First Tube Amp
How about a nicely restored Dynaco Stereo 70? A classic PP design using pairs of EL34's, 5AR4 rectifier and a pair of 7199's. And GOOD iron! Probably the most popular tube amp ever (500,000 made!). I own two: a new input board version and a full-custom version with a separate power supply chassis. Outstanding amplifiers! |
You made a good choice buying a less-expensive amp to start. Let your ears grow into it and then you'll be in a better position to decide on whether you want to stay with tubes or not. Tubes are not a panacea for the audiophile. Like with vinyl, the more obsessive are always living in a constant state of anxiety of whether they should roll the tubes, whether a tube is deteriorating, etc. These are not concerns with SS. Less choices = less anxiety for some. Also, at least with my amp, it takes almost an hour to sound its best. Sometimes I wish I just had a SS amp & CD player I could leave on all the time and still have optimum sound. |
An $800 Chinese made tube integrated amplifier is not necessarily considered cheap and should sound good. The main issue with the amps in that price range is not their sound quality but their consistency in quality. If yours sounds good and is quiet with such high efficiency speakers, then you have a "good" one. Enjoy it and if you want even better sound, look into NOS EL34 or 12AX/U7 tubes. Plenty of options depending on your budget. |
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I am struggling with returning this amp, in the midst of a paradigm shift: chinese junk has become on par with high end, how can it get better than this? What would other types of tube amps of better quality offer?A Chinese amp is usually made from lower quality parts, if what we've been seeing is any example. As to how much better it can get, if you understand that tubes can indeed bring a lot to the table, then as a warning: the sky is the limit. Quik Tips 101: SETs have a lot more bloom than push-pull but don't have as much power or as much bandwidth. OTLs dispense with the output transformer and are thus even wider bandwidth and lower distortion, but you have to be more careful about what speaker you use. In all cases, different tubes used can change the sound- often making it considerably better! Also in all cases, avoid 4 ohm speakers if you want the best return from your tube amplifier dollar investment (the same is true of solid state though...). Keep you speaker cables short- longer cables reduce bass impact and resolution. Tubes can fail at inopportune times- keep a few spares on hand. Google is your friend- some amps are far more reliable than others. Above all have fun and don't make yourself crazy auditioning the various brands and vintages of tubes that work in your amps- get it so that it sounds right and then spend the money on more music. Also, if you like what a tube amp can do, tube preamps do that too!! |
Congrats on taking the leap and seeing what all the fuss is about. It took me many decades before I had the nerve to try tubes and ultimately change my system to exploit tubes for all my electronics. I won’t be going back to solid state. It took me three tube amps and two preamps before I nailed down what I believe is best for my speakers. Hopefully you got lucky right out of the gate. What speakers are you using, and what is the impedance rating for them? Mating speakers to any amp is very important. At 98db efficient you very likely have plenty of power to drive them. If the amp/speaker match makes for great "dance partners", you have solved a challenge some never do. It took me a couple of gear swaps, but I have it now. You asked about tube amp types. The amp you described (push-pull, 4 EL34, 2 12AX7, 2 12AU7 tubes) is a very common and proven tube amp design. Pricing and sound quality are functions of build quality (circuit boards or hand wired), parts quality including tube choices, labor rates, fit and finish, and always the quality of the output transformers. SET amps benefit from simpler designs with less parts in the signal path, and a more pure sound from the tubes, although with lower power output. These amps are where owners of very efficient speakers (98db qualifies) often tend to gravitate to, due the beauty of the sound. There is an entire sub-culture that lives in the high efficiency world. I don’t play here. My speakers need 40 or more watts, so I’ve been tied to push-pull designs. The only other major category of tube amps are OTL designs, amps that eliminate the iron core output transformers, the hardest component to get right. These often offer stunning sound with amazing sound stage, but come with other realities that may bring higher cost into the picture. Not to confuse you further, but David Berning designs also fit into the OTL category in that they also avoid the iron transformers, but use completely different methods to manage the speaker impedance handshake. All tube amp designs benefit from using better tubes. This will drive you crazy but really turns this into a hobby. Enjoy what you have for now. All the tube types in your amp give you lots of options should you take that step into the abyss. |
Welcome to the wonderful world of vacuum tube audio. A word of caution on SETs. In your OP, you talked about classical, which can have a very wide dynamic range. Although your speakers are quite high efficiency, these peaks can require lots and lots of power (logarithmic relationship between volume and power). This is important because an SET amp's distortion rises quickly with power output.
