2003年11月30日 · The 12DW7 has two different sides, one with a gain factor of 100 like a 12AX7, and one with a low gain factor of about 20, like a 12AU7. The pinout of the two tubes is the same, so there's no harm done substituting one for the other.

2016年3月15日 · I have a stash of 12dw7 tubes, about 50 50 with Sylvania, RCA, look Sylvania, some GE, and Mullard Gr Briton. All my American Sylvania etc, have big plates, they push the gm on the tester for sure, my Mullards have smaller skinny plates. Mullard has a reputation for good midrange in 12ax7s, and...

2005年4月11日 · Both the 12AX7 and 12DW7 have twin triodes, meaning there's two independent sections. On the 12AX7 both sections have a gain of 100. On the 12DW7, one section is a gain of 100 (just like a 12AX7) but the other half has a gain of 17 which is basically a 12AU7. I'd use what the circuit calls for!

2014年10月14日 · I had to open my blackface walkabout to tighten down the transformer nut (thing keeps coming loose, I need to put some silicone on it) and decided to drop a Mullard 12DW7 in position 1 (left most tube slot). I have only been able to hear it at practice volume but using my RA Deep 5 with it, the...

2019年6月29日 · The 12DW7 (7247) is a dual triode that is basically half 12AX7 and half 12AU7. Depending on the amps design, you might be able to substitute a 12AX7 for a 12DW7.

2005年4月11日 · My amp tech has mentioned that it can be hard to find “good” 12DW7’s. This may not be the case anymore as I hear that JJ is making some good tubes these days(?). But it got me to thinking, if I we’re to change out all the 12DW7’s in an early Ampeg SVT to 12AX7’s, would there be a significant...

2009年7月13日 · 2 Vintage Sylvania 12AX7 Halo or "O" Getters Left! $50 shipped for the pair and PayPal accepted or $25 each. I originally purchased these tubes for an Ampeg V4 rebuild. I have 4 NOS 7027A's, 3 12AX7's, 1 12AU7, and 1 NOS 12DW7. The tubes all tested...

2011年12月25日 · The 12DW7 is half 12AX7 and half 12AU7. 12AX7 and 12AU7 have different gain structures and different operating points; so it would be necessary to modify the CTM300 for 12AX7 tubes to operate properly.

2007年7月17日 · 12DW7 in Ampeg SVT - JJ vs. NOS Discussion in ' Amps and Cabs [BG] ' started by Hoss, Jul 16, 2007 .

2012年12月1日 · I have a kustom 300hd head that has bad high frequency hiss. I was sold a replacement for the 12ax7 but now I realize the tube is marked ecc832 which is 12dw7? Can I use it?