Never heard a negative word about Sugden amps — only positives so not surprised. Congrats and enjoy!!!
Class A integrated amp recommendations
Greetings 'goners after a prolonged absence from posting here but eavesdropping on your conversations in the interim! I was hoping to get some feedback on your experiences with class A integrated amps. My audio journey thus far provides some context.
The core of my system, Sim Audio Moon I5 integrated, Joseph Audio RM7si Signature on 20” Sound Anchor stands has remained unchanged for about 20 years. Sources are Sim Audio Moon Nova and Rega Jupiter2000 CD players, Sim Audio Moon LP3 phono for my AR ES-1 turntable with Audio-Technica AT-VM95SH cartridge. Cables are Zu Audio.
Primary music interests are acoustic jazz, small scale classical, classical/crossover, some orchestral; but I can, and do, veer all over the map when a bout of nostalgia hits: classic and prog rock, punk, grunge, reggae, singer/songwriter. For me, it’s always been about the music. The stereo is only a tool. It is not the work. During that time I’ve not felt the need or urge to chase gear. I enjoy music.
Until about 6 months ago when I acquired a new turntable: Technics SL-1210GR with Audio Technica AT33PTG/II and Ortofon 2M Black cartridges. Then a PS Audio Stellar phono. And now, as I’m about to retire, I feel like a kid! Those Blue Note reissues have awakened some kind of Mr. Hyde in me that wants to try new stuff!
Hence this post. Your experiences with Class A integrateds feeding speakers similar to mine would be greatly appreciated. I'm intrigued by, but have not heard, gear from Pass Labs, Sugden, and Luxman. Of course, cost is a concern as the law of diminishing returns keeps me away from the insanity of uber-pricing.
Kind Regards
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Thanks Coltrane1 for the kind words on the thread question. After much wrangling, almost pulling the trigger on subs, I found a very reasonably priced used Sugden IA-4, which brought me back to my original intention when I opened this thread. It's been in my system for a few weeks now. I must confess that I'm infatuated with this amp. My first impressions is that this amp is certainly a level up from my Sim Audio I5. The soundstage appears a little wider but more significantly, deeper, more 3d. The presentation seems richer, more saturated to use a color analogy. I was looking for was more detail, a more vibrant presentation at lower volume levels. The Sugden has given me that! Will it be an end game amp for me? I can't say just yet. I would still like to audition other Class A integrateds, especially the INT-60. And I haven't discounted adding subs. In the meantime, I'm setting my system up so that I can A/B test the two amps. Again, my thanks and regards to all who took the time to comment. Cheers |
Firstly, that’s one of the finest thread questions I’ve read in a long time. Well done! I’ll get to the point - Another vote for tubes. I own a pair of Martin Logan Summit’s. The price you pay for their mid range brilliance are power requirements. But the fairly new Summits aren’t nearly as difficult to drive as their early predecessors. So that’s where I chose to purchase a pair of used KT88/EL34 monoblocks. That’s some 80 watts total of glorious tube power. That’s much more power than is necessary for these speakers. I too, if you’ve not guessed from my username by now, possess a penchant for vinyl Blue Note releases. In fact, they’re a must! Bottom line. I purchased a fabulous used tube preamp, and used tube monoblocks, for about $1500 less than the going price of a used Pass Integrated. Would I switch if I had the opportunity? No, I wouldn’t. Fact is, I’m done acquiring audio gear after some 40 years in this hobby. And I’ve not quite reached my golden years. But they’ll be experienced with tube gear. For, sooner or later, one has to stop chasing the rabbit, and simply chill in the moment. Enjoy! |
Perla S50. It’s not Class A, but AB, however it sounds very organic, very class A. Single ended inputs only. I’d compare it to a Pass INT60, but more visceral, present, lifelike. One of those times I walked into a little crummy hotel room at a show and couldn’t un-hear it. Played on Perla’s 2 way speakers. The only other times (years later) I’d ever heard a two way speaker sound so good were Audio Note AN-E/SPe HE’s (? model names get confusing) driven by their most expensive gear, Ocean Way Eureka’s (which I bought) driven by AGD Vivace GanFET’s, and the big QLN Signatures driven by a Gryphon Diablo 300 Integrated. I am a Pass owner, btw. Good luck finding one. |
I previously owned the Sugden Masterclass IA-4 and Pass Labs INT-25. I now own the Pass Labs INT-60, which beats the Sugden and INT-25 hands down. The Sugden is no match to the Pass Labs. The INT-60 is a true reference, and an end-game amp for me in my setup. And using its true balanced differential circuitry has been a game changer for me. |
