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I am setting a new HT set for my house. I am in the market for a new AVR(onkyo 706 or 707 price range is right) Is their any benefit to having an external amp for home theater. i know they are good for music but what about a HT setup. I am looking at getting the Ascends 340 and 170 speakers. Antique sound labs has an inexpensive amp that I heard works very well. It is not that mush for one, but i did not know if anyone has tried or has heard of anyone try it. here is the link.
http://www.divertech.com/aslwaveav20dt.htm

speaker link
http://www.ascendacoustics.com/pages...m/cmt340m.html

Thanks for your help.
 

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Tubes for a HT setup? That's very strange. Tube amps aren't usually that powerful, the one you linked to not much juice. for HT you're often more concerned with oodles of clean power for the dynamics of a film soundtrack. You could do it with tubes I suppose, but cost would be enormously prohibitive to get big tube amps with that much power.
 

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Quote:
Originally Posted by ser182 /forum/post/16935724


I am setting a new HT set for my house. I am in the market for a new AVR(onkyo 706 or 707 price range is right) Is their any benefit to having an external amp for home theater. i know they are good for music but what about a HT setup. I am looking at getting the Ascends 340 and 170 speakers. Antique sound labs has an inexpensive amp that I heard works very well. It is not that mush for one, but i did not know if anyone has tried or has heard of anyone try it. here is the link.
http://www.divertech.com/aslwaveav20dt.htm

speaker link
http://www.ascendacoustics.com/pages...m/cmt340m.html

Thanks for your help.

Let's see: An AVR with 100+ watts per channel at
 

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I am setting a new HT set for my house. I am in the market for a new AVR(onkyo 706 or 707 price range is right) Is their any benefit to having an external amp for home theater. i know they are good for music but what about a HT setup. I am looking at getting the Ascends 340 and 170 speakers. Antique sound labs has an inexpensive amp that I heard works very well. It is not that mush for one, but i did not know if anyone has tried or has heard of anyone try it. here is the link.

External amps are only worthwhile if the amps in your AVR are somehow inadequate.


Tubed amps are generally boutique items for dilentantes who want bragging rights. Thing is, while I know a lot of audiophiles, I don't know any who who be impressed by someone who bypassed a perfectly good SS amp to use a tubed amp that no doubt underperforms it.


Ascend 340 speakers are fairly efficient but lack bass extension. Unless you already have one, obtaining a good subwoofer would be a logical higher priority.
 

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Quote:
Originally Posted by arnyk /forum/post/16939785


External amps are only worthwhile if the amps in your AVR are somehow inadequate.


Tubed amps are generally boutique items for dilentantes who want bragging rights. Thing is, while I know a lot of audiophiles, I don't know any who who be impressed by someone who bypassed a perfectly good SS amp to use a tubed amp that no doubt underperforms it.

I agree.


The 12AX7/6L6 combo in that amp will undoubtedly be based upon a classic topology and have a strong sonic characteristic, the classic round, thick, 'tubey' sound that lots of people like, something like my old Fisher 800B receiver.
 

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If you like the second order distortion of a tube amp over the TIM caused by the massive feedback to get bi-polar transistors low enough in odd order distortion, how about looking for some MOSFET amps. Old Haflers, B&K etc. Personally, I'd worry about your speakers and room treatments. The AVR is probably more than good enough.
 

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Quote:
Originally Posted by tvrgeek /forum/post/16943652


If you like the second order distortion of a tube amp over the TIM caused by the massive feedback to get bi-polar transistors low enough in odd order distortion, how about looking for some MOSFET amps. Old Haflers, B&K etc. Personally, I'd worry about your speakers and room treatments. The AVR is probably more than good enough.

Even the old Haflers were among the very cleanest power amps of the day. I've ABXed them against clean tubed amps and the competitive bipolar amps of the day and there was no sonic difference.


MOSFET output stages make so little diffrerence that millions of them are manufactured and sold without any mention of how their output stages are implemented.


The idea that TIM even exists as a unique form of distoriton is held in very low regard these days. That bipolar output stages or amps with lots of loop feedback are somehow necessarily afflicted with them is also yet another audiopile myth.


If a power amp can produce full power at 20 KHz with low distortion, then it is by definition immune to TIM and with a signficant safety margin.


There are a number of notable examples where audiophiles and reviewers dismissed certain amplifiers like the Bose high powered amp of a number of decades ago on the grounds that their distortion increased at high frequencies in published tests. On closer examination, TIM was not the problem. The problem was that the power amps power rating was set a little too high. At slightly lower power levels such as dominate typical use, there was no signficant or excess distortion, audible or measurable. The measurable distotortion was due to the fact that the amp had to be pushed into clipping at high frequencies to meet its overstated specs, and it clipped because of fractional dB losses in its output stage stabilization network. At all levels below clipping, the amp was clean. The ultimate fix was to add a few turns to the power tranformer secondary, so that the amp did not clip within ratings.


