For Sale To classicaudio.com Home

You paid for 300 Watts,
are you sure you're getting it?

We cannot over emphasize the importance of the proper testing of classic audio equipment.
Over the course of several decades, subtle problems can arise that can
ONLY be revealed through vigorous testing.

Just hooking a piece up to a pair of speakers IS NOT ENOUGH!

We posses the equipment and expertise to ensure that the item you purchase is performing properly.

Services performed on all items offered
for sale by classicaudio.com are as follows:

Switches and controls are cleaned, as needed.
All burned out indicator or dial illumination lamps are replaced.
All inputs, outputs and functions are tested.
Any necessary repairs or modifications are performed.
The FM section is aligned for maximum sensitivity, maximum separation, minimum distortion and correct dial calibration.
Amplifiers, including receivers and integrateds, are tested for rated power output, distortion and noise. The DC offset and bias are checked and adjusted.

Special note regarding Nakamichi cassette decks:
These are truly fine tuned instruments that require skill in servicing. We have been servicing Nakamichi decks since the early 1980's. We have a full complement of factory service manuals, test tapes and alignment jigs.

'The Bench' consists of laboratory grade test equipment manufactured by Sound Technology, Marantz and Nakamichi. This includes the Sound Technology model 1700B distortion measurement system with IM option, Sound Technology model 1000A FM alignment generator, Sound Technology model 1200A stereo test panel, Sound Technology model 1500 Tape Recorder Test System, the Marantz MTP-400 4 channel test panel and the Nakamichi T-100 audio analyzer.

 

 This is an example of pre-mature clipping of one half of the output waveform of an amplifier. Note the flattening of the bottom of the sine wave. The amplifier under test is rated at 50 watts RMS into 8 ohms. The problem occured at around the 40 watt level, and only in one channel. The bottom trace is the distortion component. This type of problem CAN NOT be found with listening tests. In fact, this item was acquired with the understanding that it worked perfectly, and was used in a system for some time. The problem was discovered during routine performance tests prior to
offering the unit for sale by classicaudio.com

 

 Many people ask us how hard it is to clean switches and controls. The level of difficulty depends on the brand and model being serviced.
The model pictured above (a Pioneer SX-1050) was slightly above average in difficulty.

The switches and/or controls must be accessed from the rear.
Attempting to apply cleaner from the front rarely works.

In order to get to the function selector switches the front panel had to be removed.
Then the board below the target board had to be removed.
Finally, the function switch board was able to be removed and the switches cleaned.
Yes, it can be a considerable amount of work to clean a switch.

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