When were the best tube amps made?

today - Japan

Luxman SQ88uC sounds awesome! 

not sure whether Zero Autoformers are really zero cost. I used them on a Graaf GM20 about 15 years ago and while bass was significantly tightened, the overall SQ lost pizzazz. It felt a bit like a Ferrari on Qualudes…

@antigrunge2 The result depends largely on the interface of the amp to the load. In our case, it works really well if the load is lower than the amp is comfortable with. There are tradeoffs if part of the load (like the mids and high) are easy to drive while the woofer isn't. However sometimes in that case, if the speaker can be bi-wired, you can run the ZERO just on the woofer to correct the impedance and run direct on the mids and highs.

If the amp uses feedback, as in the case of the Graaf (IIRC) then its a good idea to have the feedback at the output of the transformer, which would take some work... So its not a cure-all solution, but it is one that can be very effective if the stars align.

In a talk Roger Modjeski (Music Reference, RAM Tube Works) said Tim de Paravicini (EAR-Yoshino) told him he could tell what a tube amp sounded like by looking at it’s transformers. Both Roger and Tim extensively studied the art and science of transformer design, and wound their own.

@atmasphere,

not sure whether Zero Autoformers are really zero cost. I used them on a Graaf GM20 about 15 years ago and while bass was significantly tightened, the overall SQ lost pizzazz. It felt a bit like a Ferrari on Qualudes…

Transformers are the key element for both SET and push pull.  Even for OTL the power transformer is relevant.  Likely the best commercial winders were in Japan in the late '90s, companies like HIrata Tango and Tamura.

@rogerh113 Excellent power transformers can be made by a good number of companies here in the US.

If you take an OTL and run the ZERO autoformer on it, you wind up (if you see what I did there) with the possibility of an amplifier with much greater bandwidth than any conventional tube amp. This is because the ZERO has such low turns ratio and extremely low distributed capacitance that its bandwidth is very wide- about 2Hz to 1 MHz- wider than any tube amp made. Usually the bandwidth limitation is in the output transformer.

Really great thread with lots of thoughtful responses. Thanks!

To me, the answer becomes obvious when you substitute “motorcycles” or “cars” for tube amps.  Clearly the best are being made today. But it doesn’t mean that all cars today are “better” than all cars made in 1960. It would also be logical to suggest the best amps from 1960 (and all amps were tube then) will outperform many of the tube amps made today.  This is especially apparent when based on subjective levels of performance or aesthetics. 
 

I’m interested also in the comparison to the recording side. Are all recordings made today better than all recordings made in 1960?  No, but the best recordings are being made today.

The science is settled. 

@alexberger Thank you for your list. Matching the amp to the speaker is critical, similar to a cartridge to an arm. However, there are many choices of amps for most speakers. I also have an upgraded Dynaco ST70 in my living room system. It is not ultralinear any longer but voltage regulated using different taps on the transformer as well as the standard upgrades to power cap (huge), ss rectifier (kept the tube for slow turn on) RCA plugs and speaker terminals, etc), . It has superb bass and is extremely musical sounding lacking only the resolution of the EAR 890 I use in the main system. Those 35 watts work great on a Legacy Signature III with 6-10" woofers. It’s a little underpowered for my Focus with 6-12" woofers and much lower bass impedance.

@mulveling @sns  Yes, I chose an AR SP-14 over the 9. I did not like the 9.  The 14 had some superior sound advantages.  The SP-10 was my favorite and the SP-8 my second favorite of the era.  They had big, bold, full bodied sound (like a Fisher 200? preamp that I briefly owned).  Comparable to a McIntosh MC30 full range.  

My neighbor has an AR LS-28.  It sounded thin and blah until he installed 6H6/6N6 tubes for the 6H30s.  Wow, fantastic improvement.  I would own that pre-amp if I didn't have my own excellent pre-amps (multiple systems).  

