The interesting thing is that many, many pop recordings have quite amazing soundspaces engineered into them, far more impressive than most orchestral recordings in fact, but these would be rarely appreciated because the systems are not of a high enough quality to be able to extract the full picture - too much "dirt" gets mixed in with the low level detail, courtesy of the replay chain - and the result is that the recordings sound like a congested mess, it's impossible to decipher what's going on, acoustically. It requires a minimum level of SQ to get the necessary clarity, and then vast vistas open up, huge spaces in which the musical elements occur.
Lynn, #12552 post really nailed it all! To have at it again though, if one actually reads (that's what we do here) the complete owners manuals of amps like my First Watt J2, http://www.firstwatt.com/pdf/prod_j2_man.pdf , its clear that each and every design feature you insist on are precisely what Nelson Pass deliberately pursues when he builds amps like this one-or any of the First Watt and Pass Labs (i.e. XA30.5) Class A models going back to at least 2007.
And yet, you report that they seem to be lacking the tonality and 3-D spaciousness of your particular tube amps. I certainly don't doubt your account of the experience. However, true or false: How many times did you hear First Watt and/or Pass Labs Class A amps, built circa 2006 or later on speaker designs which you have repeatedly stated here that you don't like? Chiefly, that would be the Lowthers, yes?
As it happens, Lowther America's Jon Ver Halen and Nelson Pass have held numerous shows together. Indeed, Jon sells new and used First Watt amps First Watt Amplifiers (Jon's wrong about the J2 being pp; its se).
That Nelson Pass likes the sound of Lowthers is clearly obvious. But though I've never had the chance to hear any of them, I very strongly suspect that I would not like them, also for obvious reasons.
But, assuming you've never heard Class A amps of his (not the AB Pass Labs models) built over the last several years driving anything but Lowthers, how could you possibly know how they would sound driving Gary Dahl's system-or even your Ariels?
But if you check out the J2 manual I would very much like to know if all of what Nelson sought to achieve with that single-end all JFET design is how much different than the design criteria you've pursued with PX25s, 300Bs, 2A3s or other tubes.
And yet, you report that they seem to be lacking the tonality and 3-D spaciousness of your particular tube amps. I certainly don't doubt your account of the experience. However, true or false: How many times did you hear First Watt and/or Pass Labs Class A amps, built circa 2006 or later on speaker designs which you have repeatedly stated here that you don't like? Chiefly, that would be the Lowthers, yes?
As it happens, Lowther America's Jon Ver Halen and Nelson Pass have held numerous shows together. Indeed, Jon sells new and used First Watt amps First Watt Amplifiers (Jon's wrong about the J2 being pp; its se).
That Nelson Pass likes the sound of Lowthers is clearly obvious. But though I've never had the chance to hear any of them, I very strongly suspect that I would not like them, also for obvious reasons.
But, assuming you've never heard Class A amps of his (not the AB Pass Labs models) built over the last several years driving anything but Lowthers, how could you possibly know how they would sound driving Gary Dahl's system-or even your Ariels?
But if you check out the J2 manual I would very much like to know if all of what Nelson sought to achieve with that single-end all JFET design is how much different than the design criteria you've pursued with PX25s, 300Bs, 2A3s or other tubes.
But might the 1.4" driver have better sound quality overall, albeit a restricted top end?
As my living room is only 18 ft x 14, Radians are typically >111db sensitive, the Altec 416s are 98db sensitive, I'd be bi-amping the system with a pair of 25 wpc amps and that I very likely can't tolerate SPLs more than 83db at 11 ft, would shelving down the lower band of Radian driver be better than boosting its high end?
But when should the Altecs start playing? Gary crosses his so that they start playing at 700Hz.
And won't boosting the high end risk causing distorted or compressed sound?
Thanks again Gary for all your help with the Altecs.
Frankly, though, its intimidating to press on with the rest of the build; I just don't have quite enough technical knowledge and/or time to make most of the measurements. But I spent way too much time and money to turn back. And I want my living room system! So the next step is ordering the parts: AH425 horn and Radian 745NeoBe driver. But what Slagle autoformer ? intact audio
I'm bi-amping the system, so aside form the passive HF EQ you and Pierre worked out, will I need any other kind of filter?
