Tube Amps With Good Bass Qualities


I have been reading over posts about tube amps and their bass qualities. I understand that for the most part, that a ss amp with have an edge in bass qualities compared to a tubed amp. Damping factor, etc. But I can give up a little of that edge for what I enjoy in the midrange qualities of a tubed amp. So my question is, what tube power amps have you heard that have good bass qualities?  Raven, Quicksilver, Mac, etc.?   Let's give a price point. 5K or under. What do you think?
jwlaff
Thank you, I have kind of the same experience, not using the WE+ but the CV-181-TII (Shuguang BT) very decent tube, comparable to the Psvane, the Psvane is prone to failure IME, and very similar to the BT. Like you RCA and Raytheon NOS 40's and 50's produce good results, I have short bottle Sylvanias not bad boys but same plate if I remember correctly these are 6SN7W and sound is good too. The standard chrome top from Sylvania I agree produces some sparkle (I thought it was just me as most people like the chrome tops). If Ralph could have made the M60 and MA1 with the driver tubes sockets a little more spread you could use the boutique chinese in every position, that will mean possible re design the chassis of course
@luisma31, I've stuck with the SED winged C power tubes.  I haven't seen anything likely to be better for any kind of reasonable cost.  I've done a good bit of tube rolling on the 6SN7s, using a few NOS RCA, Sylvania, and GE tubes, as well as a few different current production brands.  Right now, I have a Shuguang WE+ at the position requiring the GTA/GTB tube.  I've tried other tubes in that position, including various NOS RCAs, Sylvanias, and a GE GTA, and I like the Shuguang WE + best.  It is a very large tube, and it will only fit in the isolated front position because of its size.   In the rear positions not requiring a GTA/GTB tube, the best I've found in the rear middle is a NOS Sylvania Bad Boy.  Every other tube I have tried in that position results in decreased dynamics and top end sparkle.  For the rear row right and left tubes, I really liked the early 50's NOS RCA grey glass.  I recently picked up one of the new Sophia Blue Glass tubes and rolled that into the rear right position.  I really like that tube, and I am thinking about getting another pair for the left rear position.  Those are very nice tubes!  Sweet and smooth.  I don't know how the various tube locations in the M-60s (MK 3.3) correspond to the MA-1 amps.   I'm curious about your experience with the 6SN7s.
@brownsfan
Another vote for Atman-Sphere

I completely agree, and I will also add that most speakers with  drivers presenting a 8/10 ohms load (or more) "nominal" will provide good bass qualities for most tube amps, that's the "happy match" you mentioned. I have MA-1's and love the sound. BTW which "right tube complement" you have (power and driver tubes)




Another vote for Atman-Sphere.  I have the M-60s with the upgraded power supply driving speakers that are basically 10 Ohms (minimum is about 8, I think), and the bass is deep and articulate.   I couldn't be happier.  But as has been well articulated above, you have to have a happy match between speaker and amp.   If you don't get this right you are going to have issues.  BTW, these amps are gems from top to bottom.  Get the right tube complement and these amps sing like angels.
Manley Mahi Mahi mono blocks.  These are scary good providing a solid foundation for bass.  They are very quick with EL 84 tubes and get the midrange right.  These blast away so many stereotypes falsely attributed to tube amplification.
Agreed on the Line Magnetic. The LM-805ia - which has replaced the 508ia but with similar specs - lists for the OP's 5k price point and has a negative feedback control with 4 positions.
Line Magnetic, absolutely insane performance for the money. LM 518ia is long time Stereophile class A integrated and the LM 508ia has even more oomph and more dynamic.
The M-125 has excellent mid-bass. I roll mine off ≈88Hz, so can't comment on the low bass. Square wave is very good, so I'd imagine the low bass is fine.

As built by VTA, the M-125's were very noisy, but can be quietened quite a bit. In my case, almost 40db.

