Walter66
Well-known member
- Joined
- Jul 13, 2020
- Messages
- 208
Hello,
planning to use a triod wired-pentode in the second stage of a MM phono preamp, Wondering which tube would make more sense concerning tube noise:
-E80CF: A. F. amplifier tube, pentode in triode mode operation
-ECL84: output pentode in triode mode operation
Both can drive the LCR network for RIAA equalisation via a 20K-600 Ohm transformer.
Will there be any restriction for not using a power pentode in a phono stage due to more noise compared to the E80CF?
Is the E80CF the tube better suited by design for such a phono unit, because its general low level A. F. amplifier tube?
Both can be run @ 8/10mA and 180V anode voltage, triode mode for low output resistance.
Both show linear operation with the simulation attached.
Which one to be preferred, please?
![ECF80 pentode simu triode.jpg ECF80 pentode simu triode.jpg](https://cdn.imagearchive.com/groupdiy/data/attachments/78/78089-c1a5834eeb68daaad25ee7d1a5ee5c9a.jpg)
![ECL84 pentode als triode.jpg ECL84 pentode als triode.jpg](https://cdn.imagearchive.com/groupdiy/data/attachments/78/78092-eb9206f1fa07615c7448d92641ef493c.jpg)
planning to use a triod wired-pentode in the second stage of a MM phono preamp, Wondering which tube would make more sense concerning tube noise:
-E80CF: A. F. amplifier tube, pentode in triode mode operation
-ECL84: output pentode in triode mode operation
Both can drive the LCR network for RIAA equalisation via a 20K-600 Ohm transformer.
Will there be any restriction for not using a power pentode in a phono stage due to more noise compared to the E80CF?
Is the E80CF the tube better suited by design for such a phono unit, because its general low level A. F. amplifier tube?
Both can be run @ 8/10mA and 180V anode voltage, triode mode for low output resistance.
Both show linear operation with the simulation attached.
Which one to be preferred, please?
![ECF80 pentode simu triode.jpg ECF80 pentode simu triode.jpg](https://cdn.imagearchive.com/groupdiy/data/attachments/78/78089-c1a5834eeb68daaad25ee7d1a5ee5c9a.jpg)
![ECL84 pentode als triode.jpg ECL84 pentode als triode.jpg](https://cdn.imagearchive.com/groupdiy/data/attachments/78/78092-eb9206f1fa07615c7448d92641ef493c.jpg)
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