Frankly, though, its intimidating to press on with the rest of the build; I just don't have quite enough technical knowledge and/or time to make most of the measurements. But I spent way too much time and money to turn back. And I want my living room system! So the next step is ordering the parts: AH425 horn and Radian 745NeoBe driver. But what Slagle autoformer ? intact audio
I'm bi-amping the system, so aside form the passive HF EQ you and Pierre worked out, will I need any other kind of filter?
Great! So if I can successfully build Gary Dahl's system, I will truly hear everything that would otherwise be buried in these recordings.
Oltos,
A lot depends on whether you are after a very wide sound field or you can settle for a narrower dispersion angle. With the 1.4 inch drivers you most likely will have a narrower dispersion angle, you just can't get around the fact that the dispersion angle is going to have a lot to do with the exit angle of the driver chosen and many of the 1.4" exits will beam into a narrower angle at the high frequencies. You also will have a lower break point before the mass of that larger diaphragm will start rolling off the high. I don't know how well the current Radians with the Be diaphragms extend this high but I have never seen a 1.4" in the older drivers that could possibly get over 16Khz even with eq. These are some of the reasons I prefer the 1" exit drivers. Can you push a 1" down to 700hz, it has been done for years with smaller Altec drivers and no reason that a 1" or 1.4" can't do that at the levels that you are taking about, you aren't after concert level so that is to your advantage. It isn't going to take much power to driver a compression driver horn combination up way higher than you desire. You can use this to your advantage and not only shelve the lower end down to make the higher frequencies appear to reach higher into the band, it is a simple trick to use, you have plenty of headroom to play with. Your limitations are going to be with the cone driver, that is where you will most likely run out of power and clip the amp on heavy bass notes. I've never heard a 2" exit compression driver I could live with, even in PA application I couldn't stand those things, you always ended up needing to use a 1" driver and a second horn to make those work and get decent top end extension. And in those application I would much rather have a cone driven midrange driver to cover the vocal range, compression drivers just have a certain sound when covering that range, it isn't my preferred method but that is a personal choice.
A lot depends on whether you are after a very wide sound field or you can settle for a narrower dispersion angle. With the 1.4 inch drivers you most likely will have a narrower dispersion angle, you just can't get around the fact that the dispersion angle is going to have a lot to do with the exit angle of the driver chosen and many of the 1.4" exits will beam into a narrower angle at the high frequencies. You also will have a lower break point before the mass of that larger diaphragm will start rolling off the high. I don't know how well the current Radians with the Be diaphragms extend this high but I have never seen a 1.4" in the older drivers that could possibly get over 16Khz even with eq. These are some of the reasons I prefer the 1" exit drivers. Can you push a 1" down to 700hz, it has been done for years with smaller Altec drivers and no reason that a 1" or 1.4" can't do that at the levels that you are taking about, you aren't after concert level so that is to your advantage. It isn't going to take much power to driver a compression driver horn combination up way higher than you desire. You can use this to your advantage and not only shelve the lower end down to make the higher frequencies appear to reach higher into the band, it is a simple trick to use, you have plenty of headroom to play with. Your limitations are going to be with the cone driver, that is where you will most likely run out of power and clip the amp on heavy bass notes. I've never heard a 2" exit compression driver I could live with, even in PA application I couldn't stand those things, you always ended up needing to use a 1" driver and a second horn to make those work and get decent top end extension. And in those application I would much rather have a cone driven midrange driver to cover the vocal range, compression drivers just have a certain sound when covering that range, it isn't my preferred method but that is a personal choice.
I think it not so much "settling for" a narrower dispersion angle, as a choice between better 3D focused on the listening chair, and filling the room with energy - at the expense of some of the 3D. I tried TD-2001 on jmlc Iwata horns, sitting on top of Onkens and I got a lively energetic presentation that my wife liked best, more like a venue to her. But my taste is for the better 3D you get from round jmlc horns.
Different subject. Has anyone tried an RL HP filter / attenuator? I needed about -12dB for my set up and replaced the autoformer with swamping resistor for a simple RL filter and it works great. You can also bypass the R with a suitable C to get a lift at the top end.
martin
Different subject. Has anyone tried an RL HP filter / attenuator? I needed about -12dB for my set up and replaced the autoformer with swamping resistor for a simple RL filter and it works great. You can also bypass the R with a suitable C to get a lift at the top end.
martin
Beyma TPL-150H
Hi Oltos and Lynn,
Since I have the Beyma TPL-150H, I allow myself to chime in.... The 700 Hz limit is probably due to the PA -10dB standard. The Beyma can be used and preserves 80° horizontal dispersion down to, say, 1300 Hz, but many people prefer crossing it no lower than 1700-1800 Hz. This means that paired with a 15" driver below you will have a directivity mismatch at the crossover point due to the much narrower dispersion from the 15" driver at, say, 1700 Hz.
