Blues (Tube) OD απο Seymour Duncan

[alderbody]

μου ηρθε απο το newsletter του SD (σιμουρ ΝτιγκιΝτάνγκαν ;D) και ειπα να το μοιραστω

 

Προκειται για λαμπατο πεταλι/preamp με Blues προσανατολισμο.

 

διαβαστε:

 

http://www.seymourduncan.com/products/stompboxes/sfx11_power_gri/

 

 

 

[alderbody]

βασικα, αυτο μου φανηκε ενδιαφερον: (μεταφορα απο το newsletter)

 

Unlike its Twin Tube brethren, the SFX-11 features a duet of premium, subminiature, USA-made Phillips-Sylvania® 6111 dual triode tubes. These tubes are voiced similar to a familiar 12AU7 and represent the pinnacle of tube technology. They were designed and manufactured to meet the U.S. Government’s MIL-E-1 spec for reliability under conditions of severe shock, vibration, and temperature. They provide extremely long service life and exhibit virtually no tendency toward microphonics.

 

Speaking of tubes, too often, inexpensive tube gear runs in “starved plate mode,” where the tubes function like clipping diodes and do not actually amplify. The Twin Tube Blue’s high-plate voltage and 100% vacuum tube signal path allows the tubes to operate at their fullest potential and provide maximum dynamic range. The means you get the most gain and all the smooth, bluesy tone you expect from a high-quality tube preamp. 

 

 

[roybatty]

βασικα, αυτο μου φανηκε ενδιαφερον: (μεταφορα απο το newsletter)

.....

Speaking of tubes, too often, inexpensive tube gear runs in “starved plate mode,” where the tubes function like clipping diodes and do not actually amplify. The Twin Tube Blue’s high-plate voltage and 100% vacuum tube signal path allows the tubes to operate at their fullest potential and provide maximum dynamic range. The means you get the most gain and all the smooth, bluesy tone you expect from a high-quality tube preamp. 

 

Nα και οι μπηχτές  :)

Από FAQ γνωστού κατασκευαστή λαμπάτων (και όχι φτηνών) "πεταλιών":

Q: Don't tubes required high voltage to work?

A: This is true. To make tubes sound good and clean, they need lots of voltage. Since we are not trying to get the tubes to sound good, but are trying to get the tubes to distort, we starve them to suit our purpose. Nasty trick… but it works.

http://www.tonebone.com/tb-plexitube-faq.htm

 

Aν και σε γενικές γραμμές ο SD έχει δίκιο,αυτό δεν σημαίνει πως δεν υπάρχουν και καλά πετάλια με starved plate design,ασχέτως αν είναι περισσότερο "plexi-hybrid" παρά "plexi-tube"  ;)

 

[alderbody]

Aν και σε γενικές γραμμές ο SD έχει δίκιο,αυτό δεν σημαίνει πως δεν υπάρχουν και καλά πετάλια με starved plate design,ασχέτως αν είναι περισσότερο "plexi-hybrid" παρά "plexi-tube"  ;) 

 

σωστα. Αλλωστε το θεμα ειναι τι ζηταει ο καθενας. 

Το καθε design εξυπηρετει συγκεκριμενο σκοπο/κοινο κλπ.

[bloody_sunday]

Προσωπικά έχω ακούσει και παίξει με λαμπάτα πετάλια που είναι πολύ ωραία κι απ'τη μια, κι απ'την άλλη κατηγορία. Και ορισμένα από αυτά καθόλου "inexpensive", όπως λέει το newsletter. Oύτε πρέπει να το ρίξουμε στο πυρ το εξώτερον... να πχ. τι κάνει το πατενταρισμένο κύκλωμα των πεταλιών Cooltron της Vox (όμοιο με ένα άλλο που χρησιμοποιείται, όπως λένε τουλάχιστον, σε μερικούς high end λαμπάτους για hi fi):

 

Normally, tubes are used at high voltages and this restricts their use in battery-powered devices such as guitar effects pedals. Historically, attempts have been made to use tubes at low voltages in what has been dubbed “starvation” mode, but these circuits donΆt allow the tube to function in an acceptable manner. The tube simply cannot be biased to a satisfactory operating condition. Plus, the necessary heater (filament) current is too high to deliver acceptable battery life. Imagine how annoying it would be to have to change batteries every ten minutes during a gig!

 

HereΆs what makes the COOLTRON system tick. The COOLTRON circuit basically operates by using two very special signal paths. The first is the “servo circuit,” which provides the right conditions between the plate of the tube and the grid. This achieves controllable, stable parameters for the tube and provides the correct operating conditions for the tube to function as it would if run at a higher voltage. The second circuit is a patented power supply that provides a low voltage, low current supply to the heater elements in the tube. Since the tube is now running at such a reduced supply level, the anode current is much smaller than normal. This means that the amount of heat required at the cathode to achieve sufficient cathode current emission is much smaller – hence the ability to run the heaters at a lower level and for COOLTRON pedals to run for 16 hours on 4 x AA batteries!

 

The COOLTRON system provides true tube sonic performance at very low voltage and at reduced heater current – ideal for inclusion into guitar effects pedals.

(απ΄το σάιτ της Vox)

 

Tube-loaded stompboxes have been around for decades, and while some have featured conventional high-voltage tube circuitry, and others operated the tubes under very low voltage “starved plate” conditions, their designs have always been tethered by the need for some form of AC power. But thanks to some clever design work—including a special low-current filament/heater “chopper” power supply—the CoolTrons can operate for about 15 hours powered by four AA batteries.

 

The Cooltrons’ 12AU7A dual-triode tube is better suited for low-voltage operation than the more familiar, though closely related, 12AX7. The tube’s two triode sections are tied together, so it functions as a single tone-enhancing gain stage. (For prolonged battery life, the tube’s plates, as well as its heaters, run at approximately 3 volts DC.) This tube stage “building block” is essentially identical in all three pedals, while the rest of the circuitry—which is a mixture of op amp ICs and discrete transistors—is completely different in each design.

(από μια κριτική του Guitar Player)

 

(αν και εγώ βέβαια δεν χρησιμοποιώ το δικό μου με μπαταρίες αλλά με τροφοδοτικό, πλην όμως μου αρέσει η ιδέα γιατί ο θόρυβος είναι στην κυριολεξία μηδενικός)

[bloody_sunday]

Πίσω στο θέμα μας... ας το δούμε το πεταλάκι:

 

Aνυπομονώ να το τσεκάρω αυτοπροσώπως - δεν θα είναι και δύσκολο με το δίκτυο διανομής του γίγαντα που λέγεται Seymour Duncan, απλά εξαρτάται από το ποιο μαγαζί θα το ζητήσει για τη βιτρίνα του... Πάντως μέχρι στιγμής όλα τα λαμποβρωμοπέταλα της SD που έχω δοκιμάσει (βασιζομενα στην ίδια σχεδιαστική φιλοσοφία με τις λαμπίτσες-μινιατούρες) δεν μου άρεσαν.