A 300b SET makes about 8 watts. Even if you do not drive the amp into clipping, you may start to hear that distortion as a kind of harshness and a loss of the SET "bloom" for which the amps are prized. Depending on your room size, listening levels, etc., this may or may not be a problem for you. In my 14 x 23 x 8' room, I eventually gave up on 8-12w SETS with 94-96 dB speakers, even though I listen to music that does not have the wide dynamic range of classical. I settled on 2 amps having 30 wpc; one OTL and one push-pull. Lastly, do not get hung up on topology or tube type. Once you get past basics, it's implementation (and for non-OTL amps, transformer quality) that is/are key. There are GREAT tube amps using OTL, PP, and SET circuits, with EL-34, 300b, KT-88, EL-84 etc, etc power tubes. And +1 to the idea of a tube pre-amp. |
Thanks for responding. As someone already mentioned, speakers are 8 ohm, the DI’s, and the amp is Yaquin. Speaker cables are 6’. My room size is on the small side and I don’t particularly like to play music loud. Roxy , which 300 b do you have? By bloom do you mean harmonics. Atmosphere, I think I found the corresponding website ;-) how would something would sound with loss of “low-level detail” which is what happens with push pull amps. I’m guessing more “bandwidth” is more frequency response or range? Do SET,s lose their”bandwidth” or fail only when pushed to hard/loud? |
First I would like to congratulate you for trying something new. As you may have already heard quality does count so I’m going to tell you it’s a lot better to buy a used high-quality to band that he needs to buy a new Chinese tube amp. So I’m going to make one quick recommendation Conrad Johnson any of the premier line and a nice quality preamp |
The first time I heard tubes was with a pair of McIntosh MC30s a buddy of mine lent me. They belonged to his deceased dad and he had no way to use them then. I had had a Bryston 3B and a Citation 12 in my system. No slouches, they, but I was hooked immediately! The tube sound just can't be beat. I now own a PrimaLuna Prologue Premium Integrated amp and would never dream of going back to solid-state. P.S., my buddy is getting his McIntoshes back. He's getting the bug again... |
The build quality as mentioned above is usually the issue with these amps. They work great and sound good but the design is usually unstable so in the long run there are usually issues. There are many other tube amps that you can pick-up that are really very good. Think older CJ amps used for around $800 to $1200. These can be upgrade and sound fantastic then. Happy Listening. |
Might consider a hot rod Dynaco 70 from Vincent in Lewiston. While I do not own one myself, I’ve spoken with quite knowledgeable audiophiles who attest to the premier sound and build of the product. His upgrades are well thought out and applied. Or....you could simply consult with Upgrade Audio for tube rolling advice. |
By bloom do you mean harmonics. Atmosphere, I think I found the corresponding website ;-) how would something would sound with loss of “low-level detail” which is what happens with push pull amps. I’m guessing more “bandwidth” is more frequency response or range?@recluse 'Bloom' is an audiophile term that often refers to 2nd harmonic distortion. Often but not always. A loss of low level detail will take some of the life out of the 3D soundstage as room ambiance is often part of low level detail. IOW quieter sounds that are part of music. 'Bandwidth' is akin to frequency response. This can be important to getting things like the soundstage correct, as phase shift can occur as an artifact to 10th the cutoff frequency (so if its good to 20KHz, down to 2KHz) and to 10X the low end cutoff (so if good to 20Hz, up to 200Hz). Phase shift messes with instrument timbre and soundstage width and depth. For this reason, 2Hz to 200KHz is required to really get the soundstage right, and to assure impact in the bass. SETs have troubles making bandwidth on account of their output transformers; its a real trick to make an output transformer that allows for power and bandwidth at the same time; 7 watts is about the practical limit. It is for this reason that the smaller SETs are also the best sounding. This really limits the speakers you can use, since one of the best sounding platforms for SETs is the type 45 triode power tube, which is good for about 0.75 watts at full power. There is a bit of a diminishing return here, as a speaker that is usable with that kind of power won't be able to play any bass anyway. But these days people often supplement the bass with a powered subwoofer. When pushed hard, SETs don't loose bandwidth, but they do make considerably higher distortion. As a general rule of thumb, to really get your amplifier investment dollar out of an SET, the speakers used should allow you all the volume