[tomek]

I'm thinking of getting a new amp for my 2 channel rig.  I'm not sure which of these to go for.

H/T isn't really a big consideration, but it's certainly a plus, as is a proper headphone jack.

I was leaning towards the JVC until I read that it had a fan.  I sure don't want to hear a fan while listening to my system.  I can't listen with the computer on because I find the noise distracting.

I like the Teac because the Tripath chips seem to be really good, but it will need a preamp and i'm worried about having to match that in my system.  Plus, no remote control unless I spend a lot more on a good preamp.

I haven't heard much about the panasonic offerings, but from what I've read, there is no consensus  as to which is the best unit to buy.  Some say the old rx10 sounds best, others say the 45 or 50.  Are there any other issues with this amp?

I know i'm asking a lot here in this post, but I guess I'm just sitting on the fence and don't know what to do.

[ooheadsoo]

tomek, the headout on the JVC is ATROCIOUS.  I don't know if the panny even has one and if it does, how it sounds, but the head out is not a reason to go for the JVC.

[mcgsxr]

Can you remind me how efficient those FAB Audio speakers are Tomek, that might help people understand how much power they might like.

I recall that the set I heard at your place were pretty efficient, but I know that you have changed since.

Mark in Canada

[Zero]

Tomek,

I concur with ooheadsoo, the headphone out on the JVC is horrid.  I am not really sure about the other units.

The digital sound is certainly not for everyone.  I encourage you to find a way to purchase these units from a dealer who will give you a 30 day return option.  

Do you know what kinda sound you prefer?  If you want something that focuses more on the "tube-like" side of things -  the JVC may be right up your alley, especially if you have low impedence speakers.

If you have efficient speakers with normal impedence loads *8 or 6 ohms*, and like a more detailed and foward presentation, check out the Kenwood, or the Panasonics.

There are many choices available.. but you have to bear in mind that each of these units will have limitations, as these were never built with exotic hi-fi in mind.

Good luck.

[tomek]

sorry, for more info, the speakers are 97db efficient and are 6 ohm nominal impedance speakers i believe.

http://www.fabaudio.com/Model1.htm

so the headphone out is that bad?  on my kenwood receiver it was actually alright.  I didn't find it to be that different than a decent headamp.

the Teac seems like the best bet for my audiophile nervosa.  there are published stats out there on that Tripath chip and the lesser SI amp got that wicked writeup on 6moons.

however, i am sure that all three of these amps could have been in that guy's system that day and he would have been just as amazed and surprised at how for digital amplification has come.

[lonewolfny42]

sorry, for more info, the speakers are 97db efficient and are 6 ohm nominal impedance speakers i believe.

http://www.fabaudio.com/Model1.htm

That's a nice looking speaker !!!

[Carlman]

Why would you pair a $300USD amp/pre combo to a $10,k CAD pair of speakers?  Seems sort of odd.  I'd consider a much better amp.  I've heard the digital's... they all sound pretty good... worth twice what they cost... but for extremely high-end almost custom-level speakers I'd look for amps that can deliver a lot more than a run-of-the-mill mass-produced digital receiver from Best Buy.  Just my not-so humble opinion..

[tomek]

carlman, i'd rather not go into a long explanation of why i'm selling my $2500CDN tube amp to buy a 250 dollar receiver/amp because it's gonna open up a big can of worms and this thread will very quickly get sidetracked.

let's just say that the review of the SI Tripath amp I read on 6moons didn't surprise me at all, only the audacity to suggest just how close it was to the other high end amps he compared it to.  i commend the author of that article.

i'm looking to unload my big, heavy, power consuming, slow to warm up, etc etc etc tube amp to get something for a lot less that I hope will keep me just as close to my music.

[lonewolfny42]

i'm looking to unload my big, heavy, power consuming, slow to warm up, etc etc etc tube amp to get something for a lot less that I hope will keep me just as close to my music

Might I suggest an AKSA 100N+....tube-like sound and SS. Take a look in the Aspen Circle...home audition tour running now..... http://www.audiocircle.com/index.php?topic=11644  

[lt5dude]

I've been happy with the Teac in my bedroom system.  With a pair of hornshoppe horns and an audio experience symphonies preamp it sounds at least as good as the Bottlehead paramours that I used previously.

