Salut les gards j'ai trouver ca :
Citation:
The Sovtek 12AX7LPS tube can die an untimely death in a lot of guitar amps. You can safely use 12AX7LPS in guitar amplifiers but only if you clearly understand the following information.
The 12AX7LPS has a voltage limitation of which most people are unaware: its cathode-to-heater voltage rating is lower than most other 12AX7 tubes. Since a "regular" preamp stage has very little voltage on the cathode (a couple volts DC if that), this isn't a problem for a "regular" preamp stage. The problem is when using the 12AX7LPS in a "cathode follower" type stage. This type of stage is effective for driving EQs and effects loops. Because of this lots of amps have cathode follower stages, including Peters amps. I could estimate that well over 60% of the tube guitar amps on the market have a stage of this configuration. Higher voltage is usually on the cathode of this stage (150VDC to 180VDC is common), and since the heater voltage is low (around 6V), the voltage between the cathode and heater is too large for the 12AX7LPS to reliably handle. This can and usually does end the tube's life very early. This can cause frustration and confusion due to the amp working improperly; sometimes the problem presents itself as extra noise, instead of "no sound at all", so it can be particularly annoying until the nature of the problem is discovered. Also when the tube fails it can cause damage to the amplifier.
The 12AX7LPS will work fine in amps with cathode follower stages as long as the 12AX7LPS isn't used in those particular stages. The key is to avoid using this tube type in that sort of stage. I have never shipped amps with the 12AX7LPS but a number of Peters amp owners have bought 12AX7LPS to try in the amps after they purchased the amplifiers. You might especially want to be wary of the tubes in your amp if you've bought it used, since you can't be certain that the original tubes are included with it; it can't hurt to remove each tube and read what it says on them just to be certain they're the right type for the job. All Peters amplifiers use only 12AX7 or ECC83 (equivalent) type, and have never been shipped with 12AX7LPS.
En clair (et vue mon pietre niveau en anglais) la Sovtek LPS, contrairement a ces idée recu, n'est pas bonne en PI
, et cela est due au petit voltage qu'elle son capable d'encaisser...
Bizzarre... vu le nombre de personne qui la pronne "meilleur lampe en PI"...
Il doit y avoir une raison si tout le monde l'utilise en PI...
Je compte m'en prendre une pour la PI en plus
(moi je prend quand meme et on verra...)
Quelqu'un connaissait ca ?
