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| CD Player Upgrades MicroClone DAC Jitter Crusher Arcam Alpha 5 Linn Mimik 2 Marantz CD63 KI + Sig Rotel RCD-965BX CD Player Clock Upgrades Quad 33 Upgrades Quad 303 Upgrades Quad 405 Upgrades Accessories
Reviews |
NET Audio 405 MK3 Amplifier Boards - Designed to get the very best from your 405The NET Audio Quad 405 MK3 circuit boards are now being manufactured and will be in production around mid April 2008. The Quad 405 MK1 and MK2 can be upgrade to a very high level of sonic ability but to go further by simply modifying the original Quad boards has its limitations. For higher levels of performance to be reached new NET Audio 405 MK3 amplifier boards have been designed which still uses the famous Quad Current Dumping principal to keep with the traditions of the original 405. The boards are the same size as the Quad boards and the mounting holes are identical so the NET Audio 405 MK3 boards will easily slot straight into a 405 MK1 or MK2 chassis without any mechanical modification required to the chassis. The new NET Audio 405 MK3 boards have bee designed to obtain increased levels of detail, tighter and deeper bass response, cleaner treble and better imaging with increased load driving ability than the best 405 MK2 full upgrade that NET Audio has done. A 405 MK2 special was done as a one off design to take the 405 full upgrade to a level of performance higher than any board mod could do but was not a practical proposition for commercial sale. The new MK3 had to beat the 405 Special substantially to be worthy of sale as a NET Audio 405 MK3 and to guarantee a genuine leap in 405 amplifier performance. The output stage on the NET Audio 405 MK3 uses 30A On Semiconductor Darlington transistors to do the "dumping" and high performance On Semiconductor MJE15031 transistors as the high performance class A amplifier which feed them. These two outputs are summed and then fed to the speaker, each low and high current output delivering its own portion of the audio signal. There are no current limiting circuits on the output so that the NET Audio 405 MK3 can drive difficult loads down to 3 ohms on transients and still be within the safe operating area of the transistors. The design, however, is not intended for continued high power use (disco etc) into low impedance loads (few Hi-Fi amps ever are), as the heat sinking on the 405 is not sufficient for this, but has been designed for normal domestic use as an amplifier of very high quality used to drive speakers which may dip to 4 ohms instead of the 8 ohms with the original design. The full upgrade includes a full chassis rewire including the speaker, power supply lines and mains wiring with high quality PTFE insulated Silver plated stranded OFC copper wire and fitting of all new connectors for the input (phono) and speaker outputs (gold plated speaker binding posts). To power the boards, the NET Audio Dual Mono Power Supply is fitted so each board is run from it's own set of power supply capacitors instead of the original 405 which shared the power supply between the two channels. Please see here for further details. Fitting instructions can be downloaded here. Simply put, this is the best commercially available 405 replacement board there is bar non. A review is available from Hi-Fi Insight here and here Specifications:- Power output: Greater than 100W RMS into 8 Ohms at 240V Mains Voltage
0.0007% at 10W 50Hz
NET Audio 405 MK3 Circuit Board
NET Audio 405 MK3 Boards The NET Audio 405 MK3 amplifier boards are configurable for the variances between the MK1, MK2 and the latest graphite MK2 405s with the power switch and phono sockets on the rear panel so that the new MK3 boards can be fitted to any Quad 405 by simply removing the original Quad boards and then fitting the new NET Audio 405 MK3 boards using the same connectors on the wiring loom without any soldering being required. NET Audio 405 MK3 Boards consist of
Total Price = £220
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