However, primed by the hype about TIM, many audiophiles and reveiwers perceived all kinds of sonic problems that were in fact figments of their imagination. Similar examples exist with CD players from the early 80s.
 

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"The idea that TIM even exists as a unique form of distoriton is held in very low regard these days. That bipolar output stages or amps with lots of loop feedback are somehow necessarily afflicted with them is also yet another audiopile myth."


I will gladly listen to more on this. My experiments playing with gain, feedback, and bandwidth would seem to confirm this as a leading candidate. I find that the higher the feedback, the higher the bandwidth needs to be for similar sound. When I applied enough feedback to get a bi-polar to the .zip something THD, and the bandwidth was under 50K, they would start to sound harsh. Yet a FET with only 30K bandwidth and .5% THD with very little feedback did not have the harshness. It did have the artificial warmth from the second order harmonic distortion.

I could be out of date as I gave up on my designs 15 years ago and have been using Haflers and B&Ks for years. They are "good enough". ( Actually, never heard better)

So I came up with a simple benchmark. A 50K bandwidth, DF over 100, THD below .1 and 4 Ohm power close to twice 8 Ohm. Not that that guarantees a good amp, but the ones I consider good all could meet it. They happen to all be MOSFET.
 

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Quote:
Originally Posted by tvrgeek /forum/post/16950742


"The idea that TIM even exists as a unique form of distoriton is held in very low regard these days. That bipolar output stages or amps with lots of loop feedback are somehow necessarily afflicted with them is also yet another audiopile myth."


I will gladly listen to more on this. My experiments playing with gain, feedback, and bandwidth would seem to confirm this as a leading candidate. I find that the higher the feedback, the higher the bandwidth needs to be for similar sound. When I applied enough feedback to get a bi-polar to the .zip something THD, and the bandwidth was under 50K, they would start to sound harsh. Yet a FET with only 30K bandwidth and .5% THD with very little feedback did not have the harshness. It did have the artificial warmth from the second order harmonic distortion.

I could be out of date as I gave up on my designs 15 years ago and have been using Haflers and B&Ks for years. They are "good enough". ( Actually, never heard better)

Well some 15 years later, there are even more good amps. But even 20-25 years ago many good SS amps were good enough. I personally did the level-matched, time-synched, bias-controlled listening tests that proved it. Heck, I even invented ABX, and without Al Gore's help. ;-)


Quote:
So I came up with a simple benchmark. A 50K bandwidth, DF over 100, THD below .1 and 4 Ohm power close to twice 8 Ohm. Not that that guarantees a good amp, but the ones I consider good all could meet it. They happen to all be MOSFET.

Your benchmark specs are OK, if right on the edge, except the 4 ohm power = twice 8 ohm power which is neither required or even commonly provided in actual bench tests of amps that claim it on their spec sheets. When claimed it is usually obtained by understating the actual power that is available at 8 ohms.


That you would fall for such an obvious audiophile myth is disappointing.


You need more experience with level-matched, time-synched, bais-controlled listening tests. Come over to Hydrogen Audio where that sort of thing is widely discussed and there are many knowlegeable people who post.
 

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Quote:
Originally Posted by arnyk /forum/post/16952932


Well some 15 years later, there are even more good amps. But even 20-25 years ago many good SS amps were good enough. I personally did the level-matched, time-synched, bias-controlled listening tests that proved it. Heck, I even invented ABX, and without Al Gore's help. ;-)





Your benchmark specs are OK, if right on the edge, except the 4 ohm power = twice 8 ohm power which is neither required or even commonly provided in actual bench tests of amps that claim it on their spec sheets. When claimed it is usually obtained by understating the actual power that is available at 8 ohms.


That you would fall for such an obvious audiophile myth is disappointing.


You need more experience with level-matched, time-synched, bais-controlled listening tests. Come over to Hydrogen Audio where that sort of thing is widely discussed and there are many knowlegeable people who post.

I did say "close". I found it to be an indicator of sufficient power supply to be able to service the outputs. An indicator, that is all. Lots more caps can do a lot to overcome a smallish transformer so it would not be close on continuous but still be just fine for music. Design choice.


All the numbers are just indicators as I am sure someone could screw up a design and it still meet them.


Fan of the Hafler, "is the input just like the output" test. Used it when I bought and then made a couple of mods to my B&K 140, and then just bought a pile of DH220's and a 160 off e-bay so I have not had to worry about it since. I wish I could find about a 30W version. It seems like such a waste to use the 160 just for tweeters. Anyone know of a GOOD small amp that is affordable?


