Recommend a good tube power amp in the 100 wpc range for under $4k
Folks,
I am looking to bi-amp my Fyne F702 speakers, with a solid state amp for the low end and a tube amp for the mods and highs. The Fynes are floor standing 2.5 way units with 93 db sensitivity and 100 wpc rms power handling capacity. My preamp is a Rogue Audio RP-7, and my current solid state power amp is a Benchmark AHB2 at 100 wpc. My goal is not so much more power but to put a tube amp on the middle and highs. The Fynes have two sets of binding posts, one for lower frequencies and one for mids and highs. I am looking to go active bi-amping with a Sublime Acoustic K231 Stereo 3-Way Active Crossover.
In addition to an amplifier recommendation, what else do I need to consider? For example, if I buy an amplifier with wattage output similar to the AHB2, what other factors do I need to consider? Because I do NOT want to modify the speakers in any way, do I need to consider a gain control to match level differences resulting from other factors, such as impedance differences? Or, can I just hook up the crossover between the preamp and the two power amps and enjoy the music, which is what it is really all about anyhow?
I saw some recommendations of Line Magnetic amps. I don't know how the customer support in the United States is, but my customer journey with the Line Magnetic LM-503PA Mono Vacuum Tube Amps in Vienna is terrible.
Spoiler: Would I recommend buying a Line Magnetic product? Not when you are in Germany or Austria.
In the Summer of 2021, I spent 10k on a pair of Line Magnetic LM-503PA mono vacuum tube amps. This was by far my worst decision in 40 years of buying hi-fi gear.
So far, I have enjoyed listening with the amps for 11 months. But for 5 months, I couldn't enjoy listening with the amps because of defects and ridiculous customer support. As I'm writing this, my Line Magnetic LM-503PA is defective at the distributor for repair for more than four weeks, and Line Magnetic has not even sent the missing spare parts from China to Germany yet. But this is just the tip of the iceberg of my terrible customer experience with a Line Magnetic product.
This is why I wrote a customer report about my journey with the Line Magnetic LM-503PA mono vacuum tube amp. The report is about many customer-unfriendly emails, a dealer who doesn't answers emails at all, the European Line Magnetic distributor holding my amp hostage, and Line Magnetic in China refusing to answer my questions.
And I have NOT been disappointed, and, at even just first listening, I am far from disappointed. The switch from the Benchmark AHB2–an excellent amplifier—is astounding. The sounds is so much more “musical,” open, airy, “real.” The music seems to have much more “presence.”
I am happy for you.This is what tube amplifiers can do if well implemented. Nice outcome and no need for bi-amping.
First off, I want to thank everyone who commented and offered advice. I had no idea that there were so many different small manufacturers of such good and highly-recommended equipment. With a bit more money, my choice would have been very perplexing. As it is, I chose the Rogue Audio Stereo 100 Dark, based on personal recommendations, recommendations from here on Audiogon, and reading a number of reviews. I also contacted Rogue Audio and talked with Nick at Rogue Audio, who explained the differences between the plain and Dark models of the Stereo 100, and also said that the large majority of the Stereo 100 have recently been the dark version. Given my experience first with the RP-1 and now the RP-7 preamplifiers, I decided the Stereo 100 Dark would be it, given the moderate efficiency of the Fyne Audio F702 speakers (92 db) and the modest size of our living/listening room (12+ x ~22, with 8-foot ceilings.
And I have NOT been disappointed, and, at even just first listening, I am far from disappointed. The switch from the Benchmark AHB2–an excellent amplifier—is astounding. The sounds is so much more “musical,” open, airy, “real.” The music seems to have much more “presence.” Listening first to some Moody Blues, Beethoven’s 6th Symphony—both on quality CDs, and then an LP of Lincoln Mayorga and a friends (Volume III), the highs are clear and distinct, separation and lateral location of instruments is distinct, mid-bass is very tight with no unexpected hangover. Placement of instruments front-to-back also has great depth. Having attended many live classical concerts, I am initially struck by the realism achieved by this amplifier/preamp combination, especially at moderately—not “crazy”—high levels. This is going to take much more serious listening … which also will be incredibly enjoyable.
@lou_setriodesper Stereophile, the differences between the original RM-9 and the RM-9 MK II:
Let’s take a closer look at the Mk.II. The output power has been nudged from 100 to 125Wpc—[an increase of 1dBW—Ed.]—the new wood frame is more visually pleasing, and the On/Off switch is now rocker-style. The five-way binding posts are new—they’re made of solid copper, have ¼" studs, and are altogether more pleasing to my sensibilities. The output-tube fuses are now top-mounted together with "Fuse-Out" indicators—a major convenience—and the input/driver tubes are 6922s, tested by RAM Labs.
