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--- projects:yamaha_r840 [2025/11/20 18:12] – [Yamaha Loudness] admin
+++ projects:yamaha_r840 [2025/12/01 07:53] (current) – admin
@@ Line 1: / Line 1: @@
+~~META:
+title=Yamaha MCR-840
+description=Yamaha R-840 repair and hacking
+keywords=SEO, dokuwiki, disassembly, yamaha, R840, music, hack, hacking, audio, iPod, system connector, repair
+~~
 ====== Yamaha Audio Amp/Receiver ======
 ===== Yamaha MCR-840 =====
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 Probably more Yamaha systems can be repaired in that scheme. \\
+==== Remote control ====
+There is nothing much to say. It is a simple iR remote control. The main IC is marked "2428662 03160". \\
+iR codes for R840 can be found on page 80/150 of service manual (next to remote control schematic). \\
+Here is an unspectacular insight: \\
+{{:projects:yamaha:rc1.jpg?125|}}
+{{:projects:yamaha:rc2.jpg?200|}} \\
+I have taken the pictures so you can see at which positions the holding clips are - don't forget about the single screw in the battery compartment.
+The buttons and their layout of remote control for DVD and BD versions differ slightly. \\
 ==== Disc Player manual eject ====
 The players only turn on with system connector plugged into R840 amp (see [[projects:yamaha_r840#the_round_one|below how to simulate system connector]]). \\
@@ Line 82: / Line 96: @@
 === the flat one: writing port ===
-Yamaha devices use a so called "writing port", a flat cable, e.g. for flash ucom via RS232-adapter. It is known for updating firmware over PC software (which we don't have). \\
+This is just an FYI, IMO we cannot do anything useful with the port. \\
+Yamaha devices use a so called "writing port", a flat cable, e.g. to flash ucom via RS232-adapter. It is known for updating firmware over PC software (which we don't have). \\
 R840 uses Renesas M16C/64 R5F3640DNFA MCU. Service manual states to use FlashSta.exe (which we don't have, neither R840_xxx.mot + R840_xxx.id firmware), FYI see [[https://www.renesas.com/en/document/mat/m16c-flash-starter-m3a-0806-users-manual?srsltid=AfmBOoouDn1Ckenn0l-1YUgHz2BwZHPVGnbNhIjZUAa85k5-iwqpdRbM|Renesas M16C flashing guide]]. If you still want to look into flashing M16C MCU go to
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 [[http://www.ipodlinux.org/Apple_Accessory_Protocol/]] \\
 [[https://github.com/xtensa/PodEmu/tree/master|xtensa/PodEmu: Android application that emulates iPod to use together with old 30-pins iPod serial interface]] \\
+[[https://xdaforums.com/t/app-3-0-podemu-connect-android-to-30pin-ipod-docking-station-or-car.3234840/|PodEmu on XDA]] \\
 [[https://github.com/xtensa/oap|xtensa/oap: Implementation of iPod serial communication protocol used in old 30-pin iPod interfaces]] \\
 [[https://github.com/oandrew/ipod-gadget|oandrew/ipod-gadget: iPod usb gadget for audio playback]] \\
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 ==== Yamaha Loudness ====
-{{:projects:yamaha:loudness-schaltung-yamaha.png?direct&200|}}
+Loudness compensation is used to maintain a balanced sound at different volume levels. At low listening volume levels, the bass drivers need to produce more sound pressure to be perceived at the same level as the mid and high frequencies.
+See a collection of schematics for loudness circuits here: [[http://www.hifi-forum.de/viewthread-71-12517.html]] \\
+{{:projects:yamaha:loudness-schaltung-yamaha.png?direct&200|}} \\
 #TODO software implementation of loudness \\
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 === iR codes ===
-iR codes for R840 can be found on page 80/150 of service manual (next to remote control schematic). \\
 [[https://github.com/theCstokes/YamahaRemote/blob/master/IR_RX-V667-3067_rev0.0_Full.xls|yamaha V667 etc iR codes]] \\