• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Class AB Power Amplifier Recommendations

OP
M

mdsimon2

Major Contributor
Forum Donor
Joined
Oct 20, 2020
Messages
2,515
Likes
3,369
Location
Detroit, MI
Curious, what sub is it?

Not necessarily a specific sub, in general I view amplifier purchases as an "investment" that I will use for many systems in the future.

Currently I use Dayton RS315HFA-8s in 1.5 ft^3 sealed enclosures and Dayton RS265HF-8s in 1 ft^3 sealed enclosures. Both enclosures are slightly undersized (QTC of about 0.82) so I use some DSP to extend the response which requires more power than a slightly larger enclosure that would not require DSP.

Michael
 

Neddy

Addicted to Fun and Learning
Joined
Mar 22, 2019
Messages
756
Likes
1,031
Location
Wisconsin
I have a perfectly functional Bryston 3BNRB I'm not using anymore - might meet those requirements? Hm. Maybe not power output....?
Just a thought....
 

jomo

Member
Joined
Aug 17, 2021
Messages
34
Likes
45
Thanks. That looked promising at first until I realized the XLR was only for BTL and it had RCA for stereo inputs. I switched to balanced DACs a while ago and have no desire to go back to single ended.
Seems like the Schiit Vidar 2 exactly meets your needs, sans the SE inputs in stereo. Why not just get some cheap XLR to SE cables as you would save a ton of money on the amp. Later, if you want to power your sub, you have the balanced input to use.
 

Chrispy

Master Contributor
Forum Donor
Joined
Feb 7, 2020
Messages
7,938
Likes
6,097
Location
PNW
Not necessarily a specific sub, in general I view amplifier purchases as an "investment" that I will use for many systems in the future.

Currently I use Dayton RS315HFA-8s in 1.5 ft^3 sealed enclosures and Dayton RS265HF-8s in 1 ft^3 sealed enclosures. Both enclosures are slightly undersized (QTC of about 0.82) so I use some DSP to extend the response which requires more power than a slightly larger enclosure that would not require DSP.

Michael
I'd want at least an amp with 4 ohm capability, and better, 2 ohm, for subs, particularly if looking to better ones in the future. I wouldn't particularly want an amp only suited to 8 ohm subs and I wouldn't want to bridge an amp generally, I'd just get one of better power capability to begin with. Why I was curious. Having identical amps for all drivers wouldn't be a concern, tho.
 

dualazmak

Major Contributor
Forum Donor
Joined
Feb 29, 2020
Messages
2,850
Likes
3,047
Location
Ichihara City, Chiba Prefecture, Japan
I am looking for 5-6 stereo amplifiers for DIY speakers. My preference is to use identical amplifiers which is why I like the ability to bridge so I can get 400 W in to 8 ohm for subwoofer.

Why?

And why are you excluding various HiFi "integrated class-AB amplifiers" usually more affordable than rather expensive "power amplifiers".

At least for me, I believe that amplifiers for SP drivers should be selected in the manner of "right person in right place"; for example, you definitely do not need much powerful amplifiers to drive your highly efficient tweeters and/or supertweeters, but small power high S/N low distortion amplifiers would best fit for these highly efficient SP drivers.

As I shared here, even Greg Timbers uses "reasonable and budget" Pioneer Elite A-20 for compression drivers (super tweeters) in his extraordinary expensive multichannel stereo system with JBL Everest DD67000 which he himself designed and developed.

If you would be interested, you can find the summary of my amplifier exploration here on my project thread.
 
OP
M

mdsimon2

Major Contributor
Forum Donor
Joined
Oct 20, 2020
Messages
2,515
Likes
3,369
Location
Detroit, MI
Respectfully, I've done far too much explaining of "why" already and that is not the point of this thread. I am interested in finding products that meet the specs laid out in the OP.

Asking why I am looking for something with these specs is not helpful, especially when these posts contain no recommendations of specific products.

To those that have provided recommendations meeting the specs, thank you again! This thread has exceeded my expectations as you have identified 3 amplifiers that I was unaware of that meet the specs.

1) Cambridge Audio 840W/851W
2) Arcam PA240
3) Bryston 3B-ST

Michael
 

Koeitje

Major Contributor
Joined
Oct 10, 2019
Messages
2,306
Likes
3,965
Last edited:

SIY

Grand Contributor
Technical Expert
Joined
Apr 6, 2018
Messages
10,511
Likes
25,350
Location
Alfred, NY
Your're uninformed - it is digital by virtue of being a switching amplifier.


