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Topic: Preamp valves |
Billy Murdoch
From:
Glasgow, Scotland, U.K.
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Posted 8 Jul 2007 7:38 am |
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I know very little of electronics and would welcome any help with understanding valves(pre amp)
The different valves on offer are many,most have the ident number 12Ax 12Ay 12At and so on almost ad infinitum.
The sales blurb usually goes on to describe how great sounding the particular valve is,but it is not too easy for me to make out the benefits(Tone?)in one over the other.
For example If I were changing the valve in a
(One valve)Pre amp unit would I have to use like for like or can I go with any 12??valve,will I do any damage by using a different valve?
Best regards
Billy |
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Jonathan Cullifer
From:
Gallatin, TN
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Posted 8 Jul 2007 9:01 am
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The different tube types are of different gain values. For a given signal, a 12AX7 will amplify it the most. The other variants have a lower gain, depending on the tube. There's a chart of different gain vales (Av) here. They can be generally swapped out without any ill effect; it's just a matter of gain.
Most of the reviews you read about are about a specific brand of one of these tube types. There are some 12AX7s that sound better for steel guitar than others. There's also other mechanical issues, and every tube is a compromise between sound, noise, microphonics, and durability. |
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Billy Murdoch
From:
Glasgow, Scotland, U.K.
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Posted 8 Jul 2007 9:35 am
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Tank You Jonathan forn the very informative link
Billy |
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Paddy Long
From:
Christchurch, New Zealand
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Posted 10 Jul 2007 5:40 pm
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| Billy - Brad Sarno can probably give you the definitive word on tubes, if you tell him about the application and the current valve size ! |
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