thanks man so you are saying it doesn’t have the power reserve for dynamic swings above it’s rated power. Correct? seems that would be all fixed by getting two in bridged mode. Although I have to say I haven’t clipped mine or come close and I play loud sometimes.
your speakers are nominal 4 Ohm That makes the amp rating ~190 W The sensitivity is 90 dB, if accurate 0.1 W at average 80 dB SPL, imo loud. I listen 70-75 dB headroom 10 log 190/0.1 ~ 32 dB, peaks > 110dB Typical music dynamic range 20-25 dB You should be fine as far as overloading/clipping. Your ears are another matter.
Yeah I mostly listen to around 70-75dbs as well. here is some technical detail and talk from John Siau on the AHB2 For those who want to dig deeper Review and Measurements of Benchmark AHB2 Amp
you have a good point but i cannot see parting with my preamp. the pass amp did not start out so euphonic and other amps have given more or less degrees of it. the benchmarks hopefully will be just enough anti euphonics to balance it out.
another thing i noticed about the ahb2 is that they have very high resale value compared to other amps i have had. upwards of 70 percent which is excellent. some people have noticed fuller less anaytical sound when using them as mono blocks, also that the sound is more at ease and has better bass extension. the system at the AXPONA show used two of them as mono blocks and the sound was punchy, clear and lively. quite impressive but a touch studio monitor like. a tube preamp should help fix that. they were driving Aretai Contra 100s stand mounts with wave guides and rear passive radiators. These speakers also have a nominal 4 ohm impedance and the ahb2s had no problems at very loud levels. Aretai Contra 100S - Aretai
My experience with a single AHB2 vs the XA25 is that the latter had greater apparent detail and instrument separation despite sounding slightly darker. The AHB2 was also less 3-dimensional. I can’t help but wonder if it’s the tubes in your preamp that have become too euphonic rather than changes in your XA25. That’s what happened with nearly all valve gear I’ve owned, once the tubes began their decline. They start off clear and bright (bright in a good way) with good extension and harmonic decay, then slowly devolve to a dark, smeared presentation. Even though I recently bought another tube preamp to try in my system, forcing sale of my LA4, I will likely keep the Topping Pre90 around as a backup reference to help determine when the tubes need attention. That or I’ll just return to SS full-time. As of now, the new tube preamp (Bel Canto SEP1) is possibly the best pre I’ve owned and a refreshing/exciting experience, but I wouldn’t be surprised if that changes in the coming months.
Amps are rated in average power (no such thing as RMS power). Vpk/sqrt(2) x Ipk/sqrt(2) =(Vpk Ipk)/2 Peak is 2 x average So if an amp is rated 100 W, peak is 200 W Most amps PS can support 150% of dynamic power. My average listening level is 70-75 dB SPL Z wtd peak of 95-100 dB, 25 dB dynamic range. My meters read -30 average or 0,12 W avg Stereophile measured them. 25 dB peak ~ 38 W avg or 76 peak I've measured it using a Fluke. Peak voltage ~ 10 into 3.5 Ohm ~ 30 W avg, 60 peak Based on speaker sensitivity of 86 dB: Distance 10-11 ft 75 dB SPL ~ 0.1 W avg 100 dB peak ~ 32 W avg, 64 peak I am confident I need <40 W average and 80 W peak. My amp is rated 120 avg, 180 peak. If your speaker sensitivity is close to mine imo a second amp is not required for power needs. If you believe it will yield SQ benefit, go for it. $3k is a steal for those amps.
probably will, i have seen others buy 2 and then return 1. so psychological too, a big parasound JC5 being out matched in SQ by that little car amp seems incredible.
I'd like to report that our brother @Harris11235 is a very honorable and stand up guy without question,in out audio hobbyist community! Today at 10am my door bell rang and was handed my favorite bottle of scotch! It was delivered in that nice green pouch....Thank you sir!
technology is a good thing. I suspect you will hear more detail and greater dynamics. Especially paired with those Spendors I still would mention that the LA4 really lets the AHB2 shine. The LA4 was what made me go wow in that chain. It just adds so much to the realism and timbre of instruments.
cool preamp, hope you like it. i could be wrong but even when i put the original and other new/NOS tubes back in (which had no time to degrade because they weren't used that much) i hear no lack of the rounded sound signature.
Hmm…the first XA25 I owned was well broke-in and certainly a bit darker and warmer than the AHB2, but I still liked it well enough to make the switch. My current XA25 had only a few hours clocked when I bought it and was definitely brighter at first. Still, there are harmonics and details I hear with it that I don’t recall hearing from the AHB2. Of course, synergy is what matters most and it’s possible the AHB2 will have better synergy with your particular preamp and speakers. At least you’re scratching the itch.
yes it will be interesting how they work out- basically trying to get more neutrality and power and not lose much else. listening today to the XA25 and I think I must be crazy which is quite possible. the thing that tipped it in with the Benchmarks is their low gain- ~ 22db on the high setting. i had to adjust the gain on both Parasounds to 50% for the best sound. An amp with a fixed 29db or possibly even 26d gain would not work well with my preamp.