As to great sounding, powerful modern tube amps that are still reasonably priced is the EAR 890.  I just purchased another one inexpensively.  Paravacini knew transformers and circuit design, regardless that they are not considered state of the art and used ordinary audio parts, no special cables, fuses, tubes or footers (I use them all on the 890 except the tubes remain the same).  Zesto is copying his designs and I have not auditioned them to compare.  That's flattery and could be a trend, using common tubes in non-ultralinear designs.  I considered the VAC iq200 but the EAR is just better sounding and cheaper.  

Transformers are the key element for both SET and push pull.  Even for OTL the power transformer is relevant.  Likely the best commercial winders were in Japan in the late '90s, companies like HIrata Tango and Tamura.  I think back then there was a focus on sound and quality rather than volume and profit margin. 

Likely there are currently some good boutique winders, and maybe Western Electric were good (never heard an amp with these).  Useful to distinguish between collectable and listenable - not sure where the WE falls.

I certainly do not equate 'high tech' with 'great sound'.  Frequently the application of high tech results in additional complexity and worst sound.  Hard to make the argument that the more you process the signal the better and more realistic it sounds.....

With a single ended tube amp it is easy to build your own. But to keep it linear you can't push a tube very hard. You need heavy duty transmitter tubes. There is a WAVAC SET that sold for $350,000 that you can build with under $2000 in retail parts. It runs 833A triodes at about 1000 Volts which will make these tubes last for many years. Hammond makes a transformer more than robust enough and more robust than any bigger name or vintage transformers and Lindahl makes an input transformer for the grid suitable for a 45 SET to drive the 833A. 

This gets you SET purity you can use for less sensitive speakers such as planar magnetic speakers which have a purity that is difficult to approach with cabinet speakers. 

I second PrimaLuna.  My EVO300 integrated tube amp is wonderful when upgraded with Golden Lion KT66 tubes  

Sometime in the future.

PrimaLuna comes to mind as a company that has combined the best of modern technology with the best of vacuum tube sound quality. Their autobias has taken the mystery out of maintenance and brought tube rolling to the market for those who would otherwise not want to deal with such things. At real world pricing their products punch way above their price point. Driving tubes gently helps keep the cost of long term ownership reasonable. Lots of reasons they’ve done so well in a short time. Perhaps others will take a queue. 

40 years ago a Dynaco tube amp got me into his pursuit. There are plenty I haven't heard, but the CJ ART Stereo 150 is the one that I can unconditionally recommend. 

I have directly compared the Linlai 6sl7 withe the ken rad vt229 and I can say the Linlai elite do sound better, now hopefully they last just as long as the ken rad.

Yes- that's the one thing...

My now-departed MFA separates were certainly a joy to listen to.  Over the years the mono amps and Luminescence preamp were significantly upgraded a few times, yielding even more musical enjoyment.  I reluctantly sold those components due to their age (maintenance) and my desire to down-size.

I had a virtual closet-full of spare tubes- the most difficult to source was the quad of octal tubes for the RIAA section.  They needed to be extremely quiet and it was hit or miss- often a "big miss."  :)  Between the mono amps the preamp and power supply, the gear took a total of 26 bottles.  :)

Now I'm thoroughly enjoying a CJ control amp which has a mere 7 tubes. :)

The 80’s era ARC tube amps are generally superb. I used a ARC D70Mk2 for several years with a CAT preamp and the match was one made in heaven. Today, the ARC has been replaced by what I consider to be the best lower output tube amp on the market...the Jadis JA30Mk2, BUT it took this mono block amp to better the ARC from the 80’s.

The ARC had a criminal system for biasing, which is why i went away from it, but if it did not have this issue, i suspect i would still be enjoying it.

I have directly compared the Linlai 6sl7 withe the ken rad vt229 and I can say the Linlai elite do sound better, now hopefully they last just as long as the ken rad.

Which modern 6SN7 are better than NOS? I currently use Ken-Rad VT-231 from the 1940s in the input stage of my integrated 300B SET. They are not the most expensive NOS but still to change the pair of these tubes is expensive for me.