Complete instructions:
http://ielogical.com/Audio/VTA_M-125.php
We had an "amp try out fest" one Sunday a while back at friends house that had a pair of JBL Synthesis 1400 Array's,
https://www.stereophile.com/content/jbl-synthesis-1400-array-bg-loudspeaker-measurements
His mate came over also with his OTL 60watters
**Any** 60 watt OTL will be uncomfortable with a load like that (see JA's comments in the review at the link). This is a great example of how *not* to do it- you always want a tube amp to play loads for which it is intended!
By the way what are the woofer's in your speakers? Are your enclosures vented?
Yes. The drivers are dual TAD 1602s (Fo of 21Hz), one forward firing and the other downfiring. Flat to 20Hz is no problem at all :)
how to match a tube amp to a speaker, is one to find what the lowest dip in the speaker measurement and make sure the amp can over come that dip rather easily ? 
@oem-wheels   In a nutshell, yes.

br3098, that’s flat out wrong. If the speakers can handle < 40hz but the amp can’t, then you’ll never hear it from the speakers

Gfi’s suggestion sounds good; a pair of Shitt class A amps (~$1600), however, class A runs hot, burns a lot of electricity...

I have owned fully balanced all tube systems and good though they were, plumbing the depths was a weakness, which is why people use them on highs and mids and SS for bass. In fairness to Ralph/atmosphere, I never had the pleasure

However, I recently purchased a EVS 1200 (600 wpc) from Ric Schultz/tweakaudio. (I know what you’re thinking, but my current and future speakers are 93-96dB efficient.) It’s only got about 100 playing hours on it, but it has that inner musical detail magic that for the most part HAS BEEN the domain/allure of tube amps, but it also has gorgeous mids, lower mids and excellent bass; more bass then my speakers can project with a low end of 42Hz. I have new speakers on their way which will resolve that

It’s fairly priced at $2200, idles 24/7 at 57watts, and likely sets a new benchmark for price/performance under $3K, although... (cliff hanger)

The EVS 1200 comes with a 30 day guarantee, so nothing to lose. Mine’s not going back

Right @stfoth, the SVT. For reproducing bass, a second for the RM-200 Mk.2. I didn't want to be the first ;-) .
I guess a better way to ask my question above..... how to match a tube amp to a speaker, is one to find what the lowest dip in the speaker measurement and make sure the amp can over come that dip rather easily ? 
VAC.  Years ago, I heard a pair of the early PA-90 monos producing prodigious, authoritarian bass from Apogee Stages, which didn't make a lot of sense, but made me a VAC believer.  PA-90'S can be had for around $2200 a pair.
Yes Ralph, I remember my father's Bozak B302A's driven by a ST70 they had loads of bass. By the way what are the woofer's in your speakers? Are your enclosures vented?
Couldn't one argue that the better set-up if a tube amp is preferred, would be speakers that have powered bass drivers with a tube amp for the mids/highs? Or as an alternative, bi-amping with either a SS or class D amp for the bass. This is not a reply to the OP but merely what came to mind while reading this thread which (thanks to all) I found very informative.
jwlaff OP

I believe one may get good bass from this tube poweramp "Music Reference RM-200 Mk.II" power amplifier with speakers that have low impedance’s, using the purpose made for the job 2ohm transformer speaker output tap.

But as with most tube poweramps the lower the output tap used, the less wattage is available, so this needs to be taken into consideration.
A classic match would be Wilsons they are very low in impedance 2ohms usually in the bass yet quite high in efficiency 98db! so could be a good match for the this amp on the 2ohm tap.

Cheers George
everything to do with how well the amp can drive the speaker.

And a "leviathan" (as gavman stated) solid state amp will drive far more variety of differing speaker loads than tubes can, especially speakers with low impedance, and - phase angle, as this makes the low impedance much worse as seen by the amp. 

We had an "amp try out fest" one Sunday a while back at friends house that had a pair of  JBL Synthesis 1400 Array's,
https://www.stereophile.com/content/jbl-synthesis-1400-array-bg-loudspeaker-measurements
His mate came over also with his OTL 60watters, they ran out of steam abruptly on bass dynamics at anything slightly above normal/low volume they were nice up till that, but it wasn't nice when it did, and the amps were fine, adjusted to spec and tubes just 4 months old.
 
