Audio Research D76 tube power amplifier.

Audio Research D76 tube power amplifier. In excellent working condition. 1500.00

Includes an extra set of tubes, original documentation, original packing, and original cover.

Rogue Audio Stereo 90 Tube Amplifier - $2000

Rogue Audio Stereo 90 Tube Amplifier - $2000

It has power to spare, a beautiful round mid-range and nice, controlled bass. The imaging is outstanding as well. As a longtime audio enthusiast, I have always held an appreciation for tube-based gear. 

Rogue Audio Stereo 90 Tube Amplifier - $2000

Classic 6SN7 tubes

Rogue Audio have consistently introduced new tube audio products since the late 1990s. I like their approach of merging classic tube audio with modern internal components and design.

Bias adjustment meter in the Stereo 90

From the Rouge Audio Owners manual available here: 

The Rouge Stereo 90 features a Triode/Ultralinear switch:

The output transformer of a tube amplifier acts as the electrical interface between the very

different impedances of the loudspeaker and the tube circuitry. There are three

fundamental ways that the output transformer can be connected to the tube circuit.

1) Tetrode or Pentode connection – In this configuration, the highest power level

is achieved but at the expense of significantly higher distortion levels.

Practically speaking, this mode of operation is sonically inferior and has been

disregarded in the Stereo 90 design.

2) Triode connection – With this configuration, the lowest level of distortion is

achieved but at the expense of output power. In the case of the Stereo 90, its

power level in triode is high enough that it will likely provide plenty of power

for almost any speaker load.

3) Ultralinear operation – With this configuration, power levels near those of

tetrode mode are achieved with low distortion levels that approach those of

triode operation. For loudspeakers that demand very high levels of power,

ultralinear should provide excellent sound and plenty of power.

The triode/ultralinear switch allows the user to operate the Stereo 90 in either of

the two modes. In general, the sonic differences are subtle but for a given

loudspeaker one mode is likely to sound better than the other. There is a

complex relationship between the output transformer and the crossover network

so try both and see which one works best in your system. This switch can be

operated while the amplifier is playing but you will hear a small relay noise

through the loudspeaker. 

Product Description

Stereo 90 

General Features:

Ultra-wide bandwidth output transformers

Massive fully regulated high voltage supply

Matched quad output tubes

Heavy-duty gold plated RCA inputs

Heavy-duty gold plated binding posts

User selectable 4 and 8 ohm output taps

User selectable triode or ultralinear output

(4) KT88/6550, (2) 6SN7, (2) 12AX7 tube complement

Built in bias meter

Integral tube cage

Machined aluminum faceplate

Mechanically isolated transformers

Heavy (2 ounce) copper circuit board

All precision components

Fully tested, burned in, and auditioned

3 year limited warranty (6 months on tubes)

Specifications: 

output power: 90 WPC minimum

input impedance: 200K Ohms

frequency response: 5Hz - 50KHz ± 1dB

THD: 0.1 % @ 1 W, 1% THD @ 90 W
input sensitivity: 1.0V RMS

dimensions: 18"W x 15¾"D x 7"H

weight: 60 lbs.

power requirements: 115/230V - 50 - 60Hz

PIONEER RT-707 REEL TO REEL TAPE DECK

PIONEER RT-707 REEL TO REEL TAPE DECK 

This is a classic from the Silver Era of Pioneer in the 70's.

This is a 4-Head, 3-Motor, 2-Speed Open Reel tape deck for 7" tapes.

This Pioneer RT-707 Reel to Reel tape deck comes with the original Pioneer PR85 take-up metal reel. All lights and functions work perfectly. This unit sounds so warm and full, it will make a great addition to your classic stereo equipment.

The brushed aluminum face is in very good condition with very minimal hairline scratches.

Beautiful McIntosh MC-2100 Power Amplifier

Beautiful McIntosh MC-2100 Power Amplifier

McIntosh MC-2100 Power Amplifier is in Beautiful Condition, The chrome is shiny, all lettering is intact. This McIntosh MC-2100 Amplifier is very transparent and sounds awesome.

MacIntosh made two versions of  the MC210X amp with same circuitry, the 2100 (with no meters,   looks similar to their classic 50s tube gear) and the blue-metered 2105.

Part of Mcintosh's first generation of solid state amps and great classic, big, solid bass sound. Not thin of overly bright like so much later solid state. Very close to tube sound, with better bass. Huge soundstage, plenty of headroom. A lovely amp.

