Audio ResearchVS55usedAudio Research VS55 Amplifier, 50 Glorious Tube Watts Per Channel**Please click here to check out our newly launched SkyFi Audio website with additional items for sale** Perfect for driving efficient bookshelf speakers or large vintage floorstanding speakers.Tes...2499.00

Audio Research VS55 Amplifier, 50 Glorious Tube Watts Per Channel

Listing ID: lis9fb3j Classified 
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Time Left: 25 Days


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Ships fromRidgewood, NJ, 07450
Ships toUnited States
Package dimensions?" × ?" × ?" (60.0 lbs.)
Shipping carrierUPS
Shipping cost$69.00
Agon miniAverage Research Pricing

**Please click here to check out our newly launched SkyFi Audio website with additional items for sale**

Perfect for driving efficient bookshelf speakers or large vintage floorstanding speakers.

Tested and working perfectly in our lab.  The output tubes are pulling strong and appear to have little use.  This piece was biased to perfection and is producing full power without any drama. 

Features 8 and 4 ohm taps to get the most out of your speakers.  12V triggers will allow you to manage power from a preamp with the same connection. 

Condition is very good with no significant signs of use. 

From a review via SoundStage! written by John Potis:

"These days there are more manufacturers of high-end electronics than any reviewer can shake a stick at. But none is more time-honored than Audio Research Corporation.

...The VS55's treble grabbed my attention next. It was as honest and extended as any I’ve heard. It seemed to go on out forever and with absolutely no editorializing whatsoever, which could be a mixed bag. Good recordings sounded spectacular, offering a great measure of air and space and giving instruments occupying the highest octaves real presence.

...The VS55 does some things, such as bass and dynamics, like much more expensive amps, and better than most amplifiers I’ve heard. And it wraps it all up with such a remarkably clean and transparent treble that it’s no wonder Audio Research has maintained such an enviable reputation for all these years.


Power output: 50 watts per channel continuous from 20Hz to 20kHz

Approximate actual power available at "clipping" 52 watts (1kHz) 

Power bandwidth:  (-3dB points) 12Hz to 50kHz 

Frequency response:  (-3dB points at 1 watt) 1.0 Hz to 60 kHz 

Input sensitivity:  1.1V RMS Single-ended for rated output. (25 dB gain into 8 ohms) 

Input impedance: 100K ohms 

Single-ended Output taps:  8 ohms, 4 ohms 

Output regulation:  Approximately 1.0 dB 8 ohm load to open circuit 

Overall negative feedback:  12.5 dB 

Damping factor:  10 

Distortion:  1kHz total harmonic distortion typically 1% at 50 watts, below .05% at 1 watt 

Slew rate:  5 volts/microsecond 

Rise time:  5 microseconds 

Hum & noise:  Less than 0.2mV RMS - 100dB below rated output (IHF weighted, input shorted) 

Power supply energy storage:  166 joules 

Power requirements:  105-125VAC 60Hz (210-250VAC 50Hz) 320 watts at rated output, 500 watts maximum, 200 watts at "idle" Tube complement:  (2 matched pairs) 6550EH power output, (3) 6N1P input and driver 

Other:  Tube locations and types are screened next to each opening in the top plate, along with bias-adjustments for the two pair of 6550 Electro-Harmonix output tubes.

The rear has 12 V in/out triggers for remote installation and L / R channel access points for a voltmeter (used when setting bias).

The amp rests on four elastometer feet and use detachable 12 gauge power cord with IEC socket. 

Dimensions:  14" (35.6 cm) W x 7" (17.8 cm) H x 14" (35.6 cm) D. Rear connectors extend .88" beyond chassis 

Weight:  32 lbs. (14.5 kg) Net; 38 lbs. (17.3 kg) Shipping

Thanks for looking and please click here 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.



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

Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.

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 201.879.0000 with any questions. 

Please also click here to visit our Audiogon store to see the rest of the items we have for sale.



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, 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, Pro-Ject Audio Systems, and Sony ES, we have access to OEM parts, service, and support.  If you are local and looking for new equipment from the above-mentioned manufacturers, please drop us a line as we can arrange both sales and professional installation in the tri-state area.


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 it’s 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.   


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. 


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, cables, 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 surround 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 201.879.0000 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.  


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