Rotel RCD-855 cd player with tube output

Fongolio

Earlier in the year, after my Carver amp flamed out one of the output transistors, I took it to my tech guy for repair. While at his house he demoed for me a project of his....a modded Rotel RCD-855 cdp. I was extremely impressed with the very warm sound of unit but the price was too high for me. A few weeks ago he called to tell me he would sell me one for about half the asking cost. All I needed to do was let people listen and talk about it alot as this is a new venture of his.

He won't tell me all the details of the mods as he wants to remain exclusive with this type of modding. Here's what I do know...He starts with a Rotel RCD-855 because it had a very high quality German made swing arm laser unit and turntable motor. He's left the TDA-1541 DAC in place but modded the decoupling cap(s). The op-amps have been changed to more modern units. Now the good part, he's bypassed the on board output stage and inserted a new circuit board with two tubes for output. The board has two transformer power supplies with one dedicated to the tube warmers.

That's all the technical stuff I know so far. The result is pure magic. I've only played a couple disks so far but it's the best cd player I've heard outside a high end audio show room. Very close to vinyl like warmth and presence especially with my Carver TFM-25 and Carver C-1 pre. Freakishly wide soundstage on the SDA-1C's and depth I've never heard on cd before. Sweet articulated but not splashy highs and big bass slam with no muddiness. These are my initial impressions after just a few disks.

To say I'm stoked is an understatement. The closest to analog sound I've heard yet and it's in my rig!! Longer term review to follow.

Kelvin

danz1906

Congrats!

jchouston

Funny, I have an old Rotel 855 cd player sitting in a closet; I don’t even know if it still works. Maybe I’ll have to dig it out, but last I recall, it was either having trouble reading the discs or skipping (disclosure: it went with me through my college years so it’s probably not a manufacturing defect).

What is he charging for the mods?

And does anyone have an idea where to find a replacement button AND remote control for this unit? The eject button and the remote both got lost a loooong time ago and I’d like to find replacements and salvage some old gear!

nikolas812

I would also like to know what he is charging for this mod. I had a Rotel 855 and it was great. Even at twenty years old it was a LOT better than other newer units I have heard. I was toying around with idea of adding a tubed output stage to it. But upon further research. I realized a mod like that was beyond my abilities... If the mod was priced right. I would pick up another one in a heart beat and have him mod it...






Nik

george daniel

I have an 855 that I use everyday with a DAC,, I would be very interested in the outcome/results of this mod,, please keep us posted with your impressions--thanks and enjoy--george

Fongolio

He still isn't sure how he's going to price this mod. I got the unit with the mod for $450 cdn which considering the original electronics and laser unit have been checked and brought up to new spec and two new power supplies and the new output board with tubes have been added with all very high quality electronics I'd say I got it dirt cheap. However he wants me to demo it to people and help him sell some for a higher cost. He was originally targeting a price point of a complete unit between $800 and $900 cdn. He also is the exclusive British Columbia dealer for EAR Yashino products (Esoteric but not the TEAC brand....much higher end) who have a valve cdp that sells in the $5000 range and this mod in an a/b comparison is very nearly as refined sounding as the EAR player. I'll take some pics and post so you all can see what has been modded.

george daniel

Thanks for the follow up--I would be very interested in the mod,as I don't seem to be able to "let go" of mine.I have always felt that this was a great unit,,and I think with the right mods/upgrades, it can run with the 1000 dollar players,IMHO.:)

jchouston

Ooops, I have the 930AX, not an 855 (I must've had it confused with my Rotel 870 pre?).

I wonder if it's better or worse?

I wonder how mad my wife is for me making all that noise pulling it out of the closet while she was sleeping...

george daniel

any update on how this turned out?

george daniel

How about some pic's of the modded Rotel? Also,, now that you've had it for a month or so,what are your impressions?

Fongolio

Ok George, full review with pictures tonight or latest tomorrow morning.

george daniel

Thank you sir.BTW, your Karma is making it's way to Double G's,,should be there tomorrow.

Fongolio

Here it is George.
Two months or so into my ownership of a Rotel RCD-855 with modified tube output cd player it's time for review. My initial impressions above still stand. This is the sweetest and most analog sounding cd player I've ever heard. The soundstage on most cd's is beyond the walls of my listening room but still with very precise imaging overall. I say overall because some poorly mastered cd's don't image as well. Which brings me to my next point.

This cd player is very revealing of poorly mastered cd's. Like my Pro-ject 6.9 turntable, if a recording is poorly mastered it will be exposed. Conversly, both make good or great mastering sound like magic. A good example for this on the Rotel is an original copy of Led Zeppelin IV I have on cd. Sorry Jimmy but this sounds like crap on anything I've tried it on (the original LP sounds very similar on my system). However the same tracks that are on the Mothership remaster cd sound spectacular in comparison. Huge bottom end from Bonzo's drums. Robert's vocals soar and John Paul's keyboards have just the right kind of air. The new Beatles remastered stereo set sounds equaly awe inspiring on this unit.