you need while the amp never goes above about 20% of full power. If you follow this rule, the amp will not make appreciable distortion. If you break it, you will experience the 'way more dynamic than it has any right to be for that kind of power' that you hear many audiophiles and reviewers describe about almost any SET. (I may have ruined it for you by letting you in on this fact, as you may now be aware that some of the 'dynamics' you hear from SETs is really just distortion.) The reason this happens is because the higher ordered harmonics (5th and above) start to show up about about 20-25% of full power. The human ear uses these harmonics to sense sound pressure, so if the amp is making them, it will sound louder. This is why many people have loudspeakers that are not efficient enough for the amp, but claim that its 'loud enough' for them- the harmonics are convincing them that its loud. A sound pressure meter reveals the truth of the matter! The thing is, if you really want to experience high end audio properly, the system should **not sound loud** at any volume (and this is quite possible with SETs with careful speaker selection)! You should find yourself yelling at someone else in the room to be heard as a first indication that the volume is up. The reason this is possible is because if you use tubes, you can build a system that is free of the higher ordered harmonics. |
Recluse, your experience is more common than you think. about 5 years ago was in similar boat. used only high end SS power since I had super inefficient speakers. Sold the speakers, but kept the amps, until one day a friend let me borrow his chinese amp. Like you, was floored at the sound quality I was getting. That event set me off on a whole series of trials with Chinese tube amp purchases, including a model similar to the EL34 amp you have. With a few exceptions, all of the Chinese tube amps I tried sounded good, some better than others. But you still have not heard your Yaqin amp yet. Solder in some Jensen copper foil coupling caps to replace the inexpensive caps installed by the factory. You will be floored again at the sonic improvement, especially with speakers as efficient as yours are. best. |
Thanks for the detailed information and suggestions. I am intrigued by these tube amps, especially the SET - however wondering if I would tolerate it's limitations - as you mentioned with large orchestras. Many of your descriptions/positive traits of the SET seemed to parallel my impression of the push pull amp: I picked up more low level detail versus the SS amp, single instrument solos seem to stand out better in the symphonies I listened to. The distortion was overly pronounced during break-in and when it was cold - ear-catching to say the least, but finally leveled out to a pleasing level. I wondering if all of this will be even more pronounced with an SET. I will be looking at some that have been mentioned over and over again on the forum like CJ, Cary, PL, etc - unfortunately I will have to stay away from items that will need upgrading or soldering and the used market is non-existent where I live. Still trying to rationalize the decision to send back the Yaq. Been listening to it biased at 40. I noticed not all three of the cylindrical transformers where equally hot- just the one forward one of the trio. The volume adjuster is a little too sensitive. And there is no phono stage. These issues are minor as I mainly listen to CD's. Lastly, took the chinese amp off-line and have been listening to a powerful hybrid amp(3-4 times the cost of the Yaq amp)and am not as impressed except for the strong bass, holding up very well, albeit clean and sterile, at at high volumes. It fall short on too many other levels. Thanks again. If anyone can recommend an SET or 300b amp that works well with DI's or speakers of similar sensitivity - please chime in :-) |
My speakers are 98 db 1 watt 1 meter as well and I find 30 watts to be the minimum power to use! My room is about 17' x 21' and moderate liveliness. If your room is smaller and more lively you might be able to get by with an SET, but if it were me I'd go with an amp with more power. Our M-60s would work nicely on that speaker and perhaps our S-30 as well; if on a bit of a budget I would look at a refurbished Citation 2 from Jim McShane, a Dynaco St-70 or the venerable RM-9 if you can find one. |