The Linlai 6SN7 is really impressive. I'm familiar with the KenRad, which is one of the best vintage types. Our customers report that the Linlai is actually a bit better- combining the best of the vintage 6SN7s with none of the weaknesses, which is a really strong recommendation! We've had a few in the shop and I really couldn't fault them. I didn't like the globe version- the glass itself is resonant so if the tube were to develop microphonics the glass will exacerbate them. 

@alexberger

Which modern 6SN7 are better than NOS? I currently use Ken-Rad VT-231 from the 1940s in the input stage of my integrated 300B SET. They are not the most expensive NOS but still to change the pair of these tubes is expensive for me.

I haven’t tried the Chinese 6SN7 that get good ratings (note some of their alternate sub types may draw more heater current!). But the Russian Tung-Sol and EH have a number of advantages:

• Can be easily sourced for low noise and tight matches
• They measure VERY high for transconductance compared to vintage 6SN7. These make GREAT drivers for power tubes.
• The Tung-Sol GTB are rated for much higher plate voltages and dissipation - versus vintage 6SN7GT and VT-231 (and certainly 5692) - which some circuits require. A GT tube in a true GTB slot will not last as long. There are some vintage GTA nd GTB tubes and they can be quite nice, but they don’t have the full-on "sweet tone" of the best old GT’s

In my VAC amps I find good vintage 6SN7GT sound best in V1 slots (I like various Sylvanias, Hytron, and Tung-Sol round plates best, followed by Ken-Rads and then RCAs last). But the Russian Tung-Sol GTB are just hard to beat in the V2 driver slots. They rock there. In V1 slots, the Russian tubes lend a bit too much of a solid-state like quality to the overall sound.

For preamps, old vintage 6SN7 tubes are very hard to source to be quiet enough. Microphonics is a particularly big problem there.

So yeah, as per @atmasphere , it just depends :) 

Hi @atmasphere ,

Which modern 6SN7 are better than NOS? I currently use Ken-Rad VT-231 from the 1940s in the input stage of my integrated 300B SET. They are not the most expensive NOS but still to change the pair of these tubes is expensive for me.

Regards,

Alex.

Since I've gotten mentioned in these discussions I'll cite a few good tube examples.

CAT has a superb reputation and I've heard this from other tube designers I know and respect.

David Berning is a genius. His ZTOL circuit is one of the few real amp inventions in decades and his amps are special.

And I'm biased(pun intended, since the designers were good pals) towards the now, defunct Melos amps. Tube monoblocks with over 400 wats in triode and 25 watts class A and a damping factor 0f 20 from tubes, all from just 4 output tubes is something special. And the 400 watt rating is one pulled back from higher ratings for reliability.

And I know I'm missing at least a few other good tube amps.

@atmasphere 

Tis ever thus...

I keep flirting with the idea of getting a valve integrated for my nearfield set up which has 4 ohm monitors. My current integrated is superb.

I am odd coz i love integrateds

what are the tubes nowadays like? I keep getting the impression that NOS are the best

@lohanimal That depends on the tube. I think most of the NOS tubes are better than a lot of the new pentode power tubes.... but there are some excellent 6SN7s being made these days that our customers say are better than 'the best' NOS... And there are some very decent pentode power tubes too- so the best answer is 'it depends'.

@dynamiclinearity 

thanks for thee superb explanation. May explain why i love solid state. 

@atmasphere 

what are the tubes nowadays like? I keep getting the impression that NOS are the best

Someone above made a Harley Davidson reference, and it fits well in this discussion. The best tube amps that ever existed are being made today, but they still include the same important electrical physics element, inherent distortion. Currently Harley has to be careful not to engineer out the trademark sound of the past engines just like the makers of tube amps want to make all parts of the amps better with what engineers have learned, but still using the tube design factor. Tube amps are very highly refined today with better transformers and more capability than ever, but just the fact that they are tube amps, and will have ~.5% distortion to start, and this distortion seems to add a harmonic that is pleasing to human ears still makes them desirable and makes the current offerings from all over the cost spectrum alluring to audio lovers. I have no way to state to anyone what the best amp from past or present might be, but I can admit that I'm still interested in a MC275, and even some of the offerings from lower end players such as Monoprice and similar to play with. While I look at some vintage pieces with nostalgia and desire, knowledge and common sense tells me to buy something current with all the improvements.

