JVC RX-F10 (Tripath-based)

Zero · « **Reply #240 on:** 29 Oct 2004, 04:36 am »

I am fairly confident that I am hovering around the 300 hour mark. This thing hasnt been turned off for awhile, and recieves constant use per day. My 30 day trial period has expired some time ago.

I must say, she is still far from matching the performance of my Musical Fidelity A 3.2 integrated, but just the same - she is not shamed. The fact that she sounds this good slaps the face of anyone who doubts the capabilities of digital amps, and receivers, alike.

Truly one of the best values I have come across !

Stereodude · « **Reply #241 on:** 29 Oct 2004, 03:03 pm »

Just a warning. You can literally burn your hand on this unit. I did so today when I went to pick it up and move it after it was powered on for about an hour. It was only sitting idle for that hour (not driving speakers).

ooheadsoo · « **Reply #242 on:** 29 Oct 2004, 04:12 pm »

If that's happening, by the accounts I've read, it's likely your fan is not functioning correctly. My unit is only warm at all times.

Stereodude · « **Reply #243 on:** 30 Oct 2004, 02:16 am »

Quote from: ooheadsoo

If that's happening, by the accounts I've read, it's likely your fan is not functioning correctly. My unit is only warm at all times.

I can hear the fan spinning...

Zero · « **Reply #244 on:** 30 Oct 2004, 02:30 am »

Stereodude,

It is a tad un-nerving to get used to. My unit runs on the very warm to hot side of things at all times, the fan is flowing perfectly fine. The warmth should only be coming from the left side of the unit.

Thus far, I have encountered no hardware problems with the unit (just a stupid user). She has been on for over a week straight and shows no signs of giving way. I certainly hope not, because at $250, its not exactly a throw-away unit anymore.

ooheadsoo · « **Reply #245 on:** 30 Oct 2004, 02:41 am »

If you read JDUBS msgs, you can see that his receiver was really hot as well even though the fan was technically working. In my experience, if I disengaged the fan, the amp would not play above 12 or 13 on the volume scale before automatic shutdown. However, my receiver is always merely warm to very warm. JDUBS said that his receiver was HOT. However, when he peeked inside, he said that although the fan was spining, it was being impeded by some piece of black sticky tape. When he removed that tape, he said that the receiver cooled down to warm.

Interestingly enough, the fan is on the right side but the heat is on the left side. What's up with that? Yet, clearly the power components on the right side need to be cooled or the receiver auto shuts down. The right side has always been cool to the touch on my unit, even with the fan disengaged.

TheChairGuy · « **Reply #246 on:** 4 Nov 2004, 05:06 pm »

OK, so I did a bit o' investigating yesterday on the JVC's.

The RX-ES1sl sold for under $200 and the newer RX-F10 for $50 or more. It has been my experience in consumer electronics that replacement product is typically higher featured and most often the same or less cost...what occurred with the JVC is a bit of an anomoly.

The event that caused me to look longingly into this anomoly was that my ES1sl was such a good match with the Vandy's, and horrid with the much-tougher-load Maggies. The F10 weighs about 6/10 of a pound more...but perhaps that is only the addition of one amplification channel.

However, the specs stared at me yesterday...the ES1sl is rated at 100watts at 8 ohm,; the F10 at 6 ohm. It seems, in addition to the additional channel of amplification, additional digital (optical) input and more consistent build quality of the F10, it also might have enhancements to the power delivery or, at the very least, a different output inductor tailored for lower impedence loads.

This could be why -Richard- had such terrific synergy with his Maggies (with an F10), and with my ES1sl, abysmal results with even smaller Maggies.

There may, in fact, be more substantial differences in the two models than many of us originally thought. At $249 shipped, I may in fact try an F10 out or, look into a Zero Transformer (impedence multiplier) with the ES1sl.

Dmason · « **Reply #247 on:** 4 Nov 2004, 05:20 pm »

I seem to recall the F-10 weighing more than the ES-1; this almost certainly would have to do with the power supply chiefly, and an additional chip-amp. From what I gather, the F-10 is more robust. A friend has one, which to our amazement, could drive the daylights out of a pair of Dynaudio Contour 1.8 II,

which are a notoriously difficult load, and usually mated with jumbo amps, commonly Bryston, with BIG power supplies and caps.

Wayne1 · « **Reply #248 on:** 4 Nov 2004, 05:27 pm »

The F-10 that I modded the power inlet on actually uses a pretty much standard "analog" power supply for the audio output section. It has a fairly large power transformer right after the inlet. On the other side it has four diodes for a full wave bridge and a goodly sized pair of filter capacitors. That may account for some of the differences.

The fan on the unit blows into a tunnel that the outputs are attatched to. It draws cool air into the tunnel from the right and exhausts the hot air to the left.

There are a few pieces of thick plastic film around the fan to help funnel the air into the tunnel. It is possible that some of these pieces may have gone askew during shipping and are now blocking airflow into the fan. If you open the top cover, you should be able to see what I mean. I no longer have the unit here so I cannot post of photo of it.

Please make sure both sides of the unit are open to allow air to flow smoothly

ooheadsoo · « **Reply #249 on:** 4 Nov 2004, 05:46 pm »

Quote

the ES1sl is rated at 100watts at 8 ohm,; the F10 at 6 ohm

Wait, an amp is supposed to make MORE power into a lower impedance load, not the same. That goes against the trend of our theories.

TheChairGuy · « **Reply #250 on:** 4 Nov 2004, 06:28 pm »

Quote from: ooheadsoo

Wait, an amp is supposed to make MORE power into a lower impedance load, not the same. That goes against the trend of our theories.

