Front Panel - Manley SLAM! Owner's Manual

THE FRONT PANEL
1)SOURCE: This is the Input Selector that you use to choose the input to the SLAM!. The choices are LINE, DI, MIC, MIC ø (phase
reverse), and MIC 100 HZ (high pass filter) which has a little graphic showing the filter. LINE selects the BALANCED LINE INPUT
Combo jack (XLR or 1/4") and is intended for +4 dBu signals, but by cranking the INPUT level can be used with -10 dBv signals.
DI selects the INSTRUMENT INPUT jack and routes it through the mic preamp for lots of gain if needed. MIC also uses the BAL-
ANCED LINE Combo jack and routes it through the mic pre for 60 dB of gain (and another 20 dB by cranking the OUTPUT level).
MIC ø is the same except opposite and just phase reversed (the proper term is polarity reversed). MIC 100 Hz is normal polarity but
the lows below 100 hertz are filtered out which is useful on many vocals and overheads, to remove pops, air conditioning rumble, etc.
2) INPUT: This is the first volume control and has about 60 dB of range for MIC and DI, and from -20 to +20 for LINE. For LINE,
the normal setting will be 12:00, or straight up, but this isn't the rule or an absolute calibration. For MIC or DI, the knob might be
anywhere depending on the mic, the loudness of the instrument, the distance, etc., and it might be prudent to turn the knob down to
start, rather than starting at 12:00.
3) OUTPUT: This is the final volume control and is used to set the output level to tape or disk, and as the 'gain make-up' after the
Opto Limiter, if you need to compare 'limit and bypass'. The FET Limiter senses the signal right at the output jack, so it acts as if it
is a final limiter after the OUTPUT level. Circuit-wise the FET Limiter is directly after the Opto, and before the OUTPUT level (but
doesn't act like it) and before the final tube gain stage/ line driver. The range of this knob is about -20 dB to +20 dB with unity gain
near 12:00. Most of the time it will live between 12:00 and 3:00.
4) OPTO LIMITER: A simple threshold knob for the OPTO limiter. Fully clockwise (+26) is 'out' and a good place to start. As you
turn this knob counter-clockwise, there is more likelyhood that limiting will happen. Some dynamics units have the threshold go one
way and some the other. On the SLAM!, all of the pots, should make the signal louder when turned clockwise, (except the RELEASE
which is a switch).
5) SC HZ: Side-Chain Hertz. This is a HP filter in the Opto Limiter side-chain that makes that limiter less sensitive to low frequen-
cies. It does not affect the FET Limiter. The filter helps minimise pumping and strange volume changes. Sometimes kick drums and
bass seem to 'trigger' too much limiting. The FLAT setting, bypasses the filter, 100 filters 100 Hz by 6 dB and more for frequencies
below that. Similarly 200 filters 200 Hz 6 dB and more below but also boosts about 4 dB at 6 kHz for gentle and subtle de-essing and
can be considered a vocal setting. Normally, 2 filters like these require one to change the threshold significantly, but these are compen-
sated to minimize that.
6) FET LIMITER: Another simple threshold knob. One can blend any balance of Opto and FET limiters by using the two threshold
controls. Each limiter has its own character and advantages, and they complement each other, so that by using both, one can get most
of the advantages without the disadvantages. For example, the Opto can limit deeply, smoothly and has a high 'ratio', but is a little
slow for drums, while the FET Limiter can be very fast, but not as deep. The Opto has inherant time constants but the FET can be
adjusted for attack and release times. What the Opto misses, the FET should catch, depending on how you blend them and the FET
ATTACK time.
7) ATTACK: This just affects the FET Limiter. With compressors, 'attack knobs' are used to set how fast the compressor responds and
pulls down a signal. Traditional limiters don't have this because it compromises the 'concept' of limiting if there is any overshoot. We
compromised somewhere between 'text-book limiter' and 'typical compressor', and simulated much of the 'sound' of the attack con-
trol while still providing more transient reduction than is apparent. VF is very fast (.1 mS), F is fast (1mS) and M is moderate (10mS).
VF is the best if you need to prevent 'overs' and is closest to the traditional or text-book limiter. F and M tend to let more transient
through but are also more punchy and may be less detrimental to drums. Expect to adjust the FET LIMIT knob a bit for similar depths
of reduction when you change ATTACK (typical). There is another side-chain that grabs much of the peaks, almost inaudibly, but our
ears tend to hear the side-chain that has the ATTACK and RELEASE knobs. Use your ears to determine the best setting. Instruments
with fast transients like drums show the biggest differences, vocals less so, and soft flute-like sounds may not be affected except for a
little threshold difference.
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