Mesa/Boogie pmn - Manual (Page 14)

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BIAS SELECT: (Continued)
chording or soloing, to an all out high gain crunch or lead sound. Players that use mostly these
types of sounds may prefer the EL34 clip to the 6L6’s that come standard in the new RECT-O 50 amplifi ers. If you need a variety
of sounds and rely on a clean chording sound much of the time, you will likely prefer the stock compliment of 6L6’s that both of these
two versions are fi tted with. We feel the 6L6 is a more balanced sounding tube that produces plenty of harmonic lushness, while at
the same time delivering the rich lows that are crucial to both a warm clean sound and huge, tight high gain crunch sound.
We recommend the 6L6 for reliability: In our many tests and continued use of the currently available EL34 type power tubes on
the market today, we regret to say that they do not appear to be as rugged in construction as the available 6L6. This is another reason
why your new RECT-O 50 amplifi er was shipped with 6L6 power tubes. If you plan to use the EL34’s we suggest that you keep
a full set of tubes and extra fuses with you during all performances in the event of a tube failure occurring when using the currently
available EL34’s.
Make sure that the BIAS Switch is set correctly to match the tube type that you are using.
Failure to
do this will result in tube failure that could possibly burn resistors in the Bias supply. Although this is a fairly simple repair
for an authorized technician, it is easily avoidable.
ALWAYS CHECK THE BIAS SWITCH setting if you experiment with alternate tube types and you will enjoy uninterrupted
performances from your amplifi er.
EFFECTS LOOP: SEND, RETURN & MIX
These two 1/4” jacks are the patch point for external signal processing effects. The
EFFECTS LOOP in the RECT-O 50 is wired in parallel with the unaffected or dry signal which enables you to preserve the integrity
of the all tube tone and feel that the RECT-O 50 is capable of delivering. To use the EFFECTS
LOOP for your processors, simply connect the Effects Loop SEND jack to your fi rst effects’ Input
jack. Connect your last effects Output jack to the Effects Loop
RETURN jack.
Use the rotary MIX Control to blend in the desired amount of the processed signal with the original
dry signal. The least degradation of signal is usually found by setting the processor’s mix at 100%
and the
EFFECTS LOOP MIX Control at the lower end of the control. In this manner the least
amount of your pure tone will be processed and you will be dialing in a “very small amount” of a
“very wet” signal to be mixed with the original. This method seems to produce the best results for
tone and signal to noise ratio. The
EFFECTS LOOP interrupts the signal between the pre-amp
and power section. Therefore, the RETURN jack can double as a power amp input jack. You will also want to run the MIX Control at
90% to use the EFFECTS LOOP as a Power In patch point. Connect your last effects’ Output jack to the Effects RETURN jack. We
suggest that when using the RECT-O 50’s power section only, that you have the amp switched to Channel 1’s CLEAN mode or
Channel 2’s MODERN mode. This assures a more neutral power sensitivity thus making the RECT-O 50 more friendly to use as a
power amp. See PRESENCE Control section of this manual for more information.
EXTERNAL SWITCHING:
These jacks allow ( usually MIDI-programmed ) operation of your amplifi er’s functions from an external
switching source. The switching is accomplished by connecting ( “shorting” ) the jack’s “Tip” to its “Ring” (or ground.)
10%
FX MIX RETURN SEND
WARNING : To reduce risk of fire or
electric shock, replace fuse with
same type and rating only. Do not
expose this unit to rain or moisture.
FX LOOP
90%
SOLO CHANNEL
EXT. SWITCHING
CAUTION : To reduce risk of fire or electric
shock, do not remove cover. No user-
serviceable parts inside. Refer
servicing to qualified personnel.
REAR PANEL:
(Continued)