Converting tube radio to guitar amp

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And here's the schematic. Thanks in advance if anybody is able to help me out here.

>>1205266

Yes it is R3

But for the love of god, just trash the thing. it is of the type that the chassis is LIVE (AC on the chassis and your guitar connected to the hot side of mains). These were safe only inside the insulated enclosure.

>>1205264
If you're thinking fires were less common back in the day, that's not true. Fires were simply not reported as often - because, with these instruments, fire was a natural part of life.

>>1205264

This is a cool project OP. I take it you don't plan to ever play in public.

"Please be patient while Captain Dreadlocks takes half an hour to get his hipster amp working again. Thanks for you patience."

>>1205266
You better invest in an isolation transformer if you plan to use that thing.

>>1205306
Alright, I've got a bunch of 2W resistors on order and there's nothing you can do to stop me.

In all seriousness, I've been planning out an insulated enclosure for this thing because I do realize how dangerous this unit is, even if nothing goes wrong. I'm guessing it wasn't even safe to begin with.

>>1205317
Nope, just a fun little project that will make for a neat (and possibly very "exciting") practice amp.

>>1205335
Do you have any tips or considerations for installing an isolation transformer and/or other safety features?

Muh series filament

Go over 90Ohms, as the line vltage is no longer 110 Volts. What about 2 220 Ohm resisors in parallel?
Also, prepare to blow up the puny original loudspeaker. Replace with a cheap and nice Jensen

>>1205660
Mains voltage (in the US) is realistically still about 110 or close to it. I've seen 120 at the wall, but it's the exception to the rule.

I've already taken the original speaker off the chassis; the cone was fucked even if I wanted to use it. I have a speaker on hand that I'm planning to use (can't remember the manufacturer and can't be assed to look just this minute).

>>1205586
>I've been planning out an insulated enclosure for this thing
You still have to connect the guitar to it - with a wire.
Also expect about five watts of audio power.

>>1205814
I'm going to switch out the plug with a three prong one, add an isolation transformer to the circuit, and make any other safety fixes I can think of. I'm also planning on picking up a socket wiring tester while I'm at this.

I'd honestly be fairly surprised if the thing could even do five watts, but we'll see.

>>1205306
fuck off moron, he should fix it.

>>1205925
grounding the chassis will very likely add noise.

>>1205335
not necessary.

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>>1205264
Here is the riders.
replace the 90 ohm 2 watt resistor with a 90 or 100 ohm 5 watt resistor.

An isolation transformer is not necessary, replace all paper and electrolytic caps. if the dial lamp is not working replace it with a GE 47 bulb. don't worry about the input voltage as the schematic states it can handle 105 to 125 volts as long as all the resistors are within specs.

If the speaker is not a permanent magnet type you can't just replace it with any speaker.

the electrolytics can be replaced with either 33uf or 47uf, I would use 200 volt caps.

verify resistor ratings from their markings as many old schematics listed meg when they meant kilo ohms

>>1205264
Converting that to a guitar amp is pointless. you would be better off finding an old tube guitar amp schematic and build it.

>>1206829
I'm going to order a shitload of 5 watt resistors because I might make a hobby out of this. I have a few more radios on deck and a steady supply for cheap. I already have 630 volt caps in values close to the originals inbound.

>>1206834
This whole conversion/restoration will cost me ten to fifteen bucks. You can't even get the parts for a Champ 5C1 for close to that.

>>1206829
>An isolation transformer is not necessary
Uh huh. And why's that, considering he's going to connect his guitar to it?

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>>1206945
Assuming that your plan here is to replace the phono cartridge with an instrument jack. Are the tubes fresh? Would there be enough gain available to hear over the strings of your guitar?

>>1206964
C7 and R9, presumably. Pic related

>>1206973
That's the plan. Guitar output and phonograph output are roughly the same level, so if it ever worked it should work now.

Tubes aren't fresh but I'm not horribly concerned.