Yeah, there are lots of 12AX7 substitutes with varying amounts of gain. Off the top of my head, 7025 (which might be full gain but mil-spec), 5751, 12AT7, 12AY7. Hiwatts came with a 12AT7 in one position but it's very common to put a 12AX7 to get more gain, for example.
About them tubes.
I've been messin around with tubes for my Blackstar HT Studio 20 head as I am/was extremely unfamiliar with tubes in general. Just something I overlooked in the past and didn't bother with too much. I have been fairly pleased with the BS20H, except for the dirt channel. You basically have up to 3 to get a nice crunchy tone and after that, full on distortion, from about 3 1/2 to 10. Just wayyyyyy too much. So I took a random poster at Blackstar forum's advice and plugged in 2 EH 12AY7's instead of the 12AX7's.
It instantly changed the ENTIRE sound of both the clean and dirty channels into a sweet clean overdriven Dirty channel that can easily be cranked past 5 in both the Volume and Gain while maintaining a previously impossible clean, bright and shiny tone......with a TON of bite.
The clean channel just cleaned up even more as it was previously getting some dirst up around the 5 mark. Perfectly clean up till 7 now.
This is just 5 minutes worth of testing sa I have to run out, but man I'm glad I picked those 12AY7's up for this amp. To me, the $45 upgrade in tubes is like a $450 upgrade to the amp.
Sorry for the longish post, I'm pretty pumped about this as it's been bugging me for a while now. Anyone else run into something similar with other Amps and tubes? I know it's probably a discussion that's been had before, but maybe someone here who is new to tube amps can gleen some very valuable info from this stuff.
EDIT: Oh yeah, the lower powered tubes also act as a pseudo attenuator that keeps all tone and makes it better!!
It instantly changed the ENTIRE sound of both the clean and dirty channels into a sweet clean overdriven Dirty channel that can easily be cranked past 5 in both the Volume and Gain while maintaining a previously impossible clean, bright and shiny tone......with a TON of bite.
The clean channel just cleaned up even more as it was previously getting some dirst up around the 5 mark. Perfectly clean up till 7 now.
This is just 5 minutes worth of testing sa I have to run out, but man I'm glad I picked those 12AY7's up for this amp. To me, the $45 upgrade in tubes is like a $450 upgrade to the amp.
Sorry for the longish post, I'm pretty pumped about this as it's been bugging me for a while now. Anyone else run into something similar with other Amps and tubes? I know it's probably a discussion that's been had before, but maybe someone here who is new to tube amps can gleen some very valuable info from this stuff.
EDIT: Oh yeah, the lower powered tubes also act as a pseudo attenuator that keeps all tone and makes it better!!
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@keto...so I've read. But for someone like myself, I just wouldn't believe it made that much of a tonal difference until I've heard the results myself (after cursing the amp for being way too muddy and overdriven). I'm thinking about doing the same to my Peavy VK112 now as well. The 2nd channel Gain channel on that amp is too much as well. I also noticed a ton of harmonic nuances cutting through that used to be hidden by the excessive distortion. Might consider the Blues Jr. I have as well, but maybe with the 80% gain ones. I think that's the 12au7..not sure. I obviously need to do more research. With the help from people here, like yourself of course. I feel like a little kid at Christmas for Christ sakes.
1 - 3 of 3 Posts
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