Inefficient Speakers... Let's talk Tube Power!

I love my big dinasour inefficient speakers. They sound great. I can't leave well enough alone though. Of course I'm looking for the next step in audio bliss. It's time I start talking Tube Power. I wanna use my inefficient 86db monsters. I wanna go Tube. I need suggestions and knowledge.

If you wanna talk about terminology like sensitivity vs inefficient... you should go start a thread somewhere else.

If you (even if your right) wanna talk about small watts and 90db and up efficient speakers… you should go start a thread somewhere else.

Currently I'm verticly bi-amped with two Carver C-500 amps. So at like 3ohm on the woofer and 3 ohm on the mids and tweets, I'm pulling something like 800 plus Change watts a side. It's manly to say that... but I wanna go Tube.

So what's myth and truth? If I were to go to two 100 watt mon blocks like VTL, Rouge or Antique Audio Labs.. would that be enough? Would I have even better sound maybe going with two stereo 50-60 watt per channel tube amps and verticly bi-amping again? Are higher quality 35-50 watt mono blocks really more powerful than inexpensive 100 watt monoblocks? There's lots of opinions out there… who has big obnoxious inefficient speakers and loving them for all their man card carrying lore? Let's hear your journey. Let's hear your triumphs, let's quietly hear of your tears and deep sorrow from paths that crushed your Audio dreams. Spill it.

 

Like to solder? Can follow directions ? I can't recommend my m125s highly enough.

 

I don't think that 86 dB is that inefficient.
50 W might work.

 

I think a modern MC275 would be fine as it actually measures as 90W.

 

If I had the need, I'd be taking a close look at this.
MP-501 V4 KT120 KT150 Tube Amplifier (Refurbished)

 

Not bad… I'd do two and verticle byamp if I went that path.

 

I love the lore of Mac… but out of my price range for sure.

 

Maybe you need that VPI tube amp listed in the classifieds.

 

? ? I think I found the one your mentioning. It's $4000 and about 36 watts a channel. I don't personally think that would drive my speakers. I really don't know it won't… just know more watts with SS made a good difference. $4000 is a little steep for me. I've seen a number of 100 wpc in the $1500-2500 range. But that's kinda what I want to know from this thread. Are better quality 35 wpc tube amps better sounding than inexpensive 100WPC tube mono's?

 

Unless I misunderstood, $4,000 was the original list price. It's listed here as a used item. My experience with tube gear has been limited to Audio Research amps, which seem to be able to drive anything...without necessarily producing 100 watts.

 

VTL and Rogue Audio both make very solid amplifiers and they work well with speakers of only average sensitivity. I'd avoid ASL. Watts are watts = watts, so disregard any mystical chatter about tube power vs solid state power. The amplifier topology does make the amplifiers sound different, but they deliver what they measure, no more.

One thing that you do need to understand is marketing hype by some amp makers. Some claim to do great things, which they are not capable of. Bob Carver did everything but pose in tights and a cape for audio rags back in the day. Not saying that they didn't produce some powerful amps, but I'd take the specs with a grain of salt after reading the fine print and reviewing some independent test results. It shouldn't be so difficult, but some makers have made it that way. Both VTL and Rogue Audio are very straight forward, so no need to translate any marketspeak there.

One note, which you understand, about amplifiers is load reaction. Solid state amplifiers vary their current delivered based upon the load impedance and so the output changes quite a bit with the load in amplifiers that are stable and which have sufficient power supplies. So in a 200w amp at 8 oms, you might see 400w into 4 ohms. That doesn't happen in a tube amplifier as the transformer isolates the speakers direct interaction with the output stage and sets the impedance more or less to a more manageable load for it. So a 100w tube amp will produce about 100w into both 8 ohms and into 4 ohms. Sometimes a bit more or less depending upon the design of the amp, but you basically are not going to get blood from that turnip. All of that may mean very little if you were aware of actual power usage of your speaker system in your room. Just because you have amps that go up to 11, it doesn't mean that they are doing that all the time, or ever really. Let's say that you have a set of 86dbwm speakers and you find that 90 db average peaks is all that you find comfortable listening to without it being so loud as to cause discomfort and concern for your hearing. Let's also say that you can get those levels with a 50w amp. You likely can if your room isn't cavernous and or you sit relatively close to the speakers. So any amp with more than those 50w will simply not be used regarding loudness. You could have a 100w amp or even a 1000w amp, but if you only use 50w, the thing that you need to be concerned with is quality rather than quantity.

Now, amps do behave differently into different loads and the failing of most tube amps vs SS designs is in control of the woofer for lower bass content. When a dynamic passage is present, at volume, and with some decent amount of bass frequencies, your amplifier, regardless of its design, will need to be able to deliver more power into those woofers. It either will be capable of doing so or it will not. That isn't the same as saying that there will not be bass with some amps, assuming they are capable of delivering the bandwidth, it is just that they may not be able to control the woofer cone as tightly as a more powerful amp and the result is a "fat" sounding bass or a "slow" sounding attack to bass drum, etc. Most tube amps will struggle here a bit, so choosing one with enough power at a wide enough bandwidth is important if you want it loud and clean. Both Rogue and VTL amps do a remarkable job of this as far as tube amps go, but they still sound a touch softer than their SS counterparts. The good news is that they have 100w+ models and they also excel at clean, sweet top end which most muscle amps from the SS arena cannot match. So expect some trade-offs but overall I think those two brands will deliver some serious goods to all but the grumpiest of metal fans.
-Bill

 

This is a fantastic and very helpful post. Before I went to the Carver amps, we measured my previous outlaw Audio 755 amp. Now the test may have holes in the way we tested… we used a YouTube clip that plays a sound at different hz. We measured my sealed 12" mains hitting 19hz at 101 db's. I was very impressed. The YouTube clip might not have been accurate? But at any regard my Alons have been over 100 db's with a few different amps. Bryston 4b comes to mind. For all the crap Carver gets, (and maybe it's warranted) they did sound better than the Bryston. They are "different" than the Outlaw. The bass is tighter and quicker, but the upper detail lost something I couldn't put my finger on for quit some time. I really don't have a preference between the two. The pro's and con's just seem to wash each other. I'm looking for something flat better.

 

I vaguely remember hearing Alon speakers a long time ago. They have that big speaker/heavy driver sound that I associate with brands like Legacy and Wilson. I'd definitely look for something well over 100wpc, especially considering what you're coming from. A nice pair of Rogue M180s or Quicksilver V4 should do the trick nicely. Both of those also have 4 and 8 ohm taps that you could play with to see which sounds best to you with your speakers. The Quicksilvers look better to me and you could roll a nice variety of power tubes in them.

 

I am a big fan of BAT. I own VK-75 mono blocks that are bridged so I get 150 watts per channel. It's enough power to drive my Magnepan 1.7i speakers to my limits. At one time I compared the stereo VK-75 to a Parasound 250 watts amp and it was pathetic. The BAT amp was miles ahead in power.

Tim

 

I have had several pairs of Alon speakers come through my shop on trade. The last pair was a set of the Alon V. I tested them with a 50 and a 100w amp as well as a 14w tube amp. Alon recommends something like 400w with that speaker. They have very complex crossovers and so have some large losses there. I don't listen as loud as some people, louder than some others on occasion, but I'd have no trouble getting them as loud as I liked in a 10 x 12 room with a small amp. Bass control and dynamics are more impressive with more power, so going from 14w to 100w tube amp is a big step there. These speakers are also tri-ampable, so no trouble running the bass drivers off a SS amp and the mids and highs from the tube amp if that is what floats your boat. I did this years ago with a difficult set of speaker, PSB Stratus Gold, and it works. It will require an input level control to go in front of the more efficient amplifier to match the levels between amps and drivers. So it also acts as a sort of tone control if you don't already have one. I had some pretty nice stuff go through that system and eventually found that as beneficial as each amp type was in its role, I preferred one great amp run full range to two or three run into various drivers. That got expensive. The funny thing was that most all of the time, the attenuator had to be run in front of the tube amp, even when the tube amp was only 30wpc and the LF amp was 100w. So I had to turn down the tube amp and run the SS amp full on. The difference is not that tube watts are more powerful, it is that the tube amp would produce a watt of output with a fraction of a volt of input, where the SS amp required a full volt or thereabouts. It came down to the input sensitivity of the amplifiers, not the output wattage. For another relevant footnote, consider that I rarely ever had my preamp volume control set beyond 12 o'clock when listening, so I was never "running out of juice" with any amplifier power combination. It was all done in pursuit of quality of sound, most notably soundstage depth of the mids and highs, and the control of bass frequencies. I have different speakers now but still use a single power amplifier. I can choose from several amps as my speakers require less heroic efforts.
-Bill

 

My room is large and open. The ceiling is very busy. In this drawing you can see (from the main seating position) the right over head ceiling slopes down. Just behind is a curved dropped open ceiling at 8' high. It's not the greatest sound area. In fact all you see in this pic is really one giant open room.

 

The Jolida 1000BRC is a nice option if you like EL34 amps. It puts out 100 watts at 8 ohms, and it's pretty cheap on the used market. About $1400. Some people are off-put by the Chinese origin and the PCB construction.

 

I drove my older Energy CF-30 towers (86dB) easily with my Raven Audio Blackhawk (20wpc). Easily! (I've recently updated them with wonderful Legacy Audio Signature SEs, however.) You will love tubes if its a Raven Audio system. Guaranteed.

 

Thread reminds me i should just curb my Dahlquist DQ-10's. They've been collecting dust in the spare room for yonks now.

 

Good Lord... That's an acoustical abyss. I think I'd get another subwoofer for starters. Then try biamping the Alon woofer with the Carver in place along with a tube power amp for the mid and high portion of the speakers. Listen to that a while, then if it's a knock-out, I'd try the tube amp full range on the Alons to see if integration is better or if the Carver adding better control to the woofer has no side effects of biamping such as a lack of seamless driver integration. In either arrangement I find it hard to imagine that you'd prefer the Carver amps to the tube amp. This is assuming that you listen only in stereo when listening to music. Using the full surround system with various speaker types, amplifier types, and speaker locations can nix pretty much any attempt at better stereo performance. Having a top flight pre amp / processor is important here. If you don't have that, you might benefit more from a true stereo tube preamp with HT bypass function.
-Bill

 

If you can get away with 50 watts per channel you might want to consider this amplifier with a bunch of options - it can be purchased as a kit of built for you. At $1250 it is pretty reasonable looking. Though tubes are extra.

Grant Fidelity importing Japanese Eleket
Japanese Eleket TU-8340VK Integrated Tube Amplifier (Kit or Assembled)

If you want a little bit of bling with your tube amp - these Consonance Monoblocks are 100 watts per channel and $3400 - Grant Fidelity is the importer. Tube are extra.

Consonance Cyber 800 MKII Tube Power Amplifiers (pair)

 

I can't see the pictures at work but gather from the comments that you are filling a large room. If these are your speakers then you may have issues trying to control the woofers in a large room, at volume, with a tube amp.

The long impedance dip in the upper bass also shares a bit of phase shift that can make a somewhat difficult load. I don't think it's that bad but it isn't exactly tube friendly. I'd suggest a tube amp with some power, 100 watts or more, and something with 4/6/8 ohm taps for experimentation. 4 ohms might get it done but 6 might sound more dynamic and pleasing. If the amp didn't have a 6 ohm tap I'd always be wondering what if....

 

That's them. I have never seen this doc before. It's fascinating. My wee mind is trying to absorbe what its being fed. (Gotta imagine a 6'5" tall Harley Rider with his lips moving as he reads this doc)

 

Thanks again for the response. I listen to stereo 80% of the time. My two channel is now separate from my theater. You note the room shows my Atmos theater powered by a Marantz SR6011 for the four immersive speakers and the Old Outlaw Audio 755 powering the LCR, and surrounds from the Marantz pre. (These too are Alon Centris series speakers)

Two Channel is the Alon 4's, the Two Carvers and a Yaqin tube preamp. Source is my Roksan Radius 5.2 table and AT33SA cart.

The little Yaqin tube pre can be improved on. But its pretty good. I did a heads up agains a Audio Research tube pre and a Macintosh SS pre using several mid series Wilson Audio and Sonus Fabre Speakers. That little Yaqin actually sounded best with all the speakers we used. I tried it with an RP9 and a old heavy Sony CD player at the shop. So all in all even though there are probably better preamps, the Yaqin is pretty decent.

I have been looking at several of the Marantz 7 clones and a few pas3 pres.

 

I used an Audio-Research VT-100 to power a pair of Magnepan MMGs, very inefficient speakers, The 100 watts was very usable. I never felt like I needed more power. The price of tubes took me back to solid state.