Dr. Sample


The BOSS SP-303 Dr. Sample offers DJs and musicians a compact, easy-to-use portable phrase sampler with CD-quality sound, 8-note polyphony, 26 onboard effects and a realtime pattern sequencer—all at a price unmatched by the competition. For sampling and effects processing anytime, any place, the SP-303 can't be beat.

Professional-Quality Phrase Sampling

While the SP-303 is easily the most affordable phrase sampler on the market, its professional sound and specs are on par with far more expensive models. Up to eight mono samples may be triggered at once—even when sampling using the “Standard” 44.1kHz recording mode. Two additional modes are provided for additional sampling time or to create “Lo-fi” effects.

New Pattern Sequencer

An onboard pattern sequencer makes creating songs from loops and phrases easy. Just select the length (up to 99 measures) and play along to the internal metronome. A quantize function corrects your timing, making it possible to create drum patterns by sampling individual sounds to the pads. And unlike the limited memory of other phrase samplers, the SP-303’s sequencer can store up 7,500 notes.

26 Killer Effects

Not just a sampler, but a full-blown effects processor, the SP-303 includes 26 professional effects like reverb, flanger, delay, and Voice Transformer—plus wicked distortion, filter, Slicer, Isolator, Lo-Fi, and Vinyl Simulator algorithms for twisting your sound to the extreme. Best of all, these effects can be applied to multiple samples simultaneously or live input signals.

Resampling and More

Once you’ve found the perfect effect, you can resample the sound to a new pad. This makes it possible to get even more out of the EF-303’s effects section. And adjusting effect parameters such as filter cutoff, delay time or modulation depth, for example, is as simple as twisting a knob.

SmartMedia Compatible

The SP-303 is the only low-cost phrase sampler that can use SmartMedia cards for expanding internal sampling time (up to 200 minutes*) in addition to backing up data. You can even store .WAV and AIFF files from your PC to SmartMedia cards and load them into the SP-303 using a new import function**.

*Using 64MB SmartMedia card and Lo-fi sampling in mono.
**Requires SmartMedia adaptor or PCI adaptor card.
Maximum Polyphony
8 voices
Internal Memory
Samples: 16 (8 samples x 2 banks)
Patterns: 16 (8 patterns x 2 banks)
Memory Card (SmartMedia)
Samples: 16 (8 samples x 2 banks)
Backup: 112 (2 banks x 7 sets)
Patterns: 16 (8 samples x 2 banks)
Backup: 112 (2 banks x 7 sets)
* Only 8 MB to 64 MB SmartMedia with a power-source voltage of 3.3 V can be used.
Maximum Sampling Time
Internal Memory (Times Approximate)
STANDARD: 31 sec, LONG: 63 sec, LO-FI: 3 min, 10 sec
Memory Cards (Times Approximate)
8 MB
STANDARD: 4 min, LONG: 8 min, LO-FI: 25 min
16 MB
STANDARD: 8 min, LONG: 16 min, LO-FI: 50 min
32 MB
STANDARD: 16 min, LONG: 33 min, LO-FI: 101 min
64 MB
STANDARD: 33 min, LONG: 66 min, LO-FI: 202 min
Sampling Frequency
STANDARD: 44.1 kHz
LONG: 22.05 kHz
LO-FI 11.025 kHz
Pattern Sequencer
Maximum Note Storage: Internal Memory Approx. 7,500 notes, Memory Card (SmartMedia) Approx. 7,500 notes
Resolution: 96 ticks per quarter note
Pattern Length: 1–99 measures
26 types
Signal Processing
A/D Conversion: 20 bit
D/A Conversion: 20 bit
Nominal Input Level
Input (mic): -40– +4 dBu
Input (line): -10 dBu
Input Impedance
23 k ohms (line)
2 k ohms (mic)
Nominal Output Level
Output (line): -10 dBu
Output Impedance
2 k ohms
7 segments, 3 characters (LED)
Headphone (PHONES) Jack (Stereo 1/4 inch phone type)
MIC Jack
MIDI IN Connector
AC Adaptor Jack
Memory Card Slot
Power Supply
AC Adaptor: 120/230 V (ACI-Series), 230 (UK)/240 V (ACB-Series)
Current Draw
1000 mA
AC Adaptor: 120/230 V (Roland ACI-Series), 230 (UK)/240 V (Roland ACB-Series), Owner’s Manual
Size and Weight
170 mm
6-3/4 inches
241 mm
9-1/2 inches
67 mm
2-11/16 inches
850 g
1 lbs. 14 oz.
* 0 dBu = 0.775 Vrms
*The specifications are subject to change without notice.



Updates & Drivers


If you have questions about operating your BOSS product, please check our Knowledge Base for answers to the most common questions.
You can also contact our Product Support department by phone or email.
In addition, we have a library of Owner’s Manuals and Support Documents that you can download and reference.

Support Documents