JVC RX F10S Initial Impressions

Zero · « **on:** 24 Sep 2004, 02:47 pm »

The RX-10 arrived to my doorstep mid-afternoon yesterday, and I have been cooking her since. The power cord and the spring clip speaker wire terminals were instant indicators that this unit was not painstakingly designed with hi-fi in mind. Past experiences remind me how looks can be deceiving, so I continue on without much hesitation. Even though this unit is being used for my second system, it has some decent sized shoes to fill, as many good units once served duty on this system, including two other digital amplifiers. My current PC audio system, the system which this unit will be used on, is as follows;

E-MU 1212M Sound-Card
Polk Audio LSi-7 bookshelf speakers
Phase Technology Power-12 sub-woofer (temp)

The Polk LSi series was not designed with budget equipment in mind. They love high quality equipment and feast on high current amplifiers. Their 4 ohm load is nothing any budget product likes to face. These speakers can sound beautiful on the right equipment, but are marred with the inability to really capture ones attention at low volumes. Let’s see how the JVC initially performs with them.

The Sound

For starters, the JVC certainly adds a lot of color to the sound. I recall reading a few comments that drew comparisons between this unit and tubes. Those assessments are not far off. Right out of the box, the mid-range is very laid back, warm and inviting. The bass seems a tad over plentiful, and the highs definitely have a sharp edge and almost hollow sound to them. There was definitely a large influence of compression on dynamics and voices at all volumes. This unit also doesn’t like going past *28*, which seems to currently be its bottleneck. While I always get bad FM reception, I cant even pick anything up on this unit. Also, this unit runs very hot so it may be best to keep out of reach of children.

Ok, so you are probably asking “what’s good about the unit”? The answer is simple, there is a lot to enjoy. As time goes on the voices and highs become more tamed, loosing that “SSSSS” and “TTTTTT” sibilance. The sound is already becoming quite a bit more coherent. The mid-range hasn’t changed, and that’s a good thing. This is a very inviting sound, and is just out and out pleasant to listen to. The JVC is the essential opposite of what digital amplifiers are known for, and that is being precise, detailed, dry, and analytical.

Even with less than 24 hours of play, the LSi’s sound much better than they do on the Sony S50 ES digital drive receiver being ran downstairs on more Polk’s. The most impressive accomplishment this receiver has done thus far is making the Polk’s sound just as good at low volumes, as they do when being cranked. Even my 3k worth of Marsh gear could not accomplish this.

There is still a lot of time left before I can reach any concluding thoughts on the unit. So far, I can tell it would not be for everyone as some will definitely prefer the more detailed/clear/dynamic sound over the warm tube-like sound of the JVC. Either way, this technology just keeps getting sweeter and sweeter.

Questions: (sorry the original thread was getting way too long to go through)

Ok, I have a few questions. For one, how the hell do you get the sub woofer working? Its driving me crazy!
And lastly, how do you access “all channels driven”.

Thanks!

Sean

mcgsxr · « **Reply #1 on:** 24 Sep 2004, 02:54 pm »

I don't have one, but have read much...

About the sub - I think I remember that the unit has to be used with the DVD multi inputs to get this going?

Sorry if that leads you in the wrong direction - TheChairGuy is on vacation, so we are without one of our primary JVC gurus for the moment.

Mark in Canada

ooheadsoo · « **Reply #2 on:** 24 Sep 2004, 05:23 pm »

Assuming the F10 is just like the ES1SL,

With the DVD/Multi mode, you have to have a discrete subwoofer input. I've got an emu1212m just like you, so we're out of luck. You have to switch it to DVD mode, not multi. Once you do that, the sub will kick in provided that you've got it enabled and the xover set and speakers set to small, etc. Actually the sub will work whether the speakers are set to small or large, but you know what I mean

-I think the highs get much more clear and detailed after even more burn in.

