trash picked tube record player question

[paulnichols]

question,im what you would call below average tube tech,but i know enough to do bacic electronic repairs for myself. so I see an old record player stick out of the top of a trash can .got an old school look to it knew right off the bat it was tube powered so i snatched it ,brought it home took the two wires off the needle right to my guitar with alligator clips,not much sound at all ,but some,,

Question 1:is this thing even worth the time to f with ?

Question:2 how do I make it louder?

attetched is a link to a pic of schematic

http://www.geocities.com/pnpnpnpnp/ampsch.JPG

[tboy]

is this thing even worth the time to f with ?
Could be... I've done some phono-to-guitar amp conversions that sounded pretty good. It would help to see the schematic (I get a blank page from the link you posted). Could you try uploading it here?

[paulnichols]

got a new link check it out.let me know?

[Tom Phillips]

good job posting the schematic that really helps a lot to answer your questions my input is it would be dangerous for a guitar amp because of the transformerless pwr suppy design also volume is real low because it is a low gain circuit designed for a high output ceramic phono cartridge but it could be a fun platform to learn on if you used a line isolation transformer between the wall plug and the amp

[bigaldo]

It would be dangerous to mod this phono.Look for at least a 3 tube circuit.1 rectifer tube,1 pre-amp,1 power tube.I ran across a phono setup for the blind that has such a circuit.It was a brezze to mod because the circuit lookes alot like a Kalamzoo number 1.If you can find a simalar older guitar amp schematic to follow,the mods are very easy to convert to a guitar type amp input.
question,im what you would call below average tube tech,but i know enough to do bacic electronic repairs for myself. so I see an old record player stick out of the top of a trash can .got an old school look to it knew right off the bat it was tube powered so i snatched it ,brought it home took the two wires off the needle right to my guitar with alligator clips,not much sound at all ,but some,,

Question 1:is this thing even worth the time to f with ?

Question:2 how do I make it louder?

attetched is a link to a pic of schematic

http://www.geocities.com/pnpnpnpnp/ampsch.JPG

[Enzo]

The trick to safely using these old transformerless models is to add an isolation transformer to the mains input.

[J Martin]

To make it in to a useful amplifier you will need to and a gain stage or two. The heater voltages of all the tubes in series need to match the line voltage. It will usually need a resistor in series with the heaters to make up the difference between what the actual tube voltages add up to and the actual line voltage. The voltages of the tubes can be different, but the current draw must be the same.

Change the 25L6 to a 35L6 .15Ma heater, add a rectifier 35Z5 .15Ma heater, preamp, pentode 12SJ7, or dual triode 12SL7, both .15Ma heaters. Total of 82 volts. Add 7 to 10 watt resistor to bring it up to your local line voltage.

There are a lot of schematics around for old amps that used these tubes. Find one for a template for your build.

[tboy]

ran across a phono setup for the blind that has such a circuit.

Is that a "talking book machine?" I'd like to see pictures if you have any. :cool: