Tube Pre-amp (1 Viewer)

[Kevin_R_H]

Brett,

I fully admit my monoblocks are not "run of the mill", and that most tube amps don't have this kind of "oomph". They are 100W Triode Pure Class A Push Pull. Between the 2 mono amps, there are 16 output tubes, 8 input tubes, and 4 driver tubes.

Unfortunately, I also have to admit they cost more than $1,000.

Kevin

 

[Jonathan T]

Has anyone ever heard the amp I linked to? It won't be driving anything under 80hz. You think it will be able to put out that punchy, tight bass?

 

[LanceJ]

If I remember correctly, they were comparing the tube amp's bass to the SS amp's bass--they never said the tube's bass sounded truly bad. Another IIRC (doesn't anybody have that issue?): the tube components were from Conrad-Johnson and the SS was from Krell--both very highly regarded manufacturers.

And I've seen similar comments over the past 20+ years I've been in this hobby.

I'll admit to liking the tube concept myself: airless, hot glass bulbs with mysterious black plates and red glowing filaments working together to amplify tiny signals, finally to be sent off to operate a loudspeaker--cool. Transistors just sit there, seemingly lifeless (well, not my Technics' transistors--my receiver would make a great coffee warmer!). I guess you could say solid state just isn't as "fun" as tubes are.

LJ

 

[Scott Oliver]

There is much more going for tubes then looking pretty and being "fun".

You guys are generalizing way too much about tubes especially if you only have experience with tube amps under $1000. Considering there are only like 10-20 tube amps made that retail for under $1000 and there is probably 1000+ models of tube amps out there, I think you should keep listening further up the food chain before drawing conclusions.

I added a ~$5000 tube amp to my rig about a year ago and was able to listen to it and my previous Bryston 5B-ST back to back. I would be surprised if anyone could listen to them and pick the Bryston over the tube amp, in any category. I certainly would be amazed if someone commented that the Bryston sounded more real because it has less distortion, or the tube amp makes happy waves but can't do bass.

The Bryston had all the details and was very clean and transparent sounding, but in comparison the tube amp has everything the Bryston had but everything sounds more real, more you are there. Listening to the Bryston and just about every other SS amp I have heard I never been fooled into believeing that I wasn't listening to a stereo system. Tubes have added those little nuances. But again this is too much of a blanket statement, not all tube amps have had this effect on my ears. My Art Audio Concerto MK2 amp has, the Air Tight ATM-2 amp has, but ASL Wave 8's have not, Audio Research VS-55 amp has not, and the Rogue Audio Stereo 88 amp has not. YMMV

 

[Scott Oliver]

Jonathan as to experience with the Ella, I would do some searches in the Tube and Amp/Pre Forums at Audio Asylum. There are some folks who own the amp over there and perhaps you could send them an email if you can't find enough information to suit you throught the searches.

As for the the bass crossover, I would certainly encourage you to run the speakers full-range (at least to test it) if you do get the Ella and the Ellis speakers. Most of the folks who I have seen owning the Ellis speakers are using tube amps, so I think you are worrying a little too much about the bass. 40 watts is a good amount of power.

 

[Jonathan T]

Scott, if I do the the Ella, I'll break it in full range. But the reason why I want to use a sub is casue I listen to a wide range of music, some of it is very bass heavy (some reggae for example). I'll probably end up using some ported HE10.1s or some sealed HE12.1s. 40 watts is plenty of power, but can the speakers handle it?

About the discussion in this thread, most of what is being here is over my head. I can't make a conclusion about SS vs. tube amps based on what is being said here, there are so many point of views.

 

[Jonathan T]

I went over to the Audio Asylum forums and the general consensis over there is that the Ella is a great amp. One person said "Supposed tube characteristics of rolled off highs and lacking low bass are not at all found here". And that was with a stock amp. Furthermore, many people have said that with upgraded tubes, the bass becomes even more punchy, yet smooth when needed and extendes low.

Edit: DIYcable.com sells the ELla and other DIY HiFi Supply products. Sale price isn't as cheep as straight from the manufacture.

Edit again: shipping is included in teh price!!!

 

[Scott Oliver]

Oh also if one wants to throw out some musicians as a defense for tubes vs. SS then you should read this review:

Interview with Stereo Lab's Tim Gane - EnjoyTheMusic.com

 

[Michael R Price]

What if you could have a solid state amp or preamp that would have the usual solid-state attributes (dynamics, bass, etc) except with the smoother and "musical" sound of tubes? Or, actually, a tube amp with the good solid-state characteristics (though that's less likely)?

