Our ROETEST tube tester

MORE MODERN: Our ROETEST tube tester is a computer-based precision-type measuring device.

EXTREMELY ACCURATE: Our ROETEST is ALIGNED and CALIBRATED to full specifications on a regular basis, using a CALIBRATED Agilent Keysight 34450A (5+1/2 digits) laboratory grade multimeter.

FINEST RESOLUTION: Measurement values down to a few microvolts / microamps!! We believe that's the maximum accuracy a tube tester can have.

PRECISION: Compare THIS with your vintage or outdated tube tester: All the test voltages at ROETEST are stabilized and regulated, and this belongs not just to the anode voltage and grid voltage, but also to the filament voltages. Can you do better?

WORLD LEADING: All of our efforts are resulting in a tube test setup that can be considered as „State of the Art“.

COMPARABILITY: All measurements are taken under datasheet conditions of each tube. What does that mean? If you are looking at an old datasheet (i.e. Telefunken E88CC), all of the values are given for the "typical operations condition", and that's what our ROETEST automatically does.

PERFORMANCE: At Koschuh, even the consumer versions (example: ECC88 and 6DJ8) have to undergo the test parameters of the matching LONGLIFE type (i.e. E88CC longlife tube).

RELIABILITY: This is where it get's interesting FOR YOU: The whole testing process is automated, there is no way to cheat. Not just only we don't want to cheat, we also CAN'T. It's that simple.

DATA DATA DATA: A whole lot of data is available for EVERY single tube AND included as a print-out. In example (ECC88, list of data could vary on different types of tubes):

• Anode current: static emission (exactly as per manufacturers datasheet) in mA and %
• Symmetrical BALANCE of the triodes, visible down to a few micros
• Transconductance (german: Steilheit) in mA/V
• Anode current: in relation to different grid-voltages
• inverted or reciprocal amplification factor (german: Durchgriff, not used in GB and USA though)
• Anode current at a different anode voltage
• internal resitance (kOhms)
• Vacuum Test (change of Ia with or without a resistor in front of grid 1
• Curve tracing is available as an option (please ask)

Our measuring process is completely automated. Whilst the tube is working under fixed and stabilized datasheet conditions, the operator has NO abilities to trick or cheat in any way. Exactly after 300 seconds of operation, a whole bunch of measurements are taken on the first triode (info: the ECC88 / 6DJ8 consists of two independent triodes). After another 300 seconds, the second triode is tested within the same procedure. It takes us a total of more than 600 seconds (!!!) to test only one single ECC88 tube. This is a very time consuming process. But it gives you the most convincing test results, expert data you can rely on. Also, you can reconstruct all of our measurements, by using the same type of measuring procedure. Or simply by using a fully aligned ROETEST - as we do.

Do not trust vintage test equipment if it's not fully aligned and CALIBRATED. As an example, we have had 6 years of experience on an OLD Funke W19S tube tester ourselfes. We decided that this oldtimer is pretty much outdated nowadays, even though it was recently serviced and aligned, and running on a re-built AC mains voltage (220V +/-0.1%). We later found out that it gave us random test results. This problem belongs to many other OLD test equipments. Also, many tube sellers test after a much shorter preperation / heat-up time. Probably (but most likeley) these test results are less reliable than our PC-based measurements with stable voltages and fixed testing times. Also, consider the vast majority of OLD tube testers to be vulnerable on many different points: In example, if the AC mains voltage gains or drops just a little bit, it will greatly affect the anode current (as the Funke W19 did, unfortunately, hence we used a AC lines regulator, which did not solve all problems either). Unregulated filament voltage as often seen on vintage test equipment will result in less or more electron emission, depending on the drops and gains of the AC mains voltage, or other variables. Unstable and heat-dependent anode voltage is also commonly seen on old tube testers. And their analog instruments are sometimes unprecise. The needle of the instrument sometimes rest in different positions from time to time under same test figurea. Un-documented since human "read-out" allows cheats and "errors". Exzessive heat in old test equipment, altering components, old soldering joints, bad contacts on switches AND sometimes the tube sockets aswell. Well, old tube testers are nice to have, but the (sometimes) don't give you proper measuring results. This can ruine your day.All of this can be avoided, by using the ROETEST, as we do. So you can really buy with confidence.

TUBE TEST SERVICE: Wanna have tested your OWN tubes? Send them to me, and I will do a performance test on my ROETEST for a small testing fee. Please ask.

YOUR OWN ROETEST: contact me for sales. Pre-order now.