Sugden A21 Signature Integrated Amplifier

It seemed Art was quite pleased with the Sugden/LS-50 combo at the start, so I would think it's really not that bad a pairing, especially at moderate volume in a 10×10' room.

 

As for the LS50 ohm talk, this is what Stereophile said about the Anniversary Edition, which I don't believe is all that different from the plain vanilla version.

"Somewhat optimistically specified at 8 ohms, the LS50's impedance (fig.1, solid trace) drops to 4 ohms at 200Hz and to 5.4 ohms at the top of the audioband. The electrical phase angle is generally mild, but the combination of 5.3 ohms and –41° at 135Hz, a frequency where music often has high energy, will make the speaker work at its best with a good, 4 ohm–rated amplifier."

 

Yep, it became smoother at the extremes but more pronounced in the middle. The upper middle is where many of us including myself experience fatigue.

 

Ok, I get that air of superiority comment, but he has his likes and dislikes and doesn't sugar coat things. Personally I don't need him to. He has been less than kind to some of the gear I've owned over the years. I don't think it's coming from a bad place though, so I just roll with it and accept the useful info he provides (which is a considerable amount). Ok, enough about that...

The Sugden definitely sounds like Art describes, though as I mentioned earlier I was able to tone down it's forward midrange a fair bit. I think it's all the more reason to carefully match it to a speaker. It's why I feel it would likely mate well with a pair of B&W 705 speakers, which are quite thin sounding. I'm sure the Sugden would fatten them up a bit and for a B&W they were not difficult to drive. Another reason the VR-1 may not be a great match...they are supposedly a very full sounding speaker.

 

They're the same exact speaker. I think they quit using the 50th Anniversary labeling simply because they were past the 50 year mark.

When I paired them with my 1100, the power meters rarely moved past 10 watts at fairly loud volume, and that was in my larger room. If the Sugden is really limited to only ~10 watts at 4 ohms, then I can imagine it being strained with 90db rock in a 10'x10' room.

Sounds like the Belles has just the right amount of juice. I've come to prefer similar power levels in SS amps.

 

Yes, a couple of us do.

Both @Benzion and I do.

Benzion has the Prologue EL34 based Four in his bedroom system, connected to his Zu Audio, Dirty Weekend's MKII.

I have the KT88 based Prologue Five, that I was running with the vintage Altec Lansing A7's.

I pulled the Five out and replaced it with an EL34 based Audio Note Kit power amp, running NOS RFT EL34 tubes. I have to say that the ANK L4 with the NOS tubes is excellent with the A7's. Better than any other glass amp that I have used with them.

IMO, the Five is a very nice sounding amp with the A7's, no complaints at all with the PrimaLuna, Prologue series.

For the first time ever. I took the Emotiva XPA-2 off the front mains and placed the Five on the front mains A/B speaker selector switch.

While the Five was rather flat sounding with the Polk Audio, LSiM707's. The XPA-2 is a much better match for the 707's.

However, with the Zu Audio's Omen Definition's, the difference was remarkable. Zu, insists that their speakers sound good with both glass and sand amps. I now disagree. The Omen Definition's always had this harsh edge to them with sand amps.

That went away completely once I switched out to the KT88's in the Five, the Omen Definition's and no longer the same speakers that I have lived with all this time. The difference is night and day, remarkable.

From here on out, I will no longer be pairing the Zu's with SS amps. The Five is here to stay on the Zu's! The A/B switch will be no more. Even at low volume, the bass is still strong and articulate.

There's three of us sitting around right the minute listening to the Zu's with the Prologue Five.

For those who have not got the word as of yet, PrimaLuna has discontinued both the Four and the Five and replaced it with the Prologue Premium, which retails for $2,200.

Right now, Upscale Audio is closing out both of these power amps at some stupid cheap pricing.

The Five is going for $1,099 and the Four is going for $899. These are the best deals going on EL34 and KT88 based tube amps that I am aware of.

BTW... There are other members on the forum that have extremely high praise for AN, among those are members by the initials WJ and SH.

 

I have also heard many folks who are serious classical music lovers that only use SS amps. Classical music lovers are generally critical listeners. This SS vs. tube debate will continue ...

 

Not really a debate. Tastes are subjective. People like what they like. It's all good. Plenty of gear out there for us all.

 

The PRIMALUNA PROLOGUE FIVE is somewhat tempting given the big discounted price, even for someone like myself who has never owned a tube amp before ...

 

Yes, it definitely is. I don't think that you can do better at this price/performance point.

Yesterday, I switched from the SS Emotiva XPA-2 over to the Five. It is the first time that I have ever had tubes on the Omen Definitions. As the speaker A/B switch box was still connected, I was able to listen to the Zu's, which sounded better than I have ever heard them sound.

I never listen to classical music, but I gave it a chance with the Zu's. Better than have ever heard it before, on my system. And that is without the sub-woofer engaged. I still did notice that any "Metal" type of music, still sounds harsh on the Zu's. Eighties music, to much of a hard edge still. Vocals and Jazz, +1.

But, switching over to the Polk LSiM707's, the Five (and I think) tube amplification in general is not a good match for them, the SS amplifier's dynamics went completely away. Though, it came back somewhat, when I turned up the volume.

At low volume listening levels, the tube amp worked like a charm with the Zu's. And, at the same volume level, the Polk's sounded excellent with the Emotiva SS amp.

I think it is important for anyone who has an interest in audio to experience tube amplification, as specially if you have lived a lifetime with SS amps.

But, something to always keep in perspective, SS amps do not sound their best with every speaker. As specially high efficiency designs, which have a tendency to be unforgiven to certain source materials that have a tendency toward sharpness.

