Vacuum Tube Valley Dual Triode Characterizer
Sunday, December 18th, 2011Finally I had time to look at my VTV Dual Triode Characterizer. About a year ago I found it in a collection, since then it was on a shelf taking dust. The unit was in mint condition, only the “Triode-to-Triode Balance” button needed to be replaced.
Vacuum Tube Valley Dual Triode Characterizer ($1.199)
It has serial number 133 and it was calibrated on May 20th, 2005. Unfortunately I had to take out the PCB in order to replace the button.
It took me about one hour including some outside cleaning before it was ready for testing. It has a 12Volt/1,2Amp Power input (2.5mm), headphone out (1/4″ jack) and a scope output connection (BNC) for advanced user features.
Device Controls:
On/Off Switch – Turns instrument on or off. Regulated 12v DC power supply must be attached.
6/12V Heater – Switch to 6V for tubes having 6 volt heaters, such as 6DJ8/ECC88, 6SN7, 6CG7, etc. Switch to 12V for 12 volt heater tubes such as 12AX7/ECC83, 12AT7/ECC81, etc.
Rotary Switch – Test Gain for High-Mu Types is the position to use for high-mu tubes, such as 12AX7/ECC83, 12AT7/ECC81, 5751, etc. Switch to Test Gain for Medium Mu Types, for tubes such as 12AU7/ECC82, 6DJ8/ECC88, etc. Switch to Test Noise/Microphony for testing the noise of a tube. Adjust Speaker Volume as required.
Tube Type Switch – Switch to upper position only when testing lower mu triodes, such as 6CG7, 6FQ7, 6SN7, 12SN7 and a few others. Switch to bottom position for all other tube types.
Triode-to-Triode Balance Button – Press only when a reading of DC balance is desired. Release this button at all other times.
Triode Test Selector – Set to 1 to test triode 1 in the tube. This would be the triode on pins 1, 2 and 3. Pins 6, 7 and 8 are triode 2.
Speaker Volume – Potentiometer
Dual Meter – Gain reads on the left, Balance on the right side.
After reading the Quick Users’s Guide I put in the first tube to test an Amperex ECC81 “buggle boy”, set it to 12Volt Heater, High-Mu and switched it on. Right away the meter is nicely lightened with a dark orange light and the tube starts to glow. Leave it running for at least one minute and let the meter stabilize before reading the results.
Socket Saver and Octal Adapter ($70)
Socket Saver/Octal Adapter (optional) This will allow for testing 6SN7, 6SL7, 12SL7, 12SN7, 5691, 5692, 6113 or 6188 tube types, as well as the usual 9-pin miniature dual triode types. The adapter attaches to the front of the Characterizer, using two thumb screws that thread into the two holes on the front panel. The adapter can also be rewired to test other small-signal tube types having octal or nine pin miniature bases.
WANTED: Schematic, calibration instructions and the adapter above, please contact me !
