Yamaha CX-1 Thread

Bratwurst7s

In The Frying Pan
Subscriber
I've been wanting a CX-1 ever since I first saw one in 1998. Back then I couldn't afford one, they were going for around 2100 DM at the time.

A week ago I saw one on ebay and negotiated a price of €425. That's inside of the norm of what I've been seeing for the last few years.

It arrived well packed and in pristine condition. This is going to be so much fun...

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More later...

Cheers,
James

EDIT 15 Jan 2018: Please see post #182 for a re-cap/relay parts list spreadsheet!
 
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I've been wanting a CX-1 ever since I first saw one in 1998. Back then I couldn't afford one, they were going for around 2100 DM at the time.

A week ago I saw one on ebay and negotiated a price of €425. That's inside of the norm of what I've been seeing for the last few years.

It arrived well packed and in pristine condition. This is going to be so much fun...

View attachment 1015087 View attachment 1015088 View attachment 1015089 View attachment 1015090 View attachment 1015091

More later...

Cheers,
James
Sweet, very nice condition too. :thumbsup:
Did u get the remote too?
 
Very nice! I've got one sitting in Japan right now that I snagged from the Yahoo JP auction about a month ago...will definitely need to pick up the remote. I really love that it has loading adjustments for MC carts. I'm really looking forward to comparing it to my C-2x!
 
Nice. I had a CX-2. It was one of the best preamps I've heard, along with my CX-1000, my Adcom GFP-750, and my Schiit Freya.

I'm sure the CX-1 is a champion.
 
Good morning fellow Yamaha fans. Thanks for the nice comments. It didn't come with the remote. No matter, the remote from my RX-V3900 is The One Remote To Bind Them All. It can do everything, works with everything. :)

An MX-1 would of course be the cat's Meow, That will probably have to wait a year or 2 tho. That's OK. I have a M-70 here that's been patiently waiting for a repair and refurb. In the mean time I've decoupled my AX-1090 and am using the power amp section of it. It's a start.

Before even hooking the CX-1 up I opened it up to take a survey. Darn thing is a work of art inside.

DSC04531.jpg DSC04594.jpg DSC04597.jpg DSC04599.jpg

As you can see there is 1 main pcb, 3x larger sub-pcb's and 5 smaller sub-pcb's. Identified as "Main PCB-1" and all of the others as "Tone-Con PCB-(x)" etc. More on that later.

I was going to say there is not a single ceramic cap in the unit but that's not true. There is exactly 1. An 0.01µF safety cap in parallel with the power switch. All of the other capacitors are polypropylene, mylar and of course a boatload of elco's. No tantalum caps listed.

Cheers,
James
 
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I have taken a lot of detail photos of the different sections/boards and will be taking more when I do a re-cap and will of course be sharing them when I get that far.

As we all know Yamaha is famous for their discrepancies between 1) the schematic, 2) the parts list, 3) the pcb layouts and 4) what is actually installed. So this time before buying any caps I went through and checked every elco against those 4 criteria. The unit is surprisingly accurate for a Yamaha. I only found 1 cap that is completely different than shown and the only other discrepancy is that a lot of caps that are listed as 50v and 25v in the parts list are actually 25v and 16v respectively installed on the boards. I'll list those as I document the amp sections caps below.

But that one oddball cap is a puzzler. The schematic and parts list both show caps C206 and C211 as being 2.2µF/50v and they are both directly in the signal path (symmetricaly L&R) in the "0-DB Amp" section. I found that C211 is a 2.2µF/25v Nichicon Muse as listed/shown but C206 is a 22µF/25v Elna Duorex. I'm not understanding the reasoning behind that because to my untrained eye their position in the 2 channels is exactly the same so I would guess that their function would be the same and that their size should be the same. :(:confused::idea: ???

EDIT: Mystery solved. I mis-identified C215 as C211. C206 and C211 both have the correct 2.2µF Muse cap installed. My mistake.

There are 5 main types of caps used in the amp:
Nichicon "Great Supply" for the 2 main filter caps,
Mostly (but not all) Nichicon Muse used in the signal path (and a couple of other spots),
A few Nichicon 1µF/50v BP caps (motor control etc),
A few Elna Duorex in select positions,
And a large amount of the brown Elna caps that I've seen in a lot of other Yamaha's for the majority of the positions (including a few in various signal path positions).

