LaChapell Audio 500DT User manual

1266 Park Road
Chanhassen, MN 55317
952-401-7700
suppor[email protected]
www.digitalaudio.com
LACHAPELL AUDIO 500DT USER GUIDE
Version 1.0
May 2018

LACHAPELL AUDIO 500DT
SAFETY INSTRUCTIONS
TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER. NO USER SERVICEABLE PARTS
INSIDE. CONTACT DIGITAL AUDIO LABS FOR SERVICING.
IMPORTANT SAFETY INSTRUCTIONS
1. Read and understand this entire manual.
2. Keep this manual available for reference.
3. Heed all warnings and precautions in this manual and notices marked on the product.
4. Do not use this product near water or damp environments.
5. Refer all servicing to qualied service personnel. There are no user serviceable components inside
the product.
6. The product shall not be exposed to moisture. Do not touch the unit with wet hands. Do not
handle the unit or power cord when your hands are wet or damp.
7. The product should be connected to a power supply only of the type described in the operating
instructions or as marked on the product.
CARE
• From time to time you should wipe off the front and side panels with a dry soft cloth. Do not use
rough material, thinners, alcohol or other chemical solvents or cloths since this may damage the
nish or remove the panel lettering.
• The manufacturer cannot be held responsible for damages caused to persons, personal
possessions, or data due to an improper or missing ground connection.

LACHAPELL AUDIO 500DT 1
DIGITAL AUDIO LABS LIMITED WARRANTY
Digital Audio Labs warrants their products against defects in material and workmanship for a period of two
years from date of purchase. During this period, Digital Audio Labs will, at its option, repair the defective unit
or replace it with a new or rebuilt one.
The warranty does NOT cover:
• Damage due to abuse, misuse, or accident.
• Damage due to operation contrary to the instructions in the product instruction manual.
• Units on which the product serial number has been removed or altered.
• Units that have been serviced by unauthorized personnel.
All implied warranties, including warranties on merchantability and tness, are limited in time to the length
of this warranty. Some states do not allow time limitations on implied warranties, so this limitation may
not apply to you. Digital Audio Labs’ liability is limited to the repair or replacement of its product. Digital
Audio Labs shall in no way be held liable for incidental or consequential damages resulting from the use of
their product or its software, including, without limitation, damages from loss of business prots, business
interruption, loss of business information or other pecuniary loss. Some states do not allow the exclusion or
limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.
REPAIR POLICY
Please do not return the product without obtaining an RMA number rst. Contact Digital Audio Labs at
suppor[email protected] to acquire an RMA number. Do not return the product to the place of purchase.
Please write the RMA number on the outside of the shipping carton. Any product sent to us without a valid
RMA number may be refused. Include the following with the product: a brief description of the problem,
your name, return shipping address, phone number and the RMA number. Do not include any accessories.
DAL is not responsible for any damage to or loss of the product during transit. We recommend that
customers obtain a receipt and tracking number for all packages shipped to us. Turnaround time on repairs is
generally ten business days. If you live outside of the United States, please contact your local distributor for
warranty service.
Please return product to:
Digital Audio Labs
Attn: RMA Number
1266 Park Road
Chanhassen, MN 55317
USA
WARRANTY SERVICE
You will be required to pay the shipping charges when you ship your product to DAL. DAL will pay for return
shipping via UPS Ground or other comparable shipper. We reserve the right to inspect any product that may
be the subject of any warranty claim before repair is carried out. For warranty service, we may require proof
of the original date of purchase if you have not registered your product with DAL. Final determination of
warranty coverage lies solely with Digital Audio Labs.
NON-WARRANTY SERVICE
If it is determined that the product does not meet the terms of our warranty, you may be billed for labor,
materials, return freight and insurance. There is a $80 USD minimum charge for materials and labor.
Appropriate shipping charges will be applied. We require payment in advance of repair by credit card; we
accept Visa and Master Card. In the event the charges are over the minimum charge, DAL will contact you
and inform you of the cost of the repair before any work is completed.

