Marantz Sd9000dbx 3-head Cassette Deck - Incredible

Marantz Sd9000dbx 3-head Cassette Deck - Incredible

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Marantz Sd9000dbx 3-head Cassette Deck - Incredible:

Marantz Compudeck SD9000 DBX


Okay, Marantz fans - here's a piece that comes around maybe two or three times in a decade - the very rare SD9000DBX. Back in 1980, Marantz introduced a line of technologically advanced "Compudecks" - cassette decks utilizing advanced microprocessor circuitry to control tape movement, timer actuation, and program selection and retrieval. The SD9000 was the Flagship of the Compudeck line; the only deck in the lineup offering three heads - an erase head, a record head and a playback head. The chief advantage of having a three-head deck is that, with a flip of a switch, you can immediately compare your recording with the original source material - a must for fine-tuning the deck to yield the highest quality recordings possible.

As a global company, Marantz designed different variations of these decks for different regions. The deck marketed in the US and Canada was the two-speed version, which is consequently the deck almost always found on here in the States. Marantz also built a single speed DBX version of these Compudecks for the European market. Basically, the trade off is that with the SD9000DBX, you get DBX noise reduction (usually found only in professional decks) in lieu of the higher recording speed. DBX is considered to be the "Cadillac" of noise reduction technologies, and pretty much kills all tape hiss in your recording, without affecting dynamics as Dolby sometimes can. In addition, the SD9000DBX offers a voltage selector for 110/120/220/240 VAC, a separate DIN plug in addition to the normal RCA-style input/output jacks, and a removable line cord. In addition, this deck includes a slew of other advanced features like bias fine adjustment, an auto tape slack removal circuit, mic/line mixing, electronic timer memory, solenoid-controlled, full-logic transport, and the list goes on and on. The Marantz SD9000DBX - arguably the ultimate vintage cassette deck. This may be the last one you see for a very long time!

As rare as this deck is, the optional RMC-1 wired remote control is even rarer. If you are interested in supplementing your Compudeck with one of these super-scarce options, one is being offered in a separate sale here.


Cosmetically, this particular unit is in outstanding condition - check the detail pictures for yourself. There are a few tiny scratches on the faceplate and around the screws on the top of the tape loading bay, but these are difficult to see even in the high-resolution close-ups I've provided. The rosewood vinyl clad wood side panels are in very nice shape, with just a bit of distortion of the vinyl coating around the side screw holes. The rest of the deck is close to perfect, with no dents, dings, or engravings. The interior of the deck is minty-clean, and clear of any trace of corrosion. The original power cord is included, and the original feet are in place.

Functionally, this unit is a perfect 10 out of 10. Everything I thought to test (record, playback, Dolby and DBX tracking, programming) worked perfectly, smoothly, and noiselessly. All switches function quietly and positively, the rotary controls are smooth and noise-free.Plenty of fast-forward and rewind torque. The tape heads show minimal wear; with no grooving or pitting whatsoever. The rubber is soft and pliable; all belts and idlers have been replaced; the transport and capstan motor have been lubed, the power supply board recapped, and the heads meticulously cleaned and demagnetized. All in all, this is an outstanding specimen of a cassette deck that is getting to be almost impossible to find. Don't let this beauty slip away!


Included literature - a copy of everything I've been able to find regarding the SD9000 cassette deck over the past decade or so. Unfortunately, it specifies the two-speed unit as opposed to the DBX variation, however, the lions share of information is perfectly applicable.

Replaced parts. The old belts were also replaced, but they were so decayed that they had melted and had to be removed with a rag and some rubbing alcohol.

A shot of the power supply/bias oscillator board prior to replacing the old electrolytic capacitors ("recapping").

The same power supply board after recapping:

The idler assemblies showing the old, dried-out idler tires. When this happens, rewind and fast-forward malfunctions, and tapes start to get "eaten".

Replacement rubber and optocouplers:

Old, dead optocouplers (the black U-shaped devices). When these go, the deck plays for 2 seconds, then stops.

