Jeff Rowland Coherence One Preamp with Phono Section, Gray or Gold Finish

**Please be sure and check out our newly launched website with additional items for sale** www.skyfiaudio.com/collections/all

Two-piece preamp from highly acclaimed maker Jeff Rowland (still in business).

This unit came to us from the original owner who had it since new and took great care of it.  There are no noticeable signs of use or abuse of any kind.  

What's best, we have located a rare second set of faceplates finished in gold so you get to choose which finish you’d prefer (Gray or Gold).  We will replace them for you prior to shipping.

Fully tested and working perfectly.  These feature the highest parts quality and circuit layout we have ever seen.  A quick look inside indicates that no shortcuts of any kind were taken.  

Includes 2 piece preamp, and power cord.  

Link to manual:  Coherence1Manual.pdf

Features:         

• The preamplifier is designed to rest on top of its power supply so the user-friendly pair can be handled easily. Special shielding techniques allow for this configuration, and "hum field" contamination has been eliminated.
• Lighted, feather-touch mode switches electronically control signal. The front panel switches do not alter sonic integrity, since signal switching is accomplished at the preamplifier input stage. Absolute phase reversal and full muting are other essential front panel control functions.
• A selectable tape output section allows simultaneous recording from one source while listening to another. "Record Out: Off" position disconnects tape recorder inputs from tape out jacks, eliminating loading problems when tape recorder is not in use.
• Volume controls are chosen for their sonic neutrality. Separate right and left trim potentiometers provide 6 dB adjustment for full rotation, permitting precise channel balance.
• Input and output jacks are gold-plated, ground-fault protected connectors, which provide tight, corrosionfree connections. Simultaneous normal and inverting outputs allow for balanced cable operation.
• Extremely low-noise phono sections eliminate the need for extra circuitry when using low output moving coil cartridges. The phono modules of the Coherence One Series II have been optimized for use with moving coil cartridges; for moving magnet cartridges, a module exchange can be easily accomplished by the user. Please contact Jeff Rowland Design Group from more details.
• All main outputs are muted temporarily during initial power application, power drop or disruption. DC potential across outputs, regardless of source, will also cause a muted condition.
• All signal amplification utilizes high-voltage, high-current, Class A field effect transistor technology.
• All inputs and outputs are direct-coupled, thus eliminating the deleterious effects of capacitors in the signal path.
• Precise RIAA equalization is the result of a split-passive network in the phono section.
• Incorporation of two-stage power supply regulation: A separate outboard power supply provides tight regulation regardless of power company extremes. Additionally, this discrete component design is optimized for excellent transient behavior, thus providing very low output impedance beyond 100 kHz.
• DC power is routed, via a power cable with a locking connector, to the main preamplifier circuit board. Compensating for power cable and circuit board inductance effects, sixteen (16) feedback-free discrete regulators adjacent to each module complete DC power distribution. This total system, in addition to separate channel balance controls, provides dual mono operation and precise regulation at each stage throughout.
• Time-related distortion, particularly in low-level phono stages, is eliminated by a totally feedback-free design.
• Mil-spec circuit board material, with oxygen-free copper traces and high-temperature mask provides superior electrical characteristics.
• All signal switching is accomplished with hermetically sealed, gold- contact signal relays.
• AC power line filter offers excellent line noise rejection.
• All critical circuitry is encapsulated in a thermally-conductive epoxy to ensure excellent thermal stability, mechanical integrity and to facilitate ease of service

Coherence 1 Specs

Inputs  Phono + 3 unbalanced line

Main outputs (per channel) 1 inverting, 1 non-inverting

Dimensions  12.5 in. W x 19 in. D x 3.75 in. H        31.8 cm W x 48.3 cm D x 9.5 cm H

Weight  29 lbs., 13 kg

Gain  60 dB

Frequency Response  0.15 Hz to 220 kHz, -3 dB

RIAA Accuracy  20 Hz to 20 kHz ± 0.15 dB; +0, -3 dB, 200 kHz

Input Impedance  User selectable: 0-200 ohms adjustable, 47 k ohm fixed or any value.

THD and Noise  < 0.025% @ 1 kHz, 0.7 V RMS output

Max Output Level  18 V RMS

Gain  19 dB

Frequency Response  0.06 Hz to 650 kHz, -3 dB

Input Impedance  10 k ohms

Output Impedance  300 ohms (single-ended output) 600 ohms (balanced output)

THD and Noise  < 0.010% @ 1 kHz, 3 V RMS output

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This item will be professionally packaged and insured for safe transit to your home.   

