Warm, tube like sound from a/v Receiver/ Speaker combination for $1500, possible? (1 Viewer)

[Mal P]

G'day Michael,

Some good points indeed. With an 8 watt amp, my speakers (which have a steady impedence curve which rises at the bass - hence relatively easier to drive) can hit 99dB peaks quite well, and even more than that since most amps can handle temporary overloads without much difficulty (the 300B tubes I use can probably hit 12 watts or so for short periods, and even after that when they clip, being tubes, they clip somewhat gently). I listen at an average volume level of 75dB at my listening position, hence leaving me with around 20dB of non-overloaded dynamic range (once taking into account the natural drop-off of volume over distance). I find this to be quite satisfactory, and plenty loud, although it depends on individual taste.

I find (and I know many people feel differently) that the level of accuracy desired in Hi-Fi systems should directly reflect the quality of the recordings one listens to... if one were to listen to pristine recordings from the top labels the majority of the time, then a very neutral setup would benefit the listener quite well. However, I personally listen to some music which is recorded absolutely abysmally... and the accurate system that I had previously grated on my ears to such an extent that I stopped listening to such recordings, despite my enjoyment of the artists. I ended up trying numerous options, including several tube/solid state pre-amps and power-amps. It came down to the little Midwest Audio 300B amp which offered a nice balance between warmth and transparency - with a little bias towards warmth I replaced the gain tubes with some old RCA 1940's types and I'm now very happy with my system, and can listen to hours to all sorts of recordings without any problems and just enjoy the music - I guess that's what an entertaintment system should do.

Cheers,
Mal

 

[Michael R Price]

Mal,

Totally agreed. And something's been telling me that this sort of electronics may have higher measured distortion, but in some ways they really are more accurate - in just plain sounding good! I admire your trying of many different products and tube-rolling and wish I could do more of similar things myself.

A little other question, since you've got experience: Did you find that the dynamics or "liveliness" of the amplifier was related to its power rating? In other words could a small amp like the one you have still be as dynamic as a bigger one? (See, I have this gigantic amplifier that's really strong and fun-sounding. I'm wondering what aspects of the design cause this sort of thing... and if that could still apply to a smaller and cheaper amp.)

 

[Mal P]

G'day Michael,

Anything that strips away the un-natural harshness and grit from many recordings has to be doing something right There are actually some very decent single ended amps out there for good prices... like the Billie kit, at: DIY HiFi Supply That one has been garnering great reviews from users, and appears to be a tweakers paradise.

To your question... yes, absolutely, a low powered amplifier can be just as dynamic in terms of musicality as a big 400w beast - provided you respect its natural limitations. Those limitations have to do with what kind of speaker that can be driven with 8 watts - an 89dB/watt speaker I find to produce music that at good volume levels (say, 80dB as measured on an SPL meter) sounds dynamic, powerful and yet oh so sweet. However, that same amp driving say a 84dB/watt speaker (*cough* Dynaudio) may sound constricted, because for average listening levels, the power usage would be much higher and there would be less room to move.

It's also dependant on the design, since those few watts in single ended tube amps (or even single ended solid state amps!) run in pure class A... there's no crossover distortion/rise time (where the class B stage has to kick in when the class A power runs out) it could be argued single-ended designs have a natural advantage when it comes to dynamics.

I think most folks here would be surprised at how little power they would actually be using to achieve comfortable listening levels for music. For 99% of my listening, I would be using less than a single watt of power - and anyone who listens at levels a bit less than the sensitivity of their speakers would also be doing the same (taking into account fall in volume over distance).


Cheers,
Mal

 

[Scott Oliver]

I agree with Mal, dynamics has nothing to do with wattage, as long as you are matching it with a friendly speaker.

Of course one amp that produces 8 watts for example is not going to necessarily be the same as another 8 watt amp in terms of dynamics. Different circuit implemetations or parts quality, etc. can greatly effect dynamics.

 

[Chu Gai]

hey, let's call it for what it is...it's not stripping away, its putting on perfume for lousy recordings.

 

[RichardHOS]

Exactly what I was thinking.

While second order harmonic distortion might actually sound pleasing, and preferrable by some than the undistorted signal, I'd hardly call that "stipping away."

 

[Brett DiMichele]

The fact is that a tube amp or a solid state amp impart some
distorsion into the signal. There is *NO* perfect amplifier
circuitry any more than there is a perfect speaker.

It all depends on what sounds good to your ears. There are
SS amps out there that sound awesome and they don't even
have to cost 10K per amp to sound smooth either. There are
also many tube amps that are so close to the performance of
SS that they would probably be indistunguishable from the SS
counterpart in a DBX...

