What Power Amplifier Should I Buy?


I am looking to increase my system power. I currently am using a Bryston 2.5B cubed, which is specified at 135 Watts/CH. I am using Revel f208 speakers crossed over at 120 Hz to a 15" HSU sub. The f208 speakers have 88.5 dB sensitivity (Amir measured 88-89dB SPL at 1W into 8 ohms). I sit about 7.5 feet away from the speakers and listen up to 92 dB SPL, but mostly stay between 80-90 dB SPL at my listenin g location.

I have not had power issues. I've never seen a clipping light. I just want more oomph. I've never had a power amp with more power than the 2.5B cubed.

My budget is about $5K. I have been looking at some used 4b cubed amps.

My preamp is a vintage ML No. 38s. Digital from Bryston BDP-3/BDA-3 combo. Analog using Koetsu RS and Shelter 901 cartridges into an SUT (20x) followed by a very vintage Paragon System E used as a phono preamp (I have fully repaired this preamp, particularly the power supply).

I like the sound of the 2.5B cubed. I had a Cary 120 tube amp for some time, but grew tired of the heat and the continuous maintenance, including the insane prices for tubes. I did not experince that great "tube sound" that others rave about. I sold the Cary and went back to the 2.5B cubed.

Will the 4B cubed disappoint?

What other amps should I consifder, new or used?

Thanks for your help!

 

128x128Ag insider logo xs@2xkevemaher

I’d think this SMcAudio DNA 1 would be worth a try and should be negotiable down to $2k at this point I’d think.  Plus, if you like what you hear you can send it back in for the more recent upgrades to get even more and still be well below your budget.  I recently had my upgraded DNA 0.5 in my friend’s system and it sounded beefier and more robust than his 3B SST2, which is why I thought this might give you what you’re looking for.  Best of luck. 

https://www.usaudiomart.com/details/650135552-mccormack-smc-audio-ultra-15-dna-1-power-amplifier-upgraded/

@kevemaher,

In my opinion, I would buy a second 15'' subwoofer, you will get an improvement in imaging and sound stage and more ''oomph'' then you would from buying a bigger amp.

Mike

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OP,

One caution. Investing in a different amp at roughly the same investment level is likely to be trading one set of strengths and weaknesses for a different set. Unless you have made a big mistake on the overall sound ( like you bought a solid state and really would enjoy a warmer more natural sounding tube amp). In this case a sideways move can be of value.

My rule of thumb to avoid disappointment is to research thoroughly and invest no less than 2x. This will result in a serious improvement in all aspects of sound quality. Unless I can afford the jump, I just enjoy my system until I can.

@ditusa Thanks for showing me an alternate path. Could you explain how a second sub improves the imaging and sound stage?

Perhaps I used the wrong word. By "oomph" I meant more power for transients. I wasn't indicating that I needed more bass. I believe I have enough bass.

Oh, by the way, I use REW to calibrate and integrate the components. I aim for 1.5 dB/octave roll-off above 1KHz and 1.5dB rise from 200 Hz to 20Hz. I use a graphic equalizer to achieve an FR that's close to this.

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All competently designed (low noise/distortion/output impedance) amps will be indistinguishable.

Well that’s just silly.  BTW, I agree adding a second sub is a good idea. 

Get the bryston 4b3. You already like the bryston sound and it will give you greater extension in all areas of your system. 

Coda #8 or S5.5 both with in the budget ,

Better than most and Second to none!

Outstanding resolution and extension and liquid midrange

I had the s@me concern as you, and I recommend a look at the Odyssey power amps.  I replaced a 100 wpc tube amp with two mono Odyssey Stratos Extremes with several upgrades, almost making them equivalent to Kismet amps.  200 wpc, and the improvement was marked driving my Fyne Audio F-702s.

Perhaps a pair of Bryston 7B SST monoblocs?  If you like the Bryston sound (I do too) you can get a set of 7B SST (Super Steve Tanner) used with years of warranty left for 4-5K. I drive my woofers with these and the upgrade in sound quality and oomph was stunning. (Formerly I drove my 6 way towers with an Audio Research VT130 which is now the mid/tweeter amp.I find tubes to have flabby bass at loud levels) 

It sounds like you don't use much more than 3-5 watts per channel now.  Why would an amplifier much more powerful than the 135 watt per channel amp improve on the matter?  It seems like the only metric people care about is power, so more must be better.  It simply is not the case.  There is much more to achieving good sound than can be measured, whether that measurement is power, harmonic distortion, intermodulation distortion, slewing induced distortion, signal to noise ratio, damping factor, etc.  If if were the case that we can determine quality by any set of measurements, there wouldn't be such a vast array of market choices, alternative designs and fundamentally different approaches to design; things would be narrowed to the objective "best" at each price level.