Newly installed optocouplers. With the modern advances in infrared LEDs, these should be good for at least another 30 years!

Services Performed:

  • All idler tires and belts replaced with new
  • Defective optical couplers replaced with new
  • Motor and solenoid drive transistors replaced with new
  • All heat sink-mounted power transistors removed, cleaned, and remounted with fresh thermal compound
  • Transport disassembled, cleaned, re-lubed and reassembled (top-quality silicone grease and synthetic lubricant used)
  • Tape path thoroughly cleaned; tape heads demagnetized
  • All electrolytic capacitors on the power supply board replaced with high-quality, hi-temp Panasonic FC series capacitors
  • All electrolytic capacitors replaced in the sensitive program sensing (music search) circuitry
  • Capstan motor lubricated, motor speed calibrated


  • 3 head, 2 motor design
  • Solenoid controlled full-logic tape transport
  • Dolby B and DBX noise reduction
  • Microprocessor-controlled music search and programming capability
  • Front-panel microphone jacks, with mic/line mixing capability
  • Remote control compatible (remote NOT included in this sale)
  • Auto tape slack removal circuitry
  • Built in clock and timer for timer-controlled recording and playback
  • 400 watt rear accessory outlet (switched AND timer-controlled!)
  • Metal, CrO2, FeCr, and normal tape formulation capability
  • 12-segment, dual color LED peak level display
  • Bias fine control, output level control, headphone jack...and more

Included in the sale:

  • SD9000DBX cassette deck, serial # 11P030057, manufactured on or around October 20, 1980 (according to date stamp on capstan motor)
  • Original Marantz power cord
  • Copy of Marantz SD9000 specification sheet
  • Copy of SD9000 owner's manual
  • Copy of SD9000 service manual
  • Copy of Marantz warranty sheet
  • Copy of 2-page Compudeck promotional literature
  • Copy of SD9000 test report from June 1980 Stereo Review magazine
  • 4x6 quick reference card (this was originally a film sheet attached to the top of the SD9000 by the factory - it gives the basics of how to program the deck)


Frequency Response:
Metal: 25 Hz ~ 20 kHz (±3dB)
FeCr: 25 Hz ~ 18 kHz (±3dB)
CrO2: 25 Hz ~ 17 kHz (±3dB)
Normal: 25 Hz ~ 16 kHz (±3dB)

Wow and Flutter:

Signal to Noise Ratio:
Dolby NR 69 dB
DBX NR (I don't have the Marantz spec for this, but DBX SNRs usually range from 75-82 dB down)
Noise Reduction Off: 59 dB

Dimensions (W x H x D):
16-3/8" x 5-3/4" x 11-5/8"

22 lbs., 1 oz. (10 kg)

Additional specifications available upon request


If you are not 100% satisfied with this unit, you may return it within 14 days of receipt for a full refund of your purchase price and original outbound shipping (yes, return shipping would be your responsibility). Full refund would of course be contingent upon receiving the returned unit in the same condition in which it was sent, without any missing or exchanged parts.

As most failure-prone parts in this deck have already been replaced, I have no problem offering a full 90-day warranty on this unit. Should you have any problems within 90 days of receiving this item, I will repair it free of charge, including parts and labor, provided you handle round-trip shipping.

Due to guidelines, I accept only PayPal payment. Buyer pays fixed FedEx Ground shipping rate of $39.00, which includes shipping insurance and absolutely bulletproof packaging, for any destination in the continental US. I will ship internationally, but I will not provide rate estimates prior to sale end. The packaged deck will weigh 30 lbs., the package dimensions will be 20" x 19" x 15" - you can obtain your own international rate quote from your carrier of choice. I do not "pad" shipping charges, and will honor any confirmed legitimate shipping rate.

Buyer MUST respond within 3 days of the sale end or transaction will be void. Payment MUST be received within 10 days of the end of the sale or the transaction will be void. I reserve the right to cancel offers from any party with a response rating at or below zero, or any party with excessive negative response. Good luck and happy offerding!

Marantz Sd9000dbx 3-head Cassette Deck - Incredible:

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