Trouble with Fender Champ 5F1 clone.

[Travis]

I have new voltages for this amp with rewire:
5y3 tube:
pin2= 484 vdc
pin3=352 vac
pin6=352 vac
pin8=484 vdc

6v6 tube:
pin 1=.4
pin2=6.6vac
pin3=476vdc
pin4=461vdc
pin5=391 vdc
pin7=6.6vac
pin8=458 vdc

12ax7 tube:
pin1=278vdc
pin2=0
pin3=2.22vdc
pin4=6.6vac
pin5=6.6vac
pin6=423vdc
pin7=.09vdc
pin8=458 vdc
pin9=6.6vac

I didn't realize the heater wires were AC voltage, Crap! Now I'm not getting sound, not even a hum.

[Phil_S]

6v6 tube:
pin 1=.4 should be no connection, should be zero unless it was used as a tie point
pin2=32vdc measure a/c, should be about 3vac
pin3=486vdc, OK for now, maybe we will revisit this
pin4=470vdc, OK for now, maybe we will revist this
pin5=398 vdc, looks wrong to me
pin7=35vdc, see pin 2
pin8=467 vdc, cathode voltage should be a low negative, maybe -15 or -20.

12ax7 tube:
pin1=283vdc, probably/maybe OK
pin2=0, OK
pin3=2.22vdc, OK
pin4=45, need a/c reading
pin5=45, need a/c
pin6=472vdc, way high
pin7=.09vdc, OK
pin8=466 vdc, should a very small, maybe +2vdc give or take, like pin 3
pin9=45vdc, need a/c

Your work is very hard to follow due to all one color wire. Typical standard is red = B+, blue = plate, yellow = cathode, green = grid. There is obviously no requirement, but it makes trouble shooting much easier. If you have a set of colored markers or colored tape, you might try to mark each end of a run of wire (or even "paint" the whole wire) to help us see what you've done. The actual colors don't matter, but make it easier to see what you've done, and be consistent. If you only have one color, use a marking pattern, like long dashes and short dashes.

You've got some sort of miswire, probably more than one, and maybe an incorrect resistor value. When you give us an easier roadmap, help will be quicker to come to you.

[jjman]

I don't think you have grounded the 3rd leg on the volume pot. That doesn't explain the current problems but it need to be grounded, if not already.

[Phil_S]

How are you measuring the 6.3VAC filament supply? You should have ~3.15 on each leg to ground and ~6.3vac across the two legs. In other words, put your probes on the 12AX7, one to pin 9 and the other to pins 4&5 -- that should be 6.3VAC.

It bothers me that you have a reading on pin 1 of the 6V6. Is there anything soldered to that pin? If so, what; where does it come from?

As someone else requested, please give voltage readings with the 6V6 and 12AX7 pulled out of the amp.

[labb]

Just did a quick check on a 5F2-A (Princeton) which is pretty much a Champ with tone control. I am using a Hammond 268 ex pt with diode rectifiers that gives me 255 vdc after the diodes so My readings will be a little low.

6V6
pin 1 = 0
pin 3 = 242 VDC
pin 4 = 238.5 VDC (I added a 1K resistor on the screen)
pin 8 = 13.19 VDC (240 ohm cathode resistor)

12AX7
pin 1 = 145.1 VDC
pin 6 = 141.9 VDC


Hope this helps. I have the amp on the bench right now so I can take any readings you would like. Let me know.

I took a quick look at the original layout and it can be a little confusing.

[Travis]

Im not sure on the wiring for my OT. I have 4 wires: black, red, blue, yellow.
I have the blue wire on pin 3 of my 6v6, the red wire is on my capacitor, the black wire is on the speaker and the yellow wire is connected to a resistor that feeds a leg out to the speaker. Am i doing this right?

[Travis]

im not getting any sound now so im thinking i might have something wired up wrong. I'm not sure if i have the OT wired up correctly. I have the black going to the speaker, red going to the board, blue going to pin 3 on the 6v6, and yellow joining the 22k resistor from the board and legging out to the
+ speaker term. Am I doing this right?

[Travis]

Im going off this layout.

[labb]

For some reason I can not get to your layout..For a check go over to Weber Amps, under kits look at his layout for the 5F1 Champ...Whose OT are you using?

[Travis]

TRANSFORMER, OUTPUT, 8 WATT, 3.2 OHM, REPLACEMENT FOR FENDER

P-TF22905

Replacement for Fender Champ, VibroChamp, and Bronco amps, 4 ohms. Equivalent to #125A35A & #022905.

Specifications
Audio Watts (RMS): 8
Primary Impedance (Ohms): 7,000
Secondary Impedance (Ohms): 3.2
Mounting centers: 2-3/8"
Weight: 0.6 lbs

[joebob]

Travis, Look at this layout & schematic it may be more helpful. I was in a hurry to post something for you, so I did not search much. But this is what i found. It will give you a good idea on what it should look like with maybe a couple of exceptions. (1.) your xformer may not have a 6.3v CT (green/yellow striped wire) this should go to ground. (2.) the schematic shows the use of a pair 100 ohm resistors, this is used if you do not have a 6.3v CT (3.) the layout/schematic shoes a bleeder resistor across the 22uf/450v cap (4.) this has 2 inputs. So there maybe just a few differences then yours but you should be able to trace the layout and schematic to see if yours is not quite right.

Here is a good link that should help you too.
http://www.paulrubyamps.com/info.html

Dave

[labb]

You are right on the OT wiring...Look at your Rectifier tube wiring..a 5Y3 is normally wired: Red (PT secondary) to pins 4 and 6. Yellow (filament wiring from PT) to pins 2 and 8 (this is 5 VAC). Also pin 8 to first filter cap. Pins 1, 3 5 and 7 should not have any connections.

A good thing to do is to take the layout, the schematic a high liter and go through your amp one connection at a time.Trace out each component as you have it wire, mark it off on the schematic and the layout. Make sure all match up.

PS: Don't get discouraged. This is really part of the fun. There are folks on this board that will get you through it. Keep the faith.

[Cygnus X1]

I was going to say something snide...(like HELP I SMELL SMOKE!!!).


But I went back and read my first few posts.

All I can say is, it's a great group of folks helping out here, pay attention.
Best part is these guys have urged me to not just do, but to learn!
Got my nose back to the books, and that's what I am doing.

Props to the forum!

[Travis]

Thanks to all!! I'm working on this thing now and getting 460 volts to the speaker. Holy crap! Now I need to figure out why because I looked over the wiring several times and it's all the same. I'm missing something. Thanks again to you guys, especially in dealing with my simple problems.

[jjman]

The light socket was wired in series instead of parallel in the 1st pic. Has that been rewired? The layout you are using does not show some of the wires. One is the grounding of the volume terminal I mentioned. Another is grounding the "other" terminal on the bulb. If using original type layout, the 2 wires on the bulb should each be on the same terminal of the socket. Your latest voltages imply you fixed the heaters. Check on the alternate heater wiring strategies out there and go "original" or artificial CT type. I don't see a CT on the your heater winding, which is an original characteristic. You need the artificial CT to eliminate hum if you have gone that route.

I was going to change my V-Champ's heaters to artificial CT but the original setup isn't humming.