You should make an effort to hear for yourself an array of amplifiers.  You should not dismiss any type of amplifier based on limited experience with one particular amp; that would be like dismissing all American-made cars based on your experience with a Pinto.  I don't subscribe to the "tube sound" or "tube magic" idea because there is a VAST difference among tube amps (more variability than there is among good solid state amps) and there are many that, to me, anyway, sound more brittle, harsh, and unpleasant than most solid state amps (I particularly don't like most high-powered tube amps employing tubes like the KT88).

 

 

I’d look at the VTV Purifi amps.

 

before you get a new amp consider lowering your crossover frequency to around 70 Hz and if possible and high pass the input to your Bryson at 70 Hz. You can get some inexpensive FMODs from Lincoln Labs to try it out. 

I've had a Levinson preamp (326s) and it did not have the bottom end kick that others do.  It does other things well, but that's not a strong suit.  If the pre is holding back the low end it won't matter what amp you put behind it.

Sub, or better still subs in stereo are going to make a marked improvement in your system. That’s where the oomph is! Cheers 

Your amp MIGHT not be the cause of lack of umph. My recent experience with my ~3 year old Emerald Physics 3.4s (12" coaxial driver) in a large room I long felt that I needed subwoofer reinforcement UNTIL...

This is a mind blower and YMMV (though I doubt It) I recently addeed a single Vera-Fi Snubway (search forum for comments), admittedly plugged into a Core Power 1800, itself plugged into a 20amp dedicated line is, in a word, unbelievable. Since inserting it (it simply plugs into the wall or whatever PLC you might have- MSRP $295!!!) ) I rarely miss having a sub

HTH

IMO 15" HSU sub is for home theater. Your Revel have two 8" per enclousre(consider large for most tower designs today) mid/woofers.

Two easy experiments. Listen to some music on just the HSU.
next, defeat the EQ and let the Revel run full range without the HSU. I am sure that you will hear much more attack and punch. discernable bass notes.  Add back the HSU crossing over around 40 and then play with xover point,  slopes and flattening out your response curve.

if it doesn't get as loud as you like, then consider the bigger Bryston or speakers that are more suited to your music.

disclosure- I run my SVS sealed micro (twin 8") up to 120HZ and let my Martin Logan ESL-x (2@8" each) go full range. I would like to add another micro for stereo sub. I EQ out some hot spots with the SVS app. I also have a 15" yamaha horn loaded PA for loud listening :)

Depending on the genre and your preferences- there is bass punch and there is bass thump.

All good suggestions here, but I browsed the 2009 Stereophile review of your preamp, and the overall impression I get is that it is ‘polite’. It sounds to me like you want something a bit more dynamic, so it might be worth some investigation. As for an amp recommendation, I can only recommend Coda, as that is what I have. Find a used #8. I would look at the preamp first though.

Update/Upgrade your preamp and phono preamp. Seriously consider same brand synergy.

Current is what drives a loudspeaker - not watts. If you want more "umph" look for a high current amp that puts out at least 40A. Basic math tells us at your listening distance your Revel f208 (with 89db sensitivity) will put out over 94db with 10 watts at 1 meter. So, its not watts you are lacking. As previously mentioned, Klauss at Odyssey Audio sells extremely high value, high current amps and I bet one of his amps would provide what you are looking for.

Another vote for a pair of subs.

Likely the Revel f208's may not 'get 'er done." ( You removed the Usher speakers. ) Perhaps investing in better $peakers is the key.

The single sub may be vibrating your gear especially the turntable. 

Room is well treated so it's not that.

I agree that the pre may be the issue.  You might consider the new Bryston BR20 and collapse the BDP-3,BDA and pre all into one box.  The sale of those components cover a good portion of the BR

This is a fantastic Pre. The Raven Preamplifier by Don Sachs and Lynn Olson. Lots more here on Agon. Yes I have one and it's rumored I'm a fan.

But Speakers are requirement one.

Try crossing them lower, like much lower, say 60Hz. You're cutting the f208 above the knees by crossing them at 120Hz! I know these speakers well and realize they aren't bass monsters, but you can definitely let them play to 60 or even lower and flush out more punch.

Based on your current setup, it sounds like you're already in a great place with your Bryston 2.5B cubed, but I understand the desire for more power. The 4B cubed would be a solid upgrade, delivering more headroom and dynamic range without sacrificing the Bryston sound you enjoy. Given your listening habits, it will likely provide that extra "oomph" you're seeking without risk of clipping, especially considering your Revel F208's sensitivity and your subwoofer crossover.

