That's very interesting. Back in the 80s, when I was first getting into "high end" audio, the C-9 was new and Bob Carver was doing everything he could to piss off Stereophile, my audio buddy had a C-9. My recollection is that on 3 records it was amazing. On everything else it (at best) made recordings sound different, but mostly just made stuff sound funny. And for those 3 records you had to have your ears within a millimeter of the exact sweet spot or the magic disappeared.

Of course back then our systems were pretty pedestrian compared to my/our current Decware rigs, and what passed for stereo imaging was not much more than being able to hear the different between the left and right channel. The idea of a detailed, layered and transparent sound stage would have been crazy talk. I wonder if the Sonic Hologram was just way ahead of its time, or actually needed something like a low(er) power Decware system rather than the mega-amps with huge speakers Carver sold?

Looking forward to future installments.

The room my stereo equipment is in is probably a fairly common size for people who can dedicate a space for listening. I wish I had a larger space and maybe one day I will, but for now I have to work with a 12’x14’ with a 10-foot ceiling. The space is not ideal since I have a credenza between the speakers which I have my equipment on. The speakers are on the long wall, which in normal circumstances may not be the best but in my situation, it seems to work well since the speakers have more distance to the side walls and still gives me a little more than an 8’ triangle for my listening.  I spent almost a year trying different speaker positions and toe-in and finally settled on what I have now. The sound I was getting was about as good as the Decware system and the room would allow. Over that time, I was also adding a significant amount of room treatments. I’ve spent a great deal of time listening in this environment and had a very good feel for the Decware sound and how the room allowed it to shine. The sound was very neutral, clear, and had good imaging as well as a nice soundstage with a solid phantom center channel. What I wasn’t getting was a lot of depth, that front to back depth I hear so much about. Fortunately, I was getting some depth and a good amount of layering, so I was happy. I think the credenza and the room as a whole is limiting me to some extent.

Just a few pics of my room:









The C-9 is usually behind the credenza door but I pulled it out for the pic.




It had been quite a while since I had read anything about the C-9 and when Paul (red pill sanctuary) brought it up in his posts I started to research it again. It was definitely a cool and interesting piece of gear, but as CAJames mentioned in his post, I was wondering if the unique characteristic of the unit and my not-so-great room would be able to do justice to the C-9. You see, the C-9 is meant to be used in a very specific way. The instructions point out that it should be used exactly as described if you want to extract the most 3D holographic imaging that it’s capable of. It requires as exact a speaker placement as you can get based on the guidelines it spells out. I knew I had the right equipment to springboard from (the great Decware system) but the limitations in my room would be a problem. I really had very little wiggle room for changing speaker placement and the directions said the speakers should be roughly 5’ apart. (maybe even closer). That meant I would need to position the speakers in front of the credenza, which I knew I would probably not be doing (except to experiment with maybe). I went back and forth but ultimately decided to get one. At the time you could pick one up for $100 - $200. I paid $175, on the high side but in retrospect it was a good enough deal. As I mentioned earlier, even with the issues the unit had, once inserted into the audio chain, it just enhanced the sound from the get-go. Knowing what it could do at this point I decided to do what Tony mentioned in his post. I contacted 4krow (aka Greg) and asked if he would refresh the unit. He agreed and did a fantastic job, and I thank him for that. I now have peace of mind knowing there is fuse protection and all the updates and upgrades will carry me well into the future. For less than $400 total, I have a piece of equipment that perfectly complements and enhances my Decware system.

C-9 BEFORE :



C-9 AFTER Greg performed his magic. Outstanding!




After more play, the C-9 alleviated my uncertainty. To CAJames’ point, I thought maybe it would sound weird or somehow ‘off’, or maybe no difference at all. The C-9 didn’t ‘add’ anything, in fact, it seemed to subtract something. That something is crosstalk. When both ears hear an instrument or voice from both speakers, precise imaging seems to be affected. So, when an instrument, voice, or backup vocals are supposed to come from the left or right position in the soundstage, the sound from the opposite speaker can detract from the imaging in the soundstage. The C-9 seems to be able to eliminate/reduce the crosstalk by removing the unwanted signal to the opposite speaker when it needs to, thus eliminating the opposite speakers’ influence on the position of that sound. I have no idea how it actually works though (my technical experience is zilch on this). The kicker is it does this without altering the tone, neutrality, or base sound you’ve come to expect from your system. The result is precise imaging within the soundstage. The other important fact is that it gives depth to each instrument or voice. It seems that each instrument has a 360-degree radius of sound that emanates from its precise location as you’d expect from a live performance. The C-9 seems to not only give each instrument its own depth, but it also pulls the entire soundstage together into one cohesive soundscape. The speakers seem to disappear more easily, the left to right soundstage widens a bit and the air and separation of instruments and voices, along with the overall cohesiveness, just draws you in. I found myself wanting to leave it on at all times for all tracks. There is a much higher level of emotional engagement with the C-9 on as opposed to off. That is where it’s at for me.

