Musical Fidelity A1 - Sugden A21, how do they compare?

Many Sibelius owners have asked me how the Musical Fidelity and the Sugden A21 compare, and I was very curious too! Both amplifiers are Class A and have a similar outputs and feature sets. However, the Sugden A21, with a phono input is more than twice the price of the Musical Fidelity A1 at 3,400EUR versus 1,600EUR for the Musical Fidelity.

Musical Fidelity A1 Specifications:
Power: 25 Watts per channel into 8 Ohms
• Voltage: 42.5 Volts peak to peak
• Current: 25 Amps peak to peak
• Damping Factor: 150
• Gain: 32dB in Direct Mode, 42dB in Normal mode
• Output devices: 2 per channel
• Signal to noise ratio: 82dB
• Channel separation: 85dB
• Frequency response: + 0, –1dB, 10Hz to 40 kHz
• Line level sensitivity: 300mV rms nominal, 8V rms max
• Line level inputs impedance: 25k Ohms
• Tape Out impedance: 220 Ohms
• Pre-Out impedance: 100 Ohms
Inputs: • 1x phono RCA MM - MC, 5x line RCA
Outputs: • 1 x line level RCA fix TAPE OUT • 1 x line level RCA variable PRE OUT

Sugden A21 Specifications:
Power Output 23 Watts into 8 Ohms
Line Input Sensitivity 170mV for max. out
Phono Input Sensitivity 3mV moving magnet, 0.2mV moving coil for max. output
Phono Loading MM 47K MC 470 Ohm
Frequency Response plus minus 1dB 10Hz-20kHz
Bandwidth 6Hz-200kHz
Signal to Noise: 83dB
Gross Weight (packed) 11kgs
Dimensions 92 x 430 x 350mm hwd
Inputs ​ Five line level, four if with mm or mc phono input
Outputs Pre-out - variable, tape out - fixed
Remote Control Volume up & down

Social media links:

[jos]

A very, very thorough review! You’re certainly one of the best reviewers out there (IHMO)! And above all, a very good advice for potential buyers at the end!

[razisn]

About the A1' Class A. It is a PUSH- PULL amp. This means 2 things. Efficiency is in theory double when operating within Class A than what you mentioned (which is applicable to single ended Class A) and it can slide to class B if required, up to the limits of its rail voltage and power supply. The A1 is effectively a very high bias Class A/B fwiw. The Sugden, I believe, is single ended, being SE it can ONLY operate in Class A. Once it reaches what its bias voltage can provide it will clip.

[avro]

I've had both CLASS A amplifiers from the 80s and was very happy with both, something special about CLASS A topology.

[DonHamlin]

Excellent, thoughtful review. You pick the most interesting pieces of gear to review.

[medonkrs]

That was a fun review, thanks!
The sound sample in the end of the video is surprisingly revealing. Huge difference in sound - the A1 seems more groovy, but lacks the bass pluck/attack of the Sugden A21. Though call.

[kesm]

Day one notes on the MF A1: Heat sink temp was taken with a meat thermometer (133.9 F). I can tolerate my outstretched hand on the heat sink for around 5-7 seconds. Now with that out of the way…I have no major complaints with this amp. I have it on a A/B switcher with a Sugden A21SE. The MF A1 holds it own. I cannot say one is ‘better’ than the other. I think it will likely come down to listener preference if one is choosing between the two. The Sugden seems to have the slight edge in detail retrieval. The MF A1 bass sounds deeper (more grunt-gutsy)…& this tactile feeling in tonal quality seems to extend to the overall signature of the MF A1 amp. I had difficultly making the distinction between the two amps beyond these slight nuances. Both present music in a palpable way. These amp sources are more similar than dissimilar (to my ears). I think the MF A1 glosses over recordings moreso than the Sugden A21SE. This isn’t necessarily a bad thing…seems like it would benefit or ‘play nice’ with poorer recordings. I don’t know that there’s a fault or edge either way between the two power sources. The voices on the Sugden sound forward (sharper with sparkle). The voices on the MF A1 sound slightly further away or blended into the mix/recording. The Sugden casts the voices to the front of the mix.

The listener is rewarded by both units with an emotional connection that class A/B amps, that I’ve had, seemingly cannot match (Krell Vanguard, Hegel H390). Particularly if you prefer a warmish sound signature. I don’t find either amp overly warm in sound signature despite the chassis heat😅

Those seeking neutrality, cool/detailed/clinical sound signature (often associated with equipment that ‘measures well’) will likely be displeased. Albeit I don’t think that user profile would seek a Class A amp.

My source is an Oppo 205 (Russ Andrew’s mod). Speakers are Salk Song 3 Encores (88 db) & Spendor Classic 4/5 (84 db).

Note: Sugden A21SE temp was taken; topped out @ 93.9 F.

[marktupper]

Back in the day I had an MF A1 MK2 with a pair of floor standing Monitor Audios playing all sorts - Big time thumbs up !!

