Fingerstyle bass, exposed
Transient detail, low-frequency shape, and tube behavior without fog.
Founder’s Tin Edition
Osetra™
Sounds great. Looks fishy.
All-tube direct injection, dressed for service and built for the session. A responsive signal path with openness and packaging mischief.
20units only
$425each
Availablenow
Includes 12 VDC universal-input adapter · Requires 48 V phantom
All-tube signal path1 MΩ inputClass-A · no loop feedback4 Hz into the MHz range
Hear it
Sound before adjectives.
Compare Osetra with familiar reference hardware, then hear it on its own across electric and acoustic instruments.
02
Acoustic guitar, A/B
Switch sources without losing your place in the performance.
0:00 / 0:56
Osetra, on its own.
Telecaster
0:00 / 1:53
Acoustic guitar
0:00 / 1:08
How it’s made
Bench-built. Tin-finished.
Engineering leads, with personality close behind. See the tube and board up close, then watch the laser turn a caviar tin into studio hardware.
01 / Assembly
Built at the bench
02 / Circuit
All-tube signal path
03 / Fabrication
Cut by light
Engineering
Tube character,
not fog.
We could describe the sound all day. Have a look at the topology and the numbers.
“Extremely responsive and clean euphonic sound.”
| Product type | All-tube audio path direct box |
|---|---|
| Sound character | Extremely responsive and clean euphonic sound |
| Topology | Class-A, no loop-feedback, transformerless design |
| Frequency response | 4 Hz into the MHz range, only limited by the mic preamp |
| Instrument input impedance | 1 MΩ |
| Receiving mic-pre input impedance | 1.2 kΩ minimum |
| Adjustable input level | −∞ to +2 dB |
| Gain range | −∞ to +2 dB |
| Noise (EIN) | < −90 dBm |
| Connections | 1/4″ input · 1/4″ thru · Amphenol XLR output |
| Power (both required) | 12 VDC filament supply at 150 mA · 48 V phantom power |
| Included 12 VDC adapter | 90–250 VAC input · 3 W universal-input adapter |
| Dimensions / weight | 4.2″ diameter × 3.1″ height · 150 g |
All specifications are subject to change without notice.
Founder’s Tin
A serious tool in improbable packaging.
The first twenty Osetras are built into the object that inspired the name: a caviar tin. The sturgeon and its tiny “DI” egg are not a costume for the engineering, they are the wink that tells you a person made this.
Amels Audio continues Dave Amels’s decades of work designing electronic musical instruments, audio software, and analog recording equipment. Osetra brings that experience in circuit design, musical judgment, and professional studios to a compact tube DI.
The label is fun; the sound, serious.
Founder’s Tin Edition
Twenty tins.
That’s the edition.
Osetra is finished, direct-sale hardware—not a reservation, preorder, or waitlist.
- Edition01–20
- Price$425 USD
- AvailabilityAvailable now
- In the boxOsetra + universal-input 12 VDC filament supply adapter
- Warranty1-year parts and labor
- Mic pre requirementsMicrophone input, not line-level · 48 V phantom · 1.2 kΩ minimum input impedance
Osetra™$425
Shipping and applicable sales tax are calculated at checkout.
Founder’s Tin Edition
Buy Osetra Secure checkout by Stripe.Shipping and applicable sales tax are calculated at checkout.
Quick start / manual
Two power sources.
Both required.
Tube-life recommendationApplying the 12 V filament supply before the phantom power may extend tube life.
Instrument¼″ cable
→Osetra12 VDC filament supply
→Mic inputXLR · 48 V phantom
- 01
Turn levels down
Before connecting Osetra, turn down channel gain and monitor gain, and turn phantom power off.
- 02
Connect your instrument
Connect your instrument to the Osetra 1/4-inch INPUT.
- 03
Connect the filament supply
Connect the 12 VDC filament supply adapter to Osetra and plug the adapter into the mains voltage.
- 04
Allow warm-up
Allow approximately 30 seconds of filament warm-up for normal operation.
- 05
Connect the XLR output
Connect the Osetra XLR OUTPUT to a microphone input on your mixer, preamp, or audio interface.
- 06
Turn on 48 V phantom power
Ideally, enable 48 V phantom power after the 12 VDC filament supply is connected and powered.
- 07
Set the Osetra gain
Begin with the Osetra gain control turned down. Play normally and slowly increase the control to the desired level and character. Then adjust the receiving mic preamp as needed.
Prevent pops
- Turn down channel and monitor gains before connecting or disconnecting cables.
- Turn down channel and monitor gains before switching phantom power on or off.
- Turn down channel and monitor gains before connecting or disconnecting the 12 VDC filament supply.
No output?
- Confirm the 12 VDC filament supply is connected and powered.
- Confirm 48 V phantom power is enabled.
- Confirm the receiving input is set to MIC.
- Confirm the mic-pre input impedance is 1.2 kΩ or higher.
- Confirm the Osetra and receiving preamp gains are turned up.
Mic input, handling, and care
- Connect Osetra to a microphone input, not a line-level input.
- Keep the unit dry.
- Allow ventilation around the enclosure.
- There are no user-serviceable parts inside.
- The tube should last for many years.
- Hold the top lid—not the can—when removing connectors.
Amels Audio
Engineering with a point of view.
Amels Audio is where Dave Amels builds hardware for musicians and recording studios. Osetra starts with an original direct-coupled tube circuit and gives it an enclosure with a sense of humor: a caviar tin.