I'll be going through and listing the caps section by section along with my early thoughts on what to buy to replace them with. I'll of course be open to suggestions in that regard.
First thoughts are:
Mundorf MLytic AG 6800µF/63v for the filters,
Nichicon ES Muse BP for the signal path,
Nichicon KZ Muse in place of the Elna Duorex,
Wima MKS-2 film caps to replace all of the 2.2µF and smaller,
Panasonic FC to replace the brown Elna's.

Cheers,
James
 
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So yesterday I finally finished the cap survey and closed up the amp. As I said earlier, for starters I've uncoupled my AX-1090 and am using the CX-1 with the AX power section. The ridiculous looking blue patch on the AX is to prevent the remote from controlling both the CX and AX at the same time. I actually had to tape a piece of thin card stock over the sensor window. The IR went right through a simple piece of tape.

First off I tried out the controls with no source connected. As I said, my RX-V3900 remote works perfectly with the CX-1. I checked all of the pots and switches for noise, and step by step jogged the volume higher and higher. Dead silence. I mean Absolute Dead Silence. And this without Deox-ing. Not a single scratch or pop with any switch or pot. Fact is tho that the pre will be almost exclusively be used in Pure Direct mode.

Then I hooked up my trusty DCD-2700 and played the 1st 2 of my go-to test CD's. Loggins & Messina's Full Sail and the first Dire Straits. Pure Direct on.

Dang this is Nice! I realize that I'm being limited by the channel separation of the AX but I notice a definite improvement in imaging and of course more clarity and definition. I'm feeling that this is the begining of a lot of fun.

My first serious system was a Yamaha C-50/M-50 combo with these same Speakerlab 7's back in '83 and I've been wanting to get back to separates for 19 years since the M-50 died and I bought the AX-1090 to replace the combo. The AX-1090 has been a good sounding reliable workhorse over the years but just isn't in the same level as separates.

Finally getting there! In the meantime the speakers have been massively upgraded and the Denon also has been seriously upgraded/modded. The system is starting to sound goosebumps good.

Also, the volume control on the CX-1 seems to be more responsive to small jogs from the remote than the AX is. I can make really small adjustments to the volume with the slightest of bumps of the remote volume button.

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More later...
James
 
Interesting pictures. Looks like the CX-1 needs a booster seat to sit on the shelf with all those big boys. Congrats on getting your long awaited treasure.
 
Interesting pictures. Looks like the CX-1 needs a booster seat to sit on the shelf with all those big boys. Congrats on getting your long awaited treasure.

Thank you very much Blue. It will eventually be getting some vibration absorber feet, similar to what's barely visible under the cd player on the right. That might help a bit with the height challenge. :) Also, the shelf that it's sitting on is only 40cm deep and the pre hangs out so I'll be replacing the shelf with one 45cm deep. I don't expect to get started with the M-70 until early next year but when finished it will of course sit where the AX-1090 is.

OK. I'll start section by section and list the elco's and what I'm tenatively planning to replace them with.

The Reset section sits on it's own board in the left rear corner, "Tone-Con PCB-3" It has 3 elcos.
C565: 470µF/16v, Elna "brown" (11mm dia [12mm max], 5mm lead spacing). Replace with Panasonic FC 35v.
C561: 0.1µF/50v, Elna brown. Replace with Wima MKS-2, 0.1µF/63v.
C571: 47µF/16v, Elna brown, shown in parts list as 50v. Mounted on the back/trace side of the board. Replace with Panasonic FC 50v. 5mm dia [6mm max].
I haven't addressed the relay yet, will have to do so before ordering parts.

DSC04605.jpg

Cheers,
James
 
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The PSU section is on "Main PCB-1".
C221, C222: 4700µF/35v Nichicon Great Supply. 40mm x 40mm [max height 45mm]. Replace with Mundorf MLytic AG 6800µF/63v, 30mm dia x 40mm H.
C214, C216: 100µF/35v Elna brown (8mm dia [max 8mm]). Replace with Panasonic FM 50v.
C203, C215: 22µF/25v Elna brown (5mm dia). Shown in parts list as 50v. Replace with Panasonic FM 50v.

The protection section is on the same board.
C212: 33µF25v Nichicon Muse (6mm dia [6mm max]). Shown in parts list as 50v. Replace with Nichicon KL 35v.
C213: 2.2µF/50v Elna brown. Replace with Wima MKS-2 63v.

