Manley HIGH FREQUENCY User Manual

WARRANTY REGISTRATION

We ask that you please fill out this registration form and send the bottom half to:

MANLEY LABORATORIES
REGISTRATION DEPARTMENT
13880 MAGNOLIA AVE.
CHINO CA, 91710

Or you may fax this page to: [phone]

Registration entitles you to product support, full warranty benefits, and notice of product
enhancements and upgrades. You MUST complete and return the following to validate your
warranty and registration. Thank you again for choosing Manley.

MODEL MANLEY HIGH FREQUENCY LIMITER
SERIAL No. MHFL___________

PURCHASE DATE ______________ SUPPLIER ______________________

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PLEASE DETACH THIS PORTION AND SEND IT TO MANLEY LABORATORIES

MODEL MANLEY HIGH FREQUENCY LIMITER
SERIAL No. MHFL____________

PURCHASE DATE ______________ SUPPLIER ____________________________

NAME OF STUDIO & OWNER _________________________________________

ADDRESS ___________________________________________________________

CITY, STATE, ZIP _____________________________________________________

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WARRANTY

All Manley Laboratories equipment is covered by a limited warranty against defects in materials
and workmanship for a period of 90 days from date of purchase to the original purchaser only. A
further optional limited 5 year warranty is available to the original purchaser upon proper
registration of ownership within 30 days of date of first purchase.

Proper registration is made by filling out and returning to the factory the warranty card attached to
this general warranty statement, along with a copy of the original sales receipt as proof of the
original date of purchase. Only 1 card is issued with each unit, and the serial number is already
recorded on it.

If the warranty registration card has already been removed then this is not a new unit, and is
therefore not warranted by the factory. If you believe this to be a new unit then please contact the
factory with the details of purchase.

This warranty is provided by the dealer where the unit was purchased, and by Manley Laboratories,
Inc. Under the terms of the warranty defective parts will be repaired or replaced without charge,
excepting the cost of tubes. No warranty is offered on tubes, unless:

1. a Manley Laboratories preamplifier is used with a Manley Laboratories amplifier, and

2. the warranty registration card is filled out.
In such a case a 6 month warranty on tubes is available with the correct recording of the serial

number of the preamplifier on your warranty registration card.
If a Manley Laboratories product fails to meet the above warranty, then the purchaser's sole

remedy shall be to return the product to Manley Laboratories, where the defect will be repaired
without charge for parts and labour. The product will then be returned via prepaid, insured freight,
method and carrier to be determined solely by Manley Laboratories. All returns to the factory must
be in the original packing, (new packing will be supplied for no charge if needed), accompanied by
a written description of the defect, and must be shipped to Manley Laboratories via insured freight
at the customer's own expense. Charges for unauthorized service and transportation costs are not
reimbursable under this warranty, and all warrantees, express or implied, become null and void
where the product has been damaged by misuse, accident, neglect, modification, tampering or
unauthorized alteration by anyone other than Manley Laboratories.

The warrantor assumes no liability for property damage or any other incidental or consequental
damage whatsoever which may result from failure of this product. Any and all warrantees of
merchantability and fitness implied by law are limited to the duration of the expressed warranty.
All warrantees apply only to Manley Laboratories products purchased and used in the USA.

Some states do not allow limitations on how long an implied warranty lasts, so the above
limitations may not apply to you. Some states do not allow the exclusion or limitation of incidental
or consequential damges, so the above exclusion may not apply to you.

This warranty gives you specific legal rights and you may also have other rights which vary from
state to state.

To use this HIGH FREQUENCY LIMITER you probably don't need a serious technical manual

but some features are worth explaining all the same.

The "basis" for this design was a vintage high freq limiter used primarily to "cut" vinyl records.
The RIAA curve specifies a large amount of high frequency boost that is later removed (along with hiss
and other noise) in playback. This is fine except that to get louder records excessive highs could produce
a nasty distortion and reduce a $5000 cutting head to a smouldering mess. There were several different
high frequency limiters available to deal with this but one device in particular solved the problem in an
elegant way. With this unit, the signal was put through only a few passive parts to achieve its purpose.
The variable component was a special high quality transformer with a separate winding that controlled
its high frequency response. The technical term is "saturable reactor". We use this technique in our HIGH
FREQUENCY LIMITER and follow it with our professional line amplifier to provide make-up gain and
a low impedance output. We also use modern op-amp circuitry in the control circuit (sidechain) but only
a class A vacuum tube circuit is appropriate for the audio. We wanted it to remove nasty sibilance, not
create more. No VCA's and no op-amps in the audio path.

While we use the original name for this circuit, it is somewhat inaccurate in todays terminology.
The circuit is actually a sliding filter or voltage controlled filter (VCF) except without the distortions
typical in VCF's or VCA's.

There are two "sensing" circuits. The HI-MID circuit is a tunable band-pass filter. The HIGH
circuit is a tunable high-pass filter. The user can select which sensing circuit is most appropriate for the
problem faced. When the offending frequency passes through the filter and is "over" the THRESHOLD
then the filter begins "sliding" down from above 20 kHz until the offending frequency is reduced enough
to be below the threshold. This is indicated by the meter and LED.