I don’t know why I’m able to achieve this level of enjoyment with the C-9 since by all accounts I shouldn’t be able to. I have done nothing to my original setup and when I tried to adhere to the user guide instructions on proper speaker placement/etc. I couldn’t achieve anything near the results I got with my original setup. (not to mention the ridiculous look of having the speakers in front of the credenza). One day when I have a different room I will certainly try again, but for now I’m leaving it as is. I’m not getting a true holographic image with this setup but to be honest, I’m getting what seems to be a true to life image/soundscape in front of me as you would in a small venue with the performers spread out in front of you. I know the room treatments help a great deal and getting your setup/speaker placement to your liking with your Decware (or other high end) gear before inserting the C-9 is critical as well. From there, I think anyone with a conventional setup can still benefit from the C-9.

Another topic I’d like to talk about will be the different recording formats that Paul (RPS) has sent me on various CD’s. Paul was kind and generous enough to send me over 30 CD’s with some great music on them that he had created to help me evaluate the Carver C-9. I hope to follow up shortly. Thanks for hanging with me so far.

Thanks MM, it took a couple of years+ to get to this point with my system and room treatment.

You make a good point about the QRD diffusers. I hope to add them at some point, but I don't think I'll be able to until I change rooms. Those absorbers just have a 'scatter plate' attached to the front and are a poor attempt at mimicking some diffusion along with absorption. I've heard the QRDs do a great job, and I hope to incorporate them down the line. I do have absorbers at the first reflection points as well as rear bass traps and absorbers at the back wall (not shown in any of the pics). These room treatments are nothing like GroovySauce or red pill sanctuary have, (and others) but surprisingly they make a big enough difference. Groovy and RPS have some awesome treatments, and I hope I can come close to something like that in the future. I'm sure enjoying the sound in this smallish room. (the Decware equipment makes sure of that!)

Thanks for your recommendations, appreciate it.

I figured that this is a good time to chime in about the C-9, since more than one person here has bought rebuilt C-9 units from me, and it has been a pleasure to do business with all of you. I currently have 4 units for sale at different prices and levels. Thing is, I think that there is little difference in sound from the least expensive unit at $175 (with wings) and the most expensive unit at $280. Like many of you, I get a good price on something and other times, it costs more. In my hobby (IRS somehow thinks that my hobby is a business whether there is profit OR NOT), I try to have a range of pricing that not only reflects this, but if I charge more for a unit, it is simply because I have done a lot more work on it, like putting in sockets for the integrated circuits that matter so that you can change them out if you wish, and then that requires me to put in a more substantial transformer to accommodate a little more current draw from some of the possible integrated circuits chosen.
All that said, my main purpose for the unit is to lengthen its lifespan for another few decades or more of service, all the while maintaining the same level of performance, not to mention an upgrade with most units, of the RCA jacks, so that they can accommodate more brands models of interconnect cables.
As some of you know, I am always willing to talk any kind of audio, and I suppose that is part of the rebuilding package. Some of the systems shown here are absolutely fantastic to me, and I appreciate the effort put forth by so many on this site.

Thanks for chiming in 4krow.

If anyone is thinking of exploring what a C-9 can do for your specific setup/room/equipment, this looks to be a great opportunity. Greg did a great job with my less-than-ideal unit I sent him and no doubt the one's he has available have been meticulously transformed as well. The prices seem more than fair for what you're getting. Some people will spend that much on a single Furutech connector. Of course, an extra set of ICs to complete the connection into the chain isn't cheap but worth it to see if your situation can benefit from the C-9. Granted, some room treatment will certainly help, especially first reflection points since you don't want to mess up the signals that the C-9 worked hard at correcting. Maybe that's why some people don't get good results, or the sound is less than stellar.

He was able to repair the fuse protection on mine as well as all the caps, resistors, RCA jacks, new power cord (detachable, I love that it's not captive anymore), new transformer, more robust AWG wire where appropriate, two new IC's (of the five total) that do the lion's share of processing, and probably a few other things I can't remember off the top of my head. No doubt, no stone left unturned.