I considered the other digital options as well, and since all I "needed" was an amp and the Teac was cheapest it's what I went with.  
BTW, after using the amp awhile, I changed the tubes in the pre from stock sovtec to the new groovetube 12AX7-M and that made a very noticable improvement- my point being that the amp works well with a tubed pre and when fed a better signal sounds even better.

I had no beef with the paramours' sound- I just wanted to try the cool, cheap digital amplification with the horns.  My only complaint about the Teac is the crappy binding posts.

[AphileEarlyAdopter]

Tomek,
I am using a Panasonic XR50 with a efficient Silverline Sonatina speakers (made for low watt tube amps). I think the XR50 will do well with your speakers as the manufacturer says it has very little impedence variations. Just change out the power cord with a good one. Feed it via the digital input for a transparent sound. Or use you SACD players with the analog inputs. The sound of the XR50 also get got better with the use of a Balanced power conditioner (in my case Blue Circle Music Ring MR1200).  Yesterday, I was listening to RCA Living Stereo Chopin Ballad CD/SACD. I have not heard this much of a 'weight' in any other piano recordings. The XR50 is only $250 with shipping. The XR70 should be better sounding but it is not still not here.

[TheChairGuy]

The headphone jack, as others have stated, is truly among the worst ever encountered.

As I found with my Maggies (MMG's, the smallest) recently, the JVC's life gets sucked out of it and eventually thermally shuts down on 4 ohm/low efficiency loads.  I was doing a bit of research on the topic, and it seems switching power supplies (of which the JVC and Panny have - that's why they weigh so little, yet output 100 watts x 5 or 6) can't handle 4 ohm (and certainly less) loads.  Among the problems of driving them at all, Sony's new (S-Master digital) receivers STR-da2000 to 5000es have high frequency roll off on difficult loads.  

Only the mondo expensive STR-da9000es, at $4500 list, can drive the tough loads. That's because it has two linear power supplies on board.  It also weighs 75 lbs. vs. under 30 for the others.

I think that digital amplification will improve dramatically and quickly, but there are some kinks to work thru.  On the right speakers (87db + and no lower than 4 ohm loads) thay can be magnificant value and offer some terrific sound quality.

Carlman, I don't know what or if you've heard some of these digital receivers/amps, but given the right circumstances and implementation, they embarrass the SS and tube stuff of similar cost...and a few notches above.  Personal tastes aside, they offer some world class value in audio.

If makers can establish value, and establish a market for better goods, we should be getting some stellar equipment in the coming years for far less cost, far less physical space and yet far greater energy efficiency and sound than we are used to for the money outlayed.

Right now, however, the digital (receiver) choices don't seem to fit all circumstances.  

[brj]

The sound of the XR50 also get got better with the use of a Balanced power conditioner (in my case Blue Circle Music Ring MR1200).

Was this in direct comparison to an un-balanced power conditioner?

(Ok, what do you really call such a device, anyway?  un-balanced? single-ended?)

Thanks!

[AphileEarlyAdopter]

ChairGuy,
I think the problem is not just power supplies. I think the very digital amplification technology itself is not smart enough to handle widely varying loads. This is very true of the TI Equibit based amps like Panasonic. The Tripath based eVo and others might be slightly better. Another drawback is we do not have drivers that can deliver high power.  Only D2Audio.com claims to have this technology and also the variable impedence capability.  Even with D2Audio, I dont think they have real feadback (like all other digital amplification technologies), but 'only sense the average impedence of the speaker' and alter the filter characteristics. I dont know about the Sony.  They do seem to have a way to make sure they have a perfect square wave at the output before the filter, which can be considered as feedback. This technology is available with Harman Kardon DPR2005. Users report that the HK receiver does not seem to have had good Quality COntrol.
I personally am guessing that the openness of the sound with the digital amps comes from the lack of feedback.  That is why these digital amplifiers fare well with speakers with stable load.

Re: balanced power conditioners. These are nothing but balanced power transformers that cancel out the noise by their very nature of being balanced. Instead of the voltage swinging between +120V and -120V on the phase line. You now have two wires which are at opposite polarity any time (+60 and -60V). So any noise on the phase, is inverted on the other line and when converted to DC by the power supplies. These conditioners do not necessarily address waveform deformities. ExactPower is the only company has a device which corrects the waveform and this should be used in conjunction with their balanced power transformer device. (Yes, PSAudio completely regenerates AC power to produce a pure sinewave).