It's all in what floats your boat.. I like my SS amps but I
want to play with Tubes. In the long run I may not like them
or I may fall in love with them. It's up to each individual
to make that call.

But any time you add anything to a signal that wasn't there
originaly, then that signal is not accurate it is colored.

 

[Chu Gai]

Hell Brett, I'm not trying to carve a second hole into you! I think one of the interesting aspects of the approach you took is that to a large extent you don't lose the benefits of your current amplification scheme and that you can choose to dial in the amount of 'tube sound' or 'air' or whatever happens to be StereoPhile's favorite adjective for reporting 'objectively'. At least you're not locked into things and you've retained some flexibility.

In this day, with so much emphasis on HT, the idea of perfect takes on very subjective terms with respect to amplification since for many of us it takes into account matters apart from amp itself. However it certainly is quite possible to select from a wide range of products that essentially have 'no' sound and do their job faithfully and unobtrusively. In other words they're accurate. That's not to say that people don't wind up buying the wrong receiver that's either generally underpowered or just can't deliver the goods to the speakers they've got because of the speaker's impedance curves. We see it happen all the time.

Whether tube amps sound better is simply personal preference. There's no argument from me on that. However, as was touched upon a couple of posts above, there is little dispute that SET amps, for example, have a relatively high and frequency dependent output impedance. Because of this, they tend to have different frequency response with different loudspeaker loads. Now they may sound pleasing to your ears, but accurate they most certainly are not and properly considered, they are not high fidelity.

 

[Mal P]

G'day Chu,

I agree absolutely, Single Ended Amplifiers do generally tend to have higher distortion levels in some areas (like even order HD) than amplifiers with different topologies. In some areas, they have a little less distortion (such as the crossover from class A to B power, when compared to most non-SE amps).

Given the right loudspeaker, it should be possible to create an SE amp which would be indistuingishable from a push pull amplifier. In fact, I've heard one (Valvemark Paragon 300B amp - most clean and neutral valve amp I've ever heard). Of course, choice of loudspeakers do tent to become smaller with some Single Ended amps (there are powerful beasties out there though, but perhaps lacking... refinement?).

However, considering that there is such a wide range of music available today, with (ahem) varying degrees of recording quality, most Single Ended tube amps are purchased not for their accuracy to the source, but perhaps what people perceive to be accurate to live music - the 'warming' effect is less noticeable with the best recordings, although a bit of transparency may be lost for the overall balance.

I guess whether it strips away harshness or adds warmth is a matter of view point, and semantics

Cheers,
Mal

 

[Brett DiMichele]

If accuracy was a concern when choosing tube equipment and
to some people it is. Those people have the choice of going
with Hybrid Tube/SS Rigs where the tubes are not utilized
in power stages but rather used more traditionaly in the
line source. You can get the best of both worlds in the
respect that the tubes still impart some coloration, not
nearly as much as a SET 300B based amp would and you also
get the brute SS power loads of it.

Chu,
The Tube Ultra-Q was a very great way for me to test the
waters and it's a device that even when real tube amps are
added, does not become obsolete from the rack. The tubes
can be shut down and the Parametric and Notch/Shelf features
can come in handy for taming room response curves.

I did buy tube amps though and...... They should arrive some
time this week. Kevin Deal from Upscale Audio just called me
today to let me know that my pair of 20 watt Antique Sound
Labs Wave-20's will be drop shipped from the manufacturer
before the end of the week.

To me, the wave's are the perfect way to get into tube
amplification. The Wave 20's are a big step up from the
more afforable Wave 9's but even so the 20's still only set
me back $500.00 for the pair and IMHO that's cheap for tube
gear any way you look at it.

They have specs that compete with tube equipment that costs
4 times more money.. At full power (20W) they produce 3%
Total Harmonic Distorsion and at 1W they produce 1% THD.

Sure those numbers are HUGE compared to SS but we're talking
tubes...

The 20 watt Mono's will drive my Mid's and Tweets.. I may
try them driving the whole HF and LF side of my towers but
I don't know how loud they will go pushing those dual 10"
subs (and I know the impedance curve on those 10's is steep
because my Onkyo 787 would go into Thermal Protect trying
to drive them.. AR says 8Ohm but I bet at FS the 10's most
likely dip into the 2Ohm range...)

Anyway I will let you know what's going on when my Wave20's
get here... And after I carefuly bias all the tubes with my
trusty multi-meter and I get them burned in good!

Ohh yeah.. It's a tube love fest baby!