LACHAPELL AUDIO 500DT
CONTENTS
SAFETY INSTRUCTIONS ............................................................................................................II
IMPORTANT SAFETY INSTRUCTIONS................................................................................II
CARE....................................................................................................................................II
DIGITAL AUDIO LABS LIMITED WARRANTY............................................................................ 1
REPAIR POLICY................................................................................................................... 1
WARRANTY SERVICE ......................................................................................................... 1
NON-WARRANTY SERVICE................................................................................................ 1
LACHAPELL AUDIO MODEL 500DT......................................................................................... 3
BEFORE YOU GET STARTED .................................................................................................... 3
SAFETY PRECAUTIONS...................................................................................................... 3
500DT DUAL TOPOLOGY CONTROLS .................................................................................... 4
CONTROLS ........................................................................................................................ 4
USING THE 500DT.................................................................................................................... 5
GETTING STARTED................................................................................................................... 5
SNARE ................................................................................................................................ 5
KICK.................................................................................................................................... 5
DRUM OVERHEADS ........................................................................................................... 6
BASS ................................................................................................................................... 6
GUITAR ............................................................................................................................... 6
VOCALS.............................................................................................................................. 7
500DT SPECIFICATIONS........................................................................................................... 8
OVERALL................................................................................................................................... 8
TROUBLESHOOTING ............................................................................................................... 9
COMMON ISSUES .................................................................................................................... 9
LACHAPELL AUDIO SUPPORT.................................................................................................. 9

LACHAPELL AUDIO 500DT 3
LACHAPELL AUDIO MODEL 500DT
The LaChapell Audio 500DT is a 500 series microphone preamp that features two separate
topologies or amplication paths. When the blend knob is fully to the TUBE side, the signal will
pass through a transformer before being amplied by a TrueTube™ powered 12AX7 vacuum tube.
TrueTube is LaChapell Audio’s proprietary method of supplying a full 250V to the vacuum tube so
you get loads of clean tube gain.
When the blend knob is turned fully to the OPAMP side, the signal passes directly to a solid state
preamplier. This input is transformerless and will provide clean gain with exceptionally low noise
Placing the blend control anywhere between the two extremes will “blend” the two topologies for a
wide variety of tonal options.
BEFORE YOU GET STARTED
Please read the information below before you install and use the LaChapell Audio 500DT.
• UNPACKING: Inspect thoroughly. Although we take extreme care at nal assembly and
packing, things can happen during transit. It is very important that you contact Digital Audio
Labs if there is anything broken or damaged upon receipt of package. Included in every
package should be: (1) packet of mounting screws, (1) registration card. It is a good idea for
you to retain the packaging (box & foam case) in case there is a need to return the unit for
service or repair at a later date.
• SERVICE/REPAIR - WARNING: The user should NOT attempt to service this unit in any way, due
to the risk of electrical shock and the presence of potentially lethal voltages inside the 500DT.
It is recommended that tube replacement be performed only when necessary by technically
competent individuals.
Tube replacement: Turn power supply off and remove 500DT from the chassis, wait ve
minutes to allow the vacuum tube to cool before attempting to remove it. Using your
ngers, apply a slight circular/rotating motion as you pull it away from the socket. It is
important to replace the tube with the same type. When a replacement tube is installed
double check that you’ve inserted the correct tubes into the 500DT’s tube socket BEFORE
powering up. WARNING: Warranty may be rendered void if tubes other than those
listed above have been used at any time.
SAFETY PRECAUTIONS
• Always provide adequate ventilation by allowing the top vents of your 500 series power supply
chassis to remain unobscured. Due to the vacuum tube and the internal secondary power supply,
the 500DT will get warm, blocking or defeating any existing vent is not recommended.
• Never position the power supply directly above heat generating sources such as a power
amplier.
• Always provide a source to ground (earth.) Never under any conditions should a power cord that
has the third prong for ground missing or defeated be used with the power supply.
• Do not place the 500DT in an area where there is a potential for uids to fall, spill into or come
in contact with the 500DT. If you notice uids or moisture present inside the 500DT DO NOT
turn power on! Contact Digital Audio Labs for direction.
• The 500DT should only be used with power supply frames that have a >180ma rating per bay.

LACHAPELL AUDIO 500DT 4
500DT DUAL TOPOLOGY CONTROLS
CONTROLS
• INPUT GAIN: The GAIN controls how much of the source signal is fed to the preamplifer.
• OUTPUT GAIN: The OUTPUT GAIN controls the overall output of the preamplifer. By using
both the INPUT GAIN and OUTPUT GAIN together, a wire variety of sound options are
possible.
• BLEND: This contols how much of the signal is fed into each amplication path. Fully clockwise
will send 100% of the signal to the solid state OPAMP amplication. Fully counter-clockwise will
send 100% of the signal to the TUBE amplication path.
• 48V: This toggle provides a 48V phantom power (DC) for condenser microphones.
• PAD: When engaged, the -20dB pad will reduce the signal going into the amplier stages by
-20db. This is useful for recording hot or loud sources. The PAD is inactive when using the Hi-Z
input.
• POLARITY: Reverses the polarity of the output line level signal.
• HI-Z INPUT: The Hi-Z input provides a direct input for high impedance instruments like guitar or
bass.
BLEND
PAD
OUTPUT GAIN
INPUT GAIN
PHANTOM
POWER
POLARITY
REVERSE
HI-Z INPUT

