Rolls VP549 Users Manual
The RIAA equalization curve was intended to operate as the
INPUT
OUTPUT
15 VDC
HEADPHONE/
LINE OUTPUT
+
-
VP549
MADE IN USA
www.rolls.com
global industry standard for records since 1954. However, it
is almost impossible to say when the change actually took
place.
RIAA equalization is a form of pre-emphasis on recording
and de-emphasis on playback. A recording is made with the
low frequencies reduced and the high frequencies boosted,
and on playback the opposite occurs. The net result is a at
frequency response, but with attenuation of high frequency
noise such as hiss and clicks that arise from the recording
medium. Reducing the low frequencies also limits the excursions the cutter needs to make when cutting a groove.
Groove width is thus reduced, allowing more grooves to t
into a given surface area, permitting longer recording times.
This also reduces physical stresses on the stylus which
might otherwise cause distortion or groove damage during
playback.
VP549 Phono Preamp
-
10dB
0
+
Trim - Gain
RIAA Phono Preamp
4dB
220pF
120pF
Cartridge Load Capacitance
+
-
330pF
HEADPHONE/
LINE OUTPUT
Rumble
Filter
OUTPUT
MADE IN USA
www.rolls.com
VP549
PWR
INPUT
A potential drawback of the system is that rumble from the
playback turntable's drive mechanism is amplied by the
low frequency boost that occurs on playback. Players must
therefore be designed to limit rumble, more so than if RIAA
equalization did not occur. Using a rumble lter to lter out
the subsonic frequencies many help mitigate the noise from
the turntable.
Bellari is a division of Rolls Corporation
Salt Lake City, UT
4/18
15 VDC
VP549
MADE IN USA
www.rolls.com
SPECIFICATIONS
I/ O Connectors: RCA, 1/8" TRS Stereo
Input Sensitivity: 30 dB gain @ 1kHz, 47k ohms
Input Impedance: 47k ohms
Output Impedance: 32 ohms Headphone, 470 ohms RCA
Frequency Response: 14Hz to 23kHz
Max Output Level: >10dB @ 1kHz at .1% dist.
Equalization: RIAA +/- 1 dB, 20Hz to 20kHz
Rumble Filter: 20Hz
THD: .02% @ 1KHz
S/N Ratio: >94 dB unweighted
PWR: 15 VDC
Size: 5.5"w x 3.5"d x 1.25"h
Weight: .8 lbs
Indicator: 1 Power LED
The Bellari VP549 is a phonograph preamplier with RIAA EQ.
INPUT
OUTPUT
15 VDC
HEADPHONE/
LINE OUTPUT
+
-
VP549
MADE IN USA
www.rolls.com
- RIAA equalization is a specication for the recording and playback of
phonograph records, established by the Recording Industry Association
of America (RIAA).
Thank you for purchasing the VP549. We spent a considerable amount
of time designing and developing the VP549. Hundreds of hours listening
and improving the design. We hope you enjoy using the VP549, and that
it makes listening to your vinyl collection rewarding. We sincerely appreciate the opportunity to build a product for you and participate in your
love of quality music and sound. We love what we do and we’re happy to
help. All Bellari products are hand built in Salt Lake City, Utah by people
who care about high quality music. No surface mount parts are ever used
at Bellari.
The Bellari VP549 has excellent true sound resolution. It's tone center is
right in the middle of the music, its very agile and dynamic. It performs
very well on the extremes, it never looses its solid performance in the
meat of the music. It is well rounded when needed, but has a very surprising shimmer when called on. The VP549 is well balanced and bold,
yet has a very surprising attack that will take your rig to the next level.
Rumble lter: AKA "subsonic lter" cuts very low frequencies (below 20
Hz). The purpose of a lter like this is to get rid of annoying frequencies
that disrupt the turntable's sound quality. A good rumble/subsonic lter
should be inaudible, meaning you can not hear when it is on or o in the
program material you are listening to. What it will do is help with excessive very low frequency interruptions from the turntable to the preamp.
Cartridge load capacitance: The VP549 has three settings: 120 pF,
220 pF and 330 pF. Set the switch in the position you feel sounds best to
you. The dierence might be very slight, but it is there. Most cartridges
come with a capacitance load recommendation in the spec sheet for the
cartridge. For example the Ortofon 2M series asks for a loading of 150pF
to 300pF. Most Audio Technica cartridges state 100pF to 200pF for loading. The VP549 has been tested with multiple turntables and multiple
cartridges. We have found it best to use your ears to set the loading.
You can set the loading switch to any setting 120, 220 or 330 with any
MM cartridge and no damage will be done to the VP549 or your car-
tridge. If you can not hear a dierence we would suggest that you do as
the cartridge manufacturer suggests, and set the loading switch to their
recommendation for the cartridge you are using.
15 VDC
+
HEADPHONE/
-
LINE OUTPUT
VP549
OUTPUT
MADE IN USA
INPUT
www.rolls.com
Connecting the VP549: You have an input for the VP549 that connects
to your phonograph, and the output of the VP549 plugs into your pre-
amp or amplier. The ground post is where things can get complicated.
Ground hums have always plagued the turntable. We recommend using
the ground post to connect to your turntable's ground connection. In our
experience we have never seen a situation where not using the ground
would sound better than using it.
Ground loops are a very common occurrence with audio. The more
equipment you use, the higher likelihood you will have a ground loop.
The term "loop" refers to your ground generating unwanted noise from
traveling back and forth in a loop. The turntable is usually the most likely
component to have a ground issue. Another thing you can try if you
have a ground loop is connecting the turntable ground to the RCA jack's
ground if the ground post is not remedying the issue. One thing to keep
in mind is that ground loops can be anywhere in a system so try and
isolate the components that are the issue before you spend a lot of time
looking at just one component.
-
10dB
0
+
Trim - Gain
RIAA Phono Preamp
PWR
4dB
220pF
120pF
Cartridge Load Capacitance
330pF
Rumble
Filter
MADE IN USA
www.rolls.com
VP549
Trim - Gain: Control to attenuate the signal level up or down. It is not a
volume control, meaning that signal will still be present even when the
level is turned to the lowest point (in this case -10dB as labeled). If at
half way up you are at 0 dB output level then all the way up you will have
+4dB more gain, and all the way down you will be at -10dB down from
a reference of the middle 0 dB. Most users will be best served to set
the control at the middle or 0 setting to get the best outcome. This is not
always the case. In some situations you might need more gain, like when
using a quiet record or a very low level cartridge. In the opposite situation you might need less gain from a hot or loud record, or if you have a
high output cartridge. The newer cartridges made tend to have a higher
output level than in the past. For instance, the popular Ortofon 2M series
of carts have a 6mV output. This is much hotter than carts of old, as they
were around 4mV to 5mV. When using a 6mV cart you might need to
turn the trim gain control to just below the half or 0 setting. Many factors
go into setting the proper level, but we recommend start at the middle, 0
setting.
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