Thus, dispersion-wise the Beyma TPL-150H should be matched to no larger than an 8". Some people care less about dispersion and use the Beyma together with a 10" or a 12" in order to exploit the higher sensitivity of the larger drivers. All that being said, the Beyma TPL-150H sounds very good indeed - much more natural than any of the compression drivers, I have tried. I have not tried any of the Be drivers though...
Best regards
Peter
Hi Oltos and Lynn,
Since I have the Beyma TPL-150H, I allow myself to chime in.... The 700 Hz limit is probably due to the PA -10dB standard. The Beyma can be used and preserves 80° horizontal dispersion down to, say, 1300 Hz, but many people prefer crossing it no lower than 1700-1800 Hz. This means that paired with a 15" driver below you will have a directivity mismatch at the crossover point due to the much narrower dispersion from the 15" driver at, say, 1700 Hz.
Thus, dispersion-wise the Beyma TPL-150H should be matched to no larger than an 8". Some people care less about dispersion and use the Beyma together with a 10" or a 12" in order to exploit the higher sensitivity of the larger drivers. All that being said, the Beyma TPL-150H sounds very good indeed - much more natural than any of the compression drivers, I have tried. I have not tried any of the Be drivers though...
Best regards
Peter
Great! Like Lynn said, one of the great things about horns is that you don't have to play them at (dangerously) high SPLs in order to retrieve the full dynamic range of the recording. I am so psyched to build these things.
I don't see why a 1" driver wouldn't work, but I don't recommend the old Altecs (been there done that) and I'm not familiar with any of the modern 1" units by other makers. Anyone?
For my part, I'm happy with the 1.4" drivers. They go higher than my hearing anyway, so I'm not concerned about trying to squeeze out a few more kHz. When making the choice, Lynn and I were more interested in finding drivers that would make it through the crossover region without breaking a sweat.
Gary Dahl
For my part, I'm happy with the 1.4" drivers. They go higher than my hearing anyway, so I'm not concerned about trying to squeeze out a few more kHz. When making the choice, Lynn and I were more interested in finding drivers that would make it through the crossover region without breaking a sweat.
Gary Dahl
You keep saying this, but well-recorded (and non- or minimally compressed) calssical and jazz music can have a 'crest factor' (i.e. peak-to-RMS level) of over 20 (sometimes even 25) dB.
So listening at your average 83dB level would still require the ability to put out ~105dB undistorted and unclipped peaks.
Just sayin'...
Marco
Much my own experience about the very top treble , and a view many of my contacts hold. Even the SEAS Be 1" dome rolls off at the top. It is a careful balance though. With a short waveguide you get a smaller roll off in the top treble, but lose the directivity of the LeCleac'h. Both are a good result, while the simple waveguide is cheap and gives its own distinct clarity. No wonder so many more waveguided speakers are available and look good.
Yes, I broadly envisage the same within my experience, and the dispersion angle is really a matter of taste and whether it only needs to be settee or even a single seat. The 1" is a safer bet if you wish to avoid a supertweeter.
My preference for vacuum tubes is based on two factors: performance at the device level, and a strong subjective preference.
* Performance at the device level: lowest proportion of high-order harmonics (a spectrum with a fast decline in harmonic structure), freedom from hard overload, freedom from overcurrent damage (no protection circuits required), and low capacitance at the driving terminal (60 pF vs 1000 pF for MOSFETs), in addition to the capacitance itself being highly linear (MOSFET capacitance is nonlinear and difficult to drive). As a minor point, these devices self-heatsink, and operate reliably at high internal temperatures.
The downside is they wear out (after thousands of listening hours), require a high operating voltage (typically 250V to 500V), and dissipate lots of heat. However, for a Class A amplifier, heat dissipation works out the same, which is why both transistor and vacuum-tube Class A amplifiers max out around 20~30 watts.