Post removed 
So how many tube watts does one need to drive a 3 way speaker with a flat frequency response rated at a minimum of 50W and can go down to about 33hz ?
all you have to do is play
Paula Cole -  Tiger

Sheesh. I can play that thing and it shakes the building. Easy. Just design the amp so it can't drain the power supply. Its not that hard- and its not rocket science.

Yeah- I can feel my guts moving, and the cuffs of my pants. It has nothing to do with tubes or transistors and everything to do with how well the amp can drive the speaker.
 but the weight of the sustain doesn't match what a solid state leviathon can do.

This is so correct, all you have to do is play some sustained organ or similar to immediately hear the difference, and not just on subs, but on inefficient hard to drive floor standers too, and the winner is the one that tries to rearrange your innards.

Cheers George
From the perspective of someone who listens to a lot of electronica, i have yet to hear a valve amp that can bring the fear factor in the sub bass.
I listen to a lot of electronia too. I started in 1972 when I heard Tangerine Dream on the local radio station! Since then ambient and electronia has always been an important part of my LP collection. Infinity Project put out an amazing LP called 'Mystical Experiences' that has some nice bass tracks, the second LP by Global Communication is great in that department and of course the usual suspects like Massive Attack, Future Sound of London, Forest Swords and so on- I'm always in search of the next best bass drop (but with some substance in the music, not just 'unce unce unce unce' for an entire record side...
My speakers go to 20 Hz no worries- and I've yet to hear a solid state amp that makes the bass as well. So much has to do with the amplifier/speaker interface though as I pointed out above. If you want a tube amp to play bass properly, then it should not be put at a disadvantage! A lot of people seem to want to make a tube amp fall flat on its face by subjecting it to a load for which it was never intended. This IMO is simply a waste of time and money- you want a tube amp to play bass then make sure you've done everything to allow it to do so and you will be rewarded.
From the perspective of someone who listens to a lot of electronica,  i have yet to hear a valve amp that can bring the fear factor in the sub bass. 
To my ears valves sound superior on acoustic bass instruments,  one tends to hear the leading edge with more definition, but the weight of the sustain doesn't match what a solid state leviathon can do. If you want your domestic system to do an impersonation of a superior stadium or club pa, ime you need solid state amps driving the subwoofers
Having said that, some of the most pumping reggae sound systems use(d) home made valve bass amps, and their bass was a force of naturr, redefining what bass meant, but undoubtedly those run primarily at higher frequencies than the sub bass in deep house, drum and bass etc
miostyn  I got lost with the subwoofer reference and tube amps.  The OP made no reference to that.  I've owned several subwoofers, mostly JL and of course all are solid state amplifier driven.  To your point of driving subs with tube amps you are correct.  But who does that?

The OP query references bass qualities of vacuum tube vs SS.  I own Sugden Class A solid state and Manley Mahi Mahi mono blocks.  The Sugden may have an edge with quickness, but the Manley mono blocks are musically more palpable and are not to be messed with.

To the OP, try the Mahi Mahi or the Snappers and be amazed.
+1 On Primaluna Especially the HP (they also have a sub out tap)

Found Atmosphere's response fascinating. 

If I understand correctly that you have Klipsch Heresy’s w/ a frequency response of 58-20,000 Hz..then a sub couldn't hurt. 

I run a small sub (many to find used) and wow. With a PL too under 5K. 


Bob, the smiley face was to indicate that I was kidding. I was simply responding to his comment about not wanting to mention other manufacturers who he seemed to think were inadequate to some degree. Ralph does not need to make any enemy's in this business and remaining politically appropriate is important especially where humans are concerned. IMHO they are vicious animals. Lighten up!
@mijosyn,
From what I read, I did not find Ralph extolling his amps, but only providing an overview about what happens and why.