By the same tolken, tube amps are not everyone's cup of tea. If you pair a tube amp, with a speaker that was voiced with and designed to be used with SS amps, then you may not get the euphoric results that you sought after. It is neither the fault of the speaker, nor is it the fault of the amp, it is just another case of two components that are not ideally pared with each other. Just something to keep in mind.

Anyone who is looking to get their feet wet with tube amps, the Upscale Audio's deal on the Four or the Five, is a good ticket to that train ride.

At these prices, you can't really make a bad move. Most late model used audio equipment sells for about 50% of what it does on the retail market.

The previous retail for the Five was around $1,800, so at 50%, that would be around $900. I paid $1k, for mine, used.

Once the surplus stock disappears, the value of these power amps on the used market might even increase. These really are nice amplifier's and when they are gone, they are gone forever.

I have bought a lot of my gear at closeout prices and I am very glad that I did.

We have just seen it happening with the Oppo players (I bought two 203's and am on the early list for a 205, should they do another production run in June, and I did manage an extra Shure M97xE).

One thing that tube newbies need to take into account, is that no matter how lovely tubes might appear to be, they are not the plug in and forget about them type of things that SS amps are. A quad of EH KT88 tubes (of modern day manufacture) run about $160 and have a like expectancy of about 1,000-2,000 hours. The 12AX7's and the 12AU7's are the small signal tubes that are used in the majority of tuThe good news is that modern day ones a relatively inexpensive, $10-$20 each, but will last for a long tine. But, it is prudent to keep one of each on hand, along with a matched quad of KT88's.

Just be aware of this. No need to panic!

Be Safe and Buy Yourself a Tube Amp!

S&G

 

If I do get the PL 5, it will probably pair with some bookshelves, probably PSB or Soliloquy. But my preamp is likely to be SS since my Sonic Frontiers Line 1 tube preamp has an occasional volume control problem. A modern preamp does not work for me since I want to have at least one tape loop on it ...

At 36 watts/ch into 8 ohm, I have never had such low-powered amp except in my college days.

 

As you climb the ladder, you will learn there are many paths. I started out my "official" audio journey, with a 13-WPC Pioneer integrated amplifier, that would deliver a maximum of 13-WPC. But, in reality, it would only do 8-Watts, before the T.H.D. (total harmonic distortion) rose (sharply) above one percent.

My largest amp, in the old days was a Crown DC-300A, with 150-WPC.

At present, I have amplifier's that range from 3.9-Watt, a Decware single ended pentode tube amp to a Crown 1,600-Watt class-D, SS amp.

With the super efficient A7's, the 36-WPC on the Five is more than ever sufficient for my needs. But the A7's are very efficient. I only changed it out for the EL34 based ANK L4, because the L4 is even a better fit for the A7's. It is a 35-Watt tune amp.

The KT88 based Five, works beautifully on the Zu's.

Most modern day preamp's do not have a tape loop. My iNova does provide both a preamp (whose output is controlled by the volume control) and a line level output, whose volume is expected to be controlled by the receiving line level source.

I think that new or old, as long as it is a decent sounding preamp, that should be sufficient for the five.

You will, of course need to connect the preamp to the Five by the dedicated preamp out, as the tape loop out carries a line level signal.

The PL5 with it's 36-Watts of power, should drive your bookshelf speakers to a nice room filling volume.

Most bookshelf speakers, that I have heard sound good with tube amps.

On Sunday, I have completed the removal of the speaker A/B switch from the Polk's and now they are connected to the SS XPA-2.

Now, both the Polk's and the Zu's can be operated independently form each other.

I was testing them, so that I could do a quick verification of my wiring. I turned the SS on and confirmed that the volume control on the SS iNova, controlled the volume level on the LSiM707's, it did.

I then turned the SS amp off and turned the Five on and confirmed that the iNova controlled the volume of the Zu's, it did.

Then just for yucks, I turned the XPA-2 back on, so that both the Zu's and the Polks were playing together. They sound really nice playing at the same time, big and full sounding, even with the sub off.

Now, on to today's project...

 

Just PM'ed you.

 

This sounds about right. When I bought mine from the distributer at the time, he recommended an 8 ohm load. It does sound like it has more distortion than some other amps, it is very musical and as close to tubes as Ive heard in SS...in summary slightly loose bass, a touch of distortion in treble, but the midrange and musical rightness of the design is still unmatched in certain respects. It ran burning hot even with 8 ohm.

 

IIRC, the Sugden is only about 30 watts/ch Class A. If it is a Class A running 50 watts/ch or perhaps even 100 watts/ch, the shortcomings you mentioned would not even be there. Unfortunately, the amp will be running hot like a furnace ...

 

Fully agree with your description of the a21 here!

In the future I'd like to try it on high efficiency speakers, which I don't have. Should be fantastic!

 

I'm running my a21se with these which are 95dB
https://www.heco-audio.de/en/downloads/heco-direkt
Plenty of power, don't think I've gone above 8 o'clock on the dial.

 

One on USAM... in case anybody's interested.

Sugden A21 SIGNATURE CLASS A Integrated Amplifier - MINT!

Also a Belles Aria.

Belles Aria integrated amp Black finish

 

Feel like I keep waking in your footsteps Art. I get Harbetb 7s and then finally find and snag a Campion. Then I see you went Sugden. Maybe I have your old Campion. Ha. I thought it was terrible until I hooked up expensive speaker and power cables. Niagara 1000, Gran Corona and Tellurium Ultra and TWL Spirit IC. I’m going to sell the Primaluna and Rogue. Lowest bass was missing but two REL subs do the trick.

 

I have had this model in my system twice over the years. Both times I decided to move back to SS I went with the Sugden. If you are a fan of the "tube sound" but want SS this is a great choice.