Specs: 

Power Output: 105w/ch stereo. 210w mono. 

Response 20-20kHz (+0 -0.25dB). 

Distortion 0.25%. 

Noise and hum -90dB. 

Output impedance 4, 8 and 16 ohms (2, 4 and 8 ohms mono). 

Damping factor 11. 

Input impedance 200k. 

Input sensitivity 0.5v.

Audio Research SP-6B - Classic tube preamp

Audio Research SP-6B - Classic tube preamp!

This preamp is quite neutral, dynamic, and nicely transparent. All tube phono stage. Uses 12AX7s , a very common tube to find replacements for. I have no hesitation in recommending this piece of classic audio gear! The phono stage is where this preamp excels. The tone is neutral, and the sound stage is amazing! Besides the imaging, the wonder of ARC is the excellent build quality.

Audio Research SP-6B - Classic tube preamp!

Specifications

Frequency response
SP6-B:
High level section: ±.25dB, 5Hz to 30kHz.
-3dB points below 1 Hz and above 100kHz
Magnetic phono: ±.25dB of RIAA from 30Hz to 40kHz.

Distortion (THD) SP6-B:
Harmonic distortion: Less than .01% at 2V RMS output, 20Hz to 20kHz (typically about .0005% in midband).
Intermodulation distortion: Less than .002% at 2V RMS output.

Noise & hum High level:
(1) 250 µv RMS maximum residual unweighted wide-band noise at main output with gain control minimum (86dB below 5V RMS output).
(2) More than 90dB below 1V RMS input (less than 20 µV equivalent input noise).
  Magnetic phono: 5 µV equivalent input noise, wideband RMS (-66dB reference 10mV input).
Gain Magnetic phono input to tape output, 34dB.
  Magnetic phono input to main output, 60dB.
  High level inputs to tape output, 0dB.
  High level inputs to main output, 26dB.

Input impedance 50 kOhms, all inputs. (Magnetic phono may have any value from 10 ohms to 100 kOhms substituted. Also has provision to add input capacitance for matching certain magnetic cartridges.)

Output impedance 500 ohms at 1kHz, rising to 2.1 kOhms at 20Hz, all outputs. Recommended minimum load for maximum audio quality, 20 kOhms.
  SP6-B: Less than 500 ohms main output, 1000 ohms tape output. Recommended minimum load for maximum audio quality, 50 kOhms and 250 pF maximum capacitance.


Rated outputs: 2V RMS 5Hz to 30kHz, all outputs, 60 ohm load. (Main output capability is 60V RMS output at .5% THD at 1kHz into a 500 kOhm load with 3V RMS high level input.)
Power supplies SP6-B: 4 electronically-regulated solid-state supplies. Frequency-compensated high voltage supplies have a total equivalent low frequency stability of greater than 3 farads of capacitance. Line regulation better than .001%.
Tube complement SP6: (2) 12AX7 LN, (4) 12AX7

Power requirements: 100-120/190-240 VAC, 50/60 Hz, 35 watts.
Dimensions 19" (48 cm) W x 5 1/4" (13.4 cm) H (standard rack panel) x 10 1/4" (26 cm) D. Handles extend 1 5/8" (4.1 cm) forward of front panel. Rear chassis fittings extend 7/8" (2.3 cm).
Weight 22 lbs. (10 kg) Net, 30 lbs. (13.75 kg) Shipping

Spendor BC3 - The classic BBC monitor

 Spendor BC3 loudspeakers in excellent shape. 

The classic BBC monitor in natural cherry , The Spendor BCIII loudspeaker was introduced in 1979. It is a 4-way design based on the classic BCI. It also used an additional 12" driver for bass reinforcement. It is highly sought after and is very hard to find. Spendor remains among the few high-end speaker manufacturers that design and make their own drive-units.  I have owned and listened to BC3s since 1978. For me, they have been the most natural-sounding and closest-to-electrostatic-character dynamic speakers I have yet heard, with the magic mid-range imaging.

The BC3 needs a high current amp that can drive difficult, reactive loads. They have always been cited as difficult to drive. However, my old Dynaco Stereo 70 drove them without any problems.

Musically engaging and extremely well built. Spendor approached the design of the BC3 much like the creation of a musical instrument. The result is a smooth, rich presentation with a brilliant midrange. This model was the standard for many British radio stations to this day.