Even with the smiley emoji, I think it not fair. 
Especially so when there are other dealers on Audiogon who would be much more blatant.
My 2+ cents...
bob
Thanx Ralph,
I think you just want them to recommend your amps:)))
I hear you about the financial aspects of the audio business. Not any different from any other consumer oriented activity. I include medicine in that category.
Atma-Sphere amps are expensive because a human has to sit at a bench with 13 rolls of colored wire and a soldering iron hooking up one wire at a time on an awful number of tube sockets. There are no circuit boards, another profit increasing approach. I would rather support an American worker than a Taiwanese robot. There are many solid state amps of similar power that cost a lot more although the MA-3 is seriously up there. (twice as many tube sockets)  
While the Atmasphere OTL Amps with the right speakers trump almost everything out there, I recently have been subjectively amazed by the VTA ST70 I put together, in terms of soul massaging bass, for a small fraction of the above price.
Yes that's for sure also, the main one though is the amp, it has to control the speakers movements, wild and varying loads, high and low impedances, and not be upset by any back emf from the speaker either.
None of this is a requirement to getting good neutral bass. This is not to say that the relationship between the amp and speaker isn't important, but its a simple fact that no speaker needs a great deal of damping, and many don't need much at all. What's more important is to make sure the amp isn't struggling to drive the speaker!
So why do you think so many manufacturers make low impedance loudspeakers? 16 ohm speakers are a rarity. With ESLs you don't have much choice and they all pretty much do the same thing as capacitive loads. But, dynamic speakers could be designed with higher impedance. Maybe it is a marketing problem?
I was looking at specs and I noted the ARC Ref 750 had a slew rate of 20 volts/msec. Your amp is 600 volts/msec. Why is yours so much faster and how does that effect the sound.
Next silly question. If you were using two 8 ohm drivers in a subwoofer would you hook them up parallel for 4 ohms or series for 16 ohms and why?
@mijostyn Quite simply the market is dominated by solid state amps. Four ohms is often used to make the speaker seem a little easier to drive (higher 'sensitivity'). But if you do the math you find out very quickly that sensitivity and efficiency are two different things- and with tubes, efficiency is a far more important spec. This is because compared to solid state, tube power is expensive. So you need to make the best use of it that you can. In the old days speaker designers did exactly that- that is why older speakers are often 16 ohms and usually more efficient.

(A side note, more efficient speakers are more expensive to build, in some cases by a factor of 10 (the woofers in my speakers cost about $2000 each on that account) so by going to lower efficiency a speaker manufacture can make more money. I'm of the opinion that chasing the almighty dollar has a lot to do with so many 4 ohm speakers out there. Quite often when changes happen in audio, **its not so much for performance as it is profit.** To give you some examples: when the industry went from field coils to permanent magnets it was fueled by cost savings; from tubes to transistors it was the same (no output transformer, no filament circuit); from high efficiency to low efficiency (if the amp manufacturers were able to make that much more money, why shouldn't the speaker manufacturers), from analog to digital (everything about digital is less expensive than analog from recording to playback)...)


While ESLs are indeed capacitive but unless they are self powered like some of the old Acoustats, they all have a matching transformer which steps up the voltage from the amp to drive the panels themselves. So the designer of the ESL can set the turns ratio and thus the impedance range of the speaker. This is how Martin Logan gets 4 ohms in the bass while a Sound Lab is 30 ohms.


We get the speed in the output section from having no output transformer. As a result, the output section has a lot of bandwidth- it can go up to 30MHz no problem (many years ago when we first noticed how high the bandwidth was, we tried using it with a CB radio to see if it would boost the output of the walkie talkie and the amp was easily able to do it)! So we limit the bandwidth in the voltage amplifier section mostly to prevent damage to tweeters from RFI.

If it were me, I would put two woofers in series rather than parallel (they will act the same way in the box regardless) because I would want the speaker to make the most of the tube amp connected to them that they can. I've heard many people say the amp can't control the woofers as well this way but that's poppycock- what's really happening is solid state amps make less power into 16 ohms (half of what they will do into 8 ohms). Now you can't get away with this if the woofers are dissimilar- they will tend to color each other. But if they are identical woofers this works quite well. I've heard a good number of speakers that are wired this way and they work great.


