Radio (?) Tubes

[jishnudg]

A family friend, an old Radio enthusiast, is selling off a bunch of tubes -
EBC81
EZ81
ECL82
ECC83
EF89
UF89
UM84
UBC81
UCH81
UY85
I'm planning to pick some of these up, just to try them out..never worked on any tube-based projects before...so just wanted to know, which of these can be used successfully in preamp or power amp stages?
Thanks.

[Scruffie]

The ECC83 is our friend the 12AX7 so that's probably the most useful.

And the ECL82 is useful as a triode and pentode in one package, that gets used as a power pentode (it's closeish to an EL84, I think) and phase splitter usually (I think it was used in a vintage marshall).

The rest sure some more knowledgeable guys can help with.

[stallik]

EZ81 is a rectifier tube if you were intending to build an amp with valve rectification

[StarGeezers]

  Just look up the tube spec sheets and see what the operating parameters are... and it's suitability for our type of audio projects ... We've found many odd numbered (unfamiliar)  tubes that sound really sweet in guitar amps , and can be had for a pittance , compared to the "popular" tubes...  

[amptramp]

All you need to know is here:

http://tdsl.duncanamps.com/tubesearch.php

This is an online tube manual with links to other manuals.  As StarGeezers said, here are a lot of radio and TV tubes that are good for audio and do not cost a lot because they are not popular for audio.  The EBC81 is a double diode triode (a tube with a triode and diode plates operating from the same cathode).  It has a µ of 70 which is good for situations where the µ of 100 in a 12AX7 is a little to much.  The UBC81 is the same tube with a different heater rating.

The EF89 is a remote-cutoff pentode which is suitable for use as a modulator for a tremolo or anything else where gain control is used.  The UF89 is the same tube with different heater ratings.

The UM84 is a tuning eye tube, which can still be used as an amplifier as well as indicating the signal - think how that would look on a stompbox!

The UCH81 is a triode-heptode used in radios for frequency conversion.  The heptode section offers two control grids where one can be signal and the other volume control, so you can build a tremolo where the volume modulation circuitry is completely isolated from the signal.  Use the triode as a phase-shift oscillator and the heptode as the modulator.

The UY85 is a single diode with a heater rating of 38 volts at 100 mA.

Not all of these tubes are equally useful, but there are obviously some functions that should suggest applications here.

[jishnudg]

Wow, thanks, guys - - will definitely check out all the specs first....yeah, I was going to pick up the ECC83s anyway - - at 10$ per piece (NOS BEL Mullard tubes) they'd really be a bargain

[stallik]

At those kind of prices for a mullard ecc83, I'd be tempted to buy everything you can. There's plenty here who would be interested in your surplus

[StarGeezers]

   Gentlemen.... Over at Wattkins.com  we've developed many great sounding guitar amps using those  NOS "odd" tubes...  and the inexpensive Russian military surplus tubes, which turn out to be quite GOOD !!!     May be worth having a look eh .... 

[jishnudg]

Thanks for the input, guys - - got myself a bunch of the ECC series, expect a year of tube based queries ahead

[tubegeek]

Thanks for the input, guys - - got myself a bunch of the ECC series, expect many years of tube based queries ahead

FTFY