LACHAPELL AUDIO 500DT 5
USING THE 500DT
A properly powered vacuum tube, like the one in the LaChapell Audio 500DT, will give you lots of
clean headroom with some added harmonic richness and compression as you increase the gain. At
higher input gains and/or with hot signals, the tube on the 500DT will go into overdrive providing
tube distortion.
The solid state signal path is clean and transparent with very low distortion characteristics. Because it
doesn’t add harmonics like the tube path can, it will have more clarity.
Because the LaChapell Audio 500DT allows you to use either path or a combination of the two, the
sonic possiblities are nearly endless.
GETTING STARTED
The input and output controls on the LaChapell Audio 500DT work together to provide a rich array
of sonic possibilities. Here are some things to try to get started for a variety of sources.
KICK
On Kick, try leaning on the OPAMP path so that the
attack of the beater comes through. Blend in some of
the TUBE path to get more weight and body with the
INPUT GAIN lower than the OUTPUT GAIN.
SNARE
On snare drums, the OPAMP path will provide fast
transients where the TUBE path will provide natural
compression and a bit slower transients. To let some
transients through, with some natural compression, try
setting the BLEND at about 30%.

LACHAPELL AUDIO 500DT 6
DRUM OVERHEADS
Drum overheads need clarity so try the BLEND at
around 70-80%, the INPUT GAIN around 20-30 and
the OUTPUT GAIN making up the rest of the needed
amplication.
BASS
On bass guitar, run the INPUT GAIN at around 50-55,
setting the level to your DAW with the OUTPUT GAIN.
With the blend at 60% the bass will growl courtesy of
the tube path yet have clarity and articulation from the
OPAMP path.
GUITAR
Try using the 500DT as the front end to a guitar
modeler. With the INPUT GAIN up, you can add some
true tube distortion to your tracks. With the INPUT
GAIN lower and the OUTPUT GAIN up, the TUBE
path adds some life to software modelers, while the
OPAMP path adds some bite. Blend between them for
your perfect tone.

LACHAPELL AUDIO 500DT 7
On vocals, try using the TUBE
path for an intimate vocal,
balance the INPUT GAIN and
OUTPUT GAIN to accentuate
a proximity effect on a
condenser mic.
For an aggressive vocal, try
moving the INPUT GAIN
to the 50-60 range, set the
OUTPUT GAIN so that it
doesn’t clip the converters
and then play with the BLEND
in the 30%-60% range.
For a gorgeous and soaring
vocal, lean on the OUTPUT
GAIN more, with the BLEND
closer to the OPAMP path.
VOCALS

LACHAPELL AUDIO 500DT 8
OVERALL
INTERNAL GAIN 67 dBu
INPUT IMPEDANCE 1.5 KΩ Mic / 10 KΩ Hi-Z
TUBE COMPLEMENT/TYPE 1x 12AX7 (ECC83)
TUBE PATH
THD+N 0.08%
FREQUENCY RESPONSE 20 Hz to 20 kHz
MAXIMUM OUTPUT 12 dBu
TYPICAL EIN 121
SOLID STATE PATH
THD+N 0.01%
FREQUENCY RESPONSE 20 Hz to 46 kHz
MAXIMUM OUTPUT 28 dBu
TYPICAL EIN 129
NOTE: Stated specications are typical measurements but subject to change without notice due to individual traits
unique to each tube.
500DT SPECIFICATIONS

LACHAPELL AUDIO 500DT 9
TROUBLESHOOTING
COMMON ISSUES
My signal sounds distorted.
The 500DT is capable of a lot of gain. Distortion
can be occuring in the DAW or Converter or in the
500DT itself. First try reducing the OUTPUT GAIN
to minimize any non-500DT related distortion. Next
reduce the INPUT GAIN. You can also apply the PAD
to reduce the signal coming into the 500DT.
I dont have enough gain. Make sure the PAD switch is turned off.
The pad doesnt work on the Hi-Z. That is by design. The PAD will not function with the
Hi-Z input.
I’m hearing noise.
We have found that not all 500 series frames are the
same in terms of noise. Some will introduce noise
into the signal path. Try to reduce the GAIN levels or
use the PAD to reduce noise.
LACHAPELL AUDIO SUPPORT
Phone Support: 952-401-7700
Toll Free: 844-DAL-INFO
Email Support: suppor[email protected]
Website: www.digitalaudio.com/support
DIGITAL AUDIO LABS
1266 Park Rd
Chanhassen, MN 55317

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Patents pending.