Question about Champ schematic

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surfsup
Posts: 1513
Joined: Mon Nov 29, 2010 12:21 am
Location: Chicagoland

Question about Champ schematic

Post by surfsup »

I've been going over the Ceriatone layout with a fine-toothed comb to get better at this stuff. I've managed to reverse the layout into a schematic that I've drawn up and saved as a JPEG, posted below.

The Ceriatone seems exactly the same as the vibrachamp except for a few components and values. A few questions:

1) R6 (470R 2W) on 6V6 is added - did I put this in the correct place on the schematic? Pin 4 on the 6V6 I assume is not used, but I see on the pinout it is a screen2 for the tube so not sure how to put that in the schemo
2) The two cathodes V2b and V2a are connected on the layout (blue "B" on my schematic) - did I schemo that correctly?
3) The mains ground runs to the star ground. I asked this in a separate topic earlier but I'll ask again...good practice? Should the mains ground be separate?
4) The diodes on recto tube, do I have them in the right direction?
5) boost switch? Right place?

All in all this was a great exercise, I learned alot. Oh, and I added a 2nd input. Did I do that right?

[img:1066:1067]http://ceriatone.com/images/layoutPic/f ... Layout.jpg[/img]

[img:1562:972]http://chicagocadcam.com/ChrisHahn/sche ... _Champ.jpg[/img]

Here are the passive components to match my schematic:

C01 Capacitor Rectifier 6-4 0.01 uF 3kV
C02 Capacitor Smoother 33 uF 450V
C03 Capacitor Smoother 33 uF 450V
C04 Capacitor Smoother 22 uF 450V
C05 Capacitor PT k 22 uF 63V
C06 Capacitor V1 pin6 0.022 uF
C07 Capacitor V1 cathode 10 uF 25V
C08 Capacitor V1 Treble 250 pF Red
C09 Capacitor V1 to Bass bypass 0.1 uF Yellow
C10 Capacitor V1 to Bass 0.047 uF Yellow
C11 Capacitor V1 cathode 25 uF 25V
C12 Capacitor V2 pin7 0.022 uF
C13 Capacitor V2 pin7 0.01 uF
C14 Capacitor V2 pin3 25 uF 25V
C15 Capacitor V2 pin7 0.01 uF
D1 Diode Rectifier N10047 UF
D2 Diode Rectifier N10047 UF
P1 Potentiometer Volume 1M A
P2 Potentiometer Treble 250k A
P3 Potentiometer Bass 250k A
P4 Potentiometer Speed 2M A
P5 Potentiometer Intensity 50k C
R01 Resistor Artificial CT 100R 1W
R02 Resistor Artificial CT 100R 1W
R03 Resistor Standby 100k 3W
R04 Resistor R2 - smoother 1k 2W
R05 Resistor R3 - smoother 10k 2w
R06 Resistor PT 6-4 470 2W
R07 Resistor PT k 750R 5W
R08 Resistor V1 pin6 220k
R09 Resistor V1 anode 6 100k
R10 Resistor V1 4ohm selector 2.7k
R11 Resistor V1 cathode 1.5k
R12 Resistor Bass to Boost switch 15k
R13 Resistor Speed Pot 100k
R14 Resistor V1 anode 1 100k
R15 Resistor V1 cathode 1.5k
R16 Resistor V1 Grid Stop 22k
R17 Resistor Input1 68k
R18 Resistor Input2 68k
R19 Resistor R1 - Input Jack 1M Carbon Film
R20 Resistor Speed Pot to ground 100k
R21 Resistor V2 cathode to intensity 68k
R22 Resistor V2 6-1 470k
R23 Resistor V2 pin3 4.7k
R24 Resistor V2 pin2 to ground 1M
R25 Resistor V2ak to Tremolo 1M
R26 Resistor V2ak to V1bk 47R
Firestorm
Posts: 3033
Joined: Fri Jan 25, 2008 7:34 pm
Location: Connecticut

