MARANTZ CD67 MKII SE - VISO's MOD
Hi-End tweaking on audiophile CD player

Do you think that the CD-player could stay unmodified? No, just to be able to say to my friends: "Uh, I have some time and I improved that ugly Marantz, you know, Ken Ishiwata is a good guy, but he know nothing about music..."

I'm jocking, of course. Ken is a genius, simply, and the CD67 MKII SE was considered one of the best player in the "middle" price level when I bought, some years ago. But the sound of a standard CD67 out-of-the-box is nothing compared to that of a well modded one, it's unbelievable what these players (CD53/63/57/67/OSE/KI) are capable of. If one of these players is well modded, it's definately a high-end player. A lot of modern players are blown away by such an old modded Marantz. Maybe it's because most modern DACs have part of the analog output stage integrated, I don't know.

Anyway, I start feeling that my Marantz need an upgrade just during first listening sessions on VISO 4-8-5. The soul of the sound was too much "digital", may be that old speakers I was using before (Sonus Faber, not a Radio Shack!) in some way dull it and sound better together. When I finish Altec speakers, I start immediatly with modifications, before ending VISO-300. I never think to buy a new CD-player, of course, because I knew that CD67 was a very good starting point and I knew also that a good modded CD can beat any new Top-of-the-class player today available. If you don't believe, try a search in internet about CD tweaking (or have a look at my link page), there are tons of interesting resources.

So, I bought an original Marantz Service manual for CD67 MKII SE (is better anyway to have the complete schematic of the player) and start modding as explained below. Modification have been done in different step, during about 6 month, just to understand influence of each update. At the end I can say that original CD67 MKII SE was a good player, but CD67 modded stay on an other planet. I read a lot of good opinions about mods on Marantz CD53/63/57/67/OSE/KI, but I didn't imagine such result! The wonderful caracter of original Marantz remains, but it loose all the "digital" defects. Sound is "real", fast, dynamic, naturally extended in bass and treeble, nothing loosed comparing with a good vinil turntable! I would say now it is not only a CD player, it is an high precision instrument for music! Wonderful.

OK, have a look below, modification are roughly in order of importance. If you decide to do the same BE VERY CAREFUL and do it at you own risk! You could damage definitively your CD-player, your system or yourself (if you don't unplug the power supply when making mods, I mean).

I try first changing them with paper-oil capacitor (10uF +10uF in parallel) I had at home. But after a lot of measuring the output offset I decided to remove completely. My pre is still working fine, no smoke from anywhere and I can ear the difference, mainly in bass response, a lot improved.

Be very very careful! Output capacitors maybe necessary in your system to prevent DC to enter your pre. Measure offset before removing, it must be near to zero!

Marantz (as 99% of player on the market) was using a standard Quartz oscillator. Its precision is good but it is possible to improve a lot (and reduce jiiter). On aftermarket you can find intersting circuits from LC Audio or Audiocom, or you can build your own "kwack clock", schematics are available on the net.

I choose "Superclock 2" from Audiocom, in bundle with Qpower SMD supply power (keep an eye on E-bay for Audiocom's interesting offers). For installation, remove quartz and related 2 capacitors and connect clock output directly to pin 28 on DAC (bridge U209 and pin CD05).

On Q811 Marantz is using a standard 7805, just a cheap and simple improvement could be a LM317, but if you have some money to spend substitute it with a SMD high performance stabilizer (in the photo the Audiocom Qpower I used).

Marantz OP-amp (Q605 - Q606) are solded directly on board, so you need to unsold them and insert a good quality socket. In such way you will be able to do in easy way all comparative tests you want. In the list I wrote before, as you can check, they are all single Op-amp (and some available only in SMD), so you will need an SMD adapter (easy to found on E-bay) to mount them.

At the end I choose OPA627, and it is a very big improvement. Or better is not only an improvement, it is a modification of the overall caracter of the CD-player, now much more authoritative.

Be very very careful! After this mod you will be ear a lot of noise for 1 - 2 seconds when turning on or off your player. Swiiiiiiiiish ssswOOOP Uiiiiiiiiikkkkkk! After this mod you must always follow this procedure: turn on first the CD-player and after the Ampli, turn off first the Ampli and after the CD-player, otherwise you could damage you speakers!

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I stop, anyway, because I think I reach my goal: a general improvement of my CD67 MKII SE such it could drive perfectly my Altec system. It was a very hard job, but ... wow, it works!