The wearing-out is a complex picture. Vacuum-tubes shift operating parameters in the first 10~20 hours of operation, remain stable for 1000 to 3000 hours afterward, and slowly decline in performance as emission from the cathode or filament falls off. If the vacuum tube is defective (has gas remaining in the envelope or is built with contaminated metals), then it won't operate satisfactorily in a fixed-bias circuit (commonly seen in medium to high power PP pentode amplifiers).
Marginal or near-defective tubes will operate in a self-bias circuit, but won't sound or measure all that great. (Double-checking the steady-state voltages and currents will reveal a bad actor ... drift is usually a bad sign. Good tubes fall in a pretty narrow window, about 5~10% scatter in parameters.)
Transistors have long lives, although this is a function of die temperature and how many times they are subjected to overload, and then fail suddenly without warning. The failure-mode is frequently a short, which then takes the driver stage with it, along with the emitter resistor. The circuit board can be scorched if this happens, depending on how quickly the fuse or protection circuit activates.
So the real question is, will the devices be available ten or twenty years from now, when failure occurs? Thanks to the guitar community, it looks like the classic pentodes (EL84, EL34, KT66, KT88, 6550) will be manufactured decades into the future, along with the simple discrete analog components needed to build a guitar amp. The low-tech manufacturing of vacuum tubes has the advantage of smaller capital requirements (compared to silicon manufacturing), and steady sales of millions of units into the replacement market.
* Strong subjective preference: I switched from transistors to tubes back in the early Nineties. I'm struck by the fact that just about any dumb tube circuit sounds pretty nice, while it takes a genius-level engineer to makes a good transistor amp.
I had the remarkable good fortune to work with Bob Sickler when I was at Audionics in the Seventies ... who knows what he'd be doing if he was still around. Gary Pimm has a very unusual current-mode MOSFET amplifier, although I still (marginally) prefer the original direct-heated-pentode version. Nelson Pass is a great guy and a tremendous asset to the DIY community, but based on several demos I've heard at hifi shows, his subjective goals are very different than mine. If I was told I could never listen to a tube amp again, I guess I would try the new Benchmark amplifier.
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Oltos,
Just as Lynn has his personal preferences, and they are preferences for a specific type of sound, I could not live with most tube amps on the bass speaker. The fact that he keeps bringing up the class A section of the amp tell much of this story. I would bet you money that his amp does get out of that class A region much more than he wants to admit. On any type of music where you have any kind of real dynamic swing and a strong bass note your going to require much more than 20 watts of class-A power. you are going to be into the class-B range for sure. I listen to rock and Jazz and even at a lower level of sound those bass notes from a kick drum or strong bass guitar are going to tax a lower powered tube amp to no end. Yes there are some real tube amps that can put out 150-200 watts but they are more the outlier than common today. Some of the old McIntosh power amps could do this but lean over and pay some ridiculous amounts of money for those. You really are getting into preferences for a certain harmonic distortion here, that is more than obvious at this point. Now when you start making that kind of power with a tube amp you have a mighty nice heater sitting in the room. There are some real low distortion SS amps that don't have the higher order harmonics, you just have to know what you are looking for. typically not many of the atrociously designed audiophile amps that I see out there. I've heard some real nice sweet SS amps and some that sound like a transistor radio. Build the speakers and then try some amplifiers before you make your choice. I do understand your desire to keep your hearing but if you aren't going to put a limiter or compressor on your system you are going to get peaks over 100db with a great recording. A piano is going to do that on lots of Jazz music, so will a trumpet and a great percussionist will do that many times. That doesn't mean you are listening at that level on an average but the peaks will be there and if the amp can't do that it is going to clip and kill the sound. I know a recording engineer who wears foam ear plugs whenever he is out in public, he protects those ears all the time, that is how he makes his living. At the same time he has to be able to listen to full dynamics to record or mix down a track and you do need to have that capability for playback if you aren't going to listen at really low levels. I could handle a SS amp on the bottom and a tube amp on top, but not on both unless like I say it was the rare tube amp that had some real output. Your never going to get away with that with a SE amp and a few watts even with a high efficiency cone driver, it isn't going to happen. I have no idea of how much power that Lynn's tube amps are capable of, but even for orchestral music the peaks can take some real power.