Now here's an interesting tidbit about that- when you wire the speakers in parallel the sensitivity goes up by 3dB as opposed to a single 8 ohm driver. When you wire them in series the sensitivity goes **down** by 3dB, meaning that the 16 ohm version is 6dB lower sensitivity than the 4 ohm version! But the actual efficiency in either array, or with just a single woofer is **exactly the same.** This is really confusing not just for regular people but also for speaker designers. I've run into many that think the efficiency goes up when a pair of speakers are put in parallel. But what is happening there is that they are confusing 'sensitivity' (2.83 volts at 1 meter) with efficiency (1 watt/1 meter). At 8 ohms the two are the same; into 4 ohms 2.83 volts works out to 2 watts hence the 3 dB increase; into 16 ohms 2.83 volts is 1/2 watt, hence the 3dB decrease. But if you apply 1 watt to the array whether its 4, 8 or 16 ohms if the woofers used are all the same the way it works out into 4 ohms (with 1 watt, not 2.83 volts) is 1/2 watt is dissipated by each driver and the same is true at 16 ohms, or if a single driver is used and 8 ohms it dissipates the entire watt.


There are a lot of designers that don't get this bit! I'd point one or two out to you but I really don't want them mad at me :)
Thanx Ralph. So why do you think so many manufacturers make low impedance loudspeakers? 16 ohm speakers are a rarity. With ESLs you don't have much choice and they all pretty much do the same thing as capacitive loads. But, dynamic speakers could be designed with higher impedance. Maybe it is a marketing problem? 
I was looking at specs and I noted the ARC Ref 750 had a slew rate of 20 volts/msec. Your amp is 600 volts/msec. Why is yours so much faster and how does that effect the sound. 
Next silly question. If you were using two 8 ohm drivers in a subwoofer would you hook them up parallel for 4 ohms or series for 16 ohms and why?
check out decware.com - made in Ill - excellent amps, preamps and speakers. Your speakers MUST match your amp though. I have a small 2W/ch Decware amp with 98db speakers. They sound awesome - at least to me.
Interesting that there has been no mention of power, power cables, and isolation solutions.
Even improving the source can make the amp and therefore the speakers sound better.
Yes that's for sure also, the main one though is the amp, it has to control the speakers movements, wild and varying loads, high and low impedances, and not be upset by any back emf from the speaker either.

Cheers George  
@georgehifi I didn't see your post just before mine covering the same thing. Hate when that happens. Even improving the source can make the amp and therefore the speakers sound better.
Thank you all for your input, George, Ralph, and everyone else. I've always enjoyed the sound of tube amps, but have found the bass a little "lacking, tubby, soft". But for this shortcoming, tube amps have a sound that I really enjoy. All of these posts have been very informative. I will continue to research and look at the reviews of the suggestions that people have made. I understand that it all comes down to matching an amp with the speakers. I just wanted to get a general idea of what tube amps would deliver acceptable bass. Thanks again for all the input from everyone.
Yes on the Rogue. I had the ST90 with KT120`s and still have (albeit being sold) the Rogue Atlas Magnum also with KT120`s.
Loved both !
AND... Rogue has a nice upgrade path too. In fact I`ve toyed with the idea of sending my Atlas in for an upgrade to the Magnum II for only $495...But I don`t need two systems..need to be balanced.
Rogue is Good stuff
@atmasphere 

Thanks for such great perspective from a manufacturer.  I really appreciate your contributions here...I learn a ton.
@jwlaff Here are some things to look for to get good bass out of a tube amp:
1) if the amp has output transformers, look for low frequency bandwidth to 5Hz or less. OTLs can go down lower; what's important here is to have no phase shift at 20Hz and above- that's a requirement for good impact. To do that the amp has to be full power to 2Hz. But this might not be that important if your speakers don't also go to 20Hz.  Amps that are only specced to 20Hz might not be so nice in the bass. If they really start to roll at 20Hz you can get phase shift artifact right up to 200Hz.

2) Its a really good idea to avoid loudspeakers that are 4 ohms, and especially speakers that are 4 ohms in the bass while being 8 ohms in the mids and highs. So this will included a lot of speakers with dual woofer arrays. On the 4 ohm tap most output transformers are less efficient (more of the amplifier power is being converted to heat in the output transformer) so you get a little less power, and quite often less low frequency bandwidth as opposed to the 8 or 16 ohm tap (the latter being the best; 16 ohms is the way to go with tubes).  IOW, to get the most out of your amplifier dollar, avoid low impedances (this applies to all amplifiers, not just turbes).