I stashed that SP9 in a closet for perhaps a decade, forgot I even had it. Upon rediscovery put it up for sale, sold for asking price in a minute. I see post in forums from time to time, some think that pre something special!

I wonder how much of my opinion of ARC has come from the SP9 and so many who claimed to love it at the time?

I agree that the current ARC line is much better than what I remember from the mid 1980's. 

Weird to me you'd attempt a hybrid preamp. 

AR fans will hate me for this, but AR SP9 MkIII  has remained one the WORST sounding components I ever purchased, very bad memories of that one. Hybrid design didn't work for me, SP10 would have been much better choice. This purchase probably around 1984-5.

@sns 

Yeah - have to agree. Some years ago, a few friends and I did a shootout of several preamps. There was an older AR hybrid preamp in the mix, and I believe it was specifically the SP9. Tons of gain. It performed relatively poorly. Couldn't even keep up with the entry level Rogue Metis, much less their 99, and an Athena just blew it all away. It was more on par with the Sonic Frontiers SFL-1, also a hybrid. Those hybrid preamps had a steely edge and sounded lean and unnatural compared to the all-tube preamps. 

But that SP9 has seemingly NOTHING in common with the current Audio Research preamps, which are absolutely wonderful. Still a big fan of the Reference 6 here. AR really upped its game in the current era.

Every time has good, bad, mediocre.

@erik_squires Funny you mentioned AR from 80's. AR fans will hate me for this, but AR SP9 MkIII  has remained one the WORST sounding components I ever purchased, very bad memories of that one. Hybrid design didn't work for me, SP10 would have been much better choice. This purchase probably around 1984-5.

Yesterday

In 1956 @ 328 Chauncey St. Brooklyn NY

KrisKringle 3000B amps are made in the North Pole!  Truly outstanding!

I recently purchased a Roma el34 push pull as my first tube amp. I’m on the Decware list and purchased the Roma as a temporary amp. I owned a ss Rotel amp and preamp, Velodyne sub and used both AR10’s and B&W speakers for 25 years. Had the Roma going through some Zu Audio Soul Sipremes and it sounded great. Speakers induced ear fatigue so I’ve since gone to Audio Note e/lx’s. I couldn’t wait for Decware so I purchased an Aric Audio Custom 300b PSET amp. Hand made, point to point, hand made transformer which is a completely separate 60lbs unit, host of upgrades and no circuit boards. It can’t even be compared to what I used to listen to, and I loved those old AR speakers. Not saying there wasn’t great stuff back in the day, just thAt there’s great stuff being made now. All my vintage listening friends, old amps and speakers of good to very good quality, are really impressed with the sound. So good news. There’s great sound to be had today if you’re willing and able to be patient and spend a few bucks. 
Also, having read a ton on tubes the last 6 months, I came across an interesting article on the Western Electrics if I’m not mistaken. They newer owner was able to procure the original metal supply used in the old tubes. The process and significance is explained in the article. Very interesting. 

Thanks atmashere. I read some in the beginning and a couple towards the end. I will go back and reread the entire thread. Have a good weekend. 👍

Would be really interested to hear from an engineer and tube amp builder today who has seen and heard many generations of amps.

@earthbound For the record, you did if you read this thread.

What kind of power supply capacitors did Western Electric use in 59A amplifier? I'm not sure it was already the mass production of electrolytic capacitor then.

@alexberger There were electrolytic capacitors in common production prior to WW2- by the early 1930s (the time of this amp) they were sealed aluminum cans that had all the wires exiting a single central mounting cylinder on the bottom of the part. The cylinder was threaded so the part was held in place by a single large nut. The internals of these things was frightful; electrolyte filled, with metal plate not unlike what you see in a vacuum tube supported in space. When I used to restore antique radios I would open these things up and install the replacement cap inside. From what I've seen of WE though they didn't use such parts. 