 

[Chu Gai]

You know Mal, it's a tough call sometimes as to whether the recording was faithful, botched, or we're dealing with rooms that are exascerbating problems, or if we've just chosen the wrong speakers either for our ears or even for our particular room! Mind you I'm a fan of very old, floor standing (those 4 foot jobs), tube radios from years gone by. They're not stereo, but they're nostalgic, and sometimes if you get lucky, you find the ones that pull in shortwave!
I guess maybe it's because of the limited market, but in my opinion, tube products, especially those imported from overseas, are quite overpriced.

 

[Chu Gai]

you might like this link Brett to a ton of more links with regards to tubes. looking forward to hearing about your experiences!
http://www.worldtubeaudio.com/

 

[Michael R Price]

Brett,

1% THD at 1 watt? Heck, that's even worse than my Zen amp (0.1-0.2% at 1 watt and no complaints about the sound). Remember to bias them a little high.

By the way does anyone know what kind of designs are very dynamic even if the amp isn't capable of high power? Just curious... I'm still a little skeptical that an 8 watt amp would sound as strong as a bigger one provided you don't clip it. (And my speakers are anything but friendly.)

 

[Brett DiMichele]

Mike...

I can't believe I put 1% @ 1 W..... Try 0.7% THD @ 1 Watt


Here's the full Manu Specs...

MODEL WAVE AV-20 DT
OUTPUT POWER 20w
Frequency Response at 1W 20Hz--25000Hz + 1dB
Frequency Response at full power 24Hz--25000Hz + 1dB
Distortion at 1W

 

[Brett DiMichele]

Hey Chu,

Thanks for the link! That is like a cornicopia of tube info!
(Wow I said a fitty cent word!)

 

[Chu Gai]

it'll keep your ass out of trouble and your pocket lighter Brett. now just maybe, some website out there is having a group buy on one of the tube amp methodologies out there. usually they wind up buying from overseas (China) and you'll find the prices can by 1/4 or less than what you'd pay retail. One day I'll figure out where those ASL's are coming from.

 

[Brett DiMichele]

Chu,

Somewhere in China..... I'll let you know what it says on
De Box.... But there is a delay :frowning: Kevin called today and
the Pallet of Wave20's is caught up in Canadian Customs,
something about "Foreign Wood in the pallet and crates they
have to hold them (I guess in case they had insects in the
wood.. Who knows..)

But anyway... $500.00 for a pair of 20W Tubes is cheap! I
honestly don't see how much cheaper I could get something
similar, the parts aren't cheap to build them so if they
are making $100-$150.00 profit I would say that's fair..

Take a similar amp and price it at $2K and that's where it
becomes crazy! But I guess when you drop 10K on some of
these amps you are paying for eye candy and artistry as
much as you are for sound... Hell if I was stupidly well to
do I wouldn't mind spending 100-200K on a 2Ch system just
for bragging rights..

 

[Scott Oliver]

Michael, I think you are confusing loudness with dynamics. It is true that more watts will allow you to reach higher loudness levels. But say for example an 8W amp with a friendly speaker is able to give you the loudness levels that are high enough for your listening tastes say 95 dB. Throwing more wattage into the equation will give you higher SPL's say 110dB. But what good is the extra 15dB of headroom if you never use it. That 8W amp operating within its feasible volume level (

 

[DannyL]

Brett, i just purchased the behringer unit. i have two questions. #1 do your analog warmth meters move when dialing up the tube warmth knob? mine do not, but i can hear the increased harmonics when i turn it.

#2 to engage the tubes, the effects switch must be on, but this also engages the high and low band filters; what settings do you use for neutral sound? when i turn everything to zero, there is no bass and the sound is very compressed. thanks.

 

[Brett DiMichele]

Scott,

$998.00 a pair for an amp made in the usa touting those
specs is certainly quite impressive! The only way I could
see beating that would be DIY I don't know of any other
prebuilts with that much power and flexability in that
price range new.


Danny,

The input level for the Tube-Q needs to be real high to
make those VU meters move. I am not sure what they have
the input voltage set at without looking at the manual but
it's a Pro Sound piece and as such seems to need higher
input levels. I had the same problem untill I moved mine
right into the signal chain between the DVD Player and
my Reciever (being used as a Pre). Even though the VU
meters aren't moving much the tubes are working from my
experiance.

As for the EQ Section.. Just enguage the first switch on
the left hand side of the unit for both Channels 1 and 2
and shut all the other switches off and there will be no
filtering applied.

You can use the input gains to boost the input signal
if you are using another device with a gain control like
a Pre for example. Just make sure you don't go too high
with the gain because you can clip the Tube Q (when the
Input lights light up that's exceeding the 18Dbu Headroom).