For a push-pull output stage (tube amps), the scenario is different, since one tube amplifi es the positive “going” portion of the signal and the other tube amplifi es the negative “going” portion of the signal. In fact, if the world was perfect, we would need no bias since the positive side of zero would be handled completely by one tube and the negative side of zero would be handled completely by the other tube. This would be the proper defi nition of “class B operation”. Since tubes are not perfect devices, the transition at zero is not very linear…this is as one tube turns off, the other tube may not be quite ready to turn on. This can lead to a discontinuity of the signal around zero which is the worst possible place for it to occur—as it is highly audible and rather ugly sounding. The solution once again is to bias both tubes slightly “on” to allow for a more graceful handoff between the positive and negative sides of the signal, called “AB operation”. This is done by adjusting the bias just enough to achieve the necessary results. Too much bias and current will be wasted as heat dissipated within the power tubes and output transformer greatly shortening your power tube’s useful life. Too little bias may give the amp a cold, grainy texture.
WARNINGS:
·POWER TUBES BECOME VERY HOT DURING AND AFTER BEING USED.
·NEVER CHANGE THE POWER TUBES UNTIL THEY HAVE COOLED FOR AT LEAST 15 MINUTES.
·NEVER CHANGE THE TUBES WITH THE AMP ON!!!
·DANGEROUS AND/OR LEATHAL HIGH VOLTAGES ARE PRESENT INSIDE THE AMPLIFIER CHASSIS. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONS.
SPEAKER CABINET (combo version)
•The El Diablo 60 combo’s enclosure is constructed from ¾” birch plywood in a rear-ported cabinet design. This helps to support the low frequency response of the internal loudspeaker.
•The loudspeaker is our GBE 1240-V75 loudspeaker—the same model used in our popular GFLEX cabinets.
•The combo offers a removable back if desired but we recommend keeping the back attached for the full response of the El Diablo 60’s brute force.
GETTING STARTED:
•Since your EL DIABLO 60 ships with all tubes installed and the amplifi er fully tested, biased and burned-in at the factory, the user set-up is quite simple.
•Un-box your EL DIABLO and verify that the AC input voltage selector switch matches the power in your area.
•Verify that you have the correct mains cord-set for your area. This piece of information is primarily for our international customers who may have a choice of power receptacles in their country.
•Make sure to send in your warranty registration card.
•Read your owner’s manual. There is valuable information and safety tips in this manual and the knowledge you learn here will translate into enjoyable quality tone for years to come.
OPERATING EXAMPLES:
The sample settings that follow are intended as guidelines and a starting place to help you explore all the tones your new El Diablo has to offer.
Ultimately, your guitar, pickups and technique will have a tremendous effect on your tone; adjust these settings to suit your own unique style. Please remember though, your El Diablo has a highly reactive EQ section. The controls have detents to encourage the player to use subtle adjustments. You will be amazed how a “few clicks” will change the tone and feel of your amp.
DROP TUNING | (Pentode Mode) |
High gain, modern metal | |
