c-4
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Yamaha C-4 Preamp Recap
Gone through replacing all caps along with variable resistors on this C-4. Plugged into DBT and the good news is I've got a dim glow. The bad, some smoke came up from the function board near VR123 trimmer resistor. Looks like these 2 resistors are toast (see photo). I think both R257 ( 1.2KΩ )...- Jake O Bob
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- c-4 capacitor preamp recap resistor smoke yamaha
- Replies: 107
- Forum: Yamaha
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Yamaha C4 loses volume in 1 channel
So I recently attempted restoring a C4 and noticed this issue out the box, I was sometimes getting no volume on AUX, or just 1 channel, but switching to Tuner solved it so I assumed it was an Aux input issue or dirty contacts during the recap I did a test half way through and had volume in both... -
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Yamaha C-4 starts playing after a few minutes
Dear All, First of all I want to wish to everyone Happy New Year fulfilled with health and happiness! For the holidays finally I managed to get one set of dreamed: Yamaha C-4 and M-4. The condition of both units is not mint but it is also not bad at all. My whole setup now is: PC -> USB DAC... -
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Yamaha C-4, circuit board diagram for the Function Board, good scan required.
Might anyone have a Yamaha C-4 service manual or at least a circuit board diagram for the Function Board? I already have the ones available from HiFi Engine etc and unfortunately they're close to illegible for reading some of the capacitor references. Very hard to confidently/easily recap...- Hifibythekg
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- c-4 c-4 preamp function board service manual yamaha
- Replies: 6
- Forum: Yamaha
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Yamaha C-4. Capacitor types on the main board.
Hello.. Does anyone have a list (BOM?) for replacement of capacitor types ('low ESR,' or 'good for power supply' designations is what I'm really after) on the Yamaha C-4’s main board? (The ‘Function C Board NA 07149.’) Could probably buy all Nichicon FG or Panasonic FC but would be grateful...- Hifibythekg
- Thread
- c-4 c-4 preamp capacitor nichicon capacitor range nichicon fine gold nichicon muse panasonic yamaha yamaha c-4
- Replies: 33
- Forum: Yamaha
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Power Supply Model C-4PS01 For Use with a McIntosh C-4 Preamp
McIntosh C-4 Power Supply Design Idea This post presents a Design Idea for an inexpensive power supply to power a McIntosh C-4 Audio Compensator. Early versions of this preamplifier used 6.3VAC to power the filaments. Later versions used an internal voltage doubler to provide a nominal 12VDC...- tcdriver
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- c-4 c-4ps01 mcintosh mcintosh c-8 mono power supply preamp tube
- Replies: 5
- Forum: McIntosh Audio
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2SK100 is there a replacement
Is there an available replacement for the 2sk100 double jfet? Have read that a pair of matched 2sk170-V will work. Can anyone confirm this or suggest a better or alternative solution? One of the 2SK100’s in my Yamaha C4 preamp may be faulty..- Hifibythekg
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- 2sk100 c-4 jfet jfet phono preamp yamaha
- Replies: 1
- Forum: Solid State
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VD1212 on Yamaha C4
Checking these. With one leg lifted should they read Diode test : 1184 Ohms: 5.61M ohm With leads reversed, (Black lead on black end, red on red red end of diode) on the DMM at 20M ohms it climbs to ‘I’ I know these things have a dreadful reputation but just wondered if this one was...- Hifibythekg
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- 1n4148 c-4 diode vd1212 yamaha
- Replies: 47
- Forum: Yamaha
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Yamaha C-4 dc fluctuation
Has anyone got a Yamaha C4 in which the DC maintains a stable readout within + /- 200mV of 0mV? If so, how close to 0mV has been achieved? And did any component(s) need replacement to achieve this? My understanding is that it’s actually very common to for this preamp to produce the full range...- Hifibythekg
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- c-4 dc dc adjustment yamaha
- Replies: 4
- Forum: Yamaha
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C4 preamplifier dc fluctuation
My C4 is sounding great but despite replacing the trimpots with Bourns the dc fluctuates quite energetically between -170mV and +180mV. Occasionally it will even stray further by another 100 or 200mV. Thoroughly checked all solder joins, switches cleaned etc. My question: are there any...- Hifibythekg
- Thread
- c-4 capacitor dc current preamplfier transistor yamaha
- Replies: 24
- Forum: Yamaha
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Yamaha C-4 preamp hum.
This amp appears to be working well in all regards except that there is a significant hum when Phono is selected. The hum also comes through substantially on Aux and Tuner. Hum appears to be stronger through the left channel. Hum is lessened when ’Tone Bypass’ is selected, but...- Hifibythekg
- Thread
- c-4 grounding hum yamaha yamaha c-4
- Replies: 12
- Forum: Yamaha
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Yamaha C4 - D.C. ranging 10mV- 350mV
Finally got a C4! Working, sounds great straight away. However doing the adjustments, and even after installing Bourns trimpots, the DC on both channels ranges from approx 10mV to 350mV. Very steady rise and fall over the course of a minute or two. DC is rock steady at 35.2V Question: Is there a...- Hifibythekg
- Thread
- c-4 preamp yamaha
- Replies: 2
- Forum: Yamaha
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C-4 Burning Fuses
After recapping and replacing many transistors, diodes and relays on Sansui G-9000 and Marantz 2275, I feel comfortable enough to tackle the C-4. It worked fine and then it started burning fuses immediately on turn on. I read http://audiokarma.org/forums/index.php?threads/yamaha-c-4-help.361407/...