-Others have said that the DVD/multi mode sounds clearly better. I don't know about that. I've been comparing DVD to DVD/Multi, one with my sub and the other without, all morning long and I don't have anything conclusive. One catch is that my speakers give out more bass without the sub (DVD/Multi) because of some bad room modes. With the sub, I tamed it just a tad. Other than that obvious difference, I think things are pretty close. Maybe DVD/Multi mode sounds a bit smoother and a bit more forward in the midrange and upper midrange, but it's really close to my ears. I'm not confident I could pick it out in a blind test.

Zero · « **Reply #3 on:** 24 Sep 2004, 06:52 pm »

Oohead,

Are you using the NHT's on this unit? After throwing the manual down - I decided it would be best to just tinker. In doing so, I enabled the sub but cant set the cross over for the life of me.

I detect a very small difference between dvd multi and just regular dvd mode. Like you, I wouldnt bet money on it - not at this point at least.

So what are your impressions of this unit so far?

Right now Im attempting to decide whether I think its good enough to keep, or if I should hold out and wait till this new Panny (70) hits the market. Going to try some Ascend Acoustics on this unit here within the next few weeks to see how that match goes.

ooheadsoo · « **Reply #4 on:** 24 Sep 2004, 07:17 pm »

I'm using a pair of Dennis Murphy MBOW1's that I built a month and a half ago. My system's in my sig, I think.

Basically, if you have a sub connected to the sub out, the receiver will automatically detect the sub. Just switch to DVD mode to activate it. Then, hit setting. Turn the multijog knob until it highlights crossover. Hit the set button next to the knob. Turn the knob to adjust the frequency. Hit the set button to set it and forget it. Don't forget to jog on over to front speaker and set it to sml, not lrg. I think default is small but I'm not sure.

I like the unit. I haven't heard the panasonic amps, but I'm not planning on ever using the dac in the panasonic amps, so that's pretty much out for me. I can say that I used to have a $500 diy tube headamp/preamp and that I sold it and got this JVC. I don't miss that tube pre at all. No tube hiss and the sonics are at least as good. My system is better than ever at this point than it's ever been. You may as well put chairguy's 200 hours on it and see for yourself

I don't know what else you could get for the price.

gary · « **Reply #5 on:** 24 Sep 2004, 07:51 pm »

You should see the compression at high volumes go away after about 100 hours or so. I'm pretty much convinced that the "break-in" people hear with the JVC (myself included) is the gradual decrease of distortion over time. Why this happens, I have no clue, but I'm pretty sure it does.

Gary

Zero · « **Reply #6 on:** 24 Sep 2004, 08:56 pm »

Oohead,

Thanks for the step by step. Unfortunately the crossover is still stuck in the "OFF" position. Consulting the manual is about as useless as possible. Ah well, one way or another I will figure this out.

Until then, time to keep burnin this piece in

AphileEarlyAdopter · « **Reply #7 on:** 25 Sep 2004, 01:59 am »

A6M-ZERO,
I think you have given a good idea about the JVC. It seems to gel well with other people's opinions too (like geofstro's).
To me midrange is the important part of the music, but that is not the only one. I need good bass and highs. I want very good dynamics.
To me so far the Panasonic seems to fit the bill. I do not have the harshness people complain about with the panasonic. Maybe it is some amp-speaker interaction phenomenon.
I already had(still have - boxed) an integrated amp which supposedly is good with midrange - Audio Refinement Complete. I still like the Panasonic. Another minor problem is that the JVC does not have a removable power cord. But the good thing going for the JVC is - it is able to handle any kind of speaker.

Zero · « **Reply #8 on:** 25 Sep 2004, 02:13 am »

I am hoping that in time, this thing will open itself up (before my 30 day period is out). There is a lot to love about this JVC thus far, but not enough to keep her.

ooheadsoo · « **Reply #9 on:** 25 Sep 2004, 06:27 am »

I've never seen the xover set to "off." Weird.

Keep it playing 24 hours a day. If you reach 8 or 9 days and it still doesn't sound good to you, *shrug* I don't think this is your main system right? If you're not going to get some super nice source for this system, maybe the panasonic is the way to go if you don't like the jvc's sound.

