Audio ResearchD-90usedAudio Research D-90 Vintage Tube Amplifier USA Made! 80 Glorious Watts**Please click here to check out our newly launched SkyFi Audio website with additional items for sale**Warm, musical, and engaging vintage tube amplifier from the early 80s. Made to the highest qu...1699.00

Audio Research D-90 Vintage Tube Amplifier USA Made! 80 Glorious Watts

Listing ID: lis9c52f Classified 
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Asking Price: $1,699.00

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Ships fromRidgewood, NJ, 07450
Ships toUnited States
Package dimensions?" × ?" × ?" (80.0 lbs.)
Shipping carrierUPS
Shipping cost$250.00
Original accessoriesBox
Agon miniAverage Research Pricing

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

Warm, musical, and engaging vintage tube amplifier from the early 80s. Made to the highest quality standards available at the time.

Hand soldered and assembled.

Complete with rare original box. 

The amp passed our battery of tests with good results and was able to deliver just above the full rated power.  In the listening room it powered our Klipsch speakers with authority and ease.  

A great survivor and amazing value. 

Link to Online Manual:

Description: Tube stereo power amplifier

Introduced: 1980

Discontinued: 1985

Revisions: D-90 Revised, D-90B (1981)

Options: -

MSRP (US new retail): D-90: $2,195, D-90B: $2,450 (Later increased to $2,695)


Power bandwidth: (-3dB points) 12 Hz and 60kHz
D-90B: (-3dB points) 12 Hz to 50kHz Frequency response    

Input sensitivity: 1.2V RMS for rated output (adjustable)    

Input impedance: 75 kOhms, nominal at maximum gain   

Output taps:    Output regulation: Approximately .8dB, 16 ohm load to open circuit
D-90B: Approximately .3dB, 16 ohm load to open circuit    

Overall negative feedback:17.5dB / D-90B: 21.5dB    

Damping factor: Approximately 12 / D-90B: Approximately 25 

Distortion: Intermodulation distortion: Less than .5% at 1 dB below rated output (100V p to p, 16 ohms) (SMPTE method) / D-90B: Intermodulation distortion: Less than .3% at 1 dB below rated output (100V p to p, 16 ohms) (SMPTE method)    

Slew rate: 20 V/µs / D-90B: 15V/µs  

Rise time: 2.5 µs / D-90B: 5 µs    

Hum & noise: Wideband, unweighted, more than 90dB below rated output  Line components, more than 80dB below rated output    

Power supply energy storage: 240 joules total  

Power requirements: 105-125VAC 60 Hz (210-250VAC 50 Hz) 800 watts maximum. 400 watts at "idle". 500 watts at rated power.    

Tube complement: D-90: (4) 12AX7, (2) 6FQ7, (2) 12AT7 (4 matched pairs) 6550, (1) 6550 D-90 Revised: (4) 12AX7, (2) 6FQ7, (2) 12AT7, (4 matched pairs) 5881, (1) 6550 D-90B: (1) 12AX7, (5) 6922, (4 matched pairs) 5881, (1) 12BH7, (1) 12AT7    

Other: Dimensions: 19" (48 cm) W (standard rack panel) x 7" (18 cm) H x 16.5" (42 cm) D (front panel back). Handles extend 1 5/8" (4.1 cm) forward of front panel    

Weight: 64 lbs. (29 kg) Net, 80 lbs. (36.3 kg) Shipping


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 646.852.2073 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. 


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 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.   


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