Manley SLAM! - Manual (Page 9)

8) RELEASE: This only affects the FET Limiter. There are 11 positions numbered from 2 Seconds (slowest), to 10 milli-Seconds
(fastest). Slow releases tend to be the least audible and will be cleanest. Medium release times on the SLAM! are pretty fast for a lim-
iter and where the most loudness increase tends to be, but if pushed too far also might be obvious with pumping or a volume rise after
the ‘cresendo’. This may also be near the edge of when ‘modulation’ starts to become audible, especially if there is a lot of bass en-
ergy in the signal. Achieving maximum loudness cleanly is not automatic and might require a bit of play between threshold(s) release
time and attack because it really depends on the music. The SLAM! attempts to minimise all the negatives, pumping, modulation, loss
of ‘energy’ that is typical for a limiter with fast attack and release times because this is where the maximum loudness lives - but - this
is dancing on the edge of a dangerous cliff.
The SLAM! release time can be set up for ridiculously fast releases (10 & 25 mS) that pretty much guarantee modulation distortion
with lows, which is most often undesirable but can be used as an effect and yet another paint brush. We might caution using ultra-fast
release times with bass instruments, but it can be fun on rude drums and blazing solos. There is also a CLIP setting, which introduces
a FET clipper that is fairly round like some low feedback tube circuits overdriven and is a bit reminiscent of speaker distortion. We
wanted to provide a psycho-acoustic memory of loud, and this is one way. The CLIP is best suited to enhance a moderately distorted
guitar, of fatten a synth. It is not intended to replace your Marshall, or amp simulator, but can often be used to take them a bit further.
9) STEREO LINK: A 3 position toggle. The center position disables stereo linking and is labelled DUAL MONO. All of Manley’s
previous limiter/compressors provide a LINK switch and both L&R controls have to be used for proper operation. Meanwhile, most
other compressors just use the left side while the right side controls become useless. Enough people requested, for us to include this
mode of LINKing. This is the STEREO LINK or up position. Both ways have advantages. The modern ‘left-side only’ is convenient,
easy and can be clever especially on a plug-in. The problem is that almost all implementations mono the L&R, which means sounds
that are hard right or left are 6 dB less likely to trigger limiting than sounds down the center, and anything out-of-phase won’t be seen
by the limiter at all. We think a proper ‘mastering compressor’ is supposed to react to the peak waveform of both the left and right
equally, or stop the same peaks that causes the A/D to clip. This is easy in digital, but in analog it requires the user to use both sides,
and that the limiters react equally based on whichever side has the loudest peak. So the SLAM! also has that mode “BOTH & EXT”
or the down position. This mode is also used for the back panel linking to other SLAM!s for surround projects. For recording instru-
ments the STEREO LINK mode is fine but for serious mastering the BOTH & EXT mode is usually best. ***NOTE: No LINK of the
CLIP functions, because why have one side clip the other?***
10) LED (meter): This switch controls the LED bar graph meter. In the center position is basically an PEAK display of the audio out-
put. The upper position is basically to display GR (Gain Reduction, especially the FET Limiter). The down position is a momentary
switch that RESETs the peak hold (clears the dot) and is used to select the LED meter MODE if held down for a few seconds. A full
and complete description of the LED Meter is on page 12. Suffice it to say here that it does a lot.
11) LIMIT LEFT: Push it in to engage both the OPTO Limiter and the FET Limiter and the OUTPUT level control and it lights up
blue. This is not a hard-wire bypass, nor can it be, on a Swiss Army Knife, that has multiple inputs and outputs, mic pre-amps, etc. A
hard-wire bypass on a mastering version is a bit more likely.
12) POWER: OK, we won’t do a 300 word description of a power switch this time. Push it, it lights RED, and turns on the bulk of
the Outboard Power Supply, which has been on idle drawing almost zero current. (If it doesn’t, remember that there is also a power
switch on the power supply that has to be turned on.) The VU meters should light up, and about 30 seconds later the MUTE relay
disengages (to prevent tube warm-up thumps) and audio should be available or rising gently. This box has a long warm-up time but
should be stable in a minute and very nice in 15 minutes. Power-down mutes immediately. This might be a concern in a live situation;
plan accordingly.
If you are not using it for 8 hours, you might as well turn it off to save power bills and tube life. There is a school of thought that
suggests that the initial turn-on is the hardest on tubes, and shortens their life and to some degree that is true. From our experience, it
all depends on the individual tube and some last 30 years and some 30 seconds. If you are concerned with tube life and down-time, re-
pairs etc, buy a set of extra tubes and save yourself some panic when you least need it. Changing a tube is almost as easy as changing
a light bulb and once the top cover is removed should take 20 seconds (compare that to a repair needing the ‘ol soldering iron).
13) LIMIT RIGHT: Just like 11, but for Channel 2. Push to engage limiting and the OUTPUT level.
14) VU: Selects the source for the VU meters. I/P (input) shows the level directly after the INPUT level pot and is a good place to set
the MIC-PRE gain or rough out operating levels. O/P (output) shows the output level appearing on the output jacks. GR shows the
OPTO Gain Reduction, but not the FET. Most Opto Limiters use a VU to display gain reduction. When the limiters are bypassed the
VU drops to below -20 which is not intended to imply extra hard limiting. The Opto can also be displayed on the LED meters, with an
expected increase in speed because the Vactrols in the Opto Limiter are faster than VUs.
15) VU ATTENUATE: One can also pad the VU’s down by 3 or 6 dB which is especially useful if the client is in the room and eye-
ing the VU needles pegged in the red. Mastering engineers need this because a final mix has a lower ratio of peak to average level,
and probably lower again after mastering. The SLAM! will tend to do that too. For individual tracks, we expect the 0 or no pad to be
the most common but it depends on the instrument and distorted guitars may few and moderate peaks, but some percussion has huge
peaks. We suggest the 3 dB pad for most mastering, and allowing about 3-6 dB below digital full scale on the peak meters. Why? FIR
filters usually need 1dB to 2 dB of headroom, MPEG usually requires 4-6 dB, the mastering engineer needs some room to work. The
6 dB VU pad is a hint that maybe this is project is ‘hyper-compressed’, especially if is still bending far into the red. It is nice for CD
playback though. 9