For the past five years I’ve been a very happy camper with a 3W per channel tube amplifier running my A5s. I have 515Bs on the bottom with 288s on top. I also have a pair of subwoofers picking up everything 53Hz and below. But…
I’ve been pushing that tube amplifier pretty hard and with the availability of tubes these days, I started looking into solid-state solutions. I came across an Adcom rack with two GFA 565s pushing 250 W per channel for a “can’t pass it up” price.
The 515Bs are rated at 35 W. I was wondering what kind of sound pressure levels I can get running 35 clean watts into them? I’m sure more than I would want to listen to, but I was just curious.
Last edited by alancohen; May 24th, 2022 at 07:18 PM.
Allan, for the last 12 years, I've been running a hundred watts from 80hz up. Loud and clean. With double 18's per side filling in the lows. Mostly Rock and Roll. You'll find yourself turning it up louder and LOUDER !!!! Hopefully you won't blow anything up.
Well I'm enjoying my transition to the high-power zone. I can get the volume knob to about 5 on the Adcom preamp before the A5s start to struggle. The good news is, at that level, a few drywall screws started popping through the sheetrock.
Have you tried bi-amping ? Three tube watts on the 288's and adcoms on the 515's. Probably would sound better yet.
10log(35) = 15.44 dB, so IIRC the A5s are ~ 96 dB/m once EQ'd flat, making peaks in ~111 dB range, but the Bs easily handle 100 W music power (and much more IME, but leave it to the gentle reader to find their own max comfortable power), so tack on another 4-5 dB and add +3 dB for stereo, putting it within 'spittin' distance of THX cinema reference.Originally Posted by alancohen
Anyway, just based on this review, most definitely want to bi-amp due to its incredibly high DF that implies truly excessive -fb and the consequent rolled off HF that severely limits its mids/HF transient response, i.e ideally want it flat into the hundreds of thousands of Hz IIRC, but can't remember the R-O-T. Adcom GFA-565 monoblock power amplifier Measurements | Stereophile.com
In a quick search didn't find what class it is, but for hi-eff/res speaker systems we ideally want Class A or at least 10 W in Class A of a Class A/B amp with < ~ DF = 80. Also, if the amp is too powerful for the system's average power required, then it's not in the amp's power 'sweet spot', so may not be as linear as the measurements imply and factor in it doesn't list any Class A it may not be all that 'clean' based on my understanding, just super dry/sterile sounding that at least one time defined esoteric 'ne plus ultra' among the audio 'cognoscenti'.
Just musing.........tempting to try parallel 8 ohm power resistors across the drivers and run them @ 4 ohms as a poor man's matching impedance system.
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
What about the 15067?10log(35) = 15.44 dB, so IIRC the A5s are ~ 96 dB/m once EQ'd flat, making peaks in ~111 dB range, but the Bs easily handle 100 W music power (and much more IME, but leave it to the gentle reader to find their own max comfortable power), so tack on another 4-5 dB and add +3 dB for stereo, putting it within 'spittin' distance of THX cinema reference.
Anyway, just based on this review, most definitely want to bi-amp due to its incredibly high DF that implies truly excessive -fb and the consequent rolled off HF that severely limits its mids/HF transient response, i.e ideally want it flat into the hundreds of thousands of Hz IIRC, but can't remember the R-O-T
In a quick search didn't find what class it is, but for hi-eff/res speaker systems we ideally want Class A or at least 10 W in Class A of a Class A/B amp with < ~ DF = 80. Also, if the amp is too powerful for the system's average power required, then it's not in the amp's power 'sweet spot', so may not be as linear as the measurements imply and factor in it doesn't list any Class A it may not be all that 'clean' based on my understanding, just super dry/sterile sounding that at least one time defined esoteric 'ne plus ultra' among the audio 'cognoscenti'.
Just musing.........tempting to try parallel 8 ohm power resistors across the drivers and run them @ 4 ohms as a poor man's matching impedance system.
https://starin.info/Product%20Info/B...ltec/15067.pdf
Your neighbors called. They like your music.
Right, great if you can get them or similar at reasonable prices and has historically been the way to have both high SS power and high output impedance at ~reasonable prices in the early days of SS market takeover up till auto-formers became obsolete in the mass market in general and specifically in the audio segments.
I forget now what the custom winders were getting last time I checked probably a decade or so ago now, but IIRC I could of bought some pretty serious HT receivers for a pair of low power ones.
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
Re: VOTT A5s SLP max?
Allen, can we get a update ?
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