There is one input and two outputs. The input is floating transformer balanced in parallel with
a 22K resistor. Both outputs are low impedance unbalanced. PIN 2 hot on XLRs. There is a fair amount
of confusion that unbalanced outputs are not good with balanced inputs. Not true. A good balanced input
should cancel as much hum as it can with either balanced or unbalanced signals. However, there are
many balanced line drivers that have problems driving transformer inputs (at low frequencies) and
unbalanced inputs or long lines (instability or HF oscillation). You should have no problem with hum
or any instability with this unit. There are grounding options with the terminals on the back panel.

The MONITOR OUTPUT is a 1/4 inch mono jack with a special purpose. There is a switch on
the front panel that selects the source to be monitored. In NORMAL the source is the same as the XLR
output, in SIDECHAIN it provides a way to hear the sensing filters and tune them accurately to the
problem frequency. The THRESHOLD knob will control the volume of this output. The XLR does not
have this switched signal and is intended to be fed straight to tape safely, even if the engineer is "tuning"

The BYPASS switch is not a hardwire bypass. The signal bypasses the De-essing circuit but still
goes through the input transformer, tubes and RE-ESS circuit.

The RE-ESS control is a simple 12kHz shelving EQ with 6 dB cut and boost. We named it that
just for fun. The best place to DE-ESS is individual vocal tracks usually after EQ and compression.
Sometimes the right amount of de-essing unfornunately removes some of the "AIR" on a track. That
name was taken. The RE-ESS control is set up to return some of those "nice" highs after the "bad" highs
are buried. This control is active even in BYPASS. If you are going to use this HIGH FREQUENCY
LIMITER on a mix you will notice two things. First - setting the threshold is difficult because high hats,
snares and other brite sounds will trigger some de-essing. Second - the RE-ESS control is pretty damn
effective in fixing that first thing. It is also useful during recording as a "safe" hi frequency boost (or cut).
It can be better than most EQs because it doesn't add TIM distortion as a by-product. Some feel that the
tube/transformer circuit adds the "right" warmth and not some cheezy distortion. Check it out.

While we are not in a position to tell anybody how to mix, we can communicate some mastering
engineers comments. They tell us that the most common problem today is mixes that are too brite and
over compressed. They also tell us that these are the most difficult problems to fix. As an engineer you
know it is easier to boost a little than perform surgery to some narrow band. They have good de-essers
(often ours) but de-essing a mix is difficult with hi-hats and cymbals and snares everywhere. Notching
a narrow band is bound to affect all sounds that have harmonics in that band. It is better to leave a little
less at both high and low frequency extremes for them to fine tune rather than too much that they have
to fight to remove.

NearField Monitors provide a valuable reference for most engineers. These smaller speakers are
widely recognised to be closer to the average listener's home system. They are also recognised for not
providing any accuracy in the lowest octaves. Accurate lows cost exponentially in dollars and size. You
may or not be aware that most monitor systems have sibilance problems of thier own. Of course this
doesn't directly add sibilance to a tape but if everything sounds sibilant through them how are you
supposed to be judging the top end quality of your mix? The answer, once again, is electronics. This
problem is far more likely to be amplifiers than speakers. Unfortunately most powered speakers use
better speakers than amplifiers. The amps distort somewhat (TIM) with sibilance and high frequency
transients. Shakers become pink noise. Gotta have great amps when you engineer professionally. OK,
this is a cheap plug - try our tube amps. Besides knowing how much sibilance is really happening, you
will get better mixes by hearing the details and beauty that was there to start with.

USING THE HIGH FREQUENCY LIMITER

First the easy step by step approach then if you want you can read some techno-babble.

1) Connect the XLR input and the 1/4" output. Turn the HIGH FREQUENCY LIMITER power ON and
wait a few minutes for the tubes to warm up. Don't rush - It makes big thumps as it warms up.

2) Use the console channel inserts to patch a vocal track. Don't forget to press the channel's "insert" button
if it has them.To start set all controls to half way or 12:00. Verify the signal is fine with the unit in
"BYPASS". Any hum, noise? Play tape. You might "SOLO" the track if so inclined.

3) Switch the HF LIMITER to "IN". Switch the "MONITOR OUTPUT " to "SIDECHAIN". You should
hear the brite brittle sound of the filters. If that's not bad enough, you gotta tune those filters to sound even
uglier. Switch the toggle with the triangle arrows to HIGH and adjust the HIGH control to get the worst
sibilance. Now switch the toggle to HIGH-MID and adjust the HIGH-MID control to tune in that
sibilance again. Pick the worst or the most "ESS" with the toggle.

4) Had enough? Switch the "MONITOR OUTPUT" to "NORMAL". Adjust the "THRESHOLD' control
to see meter movement and the LED flashing on sibilance. Only on the sibilance is the big trick.

5) Verify that the desired de-essing is taking place and if not re-adjust the THRESHOLD and maybe the
HIGH or HI-MID controls. Compare by switching to "BYPASS".

6) Take the channel out of "SOLO". Adjust the RE-ESS like any EQ to fine tune the highs. Probably a
little boost will help. The console INSERT button is the best way to verify "ya did it good".