EAR 834 and 8L6 are push pull class A tube amps that a very musical sounding an new, are affordably priced around $6750. Both are 50 watts and play well into most speakers (not those with multiple really big woofers with low impedances based on my experience with Legscy Focus but great with Legacy Signature IIIs). Even sweeter is the EAR 899 (discontinued) with 70 watts using a kinkless tetrode K90 tube configuration (or KT88 if one prefers, which I do and own a pair of 890s). |
@soix +1 "Plus, and very importantly, subs are not only about bass — not by a long shot. Properly integrated subs will greatly enhance both 3D imaging and greatly expand the soundstage in addition to providing more dynamics and better bass overall." Seems to be a very common misconception that adding subs is about power, whereas it is actually about finesse. |
Used Sugden for $3500 https://www.usaudiomart.com/details/649995700-sugden-ia-4-masterclass/ |
They all can work, but given your space/placement constraints I’d lean toward sealed subs that tend to be smaller (and potentially quicker) and that include DSP to help with integration. I’ll reiterate my prior suggestion for the SVS SB1000 Pro subs with a completely risk-free trial period. Why not??? At the very least you’ll come away with valuable experience and maybe even a new perspective. That said, I’d still strongly consider waiting for a nice pair of original Pulsars to come up for sale although that doesn’t preclude you from trying subs in the meantime. |
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After replacing the 40 year old Quad amp in my system two years ago with an Audio Note pure Class A integrated, I have never gone back. I listen to exactly the same music you do, but on Quad ESL-57s, also over 40 years old. After two years, I am still enjoying finding new and wonderful things in my records and CDs I have been listening to for ages. Can't imagine better clarity, openness, or the feeling of being right there in front of live musicians. Highly recommended! |
as @soix commented, properly integrated and implemented, adding subs will be the impactful change to your system (i suggest smaller rel's)... they will not overpower your room but they will make the sound truly wonderful, full range, with a vastly expanded sense of space and dimensionality
int30a is based on the older gen xa30.5 power amp whereas int25 is based on the newer xa25 power amp... both integrateds have slightly less headroom than the power amps on which they are based (but still plenty for higher efficiency speakers used in medium/smaller rooms) -- the 30 will sound slightly sweeter more rounded, whereas 25 will sound a little sharper more direct more matter-of-fact
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I respectfully disagree with this. I think adding two small subs could be revelatory to your listening experience. An example would be a pair of SVS SB1000 Pro subs that measure only about 13” square yet still get down to an honest 20Hz (-3dB) and include DSP integration software that makes them relatively easy to seamlessly blend them with your speakers and room, and a pair will only set you back $1150. Plus, and very importantly, subs are not only about bass — not by a long shot. Properly integrated subs will greatly enhance both 3D imaging and greatly expand the soundstage in addition to providing more dynamics and better bass overall. SVS offers a 45-day, risk-free trial period (including shipping both ways) and I’d highly recommend checking them out. Even if you upgrade to something like Pulsars in the future you’ll wanna keep the subs. Just something else to chew on FWIW. |
Thanks all for sharing your thoughts. The suggestions to move up the JA line have always been on my mind and is something that I aspire to. Used JAs are fairly rare and I'm patient. I should note that I'm not looking to replace the I5 but to try new amps in order to explore how the JAs sound with other amps. The I5/RM7 sig combo has been with me 20+ yrs, it's not going anywhere and is my point of reference (sure there are much better systems but also much worse). Suggestions have been made to add a subs but I think they might overpower my space and I don't really have good placement options for them anyway. More powerful amps have been suggested, but for my listening levels I don't feel that I really need more raw power. If that were the case, I'd probably move up the Sim Audio line because I do like that house sound. The rational is that I rarely exceed 32 on the volume setting which is .1 dB steps from 0-37 and .5 dB steps from 38-51. And most of the time volume is set from 24 to 30. Given that the I5 is rated for 70W with Class A operation for the first 5W, I'm guessing that for those levels, the I5 is delivering somewhere in the neighborhood of 25 to 40 watts. Of Class A/B power. So what would 30W of pure Class A sound like? I'm dying to find out... Lastly JA owners, are you out there?
