Valves in old radios

[Mr. Foxen]

I was passing a charity shop, and there was an old valve radio in there. Had a look in the back and it had what looked roughly like a 12AX7 with Mullard written on it. What are the chances of that being a useable valve for my DHA pedal? Will the fact its been used in a radio for ages mean it probably won't be very good, or is the low power use in there going to mean its a good score? Being a charity shop the whole thing was cheaper than a NOS Mullard. Oh, and might it not have actually been an ECC85/12AX7?

[thedontcarebear]

There are loads of tubes that are the same size as ecc83/12ax7, so I would assume it is one unless it says it?

[bremen]

[quote name='Mr. Foxen' post='147681' date='Feb 27 2008, 10:43 AM']I was passing a charity shop, and there was an old valve radio in there. Had a look in the back and it had what looked roughly like a 12AX7 with Mullard written on it. What are the chances of that being a useable valve for my DHA pedal? Will the fact its been used in a radio for ages mean it probably won't be very good, or is the low power use in there going to mean its a good score? Being a charity shop the whole thing was cheaper than a NOS Mullard. Oh, and might it not have actually been an ECC85/12AX7?[/quote]

Low power valves last forever(ish)...though I've never heard of Mullard calling it a 12AX7, they used the name ECC83.

[obbm]

I would think it is very unlikely that it would be a 12AX7/ECC83. Radios use the same physical profile valves such as the EF** series for the RF stages and ECLs for the audio stages.

ECC83s are more likely to be found in old PA amps (Vortexion, Linear, Grampian) and some high-end hi-fi as well as guitar amps.

The only sure way is to remove the valve and see what it says.

[DHA]

[quote name='Mr. Foxen' post='147681' date='Feb 27 2008, 10:43 AM']I was passing a charity shop, and there was an old valve radio in there. Had a look in the back and it had what looked roughly like a 12AX7 with Mullard written on it. What are the chances of that being a useable valve for my DHA pedal? Will the fact its been used in a radio for ages mean it probably won't be very good, or is the low power use in there going to mean its a good score? Being a charity shop the whole thing was cheaper than a NOS Mullard. Oh, and might it not have actually been an ECC85/12AX7?[/quote]

It won't be a 12ax7 and most likely an RF valve, in fact there will be no valves in there which be any use to you. But, why not buy it anyway and use it as a radio, they sound great and are becoming collectors items. I have an old GEC radio I did up and got working.

dave