Question about Class A

@mesch 

Yes, you are correct, that is what I will need to do. Spend quality time with it and get a good sense of what it can do and then compare back to the Vincent.

@jay73 Sorry I missed the requested info.

I would listen to the Sudgen for a while. Let it break in. Let yourself adjust to it. After some 100 hours swap back the Vincent. Then revisit your thoughts.

Glad to hear that you bought the Sudgen A21SE. IMO there is also build quality to be considered when a purchase is made, and so in this case you won't have any regrets. I think that in integrated designs, the pre and power sections can be optimized for each other as intended by the designer.

  I have owned more than one great sounding piece of gear only to have it dump because of corner cutting in quality. Ever since, I am as interested in the build quality as to performance and even price.

Another option is a used class A amp,

-Luxman L series from the early 80's they are quite good and reasonable cost. also one of the higher powered class A amps out there at 50wpc. they also do not go into class AB/B.  L530,L540,L560 these amps are the predecessor to the new production Class A amps like the L590axii.  note the L560 was the last and best but rare outside Japan, i had one and its very good if you can find one (110v though). 

-Older Pass alpha series. 

-older krell 

-sungden of course. 

Cheers. 

glen 

@mesch 

I did list some of my components earlier in the thread but here is what I am working with:

- Martin Logan Motion 40 Speakers
- MoFi Studio Deck TT w/Hana SL MC
- Questyle CMA400i DAC
- Playing with 2 different phono pre-amps at the moment (Moon 110lp V2 and Jolida JD9 MK II)
- Technics SL-G700 SACD
- Windows PC used for Streaming (Qobuz) and Library of music (Flac, DSD) using Jriver

My room is about: 20' x 11' Cathedral Style Ceilings

The reason I mentioned the switch is because I really like my Vincent too and would like to utilize it sometimes.

Unless I missed it, nowhere herein did you state the other components of your system.  Remember you are listening to a system, not a single component.

I would not involve a switch box. Listen to the Sugden for a while. Then replace with the Vincent. Repeat with extended listening sessions. The experience will lead you to understand what sonic attributes are most important to you. 

Another question, what is size of your room?

Well, I thought I would post an update.

I received the Sugden A21se a few weeks ago and have been listening to it whenever I get a moment. The only times I really can listen wholeheartedly is in the late evenings when the wife goes to bed and things outside settle down (unfortunately I have some noisy streets) and even then, the weekends are really the best time for me to listen.

So far, I don't notice a huge difference between the Sugden and my Vincent. But I would say that is probably because of the rest of the equipment. Perhaps if the Sugden had better equipment to play with, it could shine even more.

Right now it feels like, if both were considered sport cars, perhaps the Sugden would be ahead but if you looked in the rear view mirror, the Vincent is not too far behind.

It's probably too early to tell. I need to spend more time with it.

In no way, does it sound bad. I think certain tracks whether digital or vinyl have caught my attention but need more time.

Now, I am thinking I want to use both amps. I may purchase a quality switchbox. I have contacted Decware and Mapletree regarding their offerings.

So that is my quick update for now.

Nice! That is slicker than cat poop!  Looking forward to your impressions. 

Wow, this is great!

Thanks so much for this.

I really appreciate it.

https://www.sugdenaudio.com/how-to

So I got the Sugden in and listened to just a few tracks last nite before I had to go to bed.

Question about the speaker posts on the amp. So I haven't come across the type of speaker posts that the Sugden has before.

There seems to be a a ring that you can loosen to accept spades and if you are not using spades, I suppose you tighten up. But right behind that ring, there seems to be another piece that turns (which accommodates banana plugs).

At first, it seemed liked I couldn't insert my speaker wires (Audioquest Type 4 Banana) but turn that piece (as if I was unscrewing it), now speaker wires seem to be able to go in.

I assuming that is so for different sizes of banana wires?

I'll have to inspect more. Fortunately, headed into a 3 day weekend, so I should be able to spend some time with amp now.

But wanted to get anyone's feedback on the type of speaker posts/jacks that Sugden has (if you have any experience with it).

Thnx

I contacted Tone Import (the official distributor for Sugden in the US) to inquire about official dealers, I was just curios.

So I am awaiting their reply but they did inform me that the price for the A21SE is now $3750.

