Help please! 5f1 champ build with No sound!

[theguitaristspeaks]

Hello all- I recently built a 5f1 clone into a Danish cookie tin- thought it would be a cool project. Turned it on, tubes light up, no smoke, plate voltages are good, and I can clearly see a healthy glow from gas inside the 12ax7 that increases when I change the volume. But- no sound. Yes, I checked the speaker and speaker cable, and the input cable- I clearly must have wired something incorrectly- but I've been troubleshooting for days now and to no avail. Any ideas?! Any help is most appreciated!! Thanks

Tommy

 

[kevinkr]

Moved to appropriate forum

 

[kevinkr]

Detailed pictures of your build and the actual circuit you built to are the minimum required if you want some helpful comments.. 😀

 

[mcandmar]

I can clearly see a healthy glow from gas inside the 12ax7 that increases when I change the volume.

There is your problem right there, you shouldn't see anything inside the tube other than the heater glow

Double check your 12ax7 wiring, or post a few pics incase we can spot something wrong...

 

[theguitaristspeaks]

Thanks for the quick replies!! I'll get pictures up right away. The glow I'm referring to is not red-plating, but a bluish purple glow that I've seen before in healthy tube amps- although I could be mistaken.

 

[theguitaristspeaks]

Pics of the circuit board and tube sockets on the way one at a time- I can't get it to post several at once.

 

[theguitaristspeaks]

An overall of the circuit- the previous one was the 12ax7 socket and power switch/indicator (heater wire is twisted red/black)

 

[theguitaristspeaks]

Rectifier socket left of the board

 

[theguitaristspeaks]

6V6 socket on the right of the board

 

[theguitaristspeaks]

A close up of the input jack and volume pot with the 12ax7 socket visible to the left

 

[theguitaristspeaks]

Schematic diagram of the circuit

 

[theguitaristspeaks]

Circuit layout

 

[theguitaristspeaks]

This is the type of glow (not a picture of mine) visible in the 12ax7- look familiar to anyone?

 

[theguitaristspeaks]

The first pic was supposed to be this one

 

[theguitaristspeaks]

Output jack and heater center tap visible here- (I didn't have heatshrink so for now it's electrical tape... I know, i know. What a hack I am.) lol

 

[theguitaristspeaks]

A close up of the input jack and volume pot with the 12ax7 socket visible to the left

Oops. To the *right*. Lol. It's easy to see how I may have made a mistake, eh? 🙄

 

[mcandmar]

Its almost impossible for me to work out what i am looking at in those pics. Which tube is which?

I think the blue glow is caused by drawing excess current, i.e. a problem with the anode or cathode connections. What plate voltages are you seeing?
The volume control changing the color is also very strange. Also double check your wiring against these schematics...

 

[theguitaristspeaks]

Thank you macandmar, I will check out those diagrams. My rectifier voltages read at: pin 8 @ 380 V, pin 2 @ 384 V, Ac voltage in is 335 on both plates. 12ax7: pin 1 @240V, pin 6 @ 210 V, and the 6V6 reads 380 plate volts with 327 grid volts.

 

[theguitaristspeaks]

There's definitely a few subtle differences between the original Fender and the Hoffman version... I also wired it with 1 input with a 33k resistor rather than two with two 68k's. I don't get how that worjs, I'm just going by the diagram that came with the kit.

 

[theguitaristspeaks]

Mcandmar- I apologize for the messy layout- this is my first build. Lol! The rectifier is on the left of the board, the 12ax7 on the top, and the 6v6 on the right of the board.