The filter is not sufficient to supress the RF.
This is incorrect in both respects. PWM is in no way digital, and the carrier is extremely well suppressed in engineered amplifiers.
 

Beave

Major Contributor
Joined
May 10, 2020
Messages
1,394
Likes
3,015
Because digital amplifiers leak considerable amount of low frequency RF which affect the T-cell bloodcounts in your blood potentially leading to leukemia. Us, old HAM operators, know to stay out of RF fields. No guessing how I know.

Wow. Just wow.
 

AdamG

Helping stretch the audiophile budget…
Moderator
Forum Donor
Joined
Jan 3, 2021
Messages
4,747
Likes
15,728
Location
Reality
Because digital amplifiers leak considerable amount of low frequency RF which affect the T-cell bloodcounts in your blood potentially leading to leukemia. Us, old HAM operators, know to stay out of RF fields. No guessing how I know.
Would you be so kind as to provide a few reference links to Medical Journals and such for further reading? I know that our Members will be very eager to read and learn more about this. Thank you for your time and support.
 

Pecrobet

Member
Joined
Oct 24, 2018
Messages
22
Likes
18
Location
Detroit, MI
I've been casually looking for a class AB power amplifier with the following specs without much luck.

100 W x 2 into 8 ohm
200 W x 2 into 4 ohm
400 W x 1 into 8 ohm (BTL)
< 100 uV residual noise, unweighted, 20-20K BW
19 dB < gain < 28 dB
balanced inputs
< $2000

Here is what I've considered so far:

1) Benchmark AHB2: Meets all specs but price is high
2) ATI 18XX series: Gain is on high end and doesn't seem to support bridging
3) Emotiva XPA series: Gain is on high end, noise is a bit high and doesn't seem to support bridging
4) Adcom GFA-565se: Noise is about double what I am looking for
5) Rotel RB-1552 Mk II: Doesn't seem to support bridging

Anyone have other suggestions?

Michael
I recommend the Rotel RB-1552 MKII. I recently purchased this power amp. The sound quality and performance is amazing. Excellent soundstage, detail, depth and dimension. I have it connected to pair Wharfedale Linton 85's. I find myself listening for hours without fatigued.

To determine how good of an amp the Rotel was, I connected numerous speakers from B&W 606 S2's & Fyne Audio F303's to vintage Altec Lansing's & Pioneer CS-77A's.

The Rotel thrived with every speaker set. I was completely surprised how well the amp sounded with such wide array of speakers connected.
 

dualazmak

Major Contributor
Forum Donor
Joined
Feb 29, 2020
Messages
2,850
Likes
3,047
Location
Ichihara City, Chiba Prefecture, Japan
I recommend the Rotel RB-1552 MKII. I recently purchased this power amp. The sound quality and performance is amazing. Excellent soundstage, detail, depth and dimension. I have it connected to pair Wharfedale Linton 85's. I find myself listening for hours without fatigued.

To determine how good of an amp the Rotel was, I connected numerous speakers from B&W 606 S2's & Fyne Audio F303's to vintage Altec Lansing's & Pioneer CS-77A's.

The Rotel thrived with every speaker set. I was completely surprised how well the amp sounded with such wide array of speakers connected.

Essentially agree with you.

In my case, I too rather intensively tested Rotel RB-1582 MkII in comparison with BENCHMARK AHB2, ACCUPHASE E-460, YAMAHA A-S3000 and YAMAHA A-S301 in my audio setup at my home audio listening environments.

I found ROTEL RB-1582 MkII, I believe same for RB-1552 MkII, is so nicely built (rather physically large and heavy though, but needed to be so) very robust amplifier as you described for RB-1552 MkII. RB-1590 (38.1 kg, 84 lbs.!) also looks/seems very nice, of course.
- Rotel RB-1582 MkII (class-AB)_Part-1_Comparison with AccuphaseE-460 and Benchmark AHB2 in single-Amplifier + LC-network full range reference sound system: #263
- Rotel RB-1582 MkII (class-AB)_Part-2_Incorporation in multichannel multi-amplifier system and listening Sessions: #264, #265
 
Last edited:
Top Bottom