This ebony classic is the Yamaha CR-840 receiver. It was produced from 1979 to around 1981 and retailed for about $500. It was a mid range receiver in Yamaha's CR-XX40 lineup. It puts out 60 watts per channel into 8 ohms.
The CR-840 has the big flat toggle switches as do many of the other Yamaha models. Overall it has a very nice sleek hi-tech look to it, though some think the Yamaha models look somewhat sterile.
The CR-840 has a built-in AUTO-DX circuit that monitors the signal strength and amount of interference present. If needed it will automatically switch to the DX Mode IF Stage to increase the selectivity to 83dB.
It also has continuously variable loudness control which means that the frequency balance and volume are adjusted simultaneously to compensate for the ear's insensitivity to high and low frequencies at low volume settings. So, a natural-sounding balance is maintained regardless of volume level. It weighs about 30 pounds and measures 20" x 6-9/16" x 15-1/4".
One problem with the Yamaha CR-840 is that it uses output modules rather than discrete output transistors. These modules have a tendency to overheat and die. Unfortunately, original replacements are difficult to find and newly made versions tend to be out of spec and perform erratically. It has been speculated that the Yamaha IG 02970 output module was in fact a rebadged Sanyo STK 0060-II or STK-0080-II. The STK-0080-II is fairly easy to find which would make repairing these units far easier.
The Yamaha receivers have never garnered as much attention as the Pioneer and Marantz receivers but perform just as well. They do emphasize a "Natural Sound" so they tend to have a more accurate representation of sound which some find to be a little harsh. Prices are rising for these receivers though - especially the higher end models. You can find a nice working version of the CR-840 for about $150 to $200.
This is a classic upper mid-range receiver from the late 1970's. It is the Yamaha CR-820 and was on the market from around 1977 to 1979. It produced 55 watts per channel into 8 ohms and had low distortion ratings. In fact, while most manufacturers measured distortion at the rated output of the unit, Yamaha measured the distortion over a wide range of power output. They called this the Noise Distortion Clearance Range (NDCR). They trademarked the phrase 'Real Life Rated' because they measured noise and distortion at -20dB from the inputs all the way through to the speaker output as opposed to just measuring the amp section. They believed this would give a better indication of performance in a true listening environment.
The Yamaha CR-820 retailed for around $460.00 and had the classic Yamaha styling of the time with monochrome face plate, clean knobs and over sized rectangular switches. The receivers from this series all have a clean, almost sterile, machined look to them. They also came with a special plug for the headphone jack output that said 'Reserved For Yamaha Orthodynamic Headphones'. Sounds impressive!
As you can see it has controls for:
- Volume / Balance
The over sized switched control the selection of inputs and outputs. There are also a number of push button switches running along the bottom of the unit.
The CR-820 does look nice when it's illuminated. The back lighting is a light amber accented with a few red LED indicators. The low profile case is wood with a vinyl veneer. It's decent sized receiver as well measuring 17.6W x 5.7H x 15.5D in inches and weighing almost 27 pounds.
The Yamaha CR-xx20 receivers, including the CR-820, were very well built. Yamaha's CR-xx40 line, with the exception of the CR-2040 used STK parts instead of discrete transistors. The STK parts are problematic and not easily found. So, if you do like the Yamaha line then it might be best to stick with the xx20 line as they are more readily repaired.
Yamaha receivers are probably under valued. They don't have quite the same name value as Marantz, or even Pioneer, though they may be on par quality wise. The Yamaha CR-820 is a great mix of performance and looks, it can be easily repaired, and as more people discover how good they are, their price will most likely continue to climb. A really nice unit will sell for $250 to $300 while a working, average condition unit will sell for around $150 or more.