Prautes


The PRAUTES, and other products, are produced in a collaboration between Coffman Labs and Cypher Labs, bringing together two firms with advanced technology expertise. The goal: unlock an unsurpassed listening experience for the audio customer.

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The PRAUTES® is a world class vacuum tube headphone amplifier at an affordable, all inclusive price of $3900.

For one price you receive:
* The PRAUTES® in black only
* Custom 1 meter massive AC power cable in US, EU or UK termination
* High end tube complement: 50L6 or 25L6 and 12AU7 tubes made in USA prior to 1970 – true New Old Stock (“NOS”)
* High end vintage capacitors: cold war era 2 microfarad polystyrene
* Full color product manual (see bottom of this page for the download)
* High quality design and hand made attention to detail: Made in USA

The PRAUTES is primarily a headphone amplifier, although it can also power small speakers and provides a line-out stage. The controls are optimized for headphone output and the result is an unbelievable clarity, presence and expansive soundstage. The PRAUTES drives a wide range of headphone types and provides for impedance matching. A very subtle bass boost feature is included.


PRAUTES defined: understood to be a reference to proper understanding and accurate action. PRAUTES AS DEFINED BY THE ANCIENT GREEKS expresses a character in which strength and gentleness are perfectly combined. The PRAUTES amplifier seeks to do just that—present music in a manner that delivers subtlety, image, detail, and excitement, all in an accurate manner that duplicates the live experience. The Prautes amplifier combines vintage tubes, military technology, and hand made USA components to create the ‘PRAUTES’ experience. The result is a legacy piece—one that is timeless and enduring.

The PRAUTES uses a 12AU7 tube gain stage to drive a pair of 50L6 or 25L6 tubes (note in product serial number) in push-pull mode. This provides for more power than needed for almost all headphones—and can drive high efficiency speakers with about 2 watts. Five separate output impedance settings are provided to match listening equipment, including 8 ohm speakers, standard headphones, high impedance headphones and In-Ear-Monitors.

The PRAUTES amplifier bears the signature of Damon Coffman. He trained in college as a concert violinist, obtained his graduate degree in physics through the U.S. Naval Postgraduate School, then built his career as an engineer in medical technology firms. While pioneering new technologies for medical companies, Damon began searching for audio equipment that would give his favorite pieces of music the beauty of a live performance. He found some of what he was looking for in the designs of classic amplifiers from the golden age of analog audio. He then combined his passion for music, art, and craft into heirloom quality products that embody his design philosophy of simplicity, elegance, and accessibility.

We are proud of our unique approach to audio and design, and we believe that our amplifiers will be enjoyed and cherished for many years to come.


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Operation

Each of the four inputs are independent. Connect your line sources such as CD player, TV, or iPod to any of the four inputs. Since there are no digital switches (which can degrade the audio signal), it is recommended that unused devices connected to the PRAUTES be turned down or off.

The headphone outputs and speaker outputs are independent. Only the selected output is used. High efficiency (90db or more) 8 ohm speakers work best.

The line output is appropriate for powered speakers, power amplifiers, or any other device with a line input that has an input impedance of 100K ohms or greater. When used to supply a line output to another amplifier, the PRAUTES amplifier acts like a pre-amplifier.

Controls

Volume: This heritage quality finely manufactured potentiometer controls the headphone, speaker and and line output

Input Switch: Selects one of four line inputs

Input impedance on each input is 100K Ω
Tip: Use the ‘Mute’ position when changing input cables

Impedance (Ω) Switch: Headphone and speaker settings

300 Ω: High impedance headphones
100 Ω: Standard for many Studio headphones
32 Ω: Standard consumer headphones
8 Ω: Speakers or very low impedance headphones.
IEM: In-Ear-Headphones

Bass Boost Switch: Provides approximately +3dB boost with a variable roll-off point

The bass boost circuit gives a subtle increase in bass response. This control eliminates the high phase shift that occurs with typical tone controls. The boost amount is the same for all settings, but the frequency point of the boost ranges from 47Hz to 31Hz. This allows for very fine tuning of the bass response. Match this setting in coordination with the Impedance Switch to match the selected headphone, type of music chosen and your preferences.

Output Switch: Selects output type

SPK: Output to rear speaker jacks—use 8 Ω impedance
XLR: Output to balanced 4 pin XLR jacks – can drive two XLR connected phones at the same time
Mute: No speaker output — use for independent line output mode
1/4″: Output to 1/4″ (6mm) Headphone jack
1/8″: Output to 1/8″ (3.5mm) Headphone jack

Line output is always active and volume controlled. We recommend connecting to any input impedance 100K ohms or greater.

Specifications

Gain:
Line Stage: approximately 16dB
Headphone power: > 1 Watt, depending on load

Bass Boost:
31, 36, 41, or 47Hz boost of approximately 3dB (6dBm)
There are no extra active circuit elements are engaged!

Ground Lift Switch:
Use only if there is ground loop hum in your AC supply wiring.

Tube Complement:

Four 50L6 or 25L6 tubes are supplied for the output stage
Two 12AU7 tubes are supplied for the input/line stage

Annodized tube shields are provided to cover the tubes. The use of the tube shields is optional.

Frequency Response:
20Hz to 20KHz +.2dB to -.75dB into matched resistive load
Note: Can vary slightly based on tubes installed

Dimensions:
12 ½” D x 9 ½” W x 7 ¾” H / 32.5cm D x 23.5cm W x 19.6cm H

Weight:
16 pounds / 7.3 kilograms (not including AC power cable)

AC Power:
Depending on destination country the PRAUTES amplifier voltage setting is preset at the factory for 120v or 240v operation.

What makes the PRAUTES unique?

– The PRAUTES is a tube-based analog amplifier. It is powered by a small, custom made, internal regulated semiconductor power supply— thus allowing single box construction.

– The PRAUTES is hand assembled entirely in the U.S.A at Coffman Labs with point to point wiring—it should last decades. All contact points are mechanical as well as electrical

– The PRAUTES is electrically rugged and meant to last

– The PRAUTES chassis is a 100% machined (not stamped metal) and able to take abuse. All chassis parts are interlocked in specially designed machined slots so that only four bolts per side are required to keep the structure intact


Power Cable: Yes, it is included!!

Prautes® Product Manual

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