True i did swap the KT90's for th eKT88's w/o biasing. But also had a KT88 NEW intergrated for demo purposes. The amp did not perform on 88 db speakers. Divad may have better luck with his KT88. Both are chinese. Though cayin is chinese I consider that line on european standards. Ming da, and Melody are alos of european standards. The one Didad is refering to is not. |
Thanks Atmasphere and elevick for clear concise answers. I can finally grasp the issues. I will be dealing mostly with huge orchestral music and though I do not listen to loud vol, never more than 10 oclock on my JOR, still for a 845 tube the load may be too much for a 86 db speaker. The fact that its 8 ohms helps, but not much. With me speakers come first and so hope my 6550 tube will do the job. Next week will be the first time I will hook her up. Also i realized (was unaware of the ohm issue)the Tyler Lin Sig Sys is a 4 ohm speaker, so my dream of owning that model has changed now to Tyler's Lin Super Towers which is a 8 ohm and offers 4 W18's midbass per cabinet, which actually suits orch better as most cello, trombone notes fall in the range, not much in the below 35 hz. I see its important to research well before making any decision. |
Trelja, Good answer. Looking at the Thor's crssover designed by Appolito, one can see a simple yet effective design. The thing "just looks right". Its not loaded down with lots of components. Dr Appolito seems to know how to get the most music of the Seas Excel. And he did so successfully.
Newbee I realize that hypothetically it should not matter whether its a 4 OR 8 ohm laod for a "well designed tube amp". But realistically, most tube amps have their limits, depending on how well the trans are made AND the push pull tube on the block. Each tube sings differently and reacts differently to the ohm level. I refer specifically to 4 and 8 ohms, to keep things simply, disregarding 6 ohms.
Ideally tube amps work best on a 8 ohm load. Sure my JOR has driven one beast of a speaker and one moderately heavy load at 4 ohms, which was the Tyler Lin Sig Sys. But the JOR is not built for such loads over a long haul.
Pauly "4 ohms should not be any problem for a tube amp". But in my experience tube amps do not like 4 ohms, especially when the music gets complex, as in orch, even large jazz ensemble is rather thin sounding.
Push pull's , like SET amps can be picky on what speakers they prefer, for best potential.
I'll stay with 8 ohms.
The Tyler Lin Super Towers(8 ohm) is now on my radar and the Tyler Lin Sig Sys(4 ohm) is off.
Thanks Joe for that fine post, crossover network gets overlooked too often. I, like you, want to see whats inside the box BEFORE i buy.
A sealed speaker does me no good. Even if I don't know how the hell a crossover is made.
Paul
Baton Rouge |
Hiend, well sure the 300 tube, even at 4 per mono block are not a tube for 4 ohm speakers. So If it takes a beefy amp like Roge, then you lose some finesse somewhere. IOW the delicate 300 monos has the finesse that the Rogue lacks.
btw why mention 96 db at 1 watt? I never fully understood the db thing. I have a general idea ofdecibels at a certain distance. |
Paul , nice post, and in agreement. FWIW, I demoed a KT88 40 watt intergrated (chinese model/low end lab) just to see how well the 88's work out on orch. The amp is the same weight as my JOR, but offer more tubes in the pre section. Very disapointing. The 86 db Thor's sucked the amp dry. So as you say, impedance of 86 db is something not suited for some tube amps. With a impedance that low, would you say that a important factor is how well the transformers are made/output power?
Tyler's Lin Sig Sys though rated 4 ohms, has a higher db rating at 92, so my little JOR was able to actually work the large speaker into good performance, if not excellent performance. I was very surprised as the LSS has 2 more drivers per cabinet to push vs my MTM design. I was surprised the JOR came through, due to the greater sensitivity of the LSS at 92. (in spite its 4 ohms).
Thoughts? |
Paul
I googled impedance. Its a load issue, 4 ohm speakers create a heavier impedance/resistance level vs a speaker at 8 ohms. Now I'm not sure why some Seas Excel designs are 8 ohms: Thor and several Tyler designs all with lower db levels at 87, and other Tyler designs with Seas Excel are at 4 ohms but have a higher sensitivity, 92. Both use the same copper magnet/motor. Truly a beast to drive correctly and will suck the life out of any tube amp that ain't got the Trans and/or tubes to push the current up and out the voice coils and make the speaker sing. i kind of envision the Seas Excel drivers as a panel/electrostat but in the shape of a conventional cone.
