ceriatone 5f1 with junk parts voltage?

[nosaj]

I've build a 5f1 going from ceriatones layout
I've gone over and over but something is not right. It is built from junk parts new caps new resitors.

on the rectifier no tube pins 3 getting 305 VAC pin 6 305 VAC

5Y3 inserted on pin2 405 volts and pin8 423 volts

6v6 pin3 406 pin4 374

12AT7 pin1 160 pin6 153

Amp sounds like crap with low volume, want to sub in another OT, but I think the voltages are a preceeding issue. Can anyone steer me in the correct direction?

Power supply caps are 22uf 10 uf 10 uf.

Thanks,
Jason

[eschertron]

I've build a 5f1 going from ceriatones layout[ATTACH=CONFIG]32076[/ATTACH]
I've gone over and over but something is not right. It is built from junk parts new caps new resitors.

on the rectifier no tube pins 3 getting 305 VAC pin 6 305 VAC

5Y3 inserted on pin2 405 volts and pin3 423 volts

6v6 pin3 406 pin4 374

12AT7 pin1 160 pin6 153

Amp sounds like crap with low volume, want to sub in another OT, but I think the voltages are a preceeding issue. Can anyone steer me in the correct direction?

Power supply caps are 22uf 10 uf 10 uf.

Thanks,
Jason

If you are only dropping 30v across the screen node resistor then 30v/10kR = 3ma. Subtract a couple ma for the preamp, and you're left with nothing going to the screens! Doesn't add up. Also, the drawing shows pin 3 of the rectifier not connected, where you mention taking voltage readings. Is it wired correctly?

edit: also the schem calls for a 12AX7 in the preamp. Use that tube before judging the overall volume of the amp.

[nosaj]

No mistyped for the rectifier. Where would you like measurements at and I will get them for you.

Thanks,
Jason

[Diablo]

Measure the voltage across the 470R cathode bias resistor. That'll tell us if the 6V6 is drawing proper current.

[eschertron]

No mistyped for the rectifier. Where would you like measurements at and I will get them for you.

Thanks,
Jason

Is the socket wired for 5Y3 and/or 5Y4? the schem does not show it. The schem shows no connection on pin 3 of the rectifier tube. What do you have there?

edit: AC HV will be on pins 4 and 6 of the rect, DC HV will be pin 8 to ground.
on the 6V6, pin 3 to ground is the anode, pin 4 to ground is the screen, and pin 8 to ground is the cathode (what Diablo has asked for).

[Jazz P Bass]

For sure tell what rectifier you have.

There is a way to wire the socket for the 5Y3 & the 5Y4.

[nosaj]

Is the socket wired for 5Y3 and/or 5Y4? the schem does not show it. The schem shows no connection on pin 3 of the rectifier tube. What do you have there?

edit: AC HV will be on pins 4 and 6 of the rect, DC HV will be pin 8 to ground.
on the 6V6, pin 3 to ground is the anode, pin 4 to ground is the screen, and pin 8 to ground is the cathode (what Diablo has asked for).

5Y3 pin8 408 no connection on pin3 was a mistype.

6V6 pin3 407 pin4 370 pin8 49 volts (cap there is a 400v instead of 40v)

12ax7 pin1 147 pin6 137

Thanks,
Jason

[eschertron]

pin 8 of the 6V6 49vdc??!!

Check the cathode resistor (in parallel with the 400v cap you mentioned). The schem calls for 470 Ohms. DO you have a 1k or above resistor there? the cathode voltage on a single 6V6 should be around 20v to 23v (depending on plate volts). I'm thinking you have an extremely cold bias snuffing the life out of your sound.

edit: a quick look at a simulator tells me you've got ~20k Ohms resistance on the cathode. If the resistor is correct, hit the eyelets with some heat in case you have a cold joint.

[nosaj]

Welllll... I guess that K makes a difference there was a 470k in it's place, I'll change it out and report back.

Thanks a bunch,

Jason

What simulator are you using?

[Diablo]

Welllll... I guess that K makes a difference there was a 470k in it's place, I'll change it out and report back.

Thanks a bunch,

Jason

What simulator are you using?

Make sure the 470 ohm resistor has a large enough watt rating.

[eschertron]

[QUOTE=nosajWhat simulator are you using?[/QUOTE]

I have a link to a page called Interactive Valve Data Sheets from black magic amps. Useful. And entertaining!

[nosaj]

18 volts and sounding much better. Thanks a bunch kinda of neat building something from junk when it finally works. It's not the prettiest job but will put some pics up soon.

Thanks all,

Jason

[nosaj]

2watt dale work?

[eschertron]

18 volts and sounding much better. Thanks a bunch kinda of neat building something from junk when it finally works. It's not the prettiest job but will put some pics up soon.

Thanks all,

Jason

Great! Looking fwd to the pics (can't be any less pretty than the amps I've put together so far!).

Curiosity prompts me to ask what the voltages are on pins 3 and 4 of the 6V6. Should be lower, now that current is actually flowing

[Diablo]

2watt dale work?

Yes, that's fine.
Glad to hear it's making loud noise...