[RobGem]

I always think when people are over analytical about their music they have gone past the point of just laying back chilling out and loving the music in a way. I feel sorry for them because they’ve lost the ability to zone out and just love the music they have this bad habit of needing to analyse it which if you were sound engineer, I understand where they’re coming from but if you’re meant to be enjoying the music don’t analyse it you’re ruin the fun, and the moment that all being said the sudden better amplifier all round I’ve never understood the fascination for the musical facility it used to go wrong overheat and break in any of the industry that would be a big no-no yet for some reason it’s got a following

[karlludwigbonitz]

Back in 1985 the original A1 couldn´t drive my Spendor 75/1 properly. But the A100 could, very beautifully, a match made in heaven that started me on a lifelong journey. I sold the amp to a friend who is still running it today.

[johntucker]

Harley, thank you for such a nuanced, intelligent review. When I was attending an all-male Catholic college-prep high school in the U.S., we immature students would often comically mimic our Dominican teachers (for better or worse). One popular phrase we mimicked was: "You are a gentleman and a scholar!" Well Harley I think that describes you perfectly! One other point: is Lovegrove really your last name? 🙂 One might wonder if Lovegrove is a pseudonym chosen by a person who wants to market oneself as a loving person whose personality and character is reminiscent of the peace and joy one experiences in nature. 😉 Brilliant! I am presently seriously thinking of changing my surname to Lovegrove. You have my sympathy for my poor attempt at comedy. I think very highly of you, and I am happy you are on YouTube presenting your audiophile opinions and experiences. You raise the bar. Happy Holidays!

[petervirnuls]

I’ve had the original in the past. It was repaired three times, and had two further volume pots. I got tired of it, so I bought a Cyrus 2 /PSX, then Audiolab 8000C/P. Because I felt bad about selling it, I kept the A1. Some years later I connected it back up and loved the mellowness. I was ‘t that keen on it as a teenager, but as I’m now much older, it suits very well. I then tried the Krell KSA100 Mk2, and finally the FBP600. The class Asound is really different, and hard to describe - but you did a good job! The big Krell isn’t ideal in an energy crisis - can be almost 3kW when at louder volumes. Even on standby, it can be £2 per day

[Temmple]

A1 for me. More of a natural presentation. Paired with the right speaker could be a match made in heaven. Will be testing this amp with the 1TDx in the near future.

[raphaelmeillat]

Great video review as usual! Interesting exercise at the end of the video. Was listening to the comparison through a pair of headphones. Not a huge difference overall, but after repeat back and forth, Sugden definitely offers a wider soundstage, more 3D like as well. Yet, I prefer the singer's voice through Musical Fidelity's A1! So that's a tough call!

[johnmcdevitt]

I own it and I love it, my thoughts on the A1 are in alignment with Mr. Lovegrove. So what sounds great in hifi does not necessarily feel great! Kinda like popular tunes, the dull tunes are often more popular than the sharp tunes because emotion feels better than thought for many, I love my tunes both ways. Sometime fun, sometimes contemplative. For a relatively affordable secondary system designed for the fun factor feels, class-A power is an obvious consideration, the A1 delivers.

[snarf]

I am demoing an A1 with ProAc D2R speakers. I really like the combo! Directly compared to my Elex-R, i get to about 11o clock on the volume which is about 84db average on my phone's sound meter. That is plenty enough for me. I listen to heavy metal and so tolerance with poorer recordings is a must, and A1 seems to play nice. I notice plenty of texture and weight to distorted guitars, and some real grit on the bass to well recorded albums. It's all very entertaining. Sugden A21 and maybe SE demo is up next, i can stretch the finances that far, but i need to mak sure they are worth the extra over the A1 as it really is very good!!!!

[AdiMaco]

I love music. I love audio gear. I follow many review-ers on YT, Tarun aka The British AudioPhile, Steve Gutenberg aka The Audiophiliac, Audiophilia, and a few others and I have to say that I really like the way you review. It is different. You are a bit different. I like a firm grip on the bass and a fast, controlled bass. I would have loved to hear your thoughts about the kind of base these amplifiers create or re-create with your speakers. On the other hand, to be brutally honest, I didn't know what to think, theoretically, about your speakers because of the low sensitivity. Yes, I like one driver, and one source point speaker like Sibelius, but in my mind, I have always thought that that driver must be high sensitivity and the cone must be paper. Anyway, I like your YT channel very much!

[martybennett]

Hi, I can understand the analogy you are trying to make with the lightbulb as my i remember when i was child in the seventies my parents using 100 watt bulbs. However electricity in the UK is ridiculously expensive now, and no one would dream of using them anymore .

[mjjm]

Well, this week I got my Burson Mono block amps and they work great with the Sibelius speakers. I couldn’t be happier!

[crtgamer]

I listened on my monitor headphones, and at first I thought I preferred the warm tube like sound of the A1, but upon repeated listening, I realized how much wider and more 3 dimensional the Sugden sounded along with more detail.
Since I have a hybrid system which comprises of a semi decent audio interface playing digital files through a vintage amp and speakers, I have to say I can't go without the detail of my interface any longer. I love the warmth of my amp and speakers but the interface just pushes it to another level and I think for that reason I would prefer the Sugden.
If I wasn't spoilt by my audio interface's detail I would have most probably gone with the A1.
I think combining vintage warmth with some modern detail is the perfect sweet spot.

[albiepalbie]

I have the A1 matched with Quad Esl 57
No Bruckner or Headbangers so very good
Beautiful vocals - Nick Drakes 3leaves left georgeous Guitars and Strings
Sean Shibe s latest CD on Pentatone is Magic !