3) Most speakers (but not all by any means) are meant to be 'voltage driven'. This means to get flat frequency response the amp has to behave as a voltage source i.e. it can put out the same voltage into any load. No tube amp can really do that (neither can solid state) but they can be quite effective at this even with 4 ohm loads. What is needed in a tube amp to do this is a fair amount of negative feedback. The problem with this is that feedback introduces distortion of its own (while otherwise suppressing distortion and reducing output impedance). This distortion is audible as brightness and harshness; these qualities are not why people buy tube amps- they want smoothness and detail instead.
To get that many tube amp designers use other means to obtain linearity (triodes, class A, etc.) thus allowing them to run the amp without any feedback at all. This works really well, but the amp will not behave as a voltage source. Despite that, you can still get very neutral response but you do have to be more careful about speaker/amplifier compatibility. In high end audio, this is a well-known problem regardless, so this is an easy thing to do- the manufacturer of the amplifier can give you some good suggestions. For more on this issue see: http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
If you do this right you can get outstanding bass. I have yet to hear a solid state amp that can keep up with the bass I get at home; keeping in mind as FWIW sort of thing that I've played string bass in orchestras and bands since junior high (not that such really qualifies me as a bass expert, just that in my audio system I have to get the bass right to be satisfied). But my amplifiers have full power right down to 2Hz and my speakers are 16 ohms in the bass, go to 20Hz and are meant for tube amps.

Another way of putting this is quite simply regardless of the amplifier you choose (tube, solid state or class D) you really don't want that amplifier to be working hard (it will make more distortion and be less musical) so there's no point in trying to make a tube amp drive a difficult load. You'll get substandard reproduction and you'll go through tubes faster. Solid state amps might be able to drive low impedances better, but they too make more distortion in doing so, and the whole point of high end audio is to make the music sound as real as possible. So make sure your amp is driving an easy load (**especially in the bass**) and you will be rewarded.
Why is it that everyone's own tube amp makes good or the best bass?
First of all I think we are really talking about mid bass and up. Let's talk about 100 Hz down to 18 Hz. This is subwoofer territory and I have yet to see a subwoofer powered with tube amps. Part of the reason is packaging for sure as it is harder and more expensive to incorporate a tube amp into a wooden box with a furiously vibrating linear motor. But still. My subs are passive and I use QSC monsters to drive them. The thought of using a tube amp has never occurred to me. Would the ARC Ref 750's do just as good a job? Hows about the Carver Silver Seven?
It would take that kind of power to run a digitally corrected sub. Pretty expensive way to do it but would it work well? My intuition says no but in reality I have no idea. Would be fun to try.
@br3098 Not necessarily true. The amplifier's ability to control the motors of the speakers is critical.
Another vote for Manley amps.  Not always with the same speakers but I've owned several tube amps and believe Manleys are at the top of the list.

Of course that is a generalization.  Some other amp with a particular speaker might be as good or better.  But my point is to try one of the Manley lineup at your particular power and price point before deciding.
Amps don’t make good bass. Speakers create music, including bass response.
Amps control the speakers, especially the bass with damping and current, if not you’ve got crud.

Cheers George
Big party levels? I have thousands of watts available to make noise around my place...from bass amps to QSC pro stuff to a single ended 18 watt Burriss Royal Bluesman...and I can get enough mojo out of my little Dennis Had Firebottle into a pair of Heresy IIIs to shake the paint chips off yer ceiling...if you live outdoors in an abandoned rodeo stadium you may need more horsepower, but if you simply listen to music within 20 feet of my little rig (albeit helped by a couple of powered subs), you're only gonna need a few watts before your head explodes and the disco ball starts spewing mirror chunks...efficiency can't be denied.
Manley Labs Mahi Mahi or Snappers with upgraded tubes.  Mahi are a bit quicker with EL-84 tubes.  Snappers are fuller and more powerful with EL-34 tubes.  Tube costs are reasonable for replacement/upgrade and they are quite reliable.
Amps don't make good bass.  Speakers create music, including bass response.

While it's true that different designs and different tubes will sound different, if you need more bass you need to find a speaker, compatible with your amp, that will deliver the bass response you are looking for.  With your music, in your room and with your ears.