$500 jump from the previous $3250. So the audio dealer that I had visited over the weekend was correct, the price has gone up.

Darn economy, supply chain and inflation, ha.

Congrats on your purchase! Please let us know your thoughts after comparison to your Vincent. I am thinking you are going to be very happy.

I had forgotten your were using an external DAC when making my last post. 

Well Folks, I did it, I done did it.

As mentioned earlier, I had heard the A21 yesterday at a local dealer but he didn’t have the A21SE in stock and his price was too much for me.

So I came home and searched around and found a dealer in TX selling through eBay.

Well I took the chance and bought it!

The A21SE should be arriving around 2/23. The dealer offers 30 day returns.

Looking forward to this Amp.

As I mentioned before, my speaker are 92db sensitive (at least according to the Martin Logan), so I am hoping it will be a good match.

@mesch , I have a external dedicated DAC, the Questyle CMA400i, which I feel is a really nice piece.

Once the amp gets here, of course I will be comparing to my Vincent. I am really hoping it’s going to be on another level then the Vincent.

I will let you know how it goes.

I really appreciate all the feedback.

Any owners of Sugden Amps, please also chime in.

Thanks

Jay ,

You can spend yourself blind sorting through the different class A components that are available. There are some great suggestions in this feed but consider the efficiency of your speakers and go to your dealer to listen on a few options. Some dealers even let you take items home for a test drive which may be best. I personally settled on a small flea wat amplifier that only puts out a couple of watts per side, but this is married to a set of really high efficiency Klipsch speakers. Unfortunately it's going to be different for every user. For your budget however I would encourage you to consider Schiit Freya+ and a pair of their monos! They can drive most speakers and they put out pure class A to a point. With class A you will find that you only are using the first five or 10 Watts anyways so don't worry so much about having a ton of power. The nice thing about this company is they are a US company and they will let you test drive in your home no questions asked. Hope this helps and happy Sonic Bliss

Jay, if you can find one, the Luxman L-550AX should run around $2500/3000, used and in very nice condition. They're 20W class A, then switch to A/B. I own an L-590AX, which is 30W, I bought it used for $4300, and it looked like new. That amp is one iteration older than the newer, but recently discontinued L-590AXII. Prices vary, some folks ask pretty high prices for a used L-590AXII, but they come up at times for more reasonable money. I believe the models, from oldest to new are A, AII, AX, AXII. Hope this helps, they're great amps.

If your speakers are truly 92db sensitive (sometimes mfg's over-rate them), I'd recommend the Pass-Labs 30.8 stereo amp.  Definitely punches way above it's 30WPC rating and has plenty of power-supply for 4-ohm speakers.  My 94db speakers 6-ohm impedance would play very loud and they seldom moved the meter needle !  Great sounding amp and does 30WPC in pure class-A, and I believe 60WPC into 4-ohms in class-A.  Really a power-house amp and highly recommended...  

At 3X the price the Sugden A21SE had better prove an improvement over the Vincent SV-500.  Actually any of the A21 series should be.

I would not advise the purchase of an amplifier with intentions of using your Vincent as a pre unless you are planing on replacing the Vincent with a higher end preamp in the near future.

Keep your eyes open for a used Sugden A21 series integrated. Should you find one you could purchase it, compare to your Vincent and keep the one that fits best into your system. Sell the other. 

As an aside to your original quarry, have you considered the purchase of an external DAC to replace the one internal to the Vincent?  Improvement in your source may prove to be a better expenditure.

@jay73 

try the Coda 11 mentioned.   100 wpc class A to output.  Should you decide to swap speakers,  the Coda will allow for future updates.   I have zero affiliation with Coda the company,  or the preowned being sold. 

respectfully, 

jose

I have Martin Logan Motion 40's, 4-ohm and 92db sensitive. 

What speakers do you have and whats their efficiency? If Magnepans, I can tell you Aegir isn't a good match, nice sound but 85db efficient speakers make it sound stressed and clip protection will cut in at loud passages. ASR didn't find that running them as monoblocks gave that much more headroom.

really important to know your speakers impedance curve/efficiency and to look for trustworthy reviews that used your speakers with different amps. An amp thats  ho-hum with one speaker can work well with a different speaker.

So I went to the local dealer today that I mentioned earlier to hear the Sugden.

He only had the A21S available to hear.