 

[Chu Gai]

I'm not arguing preferences Scott, simply pointing out some behaviour characteristics of many tube amps with perhaps the premier poster child being the SET amp. I can't comment on what your Audio Concerto is doing. For starters even the manufacturer's website says something like "Spec's coming soon". Offhand, that's a little disturbing, selling a product and you don't have the information readily at hand. I'll be looking for it though. It's helpful, to me at least, to keep in mind that the poster has a limited, although not trivial (relative word I know) to him, funds to direct towards 'something'.

Accurate to me is not an Orwellian double speak word. I can live with what dictionary.com had: Conforming exactly to fact; errorless.

To me that mean I expect my amp to magnify the signals I give it. If I want, as a matter of preference, to process the signal, then I expect it to magnify that processed signal. Processed can mean equalized or modified in some general way. However this is someting I want control of.

I'm sure you looked at a number of tube amps Scott and settled upon what I surmise is the Concerto. Now the little I could get on that amp indicates it supposedly utilizes no negative feedback. Without debating the merits of such an approach, in a tube amp this generally means the output impedance of the amp is not vanishingly small as one would find in your solid state amp. If that's the case, the output of the amplifier will interact in a way that follows the countours of your speaker impedance plot. So look the speaker's impedance curve. The amp's output is being equalized, but not in a way that a typical equalizer would perform. Certain areas are being boosted, certain are being attenuated. It's more than a bit of a stretch to call that accurate but I'll grant you that it's musical.

Now you talk about capturing the essence of a live performance. Well people like sitting in a variety of spots. Some like it up close to the performance where they can pick out different instruments being played with localization and spacial cues. Others prefer to sit back and have it all blend in somewhat. No one person is more right than another. But is it the live performance in a concert hall, a stadium, a small concert hall, your local club, bar, or VFW? A live performance includes far more than the music. There's the ambiance, the uniqueness, the visual aspect, etc. Catching Hendrix at The Filmore East, or Bowie at Madison Square Garden doing the Spiders from Mars wasn't the greatest acoustics for sure. Live yes and something to tell your kids.

As to whether this live performance thing is best captured by tubes, processing, a judicious choice of speakers coupled with great effort in shaping the room acoustics is debateable. IMHO I favor the latter approaches.

I temper the link you provided with the group's comments regarding cabling and other matters. Frankly musically, I don't care what they use. Whatever works for them. Through it all though, all it takes is a stupid-ass recording engineer to mess things up. BTW, I like a lot of the ambient and experimentalist stuff.

As far as mimicking tubes, Carver plays with it. And if you want to spend a few dollars of your own and you still have the Brystons, you can also by utilizing resistors and/or diodes between the speakers and the amp.

 

[Scott Oliver]

"As to whether this live performance thing is best captured by tubes, processing, a judicious choice of speakers coupled with great effort in shaping the room acoustics is debateable. IMHO I favor the latter approaches. "

Chu, I agree all of these play a very important role in a system's sound, all I am saying that if you changed the tubes variable with solid-state, then I personally haven't heard a SS amp that captures the little nuances of the real thing like some of the better tube amps can. Not saying it can't be done, but just haven't heard such a SS amp yet, and that includes all the usual culprits of SS amp brands thrown around on this forum.

 

[Brett DiMichele]

Scott,

And I am sure your preference for tubes plays no part in
that either?

It's a shame we have to walk around on pins and needles
because if we say anything to the contrary of what someone
else thinks they get all upset over it.

Just because I say tubes change the sound you automaticaly
assume I refer to roll off. I got news for you, you don't
have to spend 9 grand on a tube amp to get one that WILL
play the entire audible spectrum.

My Wave 20's do 20Hz to 20Khz with no problem. The problem
lies in the output power. No 20 watt amp is going to drive
my full array of drivers in my mains (4 mids 2 tweeters and
2 10" subs) a good 100 Watt would do it (that's where the
big money comes into play, you pay for power). But when I
say tubes change the sound I am not making a blanket statement.

Lee backs it up as do most others by saying Tubes get the
midrange "right". Well how are we to know what right is? All
we know is that we prefer the sound of midrange as produced
by tube amplification. That's not to say it's right or wrong
because there IS NO such thing. It's just what you, Lee or
anyone else prefers.

