[ooheadsoo]

JDUBS reminded me that if your subwoofer has high level input, you can still use the JVC with a sub in DVD/Multi mode.

[driggity]

JDUBS reminded me that if your subwoofer has high level input, you can still use the JVC with a sub in DVD/Multi mode.

To do this do you just run the Sub off of the surround speaker terminals with the receiver set in the 5 channel stereo mode?  This may be an option for me as I was looking to upgrade my sub anyways.

[ooheadsoo]

You would run them off of the front channels.  It will be a challenge to fit both sets of wires in.  This would also negate any xover stuff the receiver does.

[driggity]

Well I don't want to run my front speakers full range so thats no good.  

I could just go the ICBM route but it seems silly to spend more on bass management than on the receiver.

[mcgsxr]

Can you not run the fronts full range through the receiver, then route to the sub, use the sub's Xover to limit the range that the front speakers run?

Mark in Canada

[driggity]

Well I was thinking that subs (especially the lower end ones that I was looking at) wouldn't have a high pass x-over to feed the speakers correctly.  Apparently I was wrong about this.  The Adire Rava, which is one sub that I was considering, does have a high pass filter on its speaker outputs.  Unfortunately its fixed, but it may still work out ok.  I'm not sure if other subs in this price range have that feature though.

And as for the JVC the sound does seem to be getting a bit better since its been playing constantly since sunday evening.  Unfortunately I've been busy so I haven't been able to do any critical listening.  Hopefully I'll get some done tonight.

[ooheadsoo]

I was listening to my signal generator right now with frequencies around 120hz to 200hz (a real pasttime of mine) and I noticed that as I turned the volume up, the pitch would drop.  As I turned the volume down, the pitch would rise.  This seems independant of the level of the source, since I can change the level of my source from +4db to -10db with the click of a mouse button.  It seems correlated to how loud the signal is, as heard over my speakers.  Could this be the much ballyhooed harmonic distortion coming into play or is it my small 5" woofers meeting its match?  Or could it just be something related to my soundcard or the signal generator (foobar 2000?)  If it is the amp, I would highly recommend very efficient speakers with this amp only.  Granted, I don't notice this in music, though I do sense some blurring and smearing at very loud volumes that I never listen to normally.  Mind you, I've never not heard my system blur up and smear at big volumes.  That could be the room, speakers, etc.

Could someone with very efficient speakers verify that this doesn't happen?  All you need is a computer and foobar  Or if you have regular or low efficiency speakers, you could verify that it does happen.

I just wired up a 14ga. foil shielded power cord with two ferrite chokes on either end of the cable to the JVC.  For once, I don't hear any improvement right away.  Could it be the ferrite chokes?  I don't know and it would be way too much of a hassle to hack off the chokes at this point

[driggity]

Did you just notice the change in pitch with your ears?  What volumes (on the JVC) were you listening to?  Did you try multiple inputs?

My computer and receiver aren't next to each other but maybe I'll move one of them and do some tests this weekend.  My system may be partially affected by the fact that the JVC isn't fully broken in yet either.  It will at least provide another data point though.

[ooheadsoo]

For some more reference:

1. This seems to be noticeable only where the amp is most power hungry.  I can't hear this change in pitch at high frequencies, and I don't hear it much up in the upper registers of the woofer's range or tweeter's range at all, and I don't hear it at all in my subwoofer's range.  I am now using 200hz as my reference for this test.

2. For what it's worth, my soundcard is set at the -10db output setting and I have an additional 7 db of attenuation going on at the mix level.  The source signal strength is at +0db.  

3. With that frame of reference, I hear the drop in frequency response starting at volume level 12 on the receiver.  By 15, it's about 1/12 of an octave down in pitch.  By 19, it's 1/6 of an octave down.  By 25, it's 1/4 of an octave down.  This is rough and slightly exaggerated.  But not by much.  The 200hz reference is throwing me off, at low levels it just sounds out flat because it's so close to 220hz (low A.)  I should really use 220, but I'm lazy

4. Yes, I am listening to this and judging the relative pitches by ear.  It is clearly obvious (to me, at least.)  I've been playing fretless/valveless instruments like the violin and trombone as an amateur for about 20 years now, and I am currently studying music history.  We can't pass our music theory classes if we can't hear this stuff

5. At 25, it's really pushing it.  I'm getting a headache and I hear some distortion.  I'm a bit dizzy and my ears ring a bit.  Since it is +0db, I believe this is the loudest the amp can play at this level, meaning a dynamic "peak" but being sustained by the signal generator.

[JDUBS]

Is anyone experiencing a buzzing noise coming from their RX-ES1?  I did a search and it "sounds" like it may be the power supply?

Its weird.  It doesn't start making the noise immediately, but more of a gradual build up.

Thanks,
Jim

[jswallac]

I do know these things have serious quality control issues.  I was 2 for 2 with defective units.  The first had the left channel go out from time to time.  It also ran very warm with the fan never coming on.  The second unit had an extremely noisy fan, or that was what I thought at first.  I now think it was likely the power supply making all that noise as it came on as soon as the unit was powered on and turned off with the unit.  I have since given up on these little amps.  Perhaps they are a good value if you can find one that works, but even when mine were working they did not come close to the sound of my entry level tube amps (Joilda or Sophia Electric).  The qualifier pretty good for an inexpensive receiver seems to be the best description.  Then again I am obviously not a satisfied customer.