Thanks JD,

Yes, I have corner bass traps in all four corners of the room. No doubt they'd be more effective if they went floor to ceiling, but I'm trying to balance aesthetics with meaningful treatments. I also have two 4'x2'x4" panels targeting lower frequencies tucked behind the listening seats. They are hidden by the seats and provide some bass treatment.  

There is no doubt that in a somewhat small room, absorbers are a must, at least for me. I have efficient speakers and the spec's say they go down to 30Hz (and I definitely believe it). I bought these speakers so I wouldn't have to deal with subwoofers for the time being (for both integration and placement concerns). They do a great job. I've used amroc to give me an idea of what room modes I'm dealing with. 40, 46, and 56Hz are the low frequencies that are of concern at the boundaries, and 61, 69, and 73Hz are the frequencies most likely to build up in all corners in a room my size (14x12x10).

Low frequencies require well made, deep/thick absorption to be effective. Unfortunately, I can't afford the room they would take up so I've opted for the next best thing, critical mass (lol). Absorption seems to the most critical to address. It seems there is almost no overdoing it in a somewhat small room. I have a total of 21 panels of various shapes, sizes, and depths (just not real deep ones). Some as you see have a 'scatter plate' attached to try and give some sort of dispersion. Obviously if one can use QRD diffusors along with something like Acoustic Fields (think GroovySauce) or DIY like red pill sanctuary has for absorption, then you'd be in treatment heaven. So, to try and answer your question about if the bass traps work, I would say that by themselves they might not do enough (although I think very helpful and would work in your room), but if you can achieve critical mass and add as much absorption as you can, even without top-of-the-line treatments, you can achieve a very satisfying effect/sound.  

I used REW to take measurements of my room before any treatments. Now I just have to get off my butt and re-measure now that I've got most, if not all of my treatments in place. Just finding it hard to stop listening and take the time to measure lol. I know it's made a difference though. One of these days I'll see what REW thinks.

Good luck on whichever path you take for room treatments.

Marc,

I am very glad to see that you finally started this interesting thread. You are off to a very good start. I do hope that you keep this thread alive with continual updates of your progress and most importantly, your music reviews. I think that is what matters most. I think many music enthusiasts will be tuned in on a regular basis to hear your thoughts regarding music in this room with the Decware equipment and the very special, way underpriced Carver signal processor.

The C9 is truly the catalyst for enhancing system levels which no other equipment has the capability of matching by comparison without it. This being a design created in the 1979 era for its initial conception, and interestingly enough, about as low cost as it gets while achieving a high quality audio standard which today remains in a class of its own. It truly leaves a stain upon the audio snob way of thinking in contrast to the traditional mindset which dictates quality and prestige representative of the price tag each component bears by that standard. These delusional people would never have a C9 in their precious overpriced system simply because it doesn't cost enough. How could it possibly be any good? Perhaps if Carver placed a ten thousand dollar price tag on it and paid the magazine review "professionals" to place it front and center within the audio community as something every true audiophile should own, then maybe, just maybe, they would be on board with that confident smug contentment which satisfies "their" perception of class.


First, I want to compliment you on your room layout and interesting decor. I like the theme you have going on in this room. Now I have a much better idea as to what this room is like. You have a fine selection of components which are certainly of the highest caliber for music enjoyment. I know that you intend to go much farther into room modifications, but you are off and running with even greater potential ahead.

I believe that if I designed and built your room to the maximum limit for optimal sound quality, you would simply not believe your newfound discovery. Too bad we are not local. It would be an interesting project just to see where it could go. But you shall have to pursue this dream on your own. You can do it. I know that because you are well informed with the right mindset to get it completed.

I must encourage you to get motivated to keep the upgrades active. You will be generously rewarded by doing so. But I guess you knew that. You have a good room setup to make it happen. Your equipment is in place. It is just a matter of room acoustics to get you where you want to be. You have a good thing going now, but there is more waiting in the future for you if you allow it to happen.

As for the Carver C9. I have two of these units which both work perfectly, and cosmetically, they both look almost brand new. Of course, I bought one of these as "sacrificial" for backwards engineering of this concept, for which I am designing and preparing to build an entirely new version of this processor using the best premium parts available on a scale at least three times the size of the original. The only electrolytic caps are the main power supply which are upgraded to premium esoteric ELNA RFS Silmic II audiophile capacitors made in Japan (old stock).  That unit is now completely stripped bare bones down to a bare PCB. I kept the newer unit in my system, as I simply will not listen to music without it. Yes, it is that good!

