Deepdark
Well-known member
I playing with my la2a circuit and different tubes for fun. First, I had some low cost JJ. Works good, have a little hum with headphone at max only. Tried chinese dump taken from a Bellari, works great (no jokes) no hum at all. Tried a old RCA 12AU7, works great, too. Tried the infamous 12ay7 (Electro hrmonix) wow! what a great sounding little beast. No hum at all. Then Sovtek 12AX7WA. Unusable. really. Louder hum than the JJ, quiet a good bit to be honnest. Not unusable, way under audio passing thourhg, but it is there. But the worst of all, the ringing. It can't even take a bit of drive without beginning to ring and sound weird. Both the 2 I tried. To be honnest, I didn't read any technical data sheet about teh WA to be sure it was ok. Maybe it's something related with Sovtek brand, I don't know. Weird.
But, it's interesting to see how different brand, different manufacturing time and so on can change the overall fonctionnality and overall performance of a given unit, it's noise characteristics, etc.
But, it's interesting to see how different brand, different manufacturing time and so on can change the overall fonctionnality and overall performance of a given unit, it's noise characteristics, etc.