@recluse, like so many Chinese amplifiers these days, Yaqin makes fairly good ones. It's no surprise at all that you have enjoyed it since it arrived. And it probably has improved since break in. As so many North American and European entities have shifted production to China, the manufacturers there attained a lot of capability. In real world terms, tube amplification reached maturity long ago, and many companies can turn out good sounding products. In fact, a good friend of mine imported Yaqin a while back, and as you and other mentioned, they sound more than decent. Ultimately, he gave up the line for the same reasons most Chinese companies struggle in this market. Some mentioned Chinese products having lesser levels when it comes to parts or build. My experience has shown those things evened out in large measure. Especially, in the upper-end companies, though Yaqin does not fall into that category. Instead, what keeps a lot of these products from ultimately rising to the very same level is the Chinese companies include far too many products in their lineups. Very few if any products see the degree of design and revision / improvement / iteration Western companies put into their products over time. It's sort of another example of quantity versus quality. As for your situation, you may find happiness living with this amplifier. Over the long-term, most audiophiles on sites like this find themselves on a quest to continually improve. If you fit that mold, you'll move on from the Yaqin at some point, and the question becomes, how close to now does that day arrive for you? |
@recluse- Not sure why you need to shy away from the used market based on local availability. This site’s classified ads are a global market for high end, mostly very gently used goods. If you stick with long time members with lots of positive feedback, you will be amazed with the quality of the gear and the people here as far as recommendations go, give us a budget or look at the comments in the forums and virtual systems sections and you will see what others are using with your speakers. |
You should consider Raven Audio. They are built in Texas, look fantastic and the music that comes out is very good. I have the Reflection MK2 integrated amp that runs about $9,900. However there entry level line up is way more affordable under $3k. Call the owner Dave Thomson. He is great to talk to and he has some of the best vintage tubes of anyone in the country. |
@recluse - have you read Terry London's review of the Double Impacts? https://hometheaterreview.com/tekton-design-double-impact-floorstanding-speaker-reviewed/ I email frequently off this forum among a birds-of-a-feather group who share common components. We try to help each other find great component matches and share experiences. Two of our little group use the DIs, one as their primary speaker and another in a HT application. Both of them as well as others in the group have committed in part or fully to Linear Tube Audio gear, although the speaker usage is a mix. What part of the country do you live in? The Axpona show in Chicago is next month and just about every type of amp referenced in this thread will be there. |
Several years a go I obtained a used but modified Jolida 502b amp with 6550 (KT-88) output tubes. I subsequently rebiased it for the less powerful EL-34s and never looked back. A purer sound and less strain on the power supply and output transformers. I can A/B it with either of two excellent sounding SS amps and for less complex music (jazz, rock) I can barely hear the difference even with instant switching. BUT... for the rich harmonics of classical music (my favorite), the tubed amp definitely takes the edge. I'm writing this since no one (I think) had mentioned Jolida amps as an alternative. I believe it is an American company that manufactures in China and are priced to compete. I think they are underrated and quite affordable, even new. Other opinions are welcome. |
As far as Chinese manufactured audio components are concerned, I’ve owned several Jungson products and they are excellent. Several SS amps, pre amps, cables, speakers, and CD players. Never a single problem, not one. Beautifully made, lucious sounding, reliable. They make tube products too. I’ve had far more issues with US made products during my 47 addiction to this hobby than anything made by Jungson. |
I second the Jolida suggestion…I recently sold mine as I prefer my little single ended Dennis Had amp (restricting me to efficient speakers, but I can live with that), but that Jolida 502P was a great amp. When I bought it around 6 years ago it cost about 1100 bucks and I payed about 100 bucks for the "factory upgrades." I talked to the Jolida people in MD a few times and they were cool. They make a newer version now with possibly "actual" balanced inputs, and switching to accommodate more power tube types. They suffer from near zero advertising and snobbery from low pricing, but don't be put off…they are great sounding amps. |
I had for 27 years tube pre- and amplifier Conrad-Johnson. Than I bought Aavik U-300, high-high-end and very expensive digital integrated amplifier. After a few days I knew, that tube amplifier is for me the best choice. I tried and bought tube integrated amplifier Octave V-16. I don't search anymore. For me is it clear: nothing else than tube. |
