En cette chaude saison, il convient d'investiguer un peu plus l'influence de la température sur les fuzz germanium.
En effet, selon la légende, pas mal de producteurs de studio mettaient leur fuzz Ge au frigo avant les prises de son, et que le son était meilleur.
récapitulatif des infos dispo (infos de TGP)
Quelqu'un de TGp avec une fulltone 69 a eu des soucis en concert en plein soleil, le son ne faisait que craquer et sauter
Témoignage de césar diaz, concepteur de pédale
Citation:
Cezar Diaz:"I was also the one to introduce Stevie to the Fuzzface. He didn’t know what one was until In Step. He had a Univibe, but he never used it, and I brought in a Tycobrae Octavia and the Fuzzfaces. I had 2 of the original ones marked NKT, which stands for New Market. They would tend to sound really good when they were nice and cool, but when they got hot, they’d go down.
The fix for any old Fuzzface that has germaniums is to put it in the freezer. Take it out, play your song and replace it with another one that’s cold. It has to be germanium though, because silicon doesn’t react the same way."
Apparament le coup du freezer donnerait plus de gain
Normalement le controle de "bias" des pédale permet de corriger ces désagrément, or je viens d'apprendre qqchose que je ne savais pas:
Bien que le controle de bias est cool et permet d'aider avec les soucis de temperature, il ne permet pas de retourner au son "normal" pour différentes raisons, la principale et qu'il ajuste généralement un seul transistor. meme si vous rebiaser le deuxieme, vous allez avoir un plus haut gain. donc bien que le son sera plus doux, la structure meme du gaan sera changé, et donc le son général également
[quote= Gas pedals]Although a bias adjust knob is cool and will help with temp issues it wont return it to "normal" operation for several reasons, the main one being it is usually only adjusting one of the transistors. Even on the second tranny you are rebiasing to accommodate the higher gain, so although you can smooth it out the gain structure is altered which means the tone is altered.
.[/quote]
Analog man/mike serait en train de plancher sur une pédale qui prendrait en compte ce phénomène.
Certains concepteur conseille meme de mettre la pédale au frigo avant de jouer (aramat effects, monolith oracle)
témoignage d'un test:
Citation:
I took it out, plugged it up, and it was glorious. Just really friggin' cool sound. Fat, huge, but kind of sputtery too. I have a bunch of great pedals, but no other fuzz I've used can replicate the sound of a Germanium Fuzz Face fresh from the freezer
Un test de AMZ FX (créateur des fameux boosteur, et pas extension de la brown sound in a box)
Citation:
I was reading some posts on HCFX and a discussion about germanium transistors and temperature caught my attention. I decided to go into the lab to do a couple of quick experiments.
Results are after the break…
Room temperature was 72°F and my fingers were warm and dry.
I picked up a germanium AC188 with a pair of needlenose pliers and managed to place it into my test rig without touching the body of the transistor with my fingers.
Using my Peak transistor tester, I checked the gain and leakage, then pressed my fingers against the transistor case for 10 seconds and tested again. Then another 10 second heating with the fingers followed by a final test.
1st Transistor
HFE, Leakage
84, 150uA
95, 380uA (after 10s)
100, 500uA (after second 10s)
2nd Transistor
HFE, Leakage
84, 150uA
96, 400uA (after 10s)
100, 520uA (after second 10s)
As you can see, handling the transistors for just a few seconds caused a substantial shift in the gain and leakage measurements. I may do some more exact tests when I get the time.
On peut voir des changement significatif de valeur, après simplement quelque secondes de pression des doigts sur les composants.
Qu'en dites vous ?