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Technics SH-8065
33-Band Stereo Graphic Equalizer
(1982-1988)

© 2011-2012 KenRockwell.com. All rights reserved.

Intro   Specs   Performance   Usage   Recommendations

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Technics SH-8065 33-band graphic equalizer

Technics SH-8065 Stereo Graphic Equalizer (also comes in classic Technics brown). enlarge. This free website's biggest source of support is when you use these links, especially this link to them at eBay, where they sell for about $250 (see How to Win at eBay). If there are none there, here's the link to all Technics equalizers at eBay. t helps me keep reviewing these oldies when you get yours through these links, thanks! Ken.

July 2012, May 2011       All Reviews    Audio Reviews

 

Introduction         top

Intro   Specs   Performance   Usage   Recommendations

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The Technics SH-8065 is a precision 33-band stereo graphic equalizer intended for careful optimization of loudspeakers and headphones in critical home environments.

This equalizer is best used to optimize a transducer's voicing. While audiophiles grasp for clues trying to use words like "nasal," "woolly," "etched," "distant," "hollow," "forward," "thin," "warm," "direct," "expressive" and so forth, the audio professional recognizes these as simple frequency response anomalies, easily rectified with subtle equalization.

Pink-noise noise-based room EQ was a misguided consumer fad from the late 1970s. Our ears distinguish direct sound from the reflected, making noise-based analysis irrelevant.

While it might seem more suited to a professional environment, it has only unbalanced 1/4" RCA connections, not balanced XLR.

It came in both conventional brushed extruded aluminum as shown, and Technics' signature dark brown, model number SH-8065 (K).

The SH-8065 offers the usual ±12 dB adjustments, and offers a selectable ±3 dB range for precision equalization. In other words, pressing the ±3 dB switch makes the full range of the sliders only ±3 dB, which is ideal for making only the most precise and delicate adjustments to otherwise perfect audio systems.

A foolish feature is a switch to reverse the effects of equalization, in other words, it turns the boosts to cuts and vice versa.

The SH-8065 is the world's first 33-band EQ; previous equalizers stopped at 31 bands, while this Technics SH-8065 adds two more third-octave sliders, one at 16 Hz and one at 25 kHz, to allow precision equalization to just beyond the ends of the audio band.

Compared to ordinary 31-band equalizers, the SH-8065 is particularly useful for the precision equalization of extreme full-range systems, especially where subwoofer performance to 16 Hz and below is important.

Personally, I used to run a pair of 18" JBL 2245H subwoofers in 8 cubic-foot enclosures with an eighth-order dedicated time, phase and frequency equalizer that made them flat to ±2 dB at 10 Hz, so I could have used one of these to optimize them to my listening room.

The Technics SH-8075 (not shown) was the same thing, but added one extra 20-200 Hz variable parametric section where the SH-8065's silly range displays were. The SH-8075 replaced the ±3 dB precision equalization option and the foolish ability to reverse the EQ curve with a second tape monitor loop.

Technics SH-8065 33-band graphic equalizer

Connections, Technics SH-8065 33-band graphic equalizer.

An unusual feature is an adjustable gain structure that optimizes the SH-8065 for two different signal levels. The gain is unity in either position, however noise and maximum output are optimized. I discus this below.

 

Technics SH-8065 33-band graphic equalizer

Rear, Technics SH-8065 33-band graphic equalizer. enlarge.

 

Technics SH-8065 33-band graphic equalizer

Power and Certification, Technics SH-8065 33-band graphic equalizer.

 

Specifications         top

Intro   Specs   Performance   Usage   Recommendations

 

Input

47k Ohms.

1 volt nominal, 8 V maximum.

Also selectable for 150 mV (see below).

 

Band Centers

Standard third-octave center frequencies:

16 Hz

20 Hz

25 Hz

31.5 Hz

40 Hz

50 Hz

63 Hz

80 Hz

100 Hz

125 Hz

160 Hz

200 Hz

250 Hz

315 Hz

400 Hz

500 Hz

630 Hz

800 Hz

1 kHz

1.25 kHz

1.6 kHz

2 kHz

2.5 kHz

3.15 kHz

4 kHz

5 kHz

6.3 kHz

8 kHz

10 kHz

12.5 kHz

16 kHz

20 kHz

25 kHz

 

Gain

Unity (0 dB), ±1 dB.

 

Channel Symmetry

±0.5 dB, 250 Hz - 6.3 kHz.

 

Channel Separation

70 dB.

 

Output

600 Ohms.

Rated 8 V RMS maximum, 0.01% THD at 1 kHz.

 

Frequency Range

5 Hz - 100 kHz, +0, -1dB.



Total Harmonic Distortion

0.0025% (-92 dB), 20 Hz - 20 kHz at 1 V.


