MOFI-McIntosh C22-Tube Pre-Amplifie-DIY Kit

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DIY KIT Project

To complete this project, high level knowledge of electronics and rich experience in terms of and testing are required.Due to time zone and language communication restrictions, we can only provide limited technical support, and you need to solve probl by yours.We do not provide information other than the product introduction page.

MOFI-C22-Tube Pre-Amplifier DIY KIT Project

SummaryMOFI-C22-Tube Pre-Amplifier , It is based on the core circuit of the McIntosh C22 Pre-amplifier.-Tech highlightsCompared with the commonly reproduction of McIntosh C22 Pre-amplifier, we improved:1、High Voltage：Two-stage buck regulator filter, Two low-pa filter (with a corner frequency of 1.6Hz&16Hz) prevents power noise from g introduced into the amplifier. Provide purer power supply (close to battery).2、The high-voltage power supply uses MOSFET as pa nsistors, which have a sense of tube sound characteristics but rejecting the rectification and regulation noise.3、high-voltage soft-start feature is included which will take about 5 second to reach the designed voltage protecting the tube from any voltage shock.4、-voltage soft-start feature for vacuum is included which will take about 5 second to reach the designed voltage(12.6v) protecting the tube from any voltage shock and extending life.5、all-in-one design, single-point grounding, ground resistance is close to the 0.02 resistance value, low noisedesign.6、 is Small with double-sided smt.7、The triangular tube layout reduces the number of dual- common tubes, further improves the separation and reduces crotalk.8、Mirror HR-pin, please shift the tube counterclockwise every three months, reduce tube ization, further extend tube life and save money.9、More cost-effective sound modification plan.

Product configuration

DIY kit: Contains the and the components needed on the , but does not include the power nsformer and the electronic tube.Finished board: Based on the well-tested board on the standard version kit, we verified all key points' voltage, and used the signal and oscilloscope for og waveform double verification. We will not use this board for listening test.All finished s are all carefully hand-soldered and fully tests, so the price is higher and le cost performance. Price-sensitive consumers but with have DIY ability are recommended to choose the kit.

Schematic & key point of debuing

comes with component s for easy installation.We only refer the schematic of the amplification part of the circuit. If you need full circuit , please read the component value with the by yours; we do not provide additionally.please keep test point voltage close enough to it, +-20% is also permitted.

DIY KIT Instruction

Since the holes are plated through, you only need to solder the parts from the bottom of the board. Do not or enlarge the holes because that would damage the through-plating.Clean both sides of the blank with paper towel and isopropyl or electronics flux remover, then solder the components to the board, starting with the lowest profile parts. This means the s and zener . Then solder the small s, small nsistors, followed by the larger s.e sure the correct part goes into each position on the circuit board. Measure each with your multimeter to ensure it's the proper value.Pay attention to the polarity of electrolytic s, s, , nsistors as well as the orientation.Clean up the solder flux residue from the board with isopropyl (or electronics flux remover) and a brush.Inspect all solder connections carefully, using a magnifying gla, to e sure there are no solder bridges or cold solder joints. Use a multimeter in s scale to check for short circuits.Since each LT1085/L17T's mounting tab is internally connected to the pin2, it will carry live voltages and should not be shorted to the chais, ground or other parts of the circuit.The K2700 are vulnerable to electrostatic discharge damage when you are handling them, so keep their pins plued into anti-static foam while working with them until you're ready to solder them to the board. Set the s pre-mounted with the K2700 aside for now.

Parts list

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DIY KIT

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Finished Board