Re: Question about Champ schematic

Post by Firestorm »

surfsup wrote: 1) R6 (470R 2W) on 6V6 is added - did I put this in the correct place on the schematic? Pin 4 on the 6V6 I assume is not used, but I see on the pinout it is a screen2 for the tube so not sure how to put that in the schemo
It goes between C3 and Pin 4 of the output tube. There is no Pin 6 (well there is, but it's not connected to anything).
surfsup wrote: 2) The two cathodes V2b and V2a are connected on the layout (blue "B" on my schematic) - did I schemo that correctly?
No they aren't. Look again. If you meant V1B and V2A, those aren't connected either. R26 goes below R11 in series to ground. Feedback from R10 is connected at that junction. If you connect the feedback directly to ground, you have no feedback.
surfsup wrote: 3) The mains ground runs to the star ground. I asked this in a separate topic earlier but I'll ask again...good practice? Should the mains ground be separate?
"Proper" practice is to give the safety ground its own connection, but this is often ignored.
surfsup wrote: 4) The diodes on recto tube, do I have them in the right direction?
Yes.
surfsup wrote: 5) boost switch? Right place?
Yes, but you have not completely followed the wiring of the tone stack shown in the layout. For example, the wiper of P3 is shown going to C9, not to C10.
surfsup wrote: All in all this was a great exercise, I learned alot. Oh, and I added a 2nd input. Did I do that right?
Not quite. R19 should go from ground directly to the input pin on the #1 jack. The shorting tab on the #2 input is connected here, too. When plugged into #1, you want the 1M to come first, then the paralleled 68Ks. There is no way to completely replicate the Fender two jack circuit and still have your grid stopper right on the tube grid pin. Once you move R19, #1 input will have 1M to ground and 56K in series to the grid; #2 input will have the 68K/68K voltage divider and 22K grid stop, so 90K in series to the grid. You may lose a little high end. If this is noticeable, you might experiment with a lower value grid stop.
surfsup
Posts: 1513
Joined: Mon Nov 29, 2010 12:21 am
Location: Chicagoland

Re: Question about Champ schematic

Post by surfsup »

R26 goes below R11 in series to ground. Feedback from R10 is connected at that junction. If you connect the feedback directly to ground, you have no feedback.
So really I should remove the line on the schemo off v1b cathode between R10 and R11 going to "B", then move R26 below R23 and move that "B" reference up to the top of R26 with ground referenced off teh bottom of R26?

I see the tonestack error. I'll fix that.

I'll correct the input jacks.

Okay that was better than I thought. Thanks so much for your help!
Firestorm
Posts: 3033
Joined: Fri Jan 25, 2008 7:34 pm
Location: Connecticut

Re: Question about Champ schematic

Post by Firestorm »

surfsup wrote:
R26 goes below R11 in series to ground. Feedback from R10 is connected at that junction. If you connect the feedback directly to ground, you have no feedback.
So really I should remove the line on the schemo off v1b cathode between R10 and R11 going to "B", then move R26 below R23 and move that "B" reference up to the top of R26 with ground referenced off teh bottom of R26?
Remove the "B" reference altogether. The line from R11 goes where you have it, but R26 goes below that, to ground.
surfsup
Posts: 1513
Joined: Mon Nov 29, 2010 12:21 am
Location: Chicagoland

Re: Question about Champ schematic

Post by surfsup »

All right I made all the corrections and reposted the schemo on the OP. Mind doing a once-over to double check my work? I think I did the input correctly as you described. Funny though, the way I had it was the same way it was on one of the original fender schemos...
Firestorm
Posts: 3033
Joined: Fri Jan 25, 2008 7:34 pm
Location: Connecticut

Re: Question about Champ schematic

Post by Firestorm »

Still don't have the input right. You DO want the way Fender did it, which is not the way you originally had it, nor this way. The 1M goes to the junction of the input 1 hot lug and the 68K. The shorting tab on input 2 goes there too. Look at a blackface schematic to see it.
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