If you want to explore alternatives, consider amps like the Pass Labs X250.8 or used McIntosh MC452, both of which are known for high power, clarity, and reliability. Either should fit within your $5K budget used. However, the 4B cubed's synergy with your current system makes it an easy recommendation.

Good luck!

I have two suggestions.

1. If you haven't already, try running your Revels full range and let the subwoofer just handle the lowest frequencies. You will need to set its crossover low - around 40 Hz to achieve this and don't run your Revels run through the sub crossover. You may find that allowing the woofers in the Revels to handle lower frequencies improves the punch factor.

2. The 203's are a fairly difficult load for an amplifier. The Bryston is no slouch but it does not increase its power into lower impedances as well as some other amps (Pass, Krell, Martin Logan, etc.). You might want to look for an amp that is rated to 2 ohms or where the testing shows that power increases substantially into low impedances. These amps are heavy and expensive to build which is why most amps don't perform this way.

I cannot explain why two subwoofers over one increases the soundstage and can improve the imaging (through enlarging the soundstage)… it does. I have heard it, and others commented,  whenever disconnecting one of my two subwoofers when I used them.

Instead of a bigger Bryston get another 2.5B and vertically biamp. I did this to good effect when I had Revel 228 Be. Don’t run them mono, but use each channel of one amp to power the highs and lows of one speaker, or horizontally one amp the highs and one the lows. That said, while the sound may be cleaner and you have a bit more headroom, the difference may not be that huge. You are probably only using a small amount of watts from your existing amp. I found it beneficial overall though, and I don’t listen that loud either.  Only issue is using a y-splitter for your preamp outputs if you don’t have one with two sets of outputs.

By the way, the advice on looking at preamps may be good also if yours is truly a ‘softer’ sounding unit. I preferred the Bryston amps with a Bryston preamp, it provided a certain jump factor that was very much missing with other preamps I tried, including Primaluna, SPL, and DAC direct. I used a BP17. The only thing I didn’t like about it was that it was noisy. Also, I eventually settled on a NAD M23 amplifier. 1st class D amp I would recommend over something like a Bryston, and I’ve owned the different technologies over the years, Pascal, Ice, Hypex, etc. The NAD gives up just a little bit of bass slam to the Bryston (not much though) but is otherwise more refined and has a nicer midrange, and provides lots of clean power (200/400w in 8/4 ohms).  It’s cheaper also, and IME was not a sideways move.  Definite improvement for my tastes.  

All of them then you can roll them.ive enjoyed emotiva dr 1.bryston 28b3.mcintosh class d 1502. Michi m8. D sonic.manly and carver tube. The fosi audio mono is a bang for the buck on Amazon happy hunting enjoy the music.

If you want to greatly increase your musicality, transparency and detail I would highly recommend buying the Atma-Sphere Class D mono blocks.

They are in your price range. They are a fluid as a great tube amp but much more transparent and detailed with great bass and smooth highs. To get better you would have to spend many times more.

 

What @larryi said that's great advice. Also putting a good tubed preamp in front of the Bryston you have could reap some benefits.

@kevemaher Wrote:

 Could you explain how a second sub improves the imaging and sound stage?

In my experience, a second subwoofer improved transient response in the bass and the sound stage became wider, bass notes became more delineated. Depth of image slightly improved. See here and here

Mike

Wow! So many great ideas.

I appreciate how these posts have recommended changes to other components, so much so that I thought I would discuss my system in a bit more detail.

The Paragon System E is used as a Phono pre only. It creates a beautiful bloom in the upper bass/ lower mids. Sometimes this works, other times not too much. I have other phono preamps I switch in from time to time.

I tried a Pass XP-12 preamp earlier this year. It was not a good experience. There was a lot of sibilance, no matter what I tried, even with a tube power amp. I did not enjoy the ergonomics, especially the grainy volume adjustment. I sent it back to the factory where Pass replaced the gain modules, but the sibilance remains. I sold it. I've tried some vintage preamps, such as the APt/Holman Preamps 1 and 2 and a 10 year old NAD. The lack of a remote (not the NAD), takes a bit of the fun away, although the APT preamps sound very good. I refurbished both with new caps.

I use a graphic EQ (dBx). I'd rather not have to use it, but need more room mode control than the passive absorbers can provide. I've experimented with analog parametrics, but found them very difficult to adjust. I've tried the miniDSP Flex, but I was underwhelmed. I'm able to do just as well with the GEQ. And the Flex has no control in the time domain (impulse response, group delay, etc...). I need Dirac for that.

The Bryston music server and D/A sound great. I'm very pleased.