It sounded good but of course how it will sound in my system would be different.

He had it hooked up to a HiFi Rose and Klipsch Heresy's (I believe).

If he had the A21SE in stock, I might have actually bought it today. 

But he states it's $3700 and he can order it.

I can understand with the current way things are, that prices can go up but I can't do $3700. I would have gone for it at the $3250 prices that I have seen.

I figure since I am willing to spend the money and if I want Sugden, then I want to get the A21SE and not settle for the A21S (which in no way is a bad unit) but I don't want to feel that I settled later.

So the journey continues.

Just curious: I am thinking about by-amping my speakers (Quantum 2). With low/mid, mid/high and high being the high pass from 200 Hz (200/600/4000), how much power is needed? 

The idea is to use mean brute amp for thw Watkins (dual coil, dual crossover) woofer (dipping below 2 ohm), and a class A (or tube?) for the high pass.

Does someone know the percentage (for example white or pink noise) of sound energy above 200 Hz (vs below 200 Hz)? Maybe the term is 'spectral energy'? 

Less scientific: Using 200 Watt input (rated at 350 W RMS) how much power goes to low pass ( under 200 Hz, woofer) and how much to the high pass (above 200 Hz)?

This may not help, but it depends.  If you have efficient horn loaded speakers > 95 dB/watt-meter, you may hear a difference. 

...Or not. My speakers are 98dB and we make class A amps; we also make class D amps and they sound very similar. Class A is a means of theoretically reducing open loop distortion but like all things its a matter of execution.

Hi Jay78,

In my opinion, I don't think there is a difference in sound.  I have Klipsch La Scalas with efficiency of 101 to 104 dB.   I experimented with Schiit Aegirs (essentially Class A), Black Ice 3502s and Cary 120S Mark II.  I actually had a twinge of buyer's remorse with the Black Ice and the Aegirs and thought they did not have significant SQ improvement over my Outlaw 2200 monoblocks.  With the La Scalas, the amps are always in Class A.   It was a nice experiment:  in the long run, it probably may not be a good return on investment.  I like the Cary because it keeps my basement warm in the winter.  It is a hot beast as it runs in Class A in triode mode at 60 watts.  I would never use it in the spring or summer.  Class A amps are essentially gorgeous space heaters.

@ronald8 , my speakers are 92db.

That is one thing that I am afraid of, that I acquire a Class A device like the Sugden but don't really hear a significant difference from what I have now (at least in my system).

This may not help, but it depends.  If you have efficient horn loaded speakers > 95 dB/watt-meter, you may hear a difference.  Most amps are Class A for the first five to 10 watts and switch to Class AB for higher power.  Class A is terribly inefficient, with a theoretical value of 50% conversion to power, the other 50% lost as heat.  In practice the value is 20-25%.  The amp is producing four watts of heat for every one watt of amplification power.

Here are two good technical descriptions about Class A without the audiophile voodoo

https://www.sound-au.com/class-a.htm

In short there is nothing wrong with Class AB.  Performance sound reinforcement, especially in arenas with rock concerts are running AB through PA speakers.  Try the Class A and see if you like it.  If you have the skills, they are very easy to build as there are thousands of designs in the literature.

@atmasphere

IME You can’t judge any amplifier by its class of operation.

wisdom from ralph yet again

people confuse technologies with results... those folks lack a fundamental understanding of engineering, which is to make specific technologies work to achieve targeted performance parameters

just like dacs when people say r2r sounds x, delta sigma sounds y... ugh...

don’t listen to anyone who says that a properly made class D amp has the qualities you seem to seek. A, A/B, D etc. each have a flavor.  Although some A/B are biased for a handful of watts at the top.

IME You can't judge any amplifier by its class of operation. For example class D amps vary in sound just as much as tube amps do- some are quite nice, others make you wonder what the fuss is about. The 'flavor' of any amplifier is essentially its distortion characteristics.  Some designers know this and others don't.

You’re going down the right road looking for class A, don’t listen to anyone who says that a properly made class D amp has the qualities you seem to seek. A, A/B, D etc. each have a flavor.  Although some A/B are biased for a handful of watts at the top. .

@mesch , as far as AVA HiFi is concerned, I would consider the AMP, not the Integrated or Control Amplifier as they call it.

