Sugden IA-4

@roxy54 thanks for the thoughtful and helpful note on the complementarity between Sugden and Devore O/93s. I know they have been exhibited together and am glad to hear that it isn’t simply the audio reviewers who praise the confluence of those two! The IA-4 is the integrated in their masterclass line; just ordered mine, so fingers crossed. Anyhow, it’s just a backup for those sometimes pesky tubes. 💡

Really appreciate this validation! I’m excited to hear it soon - hard time choosing between the Sugden IA-4 and the following:

Pass Labs Int-25
Luxman L550axii
Esoteric F-03A

Looking at measurements and the sensible, conservative, no-nonsense approach to engineering, plus reading responses like yours really helped me make the decision in favor of the Sugden. Thanks @roxy54

@roxy54 , I have been having great success partnering the Devore 0/93 speaker with the Sugden Masterclass IA-4 Integrated, which runs purely in Class A and maxes out at 33 watts per channel. It sounds so vivacious, energetic, and full of life, and also... smoooth!
The speakers disappear, the soundstage extends wall-to-wall (really amazing), the midband is liquid, attack is musical and unforced, decay is beautifully extended, center fill is flawless, bass is insistent and has strong pitch definition but perhaps I have heard firmer, treble is fatigue-free and silky, and it manages that nice balancing act of being absolutely brimming over with tonal saturation without sounding at all tentative or ponderous in pace – quite the opposite, it sounds very crystalline, clear, and alive. Honestly, it feels like a sunny wide-open set of French doors onto every record. You can tell the preamp is a thing of beauty (I can’t wait to try its pre-outs just for fun) and that the Sugden Class A output is just sumptuous.
I want to compare this with some other unusual integrateds I’ve had recently. This is a stunning, always immersive, combination that feels grander and more beautiful, though perhaps less ultimately transparent, than my recent pre-produciton Linear Tube Audio Ultralinear (with passive volume), and slightly more technicolor rich than the more self-effacing but also very pretty sounding Linear Tube Audio Z10. I never want to turn it off.

As an aside: the IA-4 has a ton of gain, so with the very sensitive Devores I was compelled to insert 12db attenuators at the line input I am using just to gain more control at the lower end of the volume potentiometer (which was actually really well channel balanced and noiseless to begin with). This just goes to show that Sugden was confident it would hold its own with lower sensitivity speakers and also honors low input legacy sources. A classy decision.

Also: I feel that it sounds way better plugged direct to wall than via my AudioQuest Niagara 1000, which slightly restricts its dynamics. I have ordered a Stellar P3 from PS Audio and have my fingers crossed this works to clean up my dirty, downtown NYC AC. Basically, it already has a highly invulnerable power supply and it always sounds glorious!

Oh, and it looks the part too! It feels (and is) very special. Thank you for validating this direction and for your kind wishes! My incoming 300B push-pull amp has its work cutout for it if it's going to best the Sugden in my system; I have my doubts!

Thanks for sharing my enthusiasm about all this John; listening to anything from Bennie Green to Rosalia to Dj Python to Szymanowski, it just keeps getting better. You were so right about Sugden's quality.
I'll likely start a new thread once my push-pull 300B comes in to share listener impressions.

Thanks!! This is a fascinating perspective and I can see the logic in it quite clearly - also a key factor in my usual preference for tube amps. The IA-4 has a damping factor of 45 and its bass is natural and believable with the O93s with good continuity between bass and mid bass. The LTA Ultralinear perhaps had “faster” bass response but I am very satisfied with the organic quality of the Sugden (which has meaningful advantages over that LTA power amp) and am of course curious to see what the Modwright 300B push-pull brings to the table. Nice to rule out the Int-25 as a contender using your sound deduction and experience. I hope you are loving the Super Nines by the way!

I prefer the IA-4 to the Z10 when used with the Devore 93s - a much more dynamic, clear, and spacious presentation. The Z10 has a mild sweetness to the sound but is a little too delicate and undramatic for me; I do like the microzotl preamps and love the Ultralinear amp and integrated. The IA-4 is more directly comparable to those, yet having a broader soundstage and better resolution of space and detail, but isn’t as hard hitting or quite as palpable. I think I just very barely prefer the Ultralinear overall but I’m sure many others would go for the Sugden instead. Both are killer integrateds.
I’m not using any of these amps right now, as I’m moving to an SA Lab Thunderbird on the basis of a suggestion by a dealer I trust. I flipped too much gear and am happy to defer to someone else!