I have compared the sound of the Panny directly to the wall (dynamic, little hashy, little soundstage) , connected to the Monster HTS2500 (smooth, but less dynamic, slightly better soundstage) with being connected to the Music Ring (smooth, dynamic and open with good soundstage).

[TheChairGuy]

AEA,

I think most of the blame can be traced to switching, and or inadequate, power supplies in most of these amps.  In the quest for lighter weight, smaller size, and lower cost...we have gotten some sonic marvels, but only in careful matches.

You can't shoehorn a 350 V/A or higher toroid power supply in the 2" tall cases that the Pannies, and JVC's have....or keep their weight down to under 20 lbs.  Sony is perhaps the first receiver maker to offer a linear power supply that allows it to drive tougher loads.  I suspect that Bel Canto and PS Audio units, at 100 watts + of Class D power and 30lbs+ each, use linear power supplies.  But, there is less savings in box size and cost once you integrate higher quality power supplies in these designs.  

The JVC is a hybrid digital...and uses substantial feedback in it's design.  ALL the TI chips do, as well. I'm not a technical type, but that would seem to be a dead alley (that is, that feedback is some culprit of the weakness of class D amplification)

Yes, conditioners do help quite a bit with the JVC, too.  I think it may be due to price point reasons however more than anything else...they simply did not allocate the $2 for EMI-RFI choke regulation within.  The differnce between the wall and my BPT is startling with the JVC.

[tomek]

how loud are the fans on these panny and jvc units?

i can't stand any extra noise!

[ooheadsoo]

Chairguy mentioned that he basically forgot that there was a fan.  I said that I could hear it but that I normally sit with my head 15" from the JVC.  At 3 feet in the middle of the night with music playing, I can't hear it.  All of this is assuming you get a good unit with properly functioning fan.  There seem to be a few people who bought units from a cheap vendor on ebay with a lot of faulty fans that made the JVC run hot and loud.

[_scotty_]

The Chair Guy has it right.  Inadequate power supplies as well as under specified output devices are part of the problem. An analogue amp has no brain and will suffer the same speaker matching problems when it is made as cheaply.  It pays to remember that
these products are built to a price point, and a low one at that. The transparency comes from the ultra low output impedance and in the case of the TI chipset the fact that the amp is chip based with only the outputs being discrete  parts. The H bridge output also eliminates waveform distortion due to deadband time. The Tripath has its sound from the low output impedance
and feedback with a very low propagation delay which means that it is more accurately applied.  The Tripath is also a chip type amp with discrete outputs.  As long as the inexpensive amps are produced without adequate
power supplies and large enough output devices they will not be universally
recommended for all situations and loudspeakers. It is almost something for nothing but not quite.  Scotty

[_scotty_]

The Chair Guy has it right.  Inadequate power supplies as well as under specified output devices are part of the problem. An analogue amp has no brain and will suffer the same speaker matching problems when it is made as cheaply.  It pays to remember that
these products are built to a price point, and a low one at that. The transparency comes from the ultra low output impedance and in the case of the TI chipset the fact that the amp is chip based with only the outputs being discrete  parts. The H bridge output also eliminates waveform distortion due to deadband time. The Tripath has its sound from the low output impedance
and feedback with a very low propagation delay which means that it is more accurately applied.  The Tripath is also a chip type amp with discrete outputs.  As long as the inexpensive amps are produced without adequate
power supplies and large enough output devices they will not be universally
recommended for all situations and loudspeakers. It is almost something for nothing but not quite.  Scotty

[_scotty_]

The Chair Guy has it right.  Inadequate power supplies as well as under specified output devices are part of the problem. An analogue amp has no brain and will suffer the same speaker matching problems when it is made as cheaply.  It pays to remember that
these products are built to a price point, and a low one at that. The transparency comes from the ultra low output impedance and in the case of the TI chipset the fact that the amp is chip based with only the outputs being discrete  parts. The H bridge output also eliminates waveform distortion due to deadband time. The Tripath has its sound from the low output impedance
and feedback with a very low propagation delay which means that it is more accurately applied.  The Tripath is also a chip type amp with discrete outputs.  As long as the inexpensive amps are produced without adequate
power supplies and large enough output devices they will not be universally
recommended for all situations and loudspeakers. It is almost something for nothing but not quite.  Scotty