Either the SET 400 or SET 120 Amps with the Vincent functioning as a Pre-Amp, I think it would make a good combo. As you stated about your previous SV-236, I really would hate to give up my Vincent. It certainly is a sweet sounding unit.

But if I decide on the Sugden, then no, choice, I would have to let it go.

For my sources, I have an external DAC (Queststyle CMA400i), MoFi Studio Deck TT with a Hana SL MC Cart and a Technics SL-G700 SACD Player. So I feel my sources are pretty decent.

Yea, I am not in a rush, need to make sure I get the right unit.

@blackfly , I've never heard the Luxman's but I can imagine they must be awesome, especially the 590 that you refer to. Just way out of budget though. But they are beautiful for sure.

But you stated, I really want to hear what Class A is all about, Hopefully Soon.

Also to point out, there are MANY Luxman M 900u Class A/B units for sale......but the older M 800a Class A units are rarely for sale too and I wonder why.......

I personally am a huge fan of Class A.  In the Luxman 509x/590axII issue, one being A/B and the other, respectively, Class A, ask yourself why so many 509x units come up for sale, and not long after being bought, but the 590, a Class A unit, is only rarely for sale.  I think the fact one is Class A is the factor.  Once I experienced it there was no going back.  I am trying to get there myself......

@jay73  I agree that the SET 120 would be the better purchase as you would not need the additional power. Are you talking about the integrated version or the amplifier? AVA makes both. 

What are your sources?  If digital you would have to replace the DAC in the SV-500. At your budget with purchase of the 120 integrated you could purchase a tube DAC if wanting some tube sound in your system.    

I must say that I once owned a Vincent hybrid amplifier, the SV-226. It was class AB. I sold it and consider that move one of my audio mistakes. It had more power than the SV-500 at 100wpc and was line level only. Fed it with an outboard DAC and phonostage for sources. I would encourage you not to be in a hurry in your decision making. Continue to explore.

I am still at a loss to recall a class A 20+wpc amplifier that retails for ~3K other than the Sudgen. Not to say they don"t exist.    

Really appreciate all the feedback so far.

@erik_squires , Thanks for that clarification. That is a good point

@mesch, You are right, I was asking about an Integrated but with all the great feedback, now I am also considering adding an amp versus a whole new integrated.

I emailed AVA and Frank responded. I was inquiring about their SET 400 Amp and if he thinks it would be a good match for my speakers.

Frank actually recommended their SET 120 instead of the 400. So I am considering that also now and of course it is much less expensive so that is a plus.

The SET 400 is out of stock right now but Frank mentioned that they are working on a whole new chassis and that is going to take another month or so. Looking forward to see what they produce.

With all the feedback and now also seriously considering AVA Products with their great review and still being very curious about the Sugden, as suggested earlier in the thread, I am going to see if I can get a demo at the dealer that I mentioned and I need to inquire about their return policy.

What I may do, is purchase the A21 and the SET 120 and then compare in home to see what I like better. If the A21 comes out on top and I really like it, I would have to return the SET 120 within their 30 day trial period and I might just go back to the local dealer and exchange the A21 for the A21se.

Those are my thoughts right now.

At the end, I have to be happy with I buy and be content with it.

BTW, I didn't suggest you buy a Luxman, but that the Luxman line has nearly identical integrateds except for the class A portion, so you could use them to compare and listen to the difference, to see if Class A was really a worthy goal all by itself.

The OP is looking for a Class A integrated amplifier.  Budget extends to 3K new/used.  The Sudgen A21SE used is the only one that comes to mind. Others?

AVA build quality value minded gear. Rave reviews all over the interweb.

Just came across this Amp: Vision SET 400 Amplifier

Any opinions on it? So far the reviews I read seem positive.

I also had the LSA Voyager 350 GAN (modded by EVS). It is not a Class A sound. It sounds more like a Benchmark AHB2 with more low-end and can go down to 2 Ohms. I sold the LSA Voyager -> Parasound A21+ -> KRELL 175XD (happy with the KRELL). I kept the Benchmark AHB2.

The KRELL stereo amps are rather ugly and big. The K-300i is not too bad looking.

Here is a review of the Parasound A21+ that mentioned Class A and low volume listening.