I will check out the group you mention. I consider myself a reasonably experienced bench tech, but certainly I am not an EE nor did I sleep in a hotel last night.
 

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Quote:
Originally Posted by ser182 /forum/post/16935724


I am setting a new HT set for my house. I am in the market for a new AVR(onkyo 706 or 707 price range is right) Is their any benefit to having an external amp for home theater. i know they are good for music but what about a HT setup. I am looking at getting the Ascends 340 and 170 speakers. Antique sound labs has an inexpensive amp that I heard works very well. It is not that mush for one, but i did not know if anyone has tried or has heard of anyone try it. here is the link.
http://www.divertech.com/aslwaveav20dt.htm

speaker link
http://www.ascendacoustics.com/pages...m/cmt340m.html

Thanks for your help.

Hi ser182,

I use tube amps for HT AND 2 Channel,I would recommend a larger tube amp 50 to 100watt plus unless you listen at low levels and no action movies etc and use 1 or 2 subs(bass requires more power)

Movies do not have any compression some have 30db plus dynamic range therefore an amp with high power is required,if you like it loud,tube amps can do that to,but its going to cost $,see if you can try some amps see if you like it etc,

Regards Victor.

MY SYSTEMS,
http://www.avsforum.com/avs-vb/showthread.php?t=1136036
 

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I have a denon avr-3805, a pretty good av receiver with rated 130 watts or so per channel. One of my best upgrades for home theater sound was replacing left and right front amps (via pre-outs) to a Rogue stereo 90 tube amp (90 watts per channel). I disconnected the center entirely (went to phantom center). I have a huge, smooth, 3-D soundstage that completely rocks the room for movies (and sounds incredible for two-channel). It's generally considered in the audio world that 1 tube watt is comparable to 3-4 solid state watts in terms of real perceived sound quality. Also THD specs are misleading because the harmonic distortions of tube and solid state are completely different (different harmonics involved) with the solid state distortions much more perceivable by human ears. Also many very good speakers (I have sonus faber) are better driven by good tubes (or very high wattage solid state) than by the power coming from the Denon.

I would say the main downside in my system is that the rear surrounds are still powered by the Denon, and the sound quality is therefore not at the same level. I may put some separate amps on those at some point.
 

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Quote:
Originally Posted by sharpnine /forum/post/17029146


It's generally considered in the audio world that 1 tube watt is comparable to 3-4 solid state watts in terms of real perceived sound quality.

And that 'general opinion' would be wrong.
Quote:
Originally Posted by sharpnine /forum/post/17029146


Also THD specs are misleading because the harmonic distortions of tube and solid state are completely different (different harmonics involved) with the solid state distortions much more perceivable by human ears.

You cannot generalise about tube and SS amps in that way. What are you referring to? A Williamson? A zero gNFB triode amp? A gainclone? A Pass Aleph or XA? A Firstwatt amp?
 

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Quote:
And that 'general opinion' would be wrong.

Since the comment was about human perception, and therefore subjective, do you mean wrong for you? Or for the many audiophiles who prefer the sound quality of tube amps and agree with this statement? You know better than they how good things sound to them?

Quote:
You cannot generalise about tube and SS amps in that way.

This whole thread has been generalizing about tube amps, which is why I commented. Of course tube amps differ; I prefer one that retains the accuracy and neutrality of solid state, but as you know many are warmer and introduce more coloration (which some call musicality).


My point is just that tube gear has as much to offer home theater setups as hi-fi two channel setups. If you don't like tube gear then fine, but there is no reason to avoid it. Admittedly tube gear can be more hassle to deal with and maintain, but then many or most on these forums are hobbyists who I expect don't mind doing some fiddling and maintenance.
 

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Quote:
Originally Posted by sharpnine /forum/post/17031345


Since the comment was about human perception, and therefore subjective, do you mean wrong for you? Or for the many audiophiles who prefer the sound quality of tube amps and agree with this statement?

A watt is a watt. I have heard it bandied about for years that X tube watts = more SS watts, and it is simply not true. People like to believe all sorts of rubbish and this is some of it. Tube amps of a given power are no more powerful than an SS amp of the same rating. As for what you mean by 'quality' in terms of power, that is simply one of the nebulous terms that means nothing outside of reviews.
Quote:
Originally Posted by sharpnine /forum/post/17031345


This whole thread has been generalizing about tube amps, which is why I commented. Of course tube amps differ; I prefer one that retains the accuracy and neutrality of solid state, but as you know many are warmer and introduce more coloration (which some call musicality).

My point was that so many philes comment upon 'tube amp sound' as though it were a particular inherent characteristic of all tube amps (same for SS amps), where is is simply not the case.
Quote:
Originally Posted by sharpnine /forum/post/17031345


My point is just that tube gear has as much to offer home theater setups as hi-fi two channel setups.