If we don’t have the original manufacture's packaging, we use heavy duty double ply corrugated boxes with Instapak expanding foam custom inserts.  In many cases this has proven to be better than the original packaging.  We also use high quality fiber reinforced tape to seal our packages.  Lightweight items will be bubble wrapped and shipped in a high-quality box. 

This item is available for pickup in Ridgewood, NJ or Union Square, NYC (with convenient parking in the building).

NJ Residents or anyone picking up without a resale certificate will need to pay NJ Sales Tax.

Use the Buy It Now button and we will cover the PayPal fees.

Thanks for looking and be sure to call or text 646.852.2073 with any questions. 

Please also be sure and visit our Audiogon e-store to see the rest of the items we have for sale www.audiogon.com/stores/skyfi

**And be sure to check out our newly launched website with additional items for sale** www.skyfiaudio.com/collections/all

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WHO WE ARE 

Skyfi Audio is a small startup business specializing in the purchase, reconditioning, and reselling of select high end audio equipment.  We only buy equipment the we admire and are passionate about. No mid-fi, no gimmicks, and no junk. 

Each piece of equipment is cosmetically restored and fully tested in our well-equipped lab by an engineer with 30+ years of experience in the HiFi world. If it does not meet or exceed the original manufactures specifications, it will not be sold.  We are very selective about the equipment we purchase, focusing on mostly analog, high-build quality, American, and European built units.

Through our sister company, which is an authorized dealer for McIntosh, Audio Research, Sonus Faber, ClearAudio, Project, and Sony ES, we have access to OEM parts, service, and support.  If you are local and are looking for any new equipment for the above-mentioned manufacturers, please drop us a line as we can arrange both sales and professional installation in the tri-state area

PURCHASING GUIDELINES

We do not accept or review any offers that do not go through the official Audiogon system. We have too many items for sale and its nearly impossible to keep track of offers outside of the official system. Please don’t message, email, or text any offers. 

If you do not see a “Make an Offer” button, it means we are not considering any offers on that item.   

PAYMENTS

We prefer working through PayPal, which allows you to use a credit card or bank transfer. We do not charge extra for any payment fees if you purchase the item at the asking price.  You can also send us a personal check (which will need to clear before shipping), certified check, money order, or wire transfer. International clients without access to PayPal should use a bank wire transfer. 

If you are picking up an item, we do not accept PayPal.  You must pay in person with cash, certified or bank check, or wire transfer.  If you make a PayPal payment and are picking up the item, it will be returned. 

TRADE IN POLICY 

We accept trade-ins of equal or lesser value under certain conditions.  Simply ask and let us know the exact model, condition, and the accessories that are included.  Such as the original box, remote, manual, etc.  We will only consider high-end equipment from mainstream manufacturers such as McIntosh, Mark Levinson, Audio Research, Krell, etc. and will typically pass on displays, projectors, receivers, dated processors, and mid-fi equipment of any type.  We will offer a fair value for your equipment, but keep in mind we are running a business and will need to be able to resell the equipment at a profit after investing a great deal of time and resources in testing, certifying, repairing, cleaning, and packaging the incoming equipment.  If you are looking for top dollar we suggest attempting to sell it directly to an end user on your own.

SELL US YOUR GEAR (Working or Broken)

We will also purchase your used or broken gear and arrange pickup if you are in our local market.  Just drop us a note for a quote but be sure to include the condition and what is included. 

HOW TO VISIT US

We are currently operating from a residence in Ridgewood, NJ.  You are welcome to make an appointment if there is a piece of equipment you would like to see in operation before or after purchase.  We have a well-equipped, dedicated listening room with tons of equipment of all makes and models.  We are not a store, so please don’t make an appointment if you are just curious as to how a speaker or piece of equipment sounds.  In essence, no tire kickers please.

If you are in NYC and cannot make it out to Ridgewood, we can arrange pickup in Union Square (14th Street) after the purchase.   You can call or text 646.852.2073 with any questions or to schedule an appointment.  We can also arrange to install, calibrate, and tune the gear in your listening room if you are local to the area.  This is super useful when purchasing large speakers or heavy amplifiers.  It is also great for ensuring your new turntable is setup correctly in its final resting place.  

Thanks for looking and please send us your email address if you would like to receive a list of the equipment we receive from time to time.  We promise not to bombard you with junk email.   

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