Zero · « **Reply #10 on:** 25 Sep 2004, 01:38 pm »

oo,

Somehow, I managed to get the cross over going and set to 80 hz. BIG difference.

I have been leaving her on 24/7, so hopefully in the next week and a half things will change. I may also put some different speakers on order.

Cheers,

Sean

lonewolfny42 · « **Reply #11 on:** 25 Sep 2004, 03:34 pm »

A6M-ZERO,

You might want to order a pair of these adaptors. They work very good with the JVC. Easy cable switching too. And on sale. They work great for me.

[/list:u]

Zero · « **Reply #12 on:** 27 Sep 2004, 04:28 pm »

Lone,

Wouldnt ya know it, all the sales happen when your completely broke. Buying the JVC, cheap as it is, was more than a huge expense for me now! This is just a sick, sick hobby.

Also, my JVC is a her, you see theres this little slot in the back and... errmm... Ive said too much already !

TheChairGuy · « **Reply #13 on:** 27 Sep 2004, 05:12 pm »

Yeahhhhhhh, a NEW JVC post. Those others were getting waaaay outta' hand!

After a vacation, I cranked the little wonder up yesterday to freshened ears...and it sounded like fine wine. It is now paired with a 2 way, 87db efficient Lineaum Tower speakers (rather than the normal 90 db efficient Vandy 1c's) and, in my modest 12 x 12' room, has room filling dynamics and all the warmth or yore. Even if the little JVC ain't nuthin' but a muscular 50 watter, it seems enough for many of us and our needs.

A few other mental notes I made to myself:

I've had a modest list of hifi equipment in the past 20 years. Tho thankful that I have had good earnings in many of them, I've always kept my sickness within reasonable expense levels. I had my gear locked up for 7 years during that stretch while I started two business' and a family because I knew the distraction it was for me. I'm back now only 4 years or so into the fray.

Every receiver (Marantz, Onkyo), every SS amp (Norh, AudioSource, NAD, Superphon) and SS Pre (Blackgate modded Superphon, Hafler, Dynaco PAT-4, IRD Purist) had me working the volume knob downwards on any combination of speakers (3D Acoustics, Klipsch, Quad 11L, modded Optimus LX-8, Camber 5.0ti, MasterCraft Audio Sound panels, Vandy 1c) that they were paired with. The IRD Purist least so, however.

Only when I had a tube pre in the form of either a Dynaco PAS-3 or PAS-4 in line did I want to twiddle the voume knob upwards and enjoy. Tho I could sustain the higher voumes, the music never sounded to me lifelike - just an ethereal version of music; comforting like lamb stew on a cold winter's day (hey, I'm Greek, I'm comforted by lamb stew

).

With the JVC, for bloody $200 odd, I am continually urged to raise the SPL's and am just pulled into the music...that sounds lifelike to me.

Those of you that have had $2000+++ amplification for some time in line may not find the JVC as stunning as I (and many others) do, but to me it is a tremendous value and has such superb articulation for that money I find it's appeal irresistible.

I have a damn nice DIYCable Exodus digital amp and my Dynaco PAS-4 sitting here, and should be playing with the tandem, but I'm soooo happy with the JVC...I'm in no urge to put it thru it's paces. That is a HUGE change of pace for me - my seemingly insatiable quest has been tamed by a $200 receiver.

Zero · « **Reply #14 on:** 27 Sep 2004, 05:21 pm »

Chair,

I think it is very important for people to put things into perspective. Yep, this JVC unit kicks butt for its price, but it has its limitations. I have been comparing it (despite not being close to the break in point) to the Musical Fidelity A3.2 integrated that I currently own - and no, its not quite up to that caliber, but its not *completely* shamed either.

Once people get past the tabu of a brand name and price, I think a few can discover a fairly satisfactory solution that wont break the bank.

I have some Ascends on the way to pair with this unit. I have a feeling this will be a beautiful match. I should know by sometime next week (if all things go well).

