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 have just the amp for you in your price range, recently retooled by jeff at conrad johnson, i dont play it anymore because i sold the preamp.  look under audiomart under conrad johnson, but its a mccormack dna 500...... 500w the 2nd best amp ever made.

Buckeye Purifi. Objectively one of the best amps on the market, and without the snake oil markup.

StringAmp d220 power amp ( same designer as for the Gamut d200 versions)

Michael has perfected the design all these years and his amps are built to last a very long time. He told me that the amps are even better sounding now, a lot of great reviews on the old Gamut amps on the net for people to investigate.

Hope to get one myself one day.

 

 

I never heard the A21, but I was very impressed with the A21+. For the cost it was an excellent amp. I sold that to get the CODA #8 and thought it was more detailed and as powerful as the A21+. I now have the CODA #16 which is better than the #8. The Benchmark LA4 with the Parsound is a great combo. The Holo Serene preamp is another similar option.

The A21+ was disappointing for me. It produced plenty of grunt but otherwise I found it inferior to a 20-year-old OG A21 I had at the time. The A21 was/is considerably quieter and cleaner sounding. I suspect that’s the real reason for why the 21+ is not THX certified despite its claimed specs. The original 21 was measured by Miller Audio Research lab back in 2011. Other than maximum unclipped power, it posted better numbers than the 21+ did in Stereophile’s measurements. 
 

I agree the Coda No.8 is more detailed—it has a lower noise floor than most amplifiers I’ve tried, which probably contributes to that detail. By comparison, the A21 is a little rolled off in the top octave, but on balance, I ultimately preferred the A21 for the way it “effortlessly” went about controlling the speakers, which I didn’t quite get from the No.8. I consider the two amplifiers roughly equal in subjective performance, but the No.8 sells for over 2X the money on the secondhand market, so in that sense I consider the 21 the better value, especially for tougher speaker loads. The difference in outright power between the 21 and No.8 becomes much more apparent on speakers like Magnepans. 
 

The potential downside of the A21 is that its inherently laidback character makes compulsory the use of transparent upstream components, like the Holo Serene you mentioned. That is, if the system’s speakers are voiced neutral or warm. 

 

@kevemaher 

 

One likelihood (based on my experience with F208s) is that your current amplification already outclasses your Revels. In other words, the speakers are likely a bigger bottleneck in the grand scheme. The 208s are nice speakers at their price point, but you’d likely get more “bang for your buck” by saving money toward a pair of pre-owned Salon 2s or others of similar clout.

IME, even a mid-tier integrated amp can scale up surprisingly well with >/=$10K speakers. I realized regrettably late in this game that loudspeakers are the major bottleneck in probably 90% of audiophile systems, even when a relatively humble amplifier is employed. For example, I am quite certain I’d rather be stuck on the proverbial “desert island” with my Børresen X3s and Yamaha integrated than with Revel 208s and cost-no-object separates. 
 

…just something to consider 🫣