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i am a pass owner and big fan but i think there would be many who would argue with the feelings expressed above, both on the question of value for $ as well as sonic differences vs luxman
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When it came time to replace my 25 year old CJ PV 5 & Solid state amp combo a few years back, I lusted after an Ayre EX-8. As my wife let me know that was out of the question, I settled on a Luxman L-550AXII. ive continue to be quite happy with the choice. It has a bit of the richness and depth I associate with tubes, without the loss of resolution. It’s a polar opposite of the plastic 2d sound of class d. the build is superb. Every day, after listening to much more expensive gear at work. I go home and enjoy the Luxman. At the time, I considered the 590ax II, but the president of Luxman America convinced me the power of the 550 was more than adequate for my 91db speakers. As I’ve heard it driving much more difficult loads, I do not doubt it would be good enough for the Joseph’s. It has far more current capability than the Pass, for example. While it doesn’t match the Ayre for detail, at 60% of the price, it is always enjoyable. The phono section is quite good, as a bonus! |
+1 for the Krell, I owned a Coda CSiB, Prima Luna Evo 400 integrated and was able to audition the Krell 300i. The Coda and Krell were outstanding. There was something really special about the Krell. I ended up getting the stand alone amps Krell 300xd Duo because of how blown away I was by the 300i. If you are looking for true class A amplification Krell is really hard to beat, the CSiB also does Class A but then shifts to A/B. Coda is an awesome piece as well, if you find one used, tremendous value, build quality is fantastic. Luxman gets high marks and makes some true class A amplification along with Pass, both seem to be a bit more polarizing, people either love their house sound or some don’t. Honestly haven’t heard anyone that doesn’t like the Krell. |
@soix has given excellent advice. Moving up the JA lineup is your best bet, IMO. Good luck! |
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I’’m guessing those are Pulsar 2s at $5k, and my impression is the upgrade from the initial version of the Pulsars isn’t as significant as it is with the Perspectives. You already have a very good integrated, and if I’m you I’d absolutely wait for an original pair of Pulsars to come available — and they do occasionally show up for $3k-$3.5k — as I think that’d make for a MUCH bigger upgrade in absolute terms than upgrading the amp for your RM7s. This one’s a no brainer to me. Again, FWIW. |
Your speakers are tube friendly https://www.stereophile.com/content/joseph-audio-rm7si-loudspeaker-signature-measurements You might consider a Jadis integrated amp, Orchestra, I 35 or I 50, they are all within your budget, used, if you decide on bigger model. The tubes for them (El 34, KT 88 or 6550) are not expensive and are still available from european or chinese producers. Point to point wiring, made to last lifetime and nothing but praise from people who have them. With music that you listen, that might be a winner. Try to hear it somewhere |
you have quite a good system already, joseph rm7 sigs are an excellent standmount monitor my suggestions to improve your sonics would be a) add one or a pair of rel subs t7i/x or t9i/x -- the sonic benefit will be substantial, even using your current i-5 amp b) amp wise, i suggest a pass int60 (int25 may not be enough juice) or a hegel h390 or 590 (not class a, but sounds as good/better) have fun, enjoy! |
If you are looking for a true class A amp the pickings are slim. The Sugden and Pass are a true class A design! @ghdprentice Some of those amps that you listed are not class A! |
I would jump on used pulsars at that price but the lowest price I've seen is $5k. Were that the case I'd wait on a new amp having spent this allocation on the speaker upgrade! I thought about hybrids and the best of both worlds scenario, even considered a heaven 11 billie just to see if like the sound but that is a class D output stage. Not that I have anything against class D its just that I've never heard one. I'm just trying to take things one step at a time by changing only one variable at a time. I have the impression that my I5 mates well with the JAs because of the relatively high peak current the BJTs can deliver for such a modestly rated amp: per the manual 16A peak (which is ridiculous for an amp rated @70 Watt RMS into 8 ohms). I believe that is the 'secret sauce' where dynamic drivers are concerned. |
I hear ya on the Perspectives, but used Pulsars can be had for around $3500 that’d surely be a very nice upgrade, and you’ve already got the stands. Anyway, you did yourself a big favor picking JAs over B&Ws IMHO, and I’m very familiar with both. Here’s a very nice hybrid integrated with tubed preamp stage and MOSFET solid state output stage with plenty of power, is in your price range, and could yield a best of both worlds situation with your wonderful speakers. I’d be shocked if this amp didn’t offer just more of everything, and you can also play with tubes to custom tailor the sound to your liking if you desire. Just another option to chew on FWIW, and best of luck. |
I should also add that my listening space is long and narrow, with low ceiling approximately 10'x30' with listening position about 12' from speakers. Most sessions are at 65 to 70 dBs with peaks to 80 dBs as measured by free app on my phone. I know, hardly an audiophile or instrument quality setup but it does serve as a reference point. |