My crossover is a Sublime Acoustic K231. This is a modern XO. I've tried XO frequencies from 75 Hz to 200 Hz. At 120 Hz, I get some help from room modes that are more apparent than with the sub. I have run the f208s full range, but was/am concerned about clipping the amp. This is one place where I need to continue experimenting.

The Revel f208 speakers are a keeper. They are the best sounding speakers I've ever had. I need to find an amp that will drive them well instead of getting more efficient speakers.

My main reason for getting a more powerful amp is to provide more headroom (which is why I use a sub). Perhaps I don't need more power. This thought has occurred to me. I could spend the money on something else.

To summarise, I feel very good about the sound from my system. However, I am always on the lookout for something else (better or just different?).

I need to update my system pics and description. I've changed a lot of components since the last photos.

I am still open to changing the preamp. I have already tried Pass, so that's out.

This continues to be a very informative discussion for me. Thanks for your participation!

I liked the PS AUDIO BK250 as well. Like it so much I bought another and now vertically biamp.  It imparts of bit of tube sound, but has a solid state output stage.  I find it to be a nice compromise.  I have the F208s but they are not hooked up to the BHK 250.  Nice speakers though.  I should try it sometime with the BHK 250.  I was using a benchmark and I feel like the speakers had a lot more to offer then the electronics I had paired with them could extract.  

Well, I’m at a loss as to how you’ll get “more oomph” or “more power for transients” as I just don’t know what that means.  I will say that after looking at your setup I think it’s highly unlikely your sub is positioned anywhere near optimally in terms of working best in your room.  Not sure what method you used for how/where to place it, but it’s almost never where you have yours and something else to consider if it’s only there for convenience.  I’d suggest reading Todd Welti’s research or even just the subwoofer “crawl method” to get ideas on finding optimal/better sub placement in your room.  FWIW, and best of luck in finding what you’re looking for. 

@kevemaher Last year I was considering the same amp you have. I talked directly to Bryston about my room and they said the 2.5 should have plenty of power. Your room is slightly smaller than mine. Based on that and your updated comments about improved transients I would consider scrutinizing the pre. I saw a well regarded poster on here one time respond to the question "What does a pre add" and the answer was "Richness". I couldn’t agree more after my testing.  Could that solve your SQ improvement needs?

Another thing to consider is the BDP-3 is now out of production. Although Bryston has a solid reputation of supporting OOP models there is no guarantee the BDP-3 will support the new OS3 that is in the works. The BR-20 Pre should have the hardware to support the new Bryston streaming OS. Then you pick up the synergy between the Bryston Pre and Amp. Fair number of reviews out there on the BR-20.

I am surprised at your experience with the Pass XP-12, I added one to my system this year and it is an excellent pre, with zero grain or sibilance that I can detect. I suspect that it is only exposing some issues with your source(s) that the ML is glossing over. I would try the Bryston preamp, and if you have issues there, then look further up the chain for issues. 

@zlone - I agree.  I have an XP-22 and it's outstanding.  I have zero sibilant.  I also had a ML pre prior to the XP-22 and bottom end is much more pronounced.

I am surprised at your experience with the Pass XP-12, I added one to my system this year and it is an excellent pre, with zero grain or sibilance that I can detect.

@zlone  @hkfan  Yeah, that’s why I’m throwing my hands up on this one.  Something’s just outta sync here along with an insufficient description on what the OP is looking for.  Sometimes ya just gotta punt, and hopefully someone else can help unlock this cryptic riddle. 

@soix Hi, I can understand your frustration.

Please tell me how I can clarify. I would like to keep seeing your inputs to my questions, even if it is not complementary. I value what you have to say.

I cannot explain why this XP-12 was a failure in my system. I did swap out other preamps such a couple of vintage APT/Holman ones. I had no problems with either. I even sent the XP-12 back to the factory. I live 30 mins from the Pass facility, so I hand carried the preamp to them and explained directly to the tech what I heard. He did find a problem with the older gain modules. He replaced them with modern ones and retested OK.  However, when I put the XP-12 back in the system. the sibliance was still there, unlike all three of the other amps. So I just don't know why I had this experience with the XP-12. I did everything I could think of to make it work.

The suspicion that the 38s preamp is masking a different problem may have some traction. The problem with the XP-12 occurred with all inputs, two phono cartridges Koetsu RS and Shelter 901, the Paragon as Phono preamp and the SUT, one Technics SL-1200G TT, a re-aligned Sansui TU-X1 tuner, and the Bryston BDP-3/BDA-3 combo. I can't see how each of these could separately create the same sibilance.

I have looked at the Bryston BP-17 cubed before. Perhaps I should pick one up and give it a try.