wires at the Speaker Jack unless one of the wires is grounded to the Output Transformer frame. Only reverse the wires at one place.

[mort]

When I've had that issue come up in the past it made the amp go BBBBBRRRRRRRRRRRRRRR very loudly...

it can also make for a voltage drop and choppy sound?

[mort]

Well I guess it can!

I had thought of that too but like I say, it sounded WAY different when it happened last time (different amp). I swapped them at the speaker jack just to rule it out and voila, problem gone.

I didn't realize that swapping at the jack also works but it only makes sense. Thanks for pointing me back to what I had taken for granted!

[eschertron]

I'm glad it's working for you, I hope you post some sound clips soon. Nice layout on that amp. I especially like the bus-bar approach: clean and classic looking!

I'm fond of this amp. I've been heavily modding my champ600, still on the PCB but many components have been swapped out at this point. FUN! I'm currently waiting on parts to convert the tone stack to a 5E3 style.

[mort]

I'm glad it's working for you, I hope you post some sound clips soon. Nice layout on that amp. I especially like the bus-bar approach: clean and classic looking!

I'm fond of this amp. I've been heavily modding my champ600, still on the PCB but many components have been swapped out at this point. FUN! I'm currently waiting on parts to convert the tone stack to a 5E3 style.

I just happened to have already made a quicky little clip for the owner of the amp. https://soundcloud.com/factsisfacts/f1

If you ever swap in an eyelet board, be careful of the fuse holder. The end spade is tall and didn't clear the cabinet and broke off the first time I slid it into its place. Bending the end spade over at 90 degrees did resolve it.

[The Dude]

BTW,....nice looking build!

[eschertron]

I just happened to have already made a quicky little clip for the owner of the amp. https://soundcloud.com/factsisfacts/f1

If you ever swap in an eyelet board, be careful of the fuse holder. The end spade is tall and didn't clear the cabinet and broke off the first time I slid it into its place. Bending the end spade over at 90 degrees did resolve it.

Thanks for sharing! I continue to be inspired by the folks on this forum.