So impedance is the resisitance of the speaker to amp. Sensitivity is how well/or poor the speaker responds to 1 pure electrical watt.
Elevick, that is odd, the Lin Sig Sys is 4 ohm BUT 92 db. Tyler somehow figured out the crossover to function at a higher rate of sensitivity.
What happens in this case is that the vol needs to be turned slightly up to achieve same results on a 8 ohm speaker. IOW my MTM Thors at 10 o clock sound at the same db as the Lin Sig Sys at with the vol at 12 o clock. WITH THE DYNAMICS BEING EXACTLY THE SAME. Jadis has done something with the process in making the trans that allows the amp to drive as their web site says "any kind of speaker"...of course I wouldn't wish to push my luck on a expensive tube amp with 4 ohm speakers. This is why I say tubes "prefer 8 ohms", its a realiability issue. Never want to over work the horse, as they say.
My next speaker will be the Tyler 3 way called the Lin Sys 2, the speaker that Sally Renyolds reviewed in Absolute Sound last Oct. She had nothing but good things to say on its performance. The dual W18's in the Thor's worked fine for past 4 yrs, now I'm ready to move up the next level and get in on some the 25-35 hz's I've been missing. |
Duke builds panels, which as you know require massive ss amp power.
Paul then you have a SET amp correct?
Would that be similiar to the 300 tube? Yes. I heard the 300 tube with orch, the load/complexity was overwhelming. Total shut down of the tube. A CJ mono block as well shut down on a ML panel with orch. So obviously orch overload is not limited to SET but can affect just about any tube amp, which in Push/pull config may have to do with the weakness in the trans. In SET's the weakness in "pulling off" orch may have to do with the characteristic of the 300/845/805 tube family |
My bad. I was only aware of Duke's mention of his Sound Labs.
The Seas phase plug is copper, and the back also looks to be copper. I was not aware of the Hex magnet. thanks for the clarification and link. |
Duke, apologies for that crass comment on what you actually do, which is build a fine speaker. Please excuse my lack of discretion. Paul its true I only have limited exposure to different tube amps, so will reconsider the SET's and other tubes on orch music. This is an issue with audiophilies, we can read about certain fantastic tube amps, but almost no opportunity to audition them. |
Audiofeil I ceratinly cannot argue any of those points ......and feel like I've won anything.
Do not allow my digressive comments and short sightedness keep us from gaining further understanding of this important subject. I am learning something here. Things maybe covered in other topics, but not sure where to look. |
My JOR is,, well the one I sold...is rated 40 watts "conservatively" as they say...does "manage" to drive the 89 db speakers. However since i never biaed the unit, I am not sure there was more highs it could have achieved. On jazz, pop, R7B there was authority. In big complex orch I was always looking for more authority. So the 40 watts was never enough to make the orch "bloom". This is the only reason I sold the amp and looked for more power. I was say a "normal" 40 watt tube amp is not going to deliver the goods on a 89 db speaker. I always felt there was more in the orch that was not comming through. |
The guy who bought my JOR , who actually owned 2 previous JOR's said the amp "should/ought" to be biased every year. Take that up with him. I figured he knows what he is talking about. said tubes wear every yr and a slight bias adjustment 'could be made". Obviously take all my posts as though i am a learning newbee. I hope no one takes anything i say with too much seriousness. Just ideas to open discussion. We can all learn something here. You too. |
Tvad, all the time I had the JOR i never thought to bias the unit to see if I could get a tad more highs. Now that i have the Defy 7, if there is something I don;'t like about the sound, i'll look into biasing the unit. But since the amp has few hours on it, should I bias the amp? It should be biased correctly with few hours use. I've never heard tube amps need biasing regularly. I should look into how to bias the defy 7. Not even sure how to go about it. There is a wooden board at the bottom. Will have mt tech friend assist me first time.