 

[Brett DiMichele]

To further elaborate...

I don't think "Tubes" inherently have bass bass performance
but the power issues are the main problem. Sure there are
some cheaper tube amps that can't do down to 20Hz but they
are not the majority. But any amp that only puts out 9,10,
40 watts is going to have a hard time running a full range
signal properly unless you have a 100+ Db efficient speaker
design (Transmission Line, Line Array etc) any speaker that
uses real large drivers for the low frequency just is not
going to work with most tiny tube amps. But you don't have
to drop 9K on some 14 tube beauty to drive them either.

There are always the hybrid choices, tube sound with the guts
of S.S so you get the best of both worlds. Semi affordable,
lots of power and great sound. (Of course you may debate
that it's great sound.. But again that's just a preference.)

 

[Chu Gai]

You know guys, I'm almost surprised that we haven't seen products come out that model various tube characteristics and interface with solid state units. In the pro world, there's a host of products out there, where a person with a solid state amp and an electric guitar can literally choose from dozens of 'classic' tube amps, guitar sounds, etc. and create hundreds of others. Now granted such an approach to a tube purist is an anathema but it sure is pragmatic. I'll have to take a look at my son's unit to see what could be done with it.

I still say we shoot the recording engineers. Let's string em up with Cardas cables.

 

[Brett DiMichele]

LOL about the engineers!

Nah don't use Cardas Cable.. I'd use TaraLabs TheOne.. It's
stronger... Plus it has pretty carbon fiber accents!

 

[Lee Scoggins]

Nah don't use Cardas Cable

I agree. I use their Golden Reference and it sounds too good to use for this purpose. Use Moster Cable instead.

 

[Lee Scoggins]

Or, actually, a tube amp with the good solid-state characteristics (though that's less likely)?

Michael, not only is it not unlikely, it is common among most High End designers today. All the current offerings from ARC, C-J, BAT, and Lamm have great bass characteristics and are fast like transistors but also have the more accurate mids and highs of a good tube amp. Technology has marched forward just like in PCs - better design, better parts, better mfg processes, etc.

You don't have to sacrifice anything to have a tube amp - in fact you gain a lot.

 

[Chu Gai]

Ohhhhhhhhhhh.....Lee!!!
Monster's gonna sue your ass for using their name in vain!

It's so hard to find specs on tube products. Since the Audio Research is a relatively low negative feedback unit, let's assume a DF of about 16. Since it's typically specified by the ratio of a nominal speaker impedance of 8 divided by the amps output impedance we have DF =16= 8/amp. So a rough guess on the AR's you've got suggest an output impedance of approximately 0.5 ohm. Not large but not small enough to have no effect on the signal being fed the speaker.

Now your 1.6's have a nominal impedance of 4 ohms and while the estimated output impedance of the AR's doesn't rival that of some SET's where values of 2 ohm are not unknown, it's still an audible factor.

Let's consider Stereophiles review of the 1.6 where they determine the 1.6's electrical impedance by clicking here. Consider Figure 1. We've got a broad impedance rise starting around 200 Hz and extending to about 2kHz. I'll grant you that your AR has neglible distortion and if audible would be subtle at best. However when you consider the output impdeance of your amp is not vanishingly small and hence interacts with the impdance of your 1.6's, then what we have is a boost in the region between 200 Hz and 2 kHz centered at about 500 Hz. This is the area I think you called midbass. It certainly encompasses part of the midrange too. I'd hazzard to say Lee, that you could get a similar effect using a parametric equalizer and varying the Q around a bit.

Now you can accomplish this musical warmth or presence using tubes or you can use other approaches.

 

[Michael R Price]

Hehe, Lee, I was thinking of Pass amps (A and XA series, I think you were talking about the X amps's bass) in particular when I mentioned more tubelike SS amps. I have a small, more primitive DIY one.

Since you mentioned it... What kind of damping factor do those more advanced tube amps have? What's the THD like at 1 watt?

 

[Chu Gai]

Those are hard specs to find Michael, at least the DF. As a general rule, I'd surmise the DF goes down as the amount of negative feedback goes down. Given that NF is like garlic to vampiric audiophiles, likely they'd be willing to accept more coloration for it's elimination as a matter of preferance.