But the most significant upgrades—those in the power supply—are invisible. Capacitor energy storage, for instance, has been increased by 50%. Most significant, according to Roger, are the dual chokes that have been added to the power supply beyond the existing filter network—a filter dedicated to each channel. These chokes not only improve the filtering action, but also serve to improve right/left channel separation. Best of all, the RM-9’s retail price is almost the same as it was in 1989: $2950 in oak with an EL34C output-tube complement. Additional finishes and output-tube complements (eg, KT88s) are available as options.
+1 to those that recommended Music Reference. I was going to suggest a Music Reference RM-9 as well. It will run EL34’s or KT88’s, I believe 6550’s too?
Another golden oldie from the 80’s to consider that also gives long tube life is a Berning EA-2100 or 2101 if you can find one.
The other thing to consider is how loud you listen to music. You will find that a 40 wpc EL34 amp can often sound as loud as a 100 wpc SS amp….a pair of Dyna MKIII’s will sound amazing too.
Lots of good choices here if you include Quicksilver, VTL, cj and ARC, but if it were me, I’d be looking for the 2 amps I recommended above.
They will have the lowend that may very well make you forget about biamping and the issues on levels ect, been there done that in the end keep it simple with an excellent amplifier pair.
Lowend control and slam with the transparency of tubes,
I recommend the Rogue Audio Atlas Magnum latest version. .Basically the power amp section of the famous Rogue Cronus Magnum III, sounds so transparent and refined with excellent open midrange that sounds better that the up range Stereo 100 IMHO. The 100 can be too burnished and dark.
Save some cash too, a great match with your preamp and speakers.
There is good reason why the Cronus Magnum is a giant killing integrated amp- he sound !
@mike4597I'm considering listing my Music Reference RM9 MK II with newer Siemens (RFT) EL34's, refurbished for me by Roger Modjeski in 2017. Let me know if interested. It's a classic amp that runs under the radar. Also allows tube rolling of many varieties of power tubes... KT66, KT77, EL34, KT88 and 6550.
Anybody here had any experience with the Cary CAD-120S II? I know their preamps get very good reviews, but there is very little on the web regarding this power amplifier.
I'm not a fan of the Raven amp aesthetics (looks like a run of the mill Chinese amp to me), but I do remember that 6L6GC kind of sound (vintage Heathkits - 5881 and 7581A) sounded absolutely wonderful with my 93dB Tannoy Kensington. Classic tube sound. That kind of tube & sound in a more modern form factor (binding posts, connectors etc) with a little more power (40 - 50 Watts at least) would be hard to beat. Haven't heard the Ravens myself, but probably not a bad choice. KT88 and KT120 seem to need a lot more power and brute force behind them to sound "whole" the way those 6L6 amps do.
5K USD allows for some formidable amplifier choices as the numerous recommendations thus far have show. Lots of push-pull tube suggestions. This Fyne is 93db sensitivity and an 8 ohm speaker impedance. I’d think that the Line Magnetic 805ai is a viable consideration. 48 watts of pure class A provided by one psir of 805 tubes.Something to think about.
Charles
I currently have a pair of VAC 200iQ and Rogue Apollo Darks (along with my solid-state Phison A2.120SE). That's an upscale analogue of the Phi 200 versus a Rogue Stereo 100. The Rogue will be more dynamic and have better bass. The VAC will be more refined smooth and sweet, especially in the midrange. Choose your preference! But I really start to miss some dynamics & slam when I go from a pair of 200iQ monos to a single 200iQ in stereo mode.
Rogue Stereo 100 with a 93dB Tannoy or Fyne will be pretty bomb. It will give you all the bass slam and dynamics, so you shouldn’t miss that from SS :) Throw some sweet NOS small tubes in there to get a good balance of tube & SS archetypes. Rogues really respond a lot to tube rolling, and the stock tubes (other than KT120) are often mediocre.
Several years ago I auditioned the old Stereo 90 on my Kensingtons, and it was a really solid step above Atlas (at the time with EL34). But that made me so rabid for upgrade, I placed an order for Apollos instead :)
Of course the other amps you list should sound good too - I just have no experience with them. I’ve long heard Manley and Tannoy (therefore Fyne) are a particularly rockin’ combination. I should have tried them too; get slight pangs whenever I see a used pair of Snappers for sale :) There's definitely something about the EL34 sound I really like.
thinking about the valid comments regarding volume...
Ric Schultz (Tweak Audio) makes passive resistor volume controls that go between the amp and interconnects. You lose the ability to adjust volume from disc to disc but...