Also I learned the JOR had a pre out and never took advantage of in use with a sub. I will have Tyler replace the woofer in his Taylo with a Seas Excel W26. And so will keep my Thor's, which I had for sale 3 days last week.
The things we learn, one must research and think for oneself of all the options avaliable. |
Divad i had a chinese KT88 amp very close in specs to the one you are looking at. I can only speak for my speakers, the amp did not have enough power. Manufacturers can say "amp has X amount of watts". but are they quality watts?
My Jadis Orch Refer rated at 40 watts, blew out the water a Rotel ss amp rated at 100 watts. Go figure. The quality of trans and specs of the tube is everything. In my experience the KT88 tube is better for higher sensitivity speakers.
I only like KT90 and 6550's,. Well I'll hear the 6550 first time in 2 weeks.
Good Luck
Paul
Baton Rouge
btw not a fan of B&W..too british |
raul. i googled amplifier output impedance and got several hits. The info if over my understanding, but will try to work with the ideas. I grasp that quality of transformers is vital in tube design, especially when driving a devil of a speaker such as are the Seas Excel. The motor on these speakers causes havoc on most tube amps. I assume.
Lets see if this link loads:
http://www.transcendentsound.com/amplifier_output_impedance.htm |
Raul you hit on a essential issue in tube amp output. The impedance factor of the speakers, how difficult is it to keep the motor of the speakers moving in a musical line as the fq's change or amount of fq's are thrown at the amp. Which big orch does. Here the quality of transformers and other internal parts is critical. Thats why i leave it up to the amp manufactore to provide me with the best possible dynamics to run the demanding speaker as are the Seas Excel. I think I have the correct amp. I am waiting on components to arrive. many folks here boo hoo the Seas Excel with no foundation of their criticisms. They seem to be disgusted with my cheering the Seas labs creation, The Excel. Funny that these complainers have nothing to say good about their favorite driver. (not speaker, DRIVERs). Most don;'t have a clue what driver is in their speakers. Most drivers are bought on the open market. Seas actually makes their drivers IN THEIR OWN LAB> Which speaker manufacturer does that??? |
Tvad, I should have posted about driver in house design vs mass market poly cones, on the topic Harbeth vs Tyler. i goofed up, and mixed comments. Back to topic of tube amps transformers and the resistance from the motor and crossovers in speaker designs. A low volt tube amp, or lets say one that has trouble maintaining proper volt current when demand gets high, will not bring out the FULL potential of certain demanding speakers. Go to Jadis' web page, look inside the DA88. Designed to meet any demand from any speaker. Quality doesn't come cheap. Although certain chinese labs are comming along quite nicely. We can talk theoy here all we want. We are more interested in which labs are actually producing a tube amp to meet demanding power hungry speakers. I'll leave the tech stuff to their engineers. I am only interested in the end result. Does the setup produce a high fidelity musical image? Thats all, nothing more. |
Yeah but can they produce a musical image equal or similar as does 2 tube amp labs that i have in mind. Its all about who can get closest to the high fidelity musical image. Audiofeil feels since i know nothing of the tech side and so suffer from deafness. 30 yrs audio critque and now I am deaf. |
Paul , ss amps may be the "ideal" for demanding speakers, but since I do not care for ss amps, I look for certain tube amps that can carry a relatively heavy load. I agree stats/panels/ribbons need ss current for optimum response. Vandersteens need good ss power as well, at least hios larger models. TRhe point of the topic was to ask the GENERALIZED question that tube amps prefer 8 ohm speakers(though even 8 ohm speakers can dip to 4 ohms on huge orchestral challenges). I think the consensus agreed, though some here want to split hairs and bring up their special agenda and objections. Which is fine. I'm staying with 8 ohms, and thats that. |
Eagleman, feel free to ask w/o feeling you will get criticized. I get snides and insults due to lack of tech knowledge, snotty attitude, "mister-know-it-all", negativity, closed minded-ness. So as long as you don't follow me, you'll do all right here. btw I liked your question and Newbee's appropriate answer. I was not aware of how the 4 ohm and 8 ohm taps respond on different fq's. I still don't grasp ohm idea. Only that 4 ohm draws more volts/current from the tube amp. So it was a good question. |