All other capacitors are upgraded to mostly polypropylene film and foil types which the larger 22uf caps are DC link caps with the four pin Kelvin connection principal designs for absolute optimal performance. The power supply is upgraded to a high quality 12v + 12v R-core transformer. There will be galvanic isolation installed by means of shielded 10k:10k isolation transformers to prevent ground loops and unwanted signal noise. And of course, extensive bypass capacitors will be used to eliminate high frequency noise within the circuit for optimal sound quality.

Every single resistor is upgraded to metal film types of tight tolerances. All five chips will be Texas Instruments premium grade, installed within gold pin riser cradles for easy replacement if needed. This also prevents heat damage to the sensitive opamps when soldering. The chips are simply inserted once the base cradle is soldered in place with all connections wired in. The diodes will be upgraded to high speed ultra fast types.

The push type switches are replaced with premium NKK DPDT Japanese toggle switches which contain silver for premium signal integrity. The RCA jacks are upgraded to premium REAL copper machined grade for optimal signal integrity. Most of the connections are to be point to point using 7n silver plated copper core internal wiring. I may use a designer board with a copper ground plane on the back side for mounting the components, but I am still considering that option.

I could go the easy route and create a Gerber file for an exact engineering clone of the original board layout, have it made in China within a three day turnaround. (this process takes only three days to have the PCB's built to spec, and in my hands! ) Unless I was to build, or sell these board kits for builders, this is not a viable choice considering cost for production, and that there is a minimum quantity. The shipping cost from DHL is scary to say the least, but they do get the order delivered overnight. I had my capacitor tester PCB boards made this way and the process was lightning fast.


My goal is to create something unique which is of my own doing. Even though it is based upon the original design, my new version is  like night and day when it comes to audiophile grade build quality and performance. I want the best possible, so I am doing what it takes to make it possible. I was considering integrating this design directly within my redesign of the ToriiMk3 which I have allowed enough room inside the new enclosure to fit it in. But as I think about it, I will most likely build a wooden enclosure for it instead. The size will be closer to that of a CD player when done.

One thing that is sure regarding my habits, is that I take my time, and allow for the thought process to perhaps come up with a better solution. This always seems to work out in my best interest concerning the end result.

I have already reengineered this design several times due to this, and it will be a much better design as a result of doing so. As you can imagine, this is going to be a very expensive jewel to create. For me, it is an absolute must to meet my strict requirements. Once finished, I will have the only model in existence built this way.  

Anyway, I am not ready to disclose additional info concerning this new processor as of yet, but full disclosure will be revealed on my thread once I get this project within the build process. This is one of three projects I have going on simultaneously which all will come together for higher advancement of my audio system. The super DAC is going to make this processor design seem easy by comparison. This is going to be super expensive to build, but worth every penny! And what I am investing into the new amplifier upgrades is also costing dearly. So this takes time. I shall reap the rewards many times over when all of these projects are finished.


But, not to take away anything regarding the original C9 processor. It is an exemplary design which was way ahead of its time in the audio world. Bob Carver invented this concept way back in 1979. I was eighteen years old then. Time is escaping me very quickly as the age of this unit reminds me so very well. It is a loss to those who don't understand how vital this unit is to real stereo projection, failing to consider its importance as a critical function which really is necessary for a complete audio system of the highest caliber. It is the crowning jewel which complements Decware amplifiers perfectly.

I am very pleased with mine in stock form. I have to push things to the extreme limit, and this is no exception. I need to explore this concept and discover the possibilities of advancement to make it even better if that is possible. I shall find out.

I tried recently to go without the C9 in my audio system due to the need to relearn what the amp signature is without any other components in the system. I needed to get this signature burned into my memory to compare with the modified sound signature I am about to create with the overhaul using revised upgrades.  I have to tell you, that period did not capture my interest. It was so obvious that a vital part of the soundscape was missing. I just can't enjoy music without it. I can never be without the C9 in my system again if I want to be completely happy with the results.

I had a thought; wouldn't it be interesting if Bob Carver was invited as a special guest to attend the next Decware gathering? Just think of the interesting conversations that would take place with he and Steve getting together for some in-depth conversation. I am sure that all in attendance would be tuned in with great interest. Mr. Carver would most likely be fascinated to meet Steve as a fellow tube amplifier designer, seeing firsthand what is going on in Decware land. I am sure he would be entertaining to say the least.

I apologize for going on about this on your thread Marc, but you know where I am coming from concerning our shared interest in the C9 processor. I hope that you can convey enough interest in others so they too can be enlightened by this design if they haven't before. Back in the day, with mediocre sound systems that most people had, they didn't get the full effect of what this design is capable of back then, at least nowhere near what it can do with a high quality tube amp such as a Decware design supplying the power. Just remember, acoustics affect everything in audio. The setup of the room and speakers is absolutely critical if you want this design to reveal its true capabilities. With a high quality set of speakers set up properly which includes critical listening position as part of the set-up, it is almost impossible not to hear the difference on a level which you will not want to do without once you experience it correctly.