I would describe the overall sound as somewhat warm. Not etched and sanitary like all other cd players I've tried in my system. It is so vinyl like that for the first time several years I'm buying more cd's than vinyl again. I keep thinking "I wonder how that will sound in the Rotel".

Lastly, the build quality of the mod is top notch as you will see in the pics attached. My tech's soldering abilities are the best I've ever seen and he is anal about cleanliness and synchronicity. The only thing I may have done differently is perhaps to have added a window or vent on top so I can see the tubes glow when the unit is in use.

To sum up to say I'm pleased is a gross understatement. $450.00 has made me rethink my position as a vinyl snob. Just when cd seems to be in it's death thro's I've found a cd player that makes me want to buy as may of many old fav's on cd I can find. Pics attached.

Kelvin

george daniel

Thanks for thr review and pic's. Is the mod avaialble to others with 855's?

TruTech

Firstly, Hello Kelvin and Hello to all here on this site. I was Crusing around the internet this evening and came across this very generous offering of praise from Kelvin.....Thanks Kelvin!!

You have taken some nice pic's here as well. I truly enjoyed modding this player for you, and always enjoy hearing from you...it's been a while now!

Glad to hear that you are enjoying the player. Would this be a good time to tell you that I have stepped it up a few notches since your revision?

The latest rev is better yet... As many of us I'm sure, we are always looking for the best in sound, which has envoked me on a quest for ever trying to find ways for improved design.

This however, will be the final on this one....I have it on par now with a player that I sell for $7,000.00 so I don't think spending any more time on it will render anything more to conquer.

The new one is direct coupled to the DAC and looses the solid state final all together. The sound is incredible, but I think your effort of describing these listening pleasures rivals mine for sure!

I noticed the question of "would he be willing to mod for others?" Of course!


Cheers, Ron

Fongolio

Thanks Ron. The pleasure has all been mine since I aquired this player from you. With every cd I play I am truly amazed at just how great a sub $1000.00 player can sound. I am very interested in hearing the new revision sometime in the not too distant future.
By the way, I hope your Christmas and New Year's was pleasant. I was actually going to call soon and give you an updated review on the cd player.

Anyone thinking about having this mod done can be assured that Ron is top notch technician and extraordinarily attentive to that last detail. By the way, if anyone remembers my sad tale of woe about the flame out on my Carver TFM-25 Ron here is the technician who resurected it from the dead. This was the amp that literaly had an output transistor blow a hole through its casing. It did copious amounts of damage to the amp but Ron restored it to better then new and it's played flawless for me since. In my mind a true master technician.

Anyway, as my review states about the Rotel RCD-855 mod this player is the most analog sounding cdp I've heard in my system and if Ron's made it even better it's a mod you may seriously want to consider. I've also heard the $7000.00 E.A.R. cdp he's talking about and I thought my Rotel came close to sounding as good. Now he's made it sound as good.....I can see an upgrade in my future.

Kelvin

TruTech

george daniel wrote:

Can you tell me more about the cost of the mods?I have an 855 that I waqnt to keep,but I want it to run with the big boys--thanks in advance--george

Hi George,

I hope you don't mind that I post this here....this may be useful to all.

It seems that my post count must be 10 or higher to reply to you privately, so I hope this gets to you.
There are several attitudes to take with this mod. For example, toroidal transformer (the newest addition) vs. two seperate transformers. Power supply mods vs. none. Chinese tubes vs. premium Russian tubes. That's just to name a few. The list is long....
This is a better one to discuss by phone or something that I can tackle another time here, but not today....too much to do!

Anyway, I think the full blown version considering all my hard costs inclusive of the toroidal transformer that is custom made for me, might be around $800.00 with view to a version that can achieved for less....I'm still working out the parameters with the recent completion of the final mods.

The completed unit will truely amaze you, as it did me! It really does sound as good as the $7000.00 unit that I sell from the U.K. This was my goal when I started all of this because I wanted the $7000.00 unit when I heard it, but surely did not want to spend that much money. This I can assure you, is a mod that is worthwhile....but, of course, I am biased!

As a note: This mod is available to other players as well, but I do like to work with players based on the TDA1541 DAC from Philips... I really like this one! Some say that this is the best DAC ever made. There are a number of players that were built with this DAC. To name a few: Philips, Adcom, Marantz, Magnavox, etc. Many can be had for reasonable cost with a view to make them into something quite incredible.

Cheers, Ron

organ

Wow. Congrats Fongolio! Thanks for sharing that and posting pics.

That looks like excellent work. Are the tubes used as buffers or gain? Sorry, if it was posted, but I did not see, what type of tubes are those?

Ron,
Nice to have you here. Hope you stick around.

dorokusai

I'm not a tube CDP fan but that's very cool.

ben62670

This is a good read. I am going to mod my Denon 2900 with tubes. Really you are simplifying the circuit with the tubes omitting a bunch of junk.
http://www.lampizator.eu

ben62670

organ wrote: »

... Are the tubes used as buffers or gain?...