Signal to Noise Ratio

100 dB DIN.

110 dB, IHF A 1966.

 

Size

430 x 153 x 330 mm (16.9 x 6.0 x 13.0 inches), WHD, including feet, sliders and rear connectors.

 

Weight

Rated 6.6 kg (14.6 pounds).

 

Power

Power cord length: 195 cm (77" or 6' 5").

Input Voltage: Selectable 110V, 120V, 220V, 240V.

Power Frequency: 50 - 60 Hz.

Rated Power Consumption: 29 Watts.

Actual Measured Power Consumption: 20 Watts at 120 Volts, 60 Hz.

 

Price

1984: $1,050 catalog price, corrected for inflation in 2011 ($500 in 1988 dollars).

1988: $1,618 catalog price, corrected for inflation in 2011 ($865 in 1988 dollars).

2011: about $250 used (How to Win at eBay).

 

Interior, Technics SH-8065 33-band graphic equalizer

Interior Circuitry, Technics SH-8065 33-band graphic equalizer. enlarge.

 

Principle of Operation

While its front panel implies, and some marketing people tried to get people to believe, that this was a dual-mono equalizer, this is an ordinary stereo EQ with everything on the same board.

The filters use gyrators (active simulated inductors) instead of actual chokes.

 

Performance         top

Intro   Specs   Performance   Usage   Recommendations

Today in 2011, expect the sliders to make some scratchy noise as you adjust them the first time. The more use use them, they'll clean up and any scratchiness will go away. This doesn't affect the sound when you leave them alone, but dirt on the resistive elements accumulated over thirty years can give occasionally intermittent results as you move the pots on an instrument just brought out of retirement.

The sliders are nicer than most graphic equalizers: they are slim, and directly connected to the pots via a dog-leg that keeps dirt from the outside from getting on the pots on the inside. When you look in the slots, you're seeing plastic; the pots are protected inside while the slider handles wiggle around to get to the hidden pots.

This sounds complicated, but in fact the pots feel more solid, delicate, direct and precise than any of the other graphic EQs I've used. They are not mushy or wiggly; they just work, and the center click is much easier to set than on other equalizers.

 

Gain

At 1 kHz, fed from 600 Ω and loaded with 100k Ω:

 

LOW (150 mV) setting

EQ OFF: 0.0 dB.

EQ ON: +0.3 dB (at all frequencies; this wasn't an errant pot.)

 

HIGH (1 V) setting

EQ OFF: +0.05 dB.

EQ ON: +0.4 dB (at all frequencies; this wasn't an errant pot.)

 

Maximum Output Levels

(THD drops to nothing at just a fraction of a dB below these levels.)

 

LOW (150 mV) setting

8.70 V RMS at onset of clipping (0.1 % THD), 100k Ω load.

 

HIGH (1 V) setting

2.97 V RMS at onset of clipping (0.1 % THD), 100k Ω load.

 

Noise

200k Ω load, A-Weighted:

Sliders zeroed

-110.4 dBV, LOW level.

-115 dBV, HIGH level.

 

Frequency Response

Technics SH-8065

With the sliders quickly clicked to zero, the response was flat to within much better than ±0.1 dB over the range covered by the sliders. Good.

 

boosty 1k

Infrasonic response: -3 dB at 4 Hz.

 

Filter Performance

The center frequency of the 1 kHz slider was within a fraction of a percent of 1,000 Hz.

At 1 kHz, the 1 kHz slider's range was +12.1 dB to -12.2 dB.

In the ± 3dB range, the 1 kHz slider gave a +3.05 to -3.05 dB range.

At 1 V RMS out in the LOW range with the 1 kHz slider at +12 dB, THD+N was 0.00195% (-94 dB), 30 kHz bandwidth.

 

boosty 1k

1 kHz boosted +12 dB.

 

boosty 1k

16 Hz boosted +12 dB.

 

boosty 1k

20 Hz boosted +12 dB.

 

boosty 1k

25 Hz boosted +12 dB.

 

boosty 1k

31.5 Hz boosted +12 dB.

 

boosty 1k

16 and 20 Hz both boosted +12 dB.

 

boosty 1k

16 Hz boosted +12 dB, 20 Hz boosted +5 dB and 25 Hz boosted +2 dB.

This alignment is to equalize the original sealed-box B&W 801 to 16 Hz. The original 801 is aligned as with a Q of 0.7 and an Fc (-3 dB) of 37 Hz, and this curve equalizes it per my actual measurements.

 

boosty 1k

20 Hz boosted +12 dB, 25 Hz cut -12 dB.

 

boosty 1k

Arbitrary bass room EQ.

 

THD

Technics SH-8065 THD

THD, 22 kHz bandwidth, 200 mV input, B&W 801 EQ setting as above.

