I believe they changed the type of output tube in the late 90s. I would suggest you put your question to Peter Qvortrup at Audio Note UK. You can find a contact on the AN UK site.
Thank you Carl, I will do so.
Are you familiar with the Soro?
If so what are your impressions?
Somewhat but I am not an electrical expert. Basically, it is a M1 preamplifier (either line or phono) and the P2SE amplifier. For a person on a budget it is hard to go wrong with one of these for 1200 used. It is a very quiet amplifier with excellent power and wonderful bass from its pentode powered 17 watts. Tubes are not very expensive, either, and there is plenty of room to work inside the chassis. Upgrades are straightforward and easy for an experienced Audio Note service person. Contact Nick at Truesound or Peter Q at Audio Note UK for more information. You would desire a newer model with the later tube spec but for the right price and condition and earlier model is good, too. Remember, though, that the older ones are getting on ten years old and you must assume some service will be required for an older model. Things like replacing output coupling caps and tubes; few hundred bucks probably. That is a good time to upgrade the speaker binding posts to silver posts.
I own an OTO check into it also. Seems some people like the sound from the OTO better than the soro. Less power but then again its plenty for me at any resonable listining level.
Basically, the OTO uses the EL34 tube which many people like. I adored my P2SE with the 6L6 tubes and the extra power (17 watts vs 10 for the OTO) was appreciated when powering medium efficiency speakers such as the Spendor SP 2/3 or low efficiency such as Spendor LS3/5A. I used both speakers with the Soro and it sounded very good. I upgraded from the Soro to a 300b SET Conqueror amplifier.
I think I should have kept the Soro; miss the extra power.
I too have heard recently that the Oto may have better sound than the Soro but I did need the extra watts as my speakers are 88db effecient. The Oto is reportedly cleaner with less grundge. I think the Soro will be so good I do not care at this point.
BTW Peter Q confirmed the slight hum is normal, so all systems go and my Soro is on the way as we 'speak'
I like the Soro SE Phono much better than the Oto. I use Tungsol 5881 (4), Ken Rad VT229 (2), Tesla ECC803 gold pins (4), Bugle Boy 6dj8 (1), And 2 12au7's, but I can't remember what I have in it now.
The phono stage is excellent for MM cartridges. Before I got my Supratek Syrah, I used both a K&K stepup, and a Tom Evans Microgroove to match it to my Denon 103r. The Tesla's really made a difference in the phono stage. For the money, I think it is the best integrated with phono out there.
I paid a grand for a later one owner unit. I considered it a steal, but they seem to be going for about $1200, or a little less. I do feel it is worth the 4k new price tag!
The only way mine will go is if a higher level AN product replaces it. Now that I have the Syrah, I want to go AN monos one day. I should have bought Carl's Conquest when he had it for sale.
If you want to greatly improve the Soro's sound, get some AN speakers and cables. I have the AZ3's, and they sound much better with the Soro than a 4k pair I also have. Could be one of the best $1500 speakers out there. Also, the AN Lexus speaker cables give quite a bang for the buck.
Thank you very much for the info.
I have a Grado Sonata (4.5mv) and look forward to a glorious midrange sound and hopefully not too much bass which I had with my old set-up which was a Plinius SA100 MKIII and Quad 99 pre. I should have known I could not go back to SS :)
I wonder how I would like the Audio Note speakers compared to my JM Reynaud Trentes and JMR wire, which I love. I have a feeling any speaker that is high effeciency like AN (94db) would naturally have a nice dynamic quality that goes beyond a simple watts vs speaker rating equation. Dynamic range is something I think most stereos are sorely lacking. Maybe someday I will find out.
And of course I will be on the lookout for some quality tubes as the unit I am buying has older ones in it.
BTW $1200 is a steal for a newer Soro. I have never seen one that low and am happy to have bought the older (6L6) model for $1300.
All the best and I may email in the future for info regarding where you bought some tubes etc.
BTW guys, do any of you use something under your Soro to control resonences? All I have is Vibrapods and may be open to buying cones. Also I do have a VenHaus PC to use and hope it works.
I've been very curious about the AN speakers too, but I just purchased a pair of JMR Trentes and with around 80 hours on them and poor setup I love them! These are a real find. I have a pair of the Magic Stands on the way too. I wonder how the JMR and AN speakers compare.
I have mine on Audiopoints. I actually have them under everything, including the battery power supply for the Teres! I also use Stardamp to control cover resonance. The cover is kinda flimsy, probably my only gripe about the Soro.
I've never heard the JMR's, so I can't compare them. But I have heard good things about them.
BTW, if you don't have the manual, email Peter Q and he'll drop one in the mail for you. Great guys, and he actualy answers all of my stupid emails!
As far as tubes go, be careful where you buy. Some places are EXTREMELY expensive. Deals happen on ebay, but here on the 'gon is probably the best place. At least you have a better chance of getting quality tubes from an audiophile.
Feel free to email anytime.
BTW I had a pair of B&W CDM 1NTs rated at 89 db ? maybe 88 , anyway I had no trouble driving them with my oto. At least at reasonable listening levels. Allthough "resonable" is a relative term.
Recently replaced the tubes with some RCA EL84s and Amperex 7025s.
I just got my Soro SE about 3 hours ago and even though it has old tubes I can say this amp is something special. It is very neutral and rich at the same time and, (like the JMR Trentes) I am constantly reminded of real people in the room playing real instruments. If anything, I think it is a little soft at the frequency extremes and slightly full sounding but with really big images and soundstage and very 3-D in a holographic sense. Also it is powering my 88db Trentes with no problem at all.
I know I have only heard it for a few hours and I usually shake my head when I read other people's post when they just hooked something up (and it is like Jesus awakened from the grave) but I am one happy camper and I expect to stay that way.
The soro is definitely a keeper until you discover the 300b single ended amplifiers....
Congrats Phil! Now, all you need to do is find a quad of Tele 5881's. If you think it sounds great now, wait till you change tubes.