Using short plate and long plate tubes together...

N

njm

New Member
Hi All,

Does anyone have any experience using both short and long plate tubes in the same amp? I have a 1959 Pilot 245-A integrated amp, and I just purchased a lot of 7 RCA 12AX7 tubes. The tubes tested NOS apparently, and four of them are long plate, and three short. My amp uses six preamp tubes, so I'd be mixing long and short. Just wondering if anyone had any insight here. Thanks!
 
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I would use the long plate in the first/important stages- as long as they aren't noisy. Long plates generally sound larger and more full/detailed. I'd try to use the short plates in the phase inverter stage or if you don't use the phono input much stick them in there.
 
c_corie said:
I would use the long plate in the first/important stages- as long as they aren't noisy. Long plates generally sound larger and more full/detailed. I'd try to use the short plates in the phase inverter stage or if you don't use the phono input much stick them in there.
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So the long plates in sockets 1-4, and then the short plates in 5 and 6. Is that right? (I'm somewhat of a noob when it comes to the precise workings of tube amplifiers, so sorry if my questions/comments are kind of obvious, senseless, etc.) So my phase inverter tube is a 12AU7A. I use a vintage Sylvania military tube I found NOS. But so is there a precise breakdown for how the preamp tubes belong to the different stages? Will my schematic show me, for example, that preamp tubes 1-3 belong to power stage, (or the correct term for that first stage), and tubes 4-6 to the phase inverter stage? Sorry for all the questions, and thanks again.
 
It doesn't matter if you are using long or short plated tubes. They are all the same tube and do the same job however you are probably approaching the psychoactive world of tube rolling for different sound. I'm not saying there is no difference in tube rolling, I'm just saying some people like me don't really care.
 
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Someone should be able to help as I'm not familiar with that amp, all my amps just have 1-2 preamp tubes. A schematic might tell you but I'm not sure how to figure that out...
 
century tek said:
It doesn't matter if you are using long or short plated tubes. They are all the same tube and do the same job however you are probably approaching the psychoactive world of tube rolling for different sound. I'm not saying there is no difference in tube rolling, I'm just saying some people like me don't really care.
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Yeah, it was one of those questions that was looking for subjective impressions from people who have bothered to form them in this regard. I'm guessing it's not a major point of consideration for most people.
 
njm said:
Right on. I'll do some more research.
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I can tell you that you will notice a difference in sound between a long and a short plate, provided you have decent speakers. It may be a big or small change depending on how picky you are, but there is a change/difference.

One of my SE amps takes a single 12AX7 so you can hear the difference much more as it’s the only “preamp” stage/tube it goes through.
 
c_corie said:
I can tell you that you will notice a difference in sound between a long and a short plate, provided you have decent speakers. It may be a big or small change depending on how picky you are, but there is a change/difference.

One of my SE amps takes a single 12AX7 so you can hear the difference much more as it’s the only “preamp” stage/tube it goes through.
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I know people prefer one or the other, so I assumed there was some difference. I use really nice sounding AR-2AX speakers, which are pretty detailed in the room I have them set up in, and the Pilot is a beautiful sounding amp, so I imagine I'll hear something. Probably what I'll do is play around with different configurations, see which I like best.
 
njm said:
I know people prefer one or the other, so I assumed there was some difference. I use really nice sounding AR-2AX speakers, which are pretty detailed in the room I have them set up in, and the Pilot is a beautiful sounding amp, so I imagine I'll hear something. Probably what I'll do is play around with different configurations, see which I like best.
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The other thing to keep in mind is sometimes the most detailed and clear sound is not the sound you want to live with every time you turn on your stereo, especially if you’re not always focusing 100% on the stereo while you listen.
 
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