 

Technics SH-8065 THD

THD, 110 kHz bandwidth, 200 mV input, B&W 801 EQ setting as above.

 

Usage         top

Intro   Specs   Performance   Usage   Recommendations

Signal Level Switch

Controls, Technics SH-8065 33-band graphic equalizer

Signal Level Switch, Technics SH-8065 33-band graphic equalizer.

The signal level, volume or gain is not changed by this switch; it merely optimizes the equalizer for different signal levels.

Technics says to use the HIGH (1V) setting if you use this between a preamplifier and a power amplifier, and the LOW (150mV) setting if you 're using this in tape-monitor or external processing loops, or between anything else other than a power amplifier.

I didn't make any noise measurements, and never heard any noise in either setting.

To my surprise, the maximum output level at clipping at 1 kHz was 3.00 V RMS in the HIGH (1V) position, but was 8.5 V RMS at clipping in the LOW (150 mV) position!

As I use this for low-level signals (not fed directly to a power amplifier), I'm keeping it at LOW (150mV).

This almost makes sense, as if Panasonic is mis-naming these on purpose. Power amplifiers would be clipping long before they are fed 3V, so it makes perfect sense to optimize the SH-8065's HIGH range for levels not to exceed 3V. In other words, in the HIGH setting, your power amp will clip long before the EQ does.

On the other hand, at low levels, if you slam the sliders up to +12dB as fed from a typical CD or other player, you easily can need the 8.5 V maximum output level. It just so happens that the full-scale output of most CD players is 2V RMS, and the SH-8065's measured maximum output of 8.5 V RMS is conveniently +12.6 dB above 2 V RMS, meaning that Panasonic knows what they are doing.

Measured noise is also higher in the LOW setting, so I think someone reversed these.

 

Controls

Controls, Technics SH-8065 33-band graphic equalizer

Controls, Technics SH-8065 33-band graphic equalizer.

 

Sliders

There are no lights on the sliders, just red lines.

 

Lights

The only lights on this equalizer are LEDs by the switches, and backlit lines on the big black left-side display.

As you select either the ±12 dB or ±3 dB ranges, these lines change from white (±12 dB) to yellow (±3 dB), color coded to the dB markings in that display. It's foolish; both colors look about the same.

 

LEDs

In normal, equalized use, all four LEDs are red. Disable EQ and its LED goes out. Hit Tape Monitor, Record EQ or Reverse EQ and the second yellow LED lights instead.

 

Variable Range

When turned on, the white lines are backlit in white when the Variable Range switch is set to ±12 dB, and to yellow when set to ±3 dB.

 

Normal and Reverse Characteristics

This reverses the effects of each slider.

When set to Reverse, raised sliders lower the level of that band.

This was a silly sales feature.

 

Recommendations         top

Intro   Specs   Performance   Usage   Recommendations

The Technics SH-8065 33-band equalizer is particularly well suited for precision equalization of top-end home systems, especially because of its extended frequency range, and second precise ±3 dB adjustment range.

This equalizer is for people needing to make exacting and precise adjustments, both by ear and with instruments.

The SH-8065 is relevant today, as there is nothing else like it for serous home use. For instance, one could pay less for a new professional dbx 231 dual 31-band EQ, however it lacks the 16 Hz adjustment, which I find important, and lacks RCA connections. More important, the dbx' sliders are too tiny. Even though the dbx 231 offers a ±6 dB range, since its sliders are less than half as long (20mm in the dbx versus 45mm in the Technics SH-8065), the adjustments are still more easy and precise in the Technics' ±12 dB range! I also doubt that any professional EQ would have its signal levels optimized for audiophile use, especially seeing how the Technics offers two choices of system level optimization for audiophile systems.

For general use as a tone control, an ordinary 10-band octave equalizer is much more convenient, because one will be moving a lot of sliders at the same time on this SH-8065 third-octave equalizer.

If you've found my work here helpful, this free website's biggest source of support is when you use these links, especially this link to them at eBay, where they sell for about $250 (see How to Win at eBay). If there are none there, here's the link to all Technics equalizers at eBay. t helps me keep reviewing these oldies when you get yours through these links, thanks! Ken.

 

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Junk below: (ignore)

Frequency Response

Most of the loss at the ultrasonic frequencies is due to the capacitive load of the equalizer's inputs. I fed these tests from a 600 Ω generator, whose outputs were reduced slightly. Fed from a lower source impedance, the high frequency response would have been flatter, but fed from a higher source impedance, which can be common in home setups, it would be further reduced.