Parasound Halo A 21+ Stereo Amplifier Reviewed - HomeTheaterReview

I owned the older Parasound A23 and I was happy to sell it. The A21+ was so much better than the A23. From what I have read the A21 is supposed to be a big step up from the A23. I would imagine the same for A23+ to A21+.

Investigate GaN amps first. There are several threads on AG that should prove helpful (one is mine). As I recall, at least one person preferred the LSA Voyager GaN amp to Nelson Pass, PLUS, GaN runs cool (less electricity) and Underwood sells them for ~ $2500. I have owned one for over a year now, and every upgrade I make around it is immediately appreciated

@rfnoise. +10

Great advise given thus far.  That Coda is a bargain.    Excellent amp, excellent service.   I have a Coda S-100 and won't part with it...  I also have Mephisto Solos,  Boulder 2050/2060 and Krell KAS amps.

Give the Coda a chance,  you won't regret it. 

Good luck in your search, 

Jose

@yyzsantabarbara , you mentioned Parasound. I was actually thinking about Parasound also but maybe the A23+. If the A21+ puts out 6 watts in Class A then the A23+ might be half that or something, I am not sure.

But I suppose it could still sound good. Overall seems to get good reviews. 

The one thing I am confused about these types of amps is, at what point or volume, does it switch to AB from A.

With the Parasound, if I listen in low volumes, am I pretty much staying within Class A territory?

The Krell, as I said before, might be out of my budget but I will keep a eye out. But I have to say one thing (don't hate me for it, haha) but at least from the pics, the aesthetics do not look that attractive). I know, I shouldn't go on looks but performance.

The Nelson Pass First Watts might be an option to.

Damn, so many good choices. 

I’m using Pass Labs XA30.8 with Martin Logan Montis. Preamp is Pass XP-12. 
Incredible sound and never runs out of headroom no matter how hard I push it. 
Purity, dynamics and details in spades. 
I wouldn’t hesitate going with Pass Labs amplifiers. 

I have to second the Krell K 300i with it’s Patent Pending I bias circuitry -  I have owned my Krell integrated for over two years and drive Maggie 1.7is. It fills the room with Class A sound and never runs hot. New it does cost $7,000 but if you find one used grab it - you will not be disappointed - build quality is amazing!

@jay73 You can find a used Parasound A21+ for around $2500. Which is what I paid for it. I traded it in for a KRELL 175XD but the A21+ was very good.

[edit] Oops. I did not realize you were referring to the Sudgen . However, have a listen to the Parasound. It is rather good and in the price range you seek. The first 6 watts are Class A.

Forget anything about marketing and of course Krell 175 doesn’t have 175 Watt Class A, even most of Pass Labs amps don’t. Normally you will have 20-30W Class A, producing a heat of more than 100-150W for that kind of power. I doubt there is a good cheap Pure Class A out there, because design, materials and heat dissipation will make it heavy and expensive.

Here is the marketing for the KRELL. iBias Technology – Krell (krellhifi.com)

Krell’s iBias Class A technology allows our latest amplifiers to run in full Class A mode to full power while minimizing heat generation. Previous efforts at using a “tracking” bias, while effective, only measured the incoming signal and set bias levels from this information. Our new patent pending iBias technology significantly elevates the effectiveness of previous designs by calculating bias from the output stage. This seemingly small change in topology results in a dramatic improvement in sound quality, especially midrange richness and purity.

Seems pretty clear to me.

@audioguy85 A dealer in Irvine, CA is selling the A21 for $2400 actually (my mistake). That’s the one that I was referring to. The A21se, they sell for $3250 as you mentioned.

@cakyol The Schitt Aegir does look interesting. I looked into it a little bit. Seems like two use the Aegir as mono’s, you need to use the balanced input and my Vincent does not have Balanced outputs.

Also, according to reviews I read, when used as mono’s, you have to be connected to 8-ohm speakers although I saw a review by New Record Day on YT and he had them connected to 4-ohm speakers but I guess it’s not official by Schitt.

And Class A is for the first 10 watts and after that it goes into it’s "Continuity" Technology which is supposed to still sound close to Class A.

But as I said, it does look like an interesting option.

@audioguy85  Ever get a chance to hear Sudgen's integrated one model up from the A-21se?

I think its called the i-4?

Class A power amp don't have an intrinsic sound.  The overall design of the amp is more important.  It's not like in tube amps where someone can hear the difference between EL84s and 300Bs.