OK folks, you’ve convinced me to reconsider. I do not want to modify the speakers, so it appears—as is often the case I found in my nearly eight decades—that the simplest course of action is most often the best answer. I will, once I convince the wife, opt for a single tube amp; if something convinces me that I don’t have enough power, which is most unlikely, I could always buy a second identical amplifier or go to monoblocs. I know there are LOTS of options out there. Given my satisfaction with my Rogue preamp, I am considering either the Rogue Stereo 100 or the Atlas Magnum III and also the McIntosh MC 275 MKII, but the Cary CAD120S MKII also has caught my eye.
Any recommendations in the roughly $5000 and under range would be most welcome. I prefer new equipment, preferably not made in Mainland China, as I don’t like supporting totalitarian regimes engaging in nefarious activities.
And, once again, thanks to all for your comments. They have been most helpful.
I think this has been well covered here but my 2c worth is that bi-amping is a great way to have imbalance in your sound and your checkbook. "On paper" bi amping seems like it makes sense but in your listening room you are going to have a sonic disaster.
If you are married to the idea of 2 amps use matched mono block tube amp but NOT bi-amping. Tubes are always welcome as they produce wonderful warm sound and a LOT of volume.
Personally I’d go with a good used Audio Research stereo tube amp with under 1500 hours on it. They are built like tanks, sound amazing, are much more affordable than the new ones, and don’t loose value if you choose to trade up. (Of course sound is a preference like blondes vs. brunettes or French wine vs. California wine. Only you can choose what "sounds best") One other thing- ignore anyone who makes fun of what YOU like.
I have a great used Audio Research VT130 tube amp for sale for sale 3.5K It was my favorite "large format" amp until I put my hand up on a pair of Ref 250SEs (8K 1900 hrs plus nearly $500 in FedEx freight. Ouch!)
Remember the KISS principal- Keep It Simple, Stupid!
This is the data point I was mentioning, right after the word "minimum." This tells you that these speakers don't need 100watts and would be fine with a tube amp.
Impedance: 8 Ohms nominal (minimum: 5 Ohms, from 150-250Hz)
https://hifiplus.com/articles/fyne-audio-f702-floorstanding-loudspeakers/
@grannyringI own the Fyne F704s and feel you are adding too much complexity to your system for no good reason. Just get one good tube amp. No need for 100 watts unless you have a huge room. One good tube amp will sound best.
Wise counsel from you, @lloydc@soixand others who caution against unwanted complexity. It seems to me that 1 quality tube amplifier would be idea with the Fyne speakers. But I understand, to each their own.
As others pointed out, gain matching will be an issue. In most cases, tube amps will have higher gains that SS amps of the same power rating. Sometimes MUCH higher. This is because they use less feedback, and also the typical input tubes like 12AX7 / 12AT7 / 6SN7 / etc provide a lot of gain.
A Rogue Atlas II (or III the current one?) Magnum is a good 100W tube amp well within your budget. There aren’t too many other budget options like this without going to a no-name Chinese amp (I’m taking about stuff named like Quin-Poo or whatever, not the PrimaLunas which are good).
Your Benchmark has 3 gain settings which helps, but even its highest gain will have trouble keeping up with a 100W tube amp. It looks like the Atlas will be a couple dB hotter than Benchmark’s high gain mode (see Stereophile measurements of Atlas - and they even comment that its gain is lower than usual for a 100W tuber amp!). So you’d need to either insert an additional volume control (and calibrate by ear and/or SPL meter), or re-think your strategy.
Personally, I wouldn’t try bi-amping unless I had two of the EXACT same amp. I’ve even had two of the "same" stereo amp, but there were minor internal differences on the units (made about a year apart), and bi-amping didn’t convince me of any benefits versus running either amp alone. The very slight sonic differences between these units seemingly worked against a cohesive musical whole when bi-amp’d.
I have lots of experience with Tannoys, similar to your Fyne (I used to own Kensington SE that were also 93dB), and the Rogue Atlas did a great job powering them alone. The Rogue amps are not "typical" tube amps in that they have great bass power and dynamics with a drier midrange. So they’re really kind of like a tube amp with SS persuasions. If you went with the Rogue, I would run it full range.
I also ran those Kensingtons with 20 - 35 Watt vintage tubes amps (Heathkit, Eico), and those very much have that "classic" tube sound, but the bass response was a bit softer and I play loud so I definitely hit their clipping limits at (rare) times. I later got the Rogue Atlas (version I, non-Magnum), and I did NOT hit any limits with that amp (except once totally by accident on a Sheffield Direct-to-Disc of Firebird Suite) :)
Incidentally, I later moved on to Rogue Apollo tube monoblocks, 250 Watts/ch, and their gain is absolutely INSANE (not always a good thing with efficient speakers). I don’t think any SS amp on earth would match it. The bass response on those amps is crazy good though :)
Want a great integrated amp for your F702s? Get the Circle Labs A200 hybrid Int amp. Tube preamp section coupled with SS output. Your Fyne speakers are a great match for the purity of this amp. This one amp will greatly simplify your system and give you the best sound. Better sound than the two amp approach you are contemplating.