 

100 kΩ analyzer load, EQ ON

5 Hz: -0.5 dB

8 Hz: -0.3 dB

10 Hz: -0.2 dB

20 Hz: -0.05 dB

50 Hz: 0.0 dB

100 Hz: 0.0 dB

200 Hz: 0.0 dB

500 Hz: 0.0 dB

1 kHz: 0.0 dB

2 kHz: 0.0 dB

5 kHz: 0.0 dB

7 kHz: 0.0 dB

10 kHz: 0.0 dB

12.5 kHz: 0.0 dB

15 kHz: 0.0 dB

17.5 kHz: 0.0 dB

20 kHz: 0.0 dB

50 kHz: -0.05 dB

100 kHz: -0.6 dB

150 kHz: -1.6 dB

 

100 kΩ analyzer load, EQ OFF

5 Hz: 0.0 dB

8 Hz: 0.0 dB

10 Hz: 0.0 dB

20 Hz: 0.0 dB

50 Hz: 0.0 dB

100 Hz: 0.0 dB

200 Hz: 0.0 dB

500 Hz: 0.0 dB

1 kHz: 0.0 dB

2 kHz: 0.0 dB

5 kHz: 0.0 dB

7 kHz: 0.0 dB

10 kHz: 0.0 dB

12.5 kHz: 0.0 dB

15 kHz: -0.0 dB

17.5 kHz: 0.0 dB

20 kHz: -0.07 dB

50 kHz: -0.2 dB

100 kHz: -0.65 dB

150 kHz: -1.2 dB

 

Noise, 100k Ω load, 30 kHz bandwidth:

Sliders zeroed

LOW (150 mV) setting

EQ ON: 6.5 microvolts (-106 dBV), unweighted.

EQ OFF: 3.5 microvolts (-109 dBV), unweighted.

 

HIGH (1 V) setting

EQ ON: 4 microvolts (-108 dBV), unweighted.

EQ OFF: 3.4 microvolts (-109.4 dBV), unweighted.

 

All sliders at +12 dB

LOW (150 mV) setting

EQ ON: 24.5 microvolts (-92.2 dBV), unweighted.

 

HIGH (1 V) setting

EQ ON: 10.5 microvolts (-99.6 dBV), unweighted.

 

All sliders at -12 dB

LOW (150 mV) setting

EQ ON: 12 microvolts (-98.4 dBV), unweighted.

 

HIGH (1 V) setting

EQ ON: 9 microvolts (-100.9 dBV), unweighted.

 

 

 

1 kHz filter response at +12 dB

0.0 dB 100 Hz

+0.2 dB 310 Hz.

+1 dB 540 Hz.

+2 dB 660 Hz

+3 dB 720 Hz.

+4 dB 770 Hz

+5 dB 810 Hz.

+6 dB 840 Hz.

+8 dB 890 Hz.

+10 dB 932 Hz.

+12 dB 993 - 1,014 Hz.

+10 dB 1,082 Hz.

+8 dB 1,136 Hz.

+6 dB 1,210 Hz.

+4 dB 1,320 Hz.

+3 dB 1,420 Hz.

+2 dB 1,600 Hz

+1 dB 2,020 Hz.

+0.2 dB 10 kHz.

 

16 Hz filter response at + 12 dB

+0.2 dB 6.3 Hz.

+1 dB 8.3 Hz.

+2 dB 10.2 Hz

+3 dB 11.3 Hz.

+4 dB 12.2 Hz

+5 dB 12.8 Hz.

+6 dB 13.4 Hz.

+8 dB 14.3 Hz.

+10 dB 15.15 Hz.

+12 dB 16.1 Hz

+12.2 dB 16.8 Hz.

+12 dB 17.3 Hz.

+11 dB 18.1 Hz.

+10 dB 18.6 Hz.

+8 dB 20 Hz.

+6 dB 21.7 Hz.

+4 dB 24.6 Hz.

+3 dB 27.1 Hz.

+2 dB 32.0 Hz

+1 dB 45 Hz.

+0.2 dB 60 Hz.

 

THD + Noise

Measured at 1 V RMS, EQ ON, pots zeroed, 100k Ω load, 30 kHz bandwidth, 400 Hz high-pass at 1 kHz and above. (Rated 0.0025% (-92 dB) at 1 V RMS, 20 - 20k Hz.)

 

LOW (150 mV) setting

0.0007% (-103.1 dB) at 20 Hz.

0.00077% (-101.5 dB) at 1 kHz.

0.0025% (-92 dB) at 25 kHz; 400 Hz - 700 kHz measurement bandwidth.

At 1 kHz and 1 V RMS out in the LOW range with the 1 kHz slider at +12 dB, THD+N was 0.00195% (-94 dB), 30 kHz bandwidth.

 

HIGH (1 V) setting

0.001% (-100 dB) at 20 Hz.

0.00087% (-101.2 dB) at 1 kHz.

0.0052% (-85.7 dB) at 25 kHz; 400 Hz - 700 kHz measurement bandwidth.