Post by drgtr1957 on Oct 27, 2014 17:50:57 GMT -5
I played one of my Streetrods Saturday and was bothered all evening by microphonics. First set was rough, but I swapped some spares in and figured it would help. It helped SOME, but I still had the ring.
So today I took the covers off, cranked the volume and gain on third gear with no instrument plugged in, and fingernail tapped all four 12AX7s, the replacements. Every single one, ESPECIALLY V2, rang like a bell in there. I'd put 3 new Tung Sols and a JJ in. Then I popped them, put a Splawn OEM in V2 and some Russian Mullards in 3 and 4, and an old Mesa SPAX7 (the old super non microphonic tube that came in the old Mark IIs, pre shrinktubing) and the Splawn in particular just went into oscillation immediately. The Mullards were about as bad, and the SPAX was even clanging.
So I'm going to try a couple of other experiments later tonight or tomorrow, with a few NOS tubes I have and the new set of gain hardened JJs I ordered. I know that V2 seems to be the most important tube in terms of high gain playing (I assume so anyway), so I wonder if a microphonic V2 will amplify those tendencies in subsequent tubes. Then again, I'm not a fan of the Russian phonies like Tung Sol and Mullard, so chances are they're just garbage anyway.Oddly, EHs in 2, 3 and 4 were very stable (Russian again) and a GT in V1 was quiet. I've got some quality JAN 5751s and AT7s, along with some Mullards and Telefunkens I'm just going to begin sequencing to see what's most reliable and what I should carry for spares.
So what tubes are hardy and stable for youse all?
So today I took the covers off, cranked the volume and gain on third gear with no instrument plugged in, and fingernail tapped all four 12AX7s, the replacements. Every single one, ESPECIALLY V2, rang like a bell in there. I'd put 3 new Tung Sols and a JJ in. Then I popped them, put a Splawn OEM in V2 and some Russian Mullards in 3 and 4, and an old Mesa SPAX7 (the old super non microphonic tube that came in the old Mark IIs, pre shrinktubing) and the Splawn in particular just went into oscillation immediately. The Mullards were about as bad, and the SPAX was even clanging.
So I'm going to try a couple of other experiments later tonight or tomorrow, with a few NOS tubes I have and the new set of gain hardened JJs I ordered. I know that V2 seems to be the most important tube in terms of high gain playing (I assume so anyway), so I wonder if a microphonic V2 will amplify those tendencies in subsequent tubes. Then again, I'm not a fan of the Russian phonies like Tung Sol and Mullard, so chances are they're just garbage anyway.Oddly, EHs in 2, 3 and 4 were very stable (Russian again) and a GT in V1 was quiet. I've got some quality JAN 5751s and AT7s, along with some Mullards and Telefunkens I'm just going to begin sequencing to see what's most reliable and what I should carry for spares.
So what tubes are hardy and stable for youse all?