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Cheers,
James
 
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"0 DB Amp". Also on Main PCB-1.
C208, C209: 2200µF/25v Elna brown (16mm dia [16mm max], 7.5mm lead spacing). Replace with Panasonic FC 2700µF/ 35v.
C227, C228: 47µF/25v Nichicon Muse (6.5mm dia [8mm max]), signal path. Replace with Nichicon KL 35v. Visible in the last photo above the big filter caps.
C206: 2.2µF/50v Nichicon Muse. Replace with Wima MKS-2 2.2µF/63v. Signal Path, L.
C211: 2.2µF/50v Nichicon Muse. Signal path (R), mate to C206. Replace with Wima MKS-2 63v.

DSC04538.jpg

Cheers,
James
 
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A couple of things that I forgot to mention earlier.

I found the service manual at HiFi Engine.
https://www.hifiengine.com/manual_library/yamaha/cx-1.shtml

And it surprised me to see that there are no component ID markings silkscreened on the pcb's anywhere that I can find. None. So using the pcb layouts from the SM becomes essential to find the components. I went through the schematic and layouts and marked all of the elcos with a yellow highlighter and then tracked them down on the actual pcb's to confirm them.

James
 
The inputs. Main PCB-1.
All of the 10µF and 22µF types are shown in the parts list as 50v but 25v are installed. All have 5mm dia, up to 8mm should fit.
All of the 10µF/25v on the inputs in the signal path are Nichicon Muse except for the 2 in the CD Buffer which are Elna brown. All will be replaced with Wima MKS2 50v.
All 1µF/50v Elna's will be replaced with Wima MKS-2 63v

Tuner:
C103, C106: 10µF/25v Nichicon Muse. Signal path.
C247, C248: 1µF/50v Elna brown.
Aux:
C106, C112: 10µF/25v Nichicon Muse. Signal path.
C249, C250: 1µF/50v Elna brown.

Tape 1, 2 & 3: C113, C116, C119, C122. C125, C126: 10µF/25v Nichicon Muse. Signal path.
Tape 2 & 3: C251, C252, C253, C254: 1µF/50v Elna brown.
Tape 3 (Rec): C141, C142: 22µF/25v Elna brown. Replace with Panasonic FM 50v.

CD, CD Buffer:
C154, C157: 10µF/25v Elna brown. Signal path.
C183, C184: 2200µF/25v: Nichicon Muse (16mm dia [16mm max], 7.5mm lead spacing). Replace with Panasonic FC 2700µF/35v.

The 1st pic shows the Tape-3 buffer in the middle, Tape-2 buffer on the left and the 2x 47µF 0-DB amp output caps on the right.
The 2nd pic shows from right to left: Tape-2, Tape-1, a (RFI?) shield and the Aux buffer.
The 3rd pic shows Aux on the right, the CD buffer in the middle and part of the Tuner buffer on the left.
Pics 4 & 5 show the 2200µF Muse caps in the output of the CD buffer.
The CD buffer has all discrete components, all of the other input buffers have op-amps, but the tape-3 op-amps are sip-8 "DD" low noise versions.

DSC04567.jpg DSC04569.jpg DSC04571.jpg DSC04580.jpg DSC04581.jpg

Cheers,
James
 
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Phono MC Head Amp, MM EQ Amp, Main PCB-1:
C131, C136: 100µF/10v Elna brown (5mm dia [8mm max]). Signal path. Parts list shows 25v, Schematic shows 10v. 10v installed. Replace with KL 100µF/35v. Signal path.
C137, C138, C139, C140, C161, C162: 1000µF/6.3v Elna Duorex (10mm dia [10mm max]). Replace with Panasonic FC 10v.
C143, C145, C146, C152: 10µF/25v Nichicon Muse. Signal path. Parts list shows 50v. Replace with Wima MKS2 50v.
C144, C148, C149, C150: 470µF/25v Elna Duorex (12.5mm dia [12.5mm max]). Replace with Panasonic FM 50v.

Phono MM EQ Amp plug-in Main PCB-2:
C168, C179: 10µF/25v Nichicon Muse (5mm dia [8mm max, but only if C185 & C188 stay 5mm dia]). Signal path(?). Parts list shows 50v. Replace with Wima MKS2 10µF/50v.
C185, C188: 10µF/25v Elna brown. Parts list shows 50v. I think that these are in parallel to ground and not in the signal path but I'm not certain. Replace with Panasonic FC 50v.

Phono Buffer:
C189, C190: 2200µF/25v Elna Duorex (16mm dia [16mm max], 7.5mm lead spacing). Replace with Panasonic FC 2700µF/35v.

I just realized that I didn't take any good photos of the Main PCB-2 daughter card so that's on my list to do when I open the amp next time.

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Cheers,
James
 
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