Just as Lynn has his personal preferences, and they are preferences for a specific type of sound, I could not live with most tube amps on the bass speaker. The fact that he keeps bringing up the class A section of the amp tell much of this story. I would bet you money that his amp does get out of that class A region much more than he wants to admit. On any type of music where you have any kind of real dynamic swing and a strong bass note your going to require much more than 20 watts of class-A power. you are going to be into the class-B range for sure. I listen to rock and Jazz and even at a lower level of sound those bass notes from a kick drum or strong bass guitar are going to tax a lower powered tube amp to no end. Yes there are some real tube amps that can put out 150-200 watts but they are more the outlier than common today. Some of the old McIntosh power amps could do this but lean over and pay some ridiculous amounts of money for those. You really are getting into preferences for a certain harmonic distortion here, that is more than obvious at this point. Now when you start making that kind of power with a tube amp you have a mighty nice heater sitting in the room. There are some real low distortion SS amps that don't have the higher order harmonics, you just have to know what you are looking for. typically not many of the atrociously designed audiophile amps that I see out there. I've heard some real nice sweet SS amps and some that sound like a transistor radio. Build the speakers and then try some amplifiers before you make your choice. I do understand your desire to keep your hearing but if you aren't going to put a limiter or compressor on your system you are going to get peaks over 100db with a great recording. A piano is going to do that on lots of Jazz music, so will a trumpet and a great percussionist will do that many times. That doesn't mean you are listening at that level on an average but the peaks will be there and if the amp can't do that it is going to clip and kill the sound. I know a recording engineer who wears foam ear plugs whenever he is out in public, he protects those ears all the time, that is how he makes his living. At the same time he has to be able to listen to full dynamics to record or mix down a track and you do need to have that capability for playback if you aren't going to listen at really low levels. I could handle a SS amp on the bottom and a tube amp on top, but not on both unless like I say it was the rare tube amp that had some real output. Your never going to get away with that with a SE amp and a few watts even with a high efficiency cone driver, it isn't going to happen. I have no idea of how much power that Lynn's tube amps are capable of, but even for orchestral music the peaks can take some real power.
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Good to see this thread live again. I can imagine what it really means to try and get the sound you are looking for. In most cases, there are technical explanations, and quite often it can be the driver itself which you cannot do much about, interface between devices which generally there is insufficient data, and whatever equipment in the devices. One of the biggest reasons I switched courses to small systems is to get a better handle on each of the areas. Even as such, it is really still a complicated situation.
I have enjoyed lots of views from the people posting in this thread, especially Lynn whom really provides very good description of his experience with different devices. These really sort of inspires me to look into different aspects to figure out what technical qualities might contribute to providing what sound qualities.
Great thread.
I have enjoyed lots of views from the people posting in this thread, especially Lynn whom really provides very good description of his experience with different devices. These really sort of inspires me to look into different aspects to figure out what technical qualities might contribute to providing what sound qualities.
Great thread.
Wouldn’t that be dictated by the type of music I’ll be playing on that system? As this will be my living room system, that’s where I’d want to play the “big soundstage stuff”; orchestral music of all types and anything that sounds like it was recorded in a large room.
So even though the wavelengths of any source material between 30 and 35Hz reproduced by my subs (which will take over where Gary’s sealed boxes cut the Altec 416s’ response off below 70Hz) won’t fully propagate in my 18 ft x 14 living room, it would far worse attempting that in my 13 ft x 12 bedroom (where the system in there I’ll use to play entirely different kinds of music; see my earlier posts).
So for the living room system (which I’m building first), wouldn’t the wide angle horn/driver be what I’d want?
I don’t get it: Gary’s a symphonic conductor with the Bremerton Symphony. Certainly, he must play lots of concert hall type classical music-all of which requires, among other things, speakers capable of a wide soundstage. So why would Gary select the 1.4” Azurahorn AH425-which you said has a narrow dispersion angle-when he could have selected the 1” AH550? Azurahorn -Le Cleac'h Acoustic Horns - ProductsThat doesn’t seem logical.
And what do you mean “appear” to reach higher in the band? If the Radian isn’t pushed (by adding EQ) to actually produce the higher frequencies (past 10kHz), then any info in that higher band (if actually present in the source material) isn’t going to get heard. Yes?
Instead, to get the Radian745NeoBe to go beyond 10kHz, Gary and Pierre (see their recent posts at the thread) designed and built a passive EQ. Gary said he’s very happy with the result.
Really? The sealed boxes only let the Altecs play down to 70Hz, and my servo subs takeover below that. And the Altecs are 98db sensitive, driven by a dedicated 25 wpc First