5E3 build with low volume

[Apexelectric]

Hey all,

Was wondering if you could offer  some assistance in troubleshooting a problem I am having with the new 5E3 build. The amp seems to function perfectly normal other than the volume level. I have been through it numerous times in making sure that all of the  component values are correct as well as double checking all of the solder joints. Tubes test out OK.  It is a typical 5E3 design other than the addition of grid stoppers, grid leak resistors, negative feedback, cut control, .022 coupling caps and selectable bypass capacitor on V1.

All the voltages seem to be in order but I would like a second opinion.   Grid stoppers are between pins 1 and 5 and grid leaks are between 4 and 6. Here are the readings.

HT secondary 343-0-343
Heaters 6.57V
Rectifier heater 5.24V
B+1 363V
B+2 325V
B+3 252V

V1 pins
1-163V
3-1.28V
6-174V
8-1.29

V2 pins
1-163V
3-1.34V
6-203V
8-19.3V

V3 pins
3-358V
4-327V
6-327V
8-21.3V

V4 pins
3-361V
4-326V
6-326V
8-21.2V

Pictures to follow

[JB]

All the voltages seem to be in order but I would like a second opinion.   


V4 pins
3-361V
4-326V
6-326V
8-369V

Assuming V3/4 are the 6V6's, have you really got 369V on the cathode of V4 or is that a typo?

[sluckey]

V3 pin 8 and V4 pin 8 should be tied together. How can they read different voltages?

[Apexelectric]

Typo on V4 pin 8. Same voltage as V3

[sluckey]

HT secondary 343-0-343??? I would expect about 450v or even more, but you only have 363?

Please describe just how low the volume is.

[Apexelectric]

Volume is backround music level like what you'd expect from a portable radio.

Secondary voltage on the transformer is 343 phase to center tap in VAC

Hammond 290BX PT

It seems to be getting the right B+ at 363V

[Tony Bones]

How is the NFB being applied?

[Apexelectric]

56k resistor attached to the 8 ohm output from the 1.5k cathode resistor of V2. Volume results are the same with or without the NFB

[Apexelectric]

Pic

[JB]

HT secondary 343-0-343??? I would expect about 450v or even more, but you only have 363?

Agreed.  Whats the B+ with only the rectifier installed?

Feels like somethings pulling a lot of current.

Tried a different rectifier?

[Apexelectric]

Found a short on the unused 4 ohm output that was causing the issue. 

[Apexelectric]

Going by the layout on the Fender 5C3 that actually shows voltages unlike the 5E3 layout/schematic which has none, the voltage at the first filter cap is listed at 360V. I have 364V. Was there a major change in the 5E3 voltages?  The readings I'm listing are at idle with all the tubes installed and with a 5Y3 rectifier. Am I missing something?

[JB]

I think you're about right.  The 5Y3 is not a very efficient rectifier so that's where most of your volt drop is going.

How does it sound?

I've played a couple of originals and a very good 'boutique' cloan with a Vox blue in it.  Wonderful amps, more of an extension of your guitar really, part of the instrument.  I'd love to build one but it's the kind of amp that needs to be turned up loud which is not domestically compatible!



 

[Apexelectric]

Sounds pretty good. Paired it with 2 x 10 Celestion Golds which sounded better than a single 12" ceramic. I think I'll tweak V1  some to see how well I can dial it in.