All our preamp tubes are stringently tested for noise and microphonics using Amplitrex testers driving an external amp. There is no extra charge for low noise and microphonics testing like with other tube vendors. Additionally the tubes undergo a battery of tests for basic performance characteristics and faults such as: Emissions, Transconductance, H-K and Grid leakage, etc...
Further, all of our E88CC's undergo a lengthened test duration to insure stability and accurate test results (as is necessary with all high current pre's).
If a tube does not pass our strict performance criteria it's tossed or sent back to JJ Electronic for evaluation.
The JJ E88CC's are true to spec examples of the classic E88CC/ECC88/6DJ8/6922 tubes. These use JJ's short plate design which makes them very resilient to microphonics and mechanical noise. The Gold Pin variation is very open and lush sounding with an extended frequency response.
We recommend these for long tail phase inverter stages or anywhere that symmetrical performance between triodes is sought. It also gives you the plate current and transconductance spec for each triode which is nice if you're trying to keep records or maintain exact consistency from tube to tube. If you need multiple matched tubes please see our "Balanced and Matched" option.