I found it interesting that you found dislike with female voices, and that some recordings are preferred with the unit disengaged.

I think this has to do with room acoustics and set-up. I know that the equipment is not the cause of this.  I will tell you that I have not heard one single recording over a wide range of genres and quality standards for which I even remotely felt the need to disengage the C9. Everything that I have played to date has benefitted by some degree by use of the C9 in my system. I want to make clear that when I installed the new Zrock3 with all upgrades, this became a marriage made in heaven when in unison with the C9 which takes this entire projection into a whole new realm of audio quality. This became the best arrangement I could have ever hoped for. The result is simply beyond the imagination, something that must be experienced if you want to discover the real truth in audio perception as it compares to sounds you hear in the real world in real time. It is the ultimate discovery beyond a shadow of doubt. I never bypass my Zrock3, but I do reduce the input on premium recordings, and I damn sure NEVER bypass the C9! That would be detrimental to the quality standard which I require in music reproduction.

Perhaps you might get the idea that I like the C9? You just may be right!



I have to go for now. I shall check back here again later. I am extremely busy these days and time is always against me it would seem.  All is good. It will get even better.

Good job on this new thread. Keep it active and don't let it get buried in the general post section as it can easily do.

I want to hear more about your perception of the music with the C9. Keep it going on a regular basis.


Later.

LOL
Will is still the reigning king !
It will take many years for Red Pill to catch up

Cheers,                    Crazy Bill

Took the C-9 dive and picked up one rebuilt by Greg (4krow). It arrived in excellent condition, set it up between my preamp and amp and I was immediately impressed with it’s SQ.  It just filled my room with a more full 3D sound and with more clarity.  Prior to the C-9 I toed my speakers slightly out to gain a fuller room 3D sound but sacrificed a bit of clarity.  With the C-9 I now toe my speakers in a bit and I get an even more full room 3D sound without sacrificing clarity.  I have yet to play a song I do not want to use the C-9.  Time will tell if that changes.  Really cool/fun tweak at an incredible  value ($200).  Glad I gave it a go…👍👍

The conversion stage is a simple solution which will not hamper the fidelity to a point where it will degrade beyond an acceptable manner, if even noticed at all.


You have options. It depends upon what you actually want to accomplish here.


Take a look at these well made affordable solutions which can be ordered on E-bay immediately.



First, the simplest way is to buy a conversion cable per the diagram:






For a more "audiophile" approach with superior audio quality, then step up to these options:



Balanced Preamp/unbalanced balance/balanced to unbalanced/RCA to XLR


https://www.ebay.com/str/happylifequalitystore?_trksid=p4429486.m3561.l161211












Here is another solution to consider. It is just a finished board ready to use, you must install into a case or mount inside a chassis.


DIY Balanced To Unbalanced Audio Signal XLR TO single-ended Converter


https://www.ebay.com/str/along1986090?_trksid=p4429486.m3561.l161211








And yet, another option:


Assembled Mono Unbalanced To Balanced /Balanced To Unbalanced /RCA To XLR Board


https://www.ebay.com/str/pinshuche?_trksid=p4429486.m3561.l161211






There are other options available. Just be sure that the option you choose will not degrade your audio signals and will actually serve the purpose of your intent.

Now you can use the Carver C-9 in a balanced system without a problem very easily at low cost. You MUST have the RCA jacks in the stock C-9 replaced with better upgrades. The best thing to do is buy a revamped unit from Greg.

You should get the idea by now that having a C9 in your system is well worth it. Just listen to those that have one and learn from it.

I guarantee you that you will NOT be disappointed! It is the ultimate finishing piece to complement Decware gear.

Thanks for the suggestions guys.

Quote:


I don't know. For me, balanced is a pretty big deal. A big enough deal that I bought two amps instead of one so I could keep the signal balanced all the way to the speakers. I have compared balanced to single ended, and for me it isn't close, although admittedly it is hard to do a true apples to apples comparison. But JMO/YMMV and all that.


Quote:


Yeah, if it isn't broke... If I were going to do the balanced to single ended conversion I think I'd go with a passive, transformer based solution like the ZBIT. But getting two C-9s would likely be cheaper and in theory keep the signal balanced. I just don't know how well it would work with double the sonic holography. Probably really awesome or really weird, so realistically I'm going to do nothing.