Well, I'm not sure always, 'cause my ES1sl makes 0 watts into 4 ohm load. That is, a thermal shutdown occurs.

I may just end up purchasing an F10 and letting everyone know if there are differences. To my knowledge no audiophool has had an F10 and ES1sl side by side yet or done an A vs. B sound check on both, either.

Onward ho with continued vigor and mirth

ooheadsoo · « **Reply #251 on:** 4 Nov 2004, 07:10 pm »

Since I use dvd mode and not dvdmulti, I may pick up an f10 next year just to try that midnight dsp mode.

TheChairGuy · « **Reply #252 on:** 5 Nov 2004, 03:49 am »

DigiDMason, noted on the Dynaudio - notoriously difficult loads I have heard then to be.

Wayne, too bad more mods aren't available aside from the IEC. What was your impression of the JVC before and after tha IEC inlet install? As I seem to remember, you are a 'tube' guy(?)

I think there may indeed be differences between 1st generation and 2nd generation JVC's...but may be most perceptable with more difficult loads.

Hmmmmmm..........

cjr888 · « **Reply #253 on:** 5 Nov 2004, 04:26 am »

Quote from: TheChairGuy

Wayne, too bad more mods aren't available aside from the IEC. What was your impression of the JVC before and after tha IEC inlet install? As I seem to remember, you are a 'tube' guy(?)

I think there may indeed be differences between 1st generation and 2nd generation JVC's...but may be most perceptable with more difficult loads.

1. Anyone out there have any test equipment or a buddy in JVC R&D?

And on an even more serious note, anyone have a service manual?

2. Waiting for my little 1st gen unit to show up, and then to wait the four years for it to break in. Should be intriguing to hear it on the Cornwalls....to really, really critique it, it should be interesting to hear it on the Fertin Field Coils..... My frame of reference certainly won't be review worthy, since the only amplifiers I have to compare it to, and that I'm currently familiar with right now aren't exactly what you'd call neutral, but certainly make beautiful music......(1930's Triodes Driving Triodes w/1940's PP OPTs running in SET config - 6sn7/UX-226/45 Mesh)

3. I've heard a lot of criticism that mostly 'points' to the power supply. I have to ask -- people seem to like a certain 'something' about these units and at $125 for the 1st gen unit, they cost less than a lot of volume controls. Say you pulled everything out of the chassis -- would there be modifications to be considered if space was not an issue, and secondly, rather than pointing figures at the power supply, could one straight out replace it with something respectable at a middle of the road price?

Just thinking that the parts for a half decent gainclone with no chassis, no connectors, binding posts or wire will cost you 50-70 without a power transformer....$125 starting price for the 'core' of an amplifier really is a cheap platform to work around......if the work is worthwhile.

Just curious where the unit could be taken if cost and space wasn't an object.

Thoughts?

Wayne1 · « **Reply #254 on:** 5 Nov 2004, 01:45 pm »

ChairGuy,

The power supply in the F10 could be upgraded. the power supply caps and diodes can be replaced with higher quality.

I didn't have the time to really go into any more mods. I took too long just getting the IEC installed

There might be a way to install a single pair of binding posts, but you would have to give up all the other speaker output connections.

There also may be a way to snake a set of wires through the maze of companents to the output connections.

If anyone would be willing to let me have an F-10 for a few months, I may be able to figure this stuff out.

cjr888 · « **Reply #255 on:** 5 Nov 2004, 02:23 pm »

Quote from: Wayne1

ChairGuy,

The power supply in the F10 could be upgraded. the power supply caps and diodes can be replaced with higher quality.

I didn't have the time to really go into any more mods. I took too long just getting the IEC installed

There might be a way to install a single pair of binding posts, but you would have to give up all the other speaker output connections.

There also may be a way to snake a set of wires through the maze of companents to the output connections.

If anyone would ...

Wayne, I have an ES1 arriving in the next couple days that I was planning on sending to you anyway per our emails -- unless you specifically want to look at the F10, I'd consider leaving it with you indefinitely to goof around with. Drop me a PM if you're looking for a unit to play with...

TheChairGuy · « **Reply #256 on:** 5 Nov 2004, 10:17 pm »

Well, okay, so I splurged and bought an F10 today. I'll see if the newer generation will drive the Maggie.

I believe it will, based on some others experience here. Give me a couple/three weeks to get a side by side done right.

Kevad · « **Reply #257 on:** 6 Nov 2004, 02:09 am »

After wading through the numerous posts here and at avsforum, my F10 was just delivered from J&R today! Definitely sounds "different" than my old gear, but can see it has potential. Will have to wait until after it's burned in to give a fair evaluation.

Quick question on the burn-in period. Should I be actively playing music or something through the amp to burn it in, or is it enough to just have it powered on?

Thanks!

Kevad · « **Reply #258 on:** 6 Nov 2004, 02:12 am »

Oh forgot to mention, I have it powering some Dynaudio Gemini Kit speakers, and haven't had any issues with the amp shutting down even at high volumes during music or movies! (Which was one of my main concerns)

TheChairGuy · « **Reply #259 on:** 6 Nov 2004, 02:24 am »

Quote from: Kevad

Oh forgot to mention, I have it powering some Dynaudio Gemini Kit speakers, and haven't had any issues with the amp shutting down even at high volumes during music or movies! (Which was one of my main concerns)

Well that buoyies my hopes further for synergy with the blood-sucking Maggies