TheChairGuy · « **Reply #15 on:** 27 Sep 2004, 07:12 pm »

A6M-Zero,

Don't close the book on the JVC until you have 300 hours on it. I made that mistake at 100, then 200 hours. It really fleshes out after 300 hours or so.

You may find it is up to task creating music on par with the Musical Fidelity unit in a week or so. It'll be interesting to know when you do tho...as well as the new pairing with the Ascends.

Zero · « **Reply #16 on:** 27 Sep 2004, 07:17 pm »

A year ago, I paired the Ascend Acoustics with the Sony S50 ES digital drive receiver. I heard these speakers incredible potential, but the clinical nature of the Sony just made for a boring (albiet very detailed) presentation. I parted with the Ascends only due to my quitting a job.

The book is definately not closed on the JVC. In fact, I dont have any plans on returning this unit back to jandr. If it matches the performance of the A3.2, I would be thoroughly impressed. I reserve lots of serious doubt that it is capable of doing so - but I have been wrong before. In tihs case, that would be a good thing!

AphileEarlyAdopter · « **Reply #17 on:** 27 Sep 2004, 09:48 pm »

A6M-ZERO,
One of the major components of an amplifier is the power supply. If the power supply in the house can be modeled as an ideal voltage source (voltage remains the same, irrespective of current). The amplifier is an ideal varying voltage source (irrespective of the current drawn by the speaker), where the the varying voltage is the amplified music signal.
So we can see how important power supply is to the amplifier.
The Musical Fidelity A3.2 has a choke regulated power supply which provides a low impedence current source to the amplifier section.
The JVC (and the Panny) uses a switching power supply which assumes an ideal voltage source for the the power supply. But we all know that the power supply socket in the house is not ideal. It does not have the transformer/capacitors that are large enough to provide whatever current the amplifier demands.
So the JVC is severely handicapped when compared to your A3.2. That is why it would be a good idea to atleast change the power cord. This reduces the output impedence of the socket as seen by the JVC. You can also plug in your JVC to an isolation transformer or balanced power transformer to mitigate this to some extent.
Many think digital amplifiers like Panasonic and the JVC to a lesser extent are detailed but lack the soundstage depth/warmth of higher end audiophile amplifiers. There is some truth to this. And the main reason is the power supply. Lots of low level harmonics are getting lost because the amplifier is not able to source the current required by the speaker. This reduces the warmth and the soundstage.
The two tweaks I mentioned power cord and balanced transformer help in this area to some extent. If not, you have no choice but to go for professional modifications or really high end audiophile amplifiers.

AphileEarlyAdopter · « **Reply #18 on:** 27 Sep 2004, 09:51 pm »

Please read all 'voltage source' as current source. An ideal current source, supplies as much current without dropping the voltage at the terminals.

Jay S · « **Reply #19 on:** 27 Sep 2004, 10:17 pm »

TCG,

I have been quite impressed by all the posts about the JVC, particulalry since it seems to be so listenable even with out any mods (apart from a power cord). What more if it had the same level of mods as the Panny XR45s that Wayne@Bolder Cable and Steve@Empirical Audio have worked on.... their mods for the Panny do include (I believe) a Jensen 4-pole cap right at the power inlet as well as upgraded (certainly in quality, not sure about capacity) power supply output capacitors. Cleaner and quicker delivery of current may well help with the soundstage as mentioned by AudiophileEarlyAdopter. The JVC doesn't seem to hurt for warmth but certainly harmonics and low level detail will be aided by a better supply. I believe a balanced transformer (like a BPT or Blue Cicle) not only provide cleaner power but also have lower impedance than a wall socket and also store some amount of energy to help supply a surge of curent on demand.

I've got a lot of $$ in my tube pre and digital amp and their associated cables... my dream is to replace them with a great digital receiver... only questions is when that will become a reality. Heck, I'd like to replace my entire system with a single box + a pair of speakers if the performance is there and it will save me $$!