I don't know what kind of caps are in the power supply, but, I can check on it as the dealer still has it.  I would guess paper in oil type, as this is commonly found in Western Electric gear.  My re-built amp uses such caps. 

I am waiting on the same dealer finding the appropriate value of Western Electric paper in oil caps for my speaker.  

Hi @larryi ,

What kind of power supply capacitors did Western Electric use in 59A amplifier? I'm not sure it was already the mass production of electrolytic capacitor then. So probably they used oil capacitors with paper and foil. This capacitors in PS sound much better than any kind of electrolytic including BG and AN Kaisai.I tried Soviet KBG-MN capacitors made with the similar technology. They really sound magical.

But do they sound better. I’ve ridden old Harley’s and recently owned a new Road King Special. There is no comparison that the new is a better bike, which doesn’t even come close to my BMW 1250GS. I like vintage stuff too but it doesn’t mean it’s better. Any engineers? How about shop owners who have 20+ years of experience? Any thoughts?

NOW most definitely unless you like flabby Bass response and such. And Yes Kt-150’s or KT120’s If the amps been built for it like a CJ Art etc. There’s zero comparison imho from the newer designs vs the older stuff from most manufacturers especially CJ and VTL (I have had several of their earlier versions including Ichibans and 450’s etc) and would not trade any of them in exchange for my current S200 signature as sounds incredible & with no fuss whatsoever. I love vintage gear like old motorcycles to look 👀 at period. “Nuff said” 

I fixed up an ST70 and a PAS 5 many years ago. Just replaced all the resistors and caps. I thought it was bass-heavy in my system, but the midrange and highs were great. For the PAS, I replaced all resistors and caps and bypassed all the tone control stuff. I am a HUGE Decware fan. Had a couple of their small entry level amps, and now have a Torii - 20WPC - EL34 based amp. I love all their stuff. Also have one of their phono preamps for a hi output cartridge, and I built an 8" full range open baffle using their cabinet design. The 'AH HA' moment for me was when I replaced my SS pre-amp with the PAS5? PAS3? I forget - and I could not believe the musicality that came out of my system. That was my conversion to tubes.

Would be really interested to hear from an engineer and tube amp builder today who has seen and heard many generations of amps. What makes a tube amp good? More dynamics, more bass, balance, all of the above etc….Have parts improved over time? I hope mine is the best!!

@decooney @mulveling  To this day Kevin Hayes will work on any VAC unit. (that I know of) Secondly before it leaves back to it's owner he personally auditions it to assure it is voiced was designed to be. I had them upgrade my CLA1 Pre amp to Mk III this summer and they did a great job on it. The upcoming amp upgrade is rather extensive so I am excited to see the outcome. 

@fthompson251 That’s cool! Will you be taking the older amp to the VAC factory in Sarasota FL I think it is?

For me this is notable testament of what some amp makers will do and others won’t when it comes to not only standing behind their product, but also upgrading it later for you too should you desire. I’ve had some older amps I wanted to keep beyond upgraded beyond caps I did myself, and the manufacturers would not do much more. Makes the original investment less worrisome too knowing that factory is there for you later on.  Good for you, Best of Luck on this. Please report back after to let us know how it goes!

I love my VAC Renaissance 70/70 Mk II, it's 20 years old and still works great  However I am taking it back to Florida this January to get the latest MKIIIs updates, then it will out live me! Handmade in the USA!

@fthompson251 I hear that's one of their classic models, definitely a keeper! There are still fans of their 300B sound before they transitioned to beam tetrodes.

I like the 45 tube tube too.  Are you using it single-ended with 94 db/w speakers?  That would be a bit on the edge.  I had a pushpull 45 amp which I used with 99 db/w speakers, and I had no issues with power, except for large choral works at somewhat high volume, but I did sense that I was at the edge.

I love my VAC Renaissance 70/70 Mk II, it's 20 years old and still works great  However I am taking it back to Florida this January to get the latest MKIIIs updates, then it will out live me! Handmade in the USA!