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Old 19th June 2017, 11:48 PM   #1
vizion is offline vizion  United States
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Default 12AX7 SE baby amp

Has anyone built a 12ax7 SE amp ? I wonder how many milliwatts it can produce.
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Old 20th June 2017, 12:50 AM   #2
kevinkr is offline kevinkr  United States
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12AX7 plate resistance is too high for practical output transformers. (EAR did do a massively parallel PP amp with 12AX7A some time ago.)

Consider the 6CG7/6FQ7 or 12AU7A for a flea power SE if this is really the way you want to go.
"To argue with a person who has renounced the use of reason is like administering medicine to the dead." - Thomas Paine
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Old 20th June 2017, 01:05 AM   #3
PRR is offline PRR  United States
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As Kevin says, you can't make a wide-band audio transformer with enough impedance to get real power out of the 12AX7 high impedance.

I plotted 22K, the reverb transformer sold for Fenders using a 12AT7 reverb driver. Say 65mW. A bit more depending how you feel about max plate voltage. (I'm sure 400V is not instant death, but also not a lot more power.)
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Old 20th June 2017, 05:30 AM   #4
vizion is offline vizion  United States
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thanks guys
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Old 20th June 2017, 03:38 PM   #5
kodabmx is offline kodabmx  Canada
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The 6N*P except 6N2 are good candidates, too.
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Old 21st June 2017, 02:14 PM   #6
Ketje is offline Ketje  Belgium
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How about a serial SE
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Old 27th June 2017, 03:22 PM   #7
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6SN7, 12AU7, or 6DJ8 would be much better candidates... I can squeeze around a half watt out of a 6SN7 in SE.
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