The tubes are feed directly off the DAC chip. There are two kinds of DACs. Current output, and Voltage output. A slight mod to the circuit allows the use of either type of DAC. Current output is preferred by the designer of the circuit.
Ben

organ

Ben,
In most cases in a cdp, the tubes add to the overall circuit. They're usually used as buffers, which means, by removing the tube section, the circuit should be simpler.
Not saying it's no good, hell no. I love the Original CD-A8T which uses a pair of 12AU7 as buffers. It also has SS output which bypass the tubes and I always prefer the tube section.
I like both tube and ss output.

If you're looking at simplifying the circuit, you should check out NOS (non-oversample) and filterless disigns. In fact, I'm thinking about trying out the MHDT Labs Paradisea DAC with a tube buffer.

organ

ben62670 wrote: »

The tubes are feed directly off the DAC chip. There are two kinds of DACs. Current output, and Voltage output. A slight mod to the circuit allows the use of either type of DAC. Current output is preferred by the designer of the circuit.
Ben

I wasn't too sure because Fongolio mentioned the op amps were upgraded. If they're at the output, the tube would be buffers. But maybe he's talking about op amps somewhere else in the circuit?

ben62670

I am going to guess that Ron is bypassing the Opamps for the newer tube mods. It would be interesting to hear what the new mods are. On my Denon I am going to have the choice of SS or tube. A lot of tube mods use a tube buffer after the OpAmps to retain the filters. The link I posted has some good reading.

TruTech

Hi Everyone!

Well it seems that some clarity is in order for the approach of buffer vs. gain.
I have added the tube stage two ways. The first design was a buffer type, which by the way Kelvin is using and the second was gain type with direct coupling to the DAC. All the solid state components have been stripped out of the latter...

The difference between the first and second approach is night and day in comparison. The direct coupled version is surreal...really...

I listened to some Jazz last evening with the completed gain type version, and I can hear even the smallest detail right down to the fingers on the guitar strings...Wow do I love this!!

Logically speaking, this is really the way to approach this because op-amps are inherently a poor choice because the slew rate is too slow...no matter which op amp you use.

I see mention here in a post for a NON oversampling design as well, which I have also experimented with to find no real advantage. This approach introduces more distortion because the sampling frequency without the oversampling is too close to the frequency of the audio that we listen to.

My take on this would be that's it's not a good idea, and offers nothing to improve the sound. (or at least that's what my trials have shown me) Some might disagree, but that's OK! Different strokes for different folks.

I always like to approach things with a "bang for the buck" attitude to get the most overall gain for the least dollars with a view to using some logic with what I know about web based mods that are just hype.

Having said that, I fear that I may get into some sensitive territory here, but everyone has their preferences, so I am not really taking a position here to say that my way is the only way to do things, merely a way I found through experimentation to get the best end result.

I need to charge out the door now to get to work, so I will check back here later.....

Ron

Fongolio

Ok Ron, now you've done it!! I need to ask the question....how difficult (or expensive) will it be for you to take my 1st gen mod to the next level? How you describe the new revision just makes me want it bad. Seriously though, can mine be easily upgraded? I'll have to call you soon on this.

Kelvin

TruTech

Kelvin,

In answer to your question, yours will be easy as most of the work is already done. The tube stage needs to be reworked slightly, and the changes to the main board would consist of mostly removing components.

I will explain the process to you when we speak on the phone. We can talk about the cost then as well.

Cheers for now!

Fongolio

EXCELLENT!!! I'll call you soon Ron. Oh one quick question....you had mentioned possibly using a toroidal transformer, does your new revision incorporate it?

Kelvin

dorokusai

Why does every response sound like a lead-in to another reply for more, technical information?

Why not just come out and post the website or email, offer the modification and be done with it? It's like we're a bunch of audio retards and its insulting. I was really interested, now, not so much.

Fongolio

dorokusai wrote: »

Why does every response sound like a lead-in to another reply for more, technical information?

Why not just come out and post the website or email, offer the modification and be done with it? It's like we're a bunch of audio retards and its insulting. I was really interested, now, not so much.

Whoooa...he has no website for this. The whole mod thing is still in development (he's been doing trial and error for some time now). He's brand new to this forum and has no idea of anyone's level of expertise. He's not actively trying to sell anything here. His first comments were on my review of his work and that he's made even better modifications. Others have asked if he'd be willing to mod their units or if it will be for sale as a whole unit. I can't speak for him but my impression is that he's not trying to push anything here but open if people express interest. I had not told him that I was posting a review here. He found it himself doing a search on the net. If you have any specific questions you could pm him. No need for such rude comments.

TruTech

Thanks Fongolio,

You did say that you could not speak for me here, although I think you may have expressed my feelings well.

When I first found this site in my search one evening, I was excited to see that you had reviewed something that I had created and were truly enjoying the experience.

It is a great feeling to create something that gives someone else a sense of enjoyment and a willingness to tell others about their experience. You are correct that I am not trying to sell anything here....merely to share with others who express an interest.

I made an assumtion that this site was for enthusiasts of audio, so I find it hard to to believe that someone would make a remark like this without reading some of the previous posts to get a sense of the conversation string.

I thought this might be a fun site, but having a re-think now.....