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

Looks like quite a good loudspeaker, and surprisingly, fairly priced for what you get. Thanks for the link! Always good to see high efficiency speakers with quality drivers.

Definitely a solid alternative to the Tannoy and 604 Duplex loudspeakers.

Hi @lynn_olson ,

In the Montreal show were the Coherent speakers Model 18 (18" coaxial Radian driver with Neodymium magnet and aluminum diaphragm).

In 2022 they used a 300B Allnic Audio T-1500 300B SET stereo amplifier. This setup sounded the best. And in my opinion it was the best on this show.

In 2023 it was M-2500  Allnic 300B Push pull monoblocs. It sounded good too. But I liked the more warmish SET sound.

And in 2024 they use other speakers with 12" coaxial and 2x 15" woofers with transistor amplification. I didn't like this sound at all.

Why do most modern 15 inch drivers like modern JBL and Tannoy are made for very powerful transistor amplifiers?  These drivers have a very high moving mass and are designed to survive very high power. It is done in compromise in sound quality and sensitivity. It shows the big audio industry players ignore low power amplifiers lovers.

@lynn_olson 

I've dragged my Levinson no 27 Power Amp out of storage. It is now 30+ years old. I have had it for 20 years. A few months ago, I replaced all the big power supply caps (8 of 'em) with brand new ones and thoroughly cleaned it up. I broke the caps in with about 50 hours of music. But then I put it away. This amp is rated minimum 100W into 8 ohms and 200W into 4 ohms. No 4 ohm speaker limitations. It weighs about 90 lbs.

I've had about 1 hour listening, so maybe too fresh. My initial reactions were that voices were better articulated than the Bryston. Dynamics might be better. I need more listening time, but I am pleased with the change so far.

Good news! Nice that the Revels respond to an amp swap. You're probably hearing better current delivery thanks to the massive supply.