..::: FRYETTE / SFDAmp / ex-VHT :::.. -Topic général-

Salut,
Quels marque d'EL34 choisiriez vous en remplacement dans une CLX, Le choix est tellement vaste, la qualité aléatoire selon les marques. Merci d'avance.

Oui il parait que c'est une bonne marque. Mes recherches me désigne des Svetlana =C=, fabriquées à St Petersburg, apparemment le top de l'EL 34 "abordable!

Salut tout le monde,
J'ai vais faire l'acquisition d'une tête FRYETTE CL50 + Fatbottom 212
Pouvez-vous svp m'expliquer à quoi servent les options ci-dessous ainsi que selon vous le meilleur réglage :
1/ POWER AMP MODE: ENHANCE/NORMAL/AUTO
2/ Boucle série ou Parallèle ? J'utilise un delay deluxe memory man
3/ Boost sur le front panel. Doit-il être activé pour l'activer ensuite sur le footswitch ?
4/ Depht, quel réglage optimal pour le fatbottom 212. Je joue du Rock - Hard rock

Après, je n'ai pas trop eu l'occasion de tester les différentes balances entre le master général et le volume de chaque canaux mais en gros comment les utiliser ? Quel impact sur le son ? Compression ?

Merci d'avance pour votre aide car en fait dès réception de la tête+baffle, je pars en répétition et n'aurait pas l'occasion de tester le matos en long en large. (je joue avec PRS CU24)

What's the difference between Series and Parallel effects processing?

The effects loop design in all current Fryette Heads and Combos, allow either Series or Parallel operation. In the Series mode 100% of the signal from the preamp section of the amp is routed through the send jack to be modified through the effects device. The modified signal is then returned to the effects return jack and sent to the power amp section for final amplification. Effects such as equalizers, compressors and multi-effects processors with fixed or programmable mix controls are typically operated in Series mode. Effects processors that can handle higher than typical guitar level signals are usually recommended in this application.

Effects such as reverbs, delays, and pitch shifting devices which can be set for 100% "wet" output can be operated in Parallel mode if desired. In Parallel mode only a portion of the preamp signal is routed to the effects send jack for processing. In this case the original signal path inside the amp is protected from the sometimes undesirable side effects of external devices such as signal loss, impedance mis-matching, coloration of the sound and distortion. The processed signal is returned to the amp to be blended with the internal dry signal and then sent to the power amp section for final amplification.

Although it is possible to use pedals in the loop, it is generally not advised as the higher signal level in the loop can overload the pedals instrument input. Although this will not damage anything, it could result in undesirable distortion and loss of dynamics.

4. What's the difference between Class A and Class A/B operation, and how does it affect the sound?

Generally speaking, the power tubes in a Class A amplifier operate at pretty close to full power whether or not a signal is being amplified. As long as the tubes are being operated at reasonable voltage and bias range we're OK. The beauty of this type of operation is that there is no significant difference between the tubes’ work interval and its rest interval. The distortion products created by this method of operation are very musical sounding and the overall tone has a pure quality.

When combined with the right output transformer, the harmonic blend created by the tube distortion characteristic and transformer saturation (that is to say, just past the point of maximum linear operation), is rich, full and fat sounding. It sounds pretty much like an amp turned up loud even when it isn't because it's operating nearly full out in a sense.

In class A/B operation the tubes are getting a big break. How much of a break is determined by the bias idle current setting. When no signal is present the tube is essentially at rest. When you begin to play, there occurs a transition from "off" state to "on" state between the push-pull pairs of tubes. This transition, known as the crossover region, produces a noticeably different type of behavior typically referred to as crossover distortion. Crossover distortion contributes harshness to the sound which can give the amp an aggressive personality. This can be interpreted as a good thing depending on what you are trying to accomplish musically. How the tubes are biased determines not only the tubes idle current, but also whether a greater or lesser amount of crossover distortion occurs. A high bias current will minimize crossover distortion, however, if set too high the tubes will overheat and could fail prematurely. Too low and increased crossover distortion will cause the amp to sound fizzy and lifeless.

The real up side of Class A/B operation is its inherent efficiency. The simple fact that each tube has a rest interval in its duty cycle allows the tube to operate at higher output during its work interval or "on" state. Thus, a power amp operating in Class A/B will typically produce about 30% more power than a comparable Class A amp. Since the typical output transformer in a Class A/B amp will not be required to operate at high continuous current, it will spend less time in saturation mode. This contributes to the clarity and detail of the power amp sound.

An additional advantage of Class A/B is that because they tend to run cooler, tube life can be extended somewhat. For strictly comparative purposes however, the essence of the debate is sound quality. We are attracted to the Class A sound because of its warmth, sonic complexity and rich harmonic content. The Class A/B sound is more articulate, dynamic and gives us the sensation of immediacy.

Du coup j'ai testé la bête et l’avantage c’est que quoi qu’il arrive ça sonne. Vos explications m’ont bien aidé et je vous en remercie.

Seul Hic, c’est mon effet Delay.
Dans la boucle en mode «série», c’est facile, ça sonne super mais manque de poil vu que 100% du signal passe par l’effet. Gros avantage est que le volume derrière l’ampli permet d’équilibrer le niveau de volume de sortie de l’effet vs le volume de l’ampli sans boucle activée.
Dans la boucle en mode «parallèle», là, je ne comprends pas. En théorie, cela devrait être mieux. Mais au contraire le niveau de volume de sortie est trop bas par rapport au son de l’ampli lorsque la boucle est désactivée. En effet, le bouton sert de Mix comme expliqué sur le site de FRYETTE. Mais comment gérer le volume ? Est-ce avec le master volume général ou le volume du canal ? (Je suis en High Db).

Sinon j'ai testé le mode classe A qui a l'air plus souple pour mon jeu. Mais au bout de quelques minutes, cela sentait un peu le plastique brûlé ;(. je ne sais pas si c'était normal alors je n'ai pas insisté. Quid ?