Which 12ax7 choice for cathode follower?
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Which 12ax7 choice for cathode follower?
Are there certain brands (NOS or current production) of 12ax7 that perform well as CF? Long or short plates matter?
Re: Which 12ax7 choice for cathode follower?
what application are you using it in? like what type of circuit?
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Re: Which 12ax7 choice for cathode follower?
Oh..sorry.
SSS
SSS
Re: Which 12ax7 choice for cathode follower?
most use a 12bz7 or 12bh7 or a 5751.
12az7 are great gain stage tubes. a 12at7 or any tube listed above are great current driving tubes. That whys Fender used the 12at7 as the PI tube a lot of times
12az7 are great gain stage tubes. a 12at7 or any tube listed above are great current driving tubes. That whys Fender used the 12at7 as the PI tube a lot of times
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Re: Which 12ax7 choice for cathode follower?
splgeo..thanks for the info . Anyone else care to comment? Maybe some folks here who have built an SSS w/CF
- martin manning
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Re: Which 12ax7 choice for cathode follower?
SSS circuit values as shown in the schematic are for a 12AX7. There are no special requirements, so I recommend you try a few and find one that you like.
Re: Which 12ax7 choice for cathode follower?
12ax7 is fine, but you'll want to avoid certain designs. For instance, through experimentation, I've found that Tung Sols aren't a good choice.
Re: Which 12ax7 choice for cathode follower?
12ax7 is fine, but you'll want to avoid certain designs. For instance, through experimentation, I've found that Tung Sols aren't a good choice.
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Re: Which 12ax7 choice for cathode follower?
Mhartman, thanks. Would that be the current production Tung Sol?
Re: Which 12ax7 choice for cathode follower?
Yes, current production. They tend to hum.
Re: Which 12ax7 choice for cathode follower?
Not IME. The one's I've used have been very quiet, and have had a nice detailed high end, IMO.mhartman wrote:Yes, current production. They tend to hum.
It's true i've lost my marbles and i cant remember where i put them
Re: Which 12ax7 choice for cathode follower?
I have a recollection of posts here or elsewhere regarding some modern 12AX7s not being up to CF duty, issues w/ the cathodes not handling the voltage well. Maybe others can follow up or the OP might want to google it.
and Merry Christmas.
and Merry Christmas.
Re: Which 12ax7 choice for cathode follower?
Maybe it was just the batch that I had. They were fine everywhere except the Post-PI CF.JD0x0 wrote:Not IME. The one's I've used have been very quiet, and have had a nice detailed high end, IMO.mhartman wrote:Yes, current production. They tend to hum.
Last edited by mhartman on Sat Dec 26, 2015 5:19 pm, edited 1 time in total.
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Re: Which 12ax7 choice for cathode follower?
I'm gonna try a few different brands...mostly NOS. Do they benefit if they have matched sections?
Re: Which 12ax7 choice for cathode follower?
I used an RFT 12AT7 NOS in CF stage , good choice!
S.
S.