Less generally because of the greater dynamic range of movies and output required.
Quote:
Originally Posted by sharpnine /forum/post/17031345


If you don't like tube gear then fine, but there is no reason to avoid it. Admittedly tube gear can be more hassle to deal with and maintain, but then many or most on these forums are hobbyists who I expect don't mind doing some fiddling and maintenance.

I have designed and built or worked on, more tube amps than the average audiophile has even seen. I simply do not buy all the mythologising about them, based directly upon my own experience of using them with a great range of speakers.

If a tube amps requires any more maintenance than simply changing tubes every few thousand hours and maybe rebiassing then, it is badly designed.
 

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Quote:
A watt is a watt.

So you believe that all amps of X watts sound the same?

Quote:
Less generally because of the greater dynamic range of movies and output required.

You are generalizing that tube amps are not able to provide great enough dynamic range for home theater. Do you believe they provide sufficient range to listen to symphonic recordings? Does a symphony have less dynamic range than a movie?

Quote:
I simply do not buy all the mythologising about them.

I think your opinion may be directed largely to people who are in love with vintage tube gear, and I agree there is more to their feelings than just sound quality comparison. Modern tube gear doesn't tend to inspire the same feelings, and I think generally stands up better in direct comparison with modern solid state gear.


I haven't had the experiences you have with tube gear. All I know is that upgrading from the 130 watt denon to the 90 watt Rogue was a revelation in detail, air, and imaging. I can hear the space, the type of mic, everything is more detailed. Upgrading to a separate solid state amp would probably also have been a big improvement, but I would have gone to at least a 250 watt SS amp in that case. I am not denigrating the denon; it is a very good unit with a very transparent preamp section. I think there's a limit to how much hardware you can cram in one box without compromising something. I don't think anyone tries to make an AV receiver with tubes or that they should. But when you go to an outboard amp then you have lots of options.
 

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Quote:
Originally Posted by sharpnine /forum/post/17034099


So you believe that all amps of X watts sound the same?

My experience is that level matched, non clipping amps are decidedly hard to tell apart. No one has done it in front of me blind before, and I have done plenty of testing on myself and others. Tube amps bring some degree of detectability due to the highish output Z and the effect it will have on FR, especially with speakers with complex crossovers and impedances.

Quote:
Originally Posted by sharpnine /forum/post/17034099


You are generalizing that tube amps are not able to provide great enough dynamic range for home theater. Do you believe they provide sufficient range to listen to symphonic recordings? Does a symphony have less dynamic range than a movie?

A well recorded symphonic work can have large dynamic range, but most modern recordings of popular works do not.

Actual measurements of dynamic range. and amplifier power requirements.

Quote:
Originally Posted by sharpnine /forum/post/17034099


I think your opinion may be directed largely to people who are in love with vintage tube gear, and I agree there is more to their feelings than just sound quality comparison. Modern tube gear doesn't tend to inspire the same feelings, and I think generally stands up better in direct comparison with modern solid state gear.

Again, where do you get this from? I haven't stated any specific models or topologies.
Most modern tube amps are slight variations or derivatives on classic topologies, typically Williamson or Mullard.

Quote:
Originally Posted by sharpnine /forum/post/17034099


Upgrading to a separate solid state amp would probably also have been a big improvement, but I would have gone to at least a 250 watt SS amp in that case.

That last statement is 100% presumption on your part, and continues the mythology that tube watts are in some way better/more than SS. It is not true.
Quote:
Originally Posted by sharpnine /forum/post/17034099


I am not denigrating the denon; it is a very good unit with a very transparent preamp section. I think there's a limit to how much hardware you can cram in one box without compromising something. I don't think anyone tries to make an AV receiver with tubes or that they should. But when you go to an outboard amp then you have lots of options.

I don't use the internal amps in receivers.
 

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A recent issue of Audio Express has tried to stir up the tube vs transistor pot again. Lots of quite reasonable to believe subjective comments and the conclusion that points to the problem. Not understanding what the amps do different so we don't know what to measure. I still fall back on David Haflers work comparing input to output. If they are the same, then.... ready for this.... they are the same. Tube amps did not do terribly well in this test. Limited bandwitdh high feedback bi-polars did not do well either.


What do we know? Well, tubes do behave differently when overloaded. Possibly an advantage in low power amps that could be pushed to the limit. Likely where a lot of the bias (sorry) against solid state came from early on. 15W tube vs 15W ss I'' take the tube.


The engineer side of me tells me a well executed ss amp is superior in all ways. My ears still tell me other wise. I can't afford speakers good enough for it to be an issue so I will stick with all my MOSFET well executed amps.
 
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