Kiwa audio upgrades offer the radio enthusiast the opportunity to improve the audio performance of many of the more popular receivers both past and present. Many communications receivers have compromised audio signal paths where the audio signal has passed through too many stages and the quality of the components used have a compounded detrimental effect. The sound of communications receivers have been described as "dull" or "wooly" but the poor audio quality is more due to a lack of clarity.
My own interest in audio quality is due to having been a broadcast and recording engineer for more than 20 years. It was always evident that certain pieces of equipment sounded better than others, but the general thinking back then was that the difference in sound was due to circuit design and not necessarily the components used.
It wasn't until 1980 that this understanding expanded to include capacitors when Walt Jung published his landmark aricles in AUDIO magazine titled "Picking Capacitors (Parts 1 & 2)". Here for the first time ever was proof of capacitor distortion and what can be expected with different capacitor types. Probably what was most important about these articles and subsequent studies was that capacitors behaved differently on their charge and discharge cycles. There was a slight time lag which resulted in a "smearing sound" or for instance some capacitors may charge correctly but fail to discharge correctly time-wise smearing the sound. This kind of distortion is evident when listening but difficult to measure when using conventional harmonic or intermodulation distortion analyzers.
I soon began installing different capacitor types in the broadcast and studio equipment and listening to the changes in sound quality. In 1980 I began installing the first "audio upgrades" in recording consoles,on-air consoles, multi-track tape machines, AM/FM audio processing equipment, stereo generators and FM exciters. An "audio upgrade" performed on studio or broadcast equipment was more involved than what is offered at Kiwa. Complete overhaul of the audio signal path and power supply/regulators was typical. DC regulators were replaced with types that ensured the lowest impedance over the widest AC bandwidth. FET's and ICs were replaced with types that had lower noise, lower DC offset and higher slew rate. The capacitors replaced were types that cost upwards of $20 each. Internal wiring was replaced with silver plated Kynar or Mogami cable. Input and output connectors were sent out to be gold plated and all the upgrades used silver solder.
Kiwa Electronics began in 1989 and the first product - the "MAP" included several of the techniques used in the audio upgrades installed in professional gear. The first "audio upgrades" to communications receivers was installed in Kiwa receivers between 1992 and 1996. These included the Icom R71, Kenwood R1000, JRC NRD525, Lowe HF-150, and the Sony ICF-2010. When it was decided to offer these upgrades to the radio enthusiast, the "in house" or receivers sent to Kiwa for upgrades always preceeded the kit form. The first audio upgrade was the R71 offered in 1996. The kit form started in 1998. Audio upgrades for other receivers like the 2010 were offered "in-house" around 1998.
Nearly all the capacitors used in the Kiwa audio upgrades are Panasonic. I have been a big fan of Panasonic capacitors for many years. The Panasonic Bipolar capacitor sounds much better than the typical electrolytic capacitor found in communications receivers. The Panasonic polyester capacitors sound very good, are small size and they are our first choice when replacing ceramic capacitors. The very best sounding capacitors are often much larger than the ones to be replaced and their cost is a magnitude higher. There is a trade-off with price/performance and I feel the types used in the Kiwa audio upgrades provide the best price/performance ratio.
The improvements in audio quality after installing an upgrade can be subtle to sounding like a completely new radio. Generally, speaking, the more capacitors replaced the more an improvement will be heard. It also depends on the type of capacitor replaced. For instance, the R71 has numerous bad sounding disc ceramic capacitors. Replacing them with the Panasonic polyester types makes a very noticeable improvement.
All the Kiwa audio upgrades comes with desoldering wick and silver solder. For best results, use only the supplied silver solder. Do not use your typical lead/tin solder.
Reference: Walt Jung's classic Audio magazine article "Picking Capacitors"click here