[ooheadsoo]

No buzzing here.  JDUBS has an interesting story about why the fan had issues though.  Perhaps he can be persuaded to share it with all of us

[tubeytubeamp]

Chairguy;

I just picked up a pair of Optimus x77 with the Linaeum monopole off of Ebay for $36. There is a nice synergy going on with the JVC. With certain types of music, they are much more coherent and musical than my JM Lab 706s which will soon be for sale on Audiogon.

I want to start modding these and my first mod will be dampening with Plast-i-Clay. Where did you pick up the plast-i-clay? I have been unable to find any retailers that carry it.

Thanks
Dennis

[ooheadsoo]

I'm going to try plumber's putty, which you can find at home depot.

[TheChairGuy]

Cool Tubey Dennis!  Wait till you hear the dipoles eventually within the ...quite nice, too.  The dipoles need some felt on the top and bottom...that's what the higher spec Linaeum brand speakers have.  Otherwise, it's not so different than the Radio Shack Linaeum speakers (except in price as Lineaum brand was made in US rather than Malaysia).

The cheapest place to find Plast-i-Clay is here:  http://www.allartsupplies.com/item.php?articleId=120

Buy the grey...it's real PlastiClay.  I bought black last time and almost died from the fumes.  They subbed another brand for Plast-i-Clay and it wasn't quite the same. I just bought 10 lbs today so it's in stock, or was.  I paid $3.29 for a 1.1 lb package of another brand at Ben Franklin Crafts a couple weeks ago.  I've never seen as good a price as All Art Supplies has on this stuff. My wife is an Art major, buys and has bought other stuff like they carry before at other places, and says it's about the best costs she has seen on many items.  FYI.

ooheadsoo, the Mortite or Dennis brand rope caulk works very well too, but it tackier to your skin.  If you use a lot of it over extended period of time, your skin will be much more raw.  It's also far more expensive per lb than Plast-i-Clay...maybe 2-3x times as much.  It works tho.

As good as Plast-i-Clay is, acoustic damping inside the speaker cabinet improves things further still.  Much more solid bass, midrange quality improves, too.  I buy Acousta-stuf from Parts Express...it has yet to help any speaker it's been applied to.  It's about $10 a 1 lb bag...enough to do two bookshelf or small towers fully.  I haven't used other damping compounds, but 'The Loudspeaker Design Cookbook' author is fond of R19 fibreglass insulation (obvious health drawback to using this, however   )

[ooheadsoo]

I think stuffing affects the tuning of the box.  It'll lower the Q of a sealed box, which is probably good.  I'd be careful with it in a ported box though.  You may ruin the tuning, which is more complicated with a port.  Fiberglass is probably the best absorbing material.  I read the specs on the health safety regulations of fiberglass lately and it's really not that bad.  Just wash your hands with soap after touching it.  Don't go pounding on it.  Don't get fascinated by its fishy odor.  That's about it.  I've got lots of fiberglass in my room right now.

I may consider that plasticlay because it is stickier.  The plumber's putty was super cheap though.  $1.19 for a pound over at the home depot or something like that.  You just can't beat that price, and no shipping to shell out.

[TheChairGuy]

I may consider that plasticlay because it is stickier. The plumber's putty was super cheap though. $1.19 for a pound over at the home depot or something like that. You just can't beat that price, and no shipping to shell out.

Wow, that is cheap.  It's waaaay more money at Ace dealers.  I seem to remember $4.00 or more and I'm not sure that was for a full lb. or not, either.

Agreed on the ported box caveats....a little is better than a lot (always adhere to sides, never block either port of driver rear).  But, it has markedly improved 3 ported boxes so far.

I think the health issue with fibreglass is in the inhalation of it in your room, not just the contact with skin.

[ooheadsoo]

SECTION V: HEALTH HAZARDS/PERSONAL PROTECTIVE EQUIPMENT
      Primary Route of Entry: Inhalation. Fiberglass wool may cause
mechanical irritation of the upper respiratory tract. Use of a respirator
such as 3M model 9900 or equivalent is recommended. Operations which
generate high airborne fiber concentrations (over 10 fibers per cc) require
additional respiratory protection.
      Skin Contact: Direct contact with the skin may cause mechanical
irritation. If irritation occurs, long sleeves, loose fitting clothing,
gloves, and eye protection are recommended. Wash exposed areas with soap and
water after handling. Wash clothes separately and rinse out washer after
each use.

      Following a thorough review of all the medical data available, the
International Agency for Research on Cancer (IARC) has classified glass wool
insulation as Group #3, "not classifiable as to carcinogenicity to humans".
IARC has stated there is "no evidence of increased risks of lung cancer or
of mesothelloma...from occupational exposures during the manufacture of
these materials, and inadequate evidence overall of any cancer risk."


From this page: http://www.guardianfiberglass.com/printouts/eng_msds2.htm

I worked with fiberglass a lot in high school.  It won't fly up everywhere and into the air unless you pound on it or something.  And it's not poisonous, it just might make your lungs itch for a little bit.  Wear gloves, don't pound on it, and you're safe from itch.  I just use plastic bags on my hands so I don't have to go wash them after handling the stuff.  How's that for lazy?  

[ooheadsoo]

I should add that I just put a OneAC CP1110 into my system.  I am very pleased indeed.  Low level detail is now superb.  I think because of that low level detail, the soundstage is better defined.

[TheChairGuy]

Filtration is a necessity with the JVC...it is merely 'okay' without it.  I think it's switching supplies are more prone to problems than linear supplies in SS and tube gear.  

There is probably more reasons, too, that are beyond my layman knowledge of such things.