I own the Fyne F704s and feel you are adding too much complexity to your system for no good reason. Just get one good tube amp. No need for 100 watts unless you have a huge room. One good tube amp will sound best.
Another way to go would be to sell the benchmark and just get a tube amp so no need to mess with an external crossover at all. At 93dB and nominal impedance of 8 Ohms, depending on what the minimum impedance is your speakers might do quite well with a 70-100Wpc tube amp. That’s what I’d do rather than messing with external crossovers, volume matching issues, etc. Another consideration is that the woofer crosses over at 250Hz reaching up into the lower mids so there may be an issue of significantly different sound signatures of the Benchmark and a tube amp blending seamlessly in that area. Just some thoughts FWIW, and best of luck in obtaining more of that tube magic.
93 db sensitivity? Depending on how much Fyne's impedance curve swings (i.e., is demanding on the amp) you don’t need anywhere near 100 wpc. I have 92 db Ascend Acoustics towers (92db) and my Mono 60 Quicksilvers handle them easily, and with sweet sounding KT77 output tubes.
You don’t need or want such complexity. A good c. 100 wpc tube amp will be fine; good tube amps (e.g. Quicksilver, Rogue, Mac) can play bass very well, and the superb ones (e.g., VAC, Rogers, VTL) play bass extremely well . Better to get a subwoofer or two.
If your speaker is set up for biamping, then the crossover inside the speaker will split the signal at the frequency that the OEM thinks is best.
Then you just need to figure out how to make it work with no external crossover.
Notice how people looking to bi-amp are usually folks that a lightbulb goes off in their head and it sounds like a good idea. and it can work. but if I were going to biamp I’d approach it like this: carefully pick the amp I live for mids and highs, try many amps. Let them drive entire speaker. then add a second ss amp to drive the lows only if the other amp was lacking.
Your plan is misguided. Unless you perform surgery on your speakers to hardwire the LF input terminals of the to the woofer and the HF inputs to the correct circuitry traces for the upper crossover (MR/TW) you will be “double crossing” your speakers. Plus, an engineered product like the Fynes often have compensatory elements in their passive network that the electronic crossover won’t be able to match. Skip the electronic XO! It’s perfectly OK to just biamp into the terminals as is with the 2 amps as long as their gains are matched. 50W tube amp should suffice. I do this with my own DIY speakers to great effect with a SS woofer amp and EL34 based upper range amp.
Power: yes, less for just mids and highs, however, consider you might want to try just the tube amp for all, then, if more power is affordable, ...
smaller means less heat, cost, and more placement options.
Crossover does not equalize gain, just distributes these frequencies to this driver ...
You need gain controls on at least one amp (preferably both), get them volume matched to each other at your favorite listening volume, then after that fundamental match, the preamp controls the volume to both amps.
Thanks for the input so far. Yes, I am looking for a bit of that “tube magic.” Switching to a tube preamp has made the music seem so much more alive, with more depth, possibly due to hearing more harmonics from the various instruments.
I now understand that I do not need anywhere near 100 wpc for the mids and highs, that probably 30 to 40 watts will be more than sufficient in our roughly 13 x 20 x 8 living room, open on one side to the dining room. A higher power tube amp would just give me power reserves I probably would never use; we like to listen at moderately loud levels—just beyond where the speakers “open up”—not very loud levels.
Someone commented that the crossover will handle gain matching between the two amplifiers, which was a major concern.
One thing I do not understand is the need to remove or disconnect internal crossovers when using an active external crossover. My speakers have two sets of binding posts, one for lower frequencies and one for mids and highs. When a manufacturer builds a speaker this way, do they not bypass at least the crossover divides the lows from the mids and the highs? (In the F702s, that would at 250 hz.). If not, what is the point of two sets of binding posts? Thus, it would seem to me that if I set the active crossover at 250 hz I am simply duplicating the internal crossover point and sending just frequencies below 250 Hz to the woofer, which is what the internal crossover does; frequencies above that are directed into the “upper” binding posts, and it seems to me that I would want to retain the internal crossover dividing the mids and highs (1.7 kHz in this case) because I am only bi-amping, not tri-amping. OR, are we getting into the “magic” of crossovers with the possibility of some undesirable interaction between the internal crossover at 1.7 kHz and the active crossover? Can someone explain.
As you can tell, I am new at this, and I greatly appreciate your advice. My current system is far beyond what air replaced in the past year—Infinity Modulus satellites (the 1992 quality model with EMIT tweeter before Infinity went mass market) and a NAD C356BEE used as a preamp feeding into a McIntosh MC2125, of which for the latter I was the original owner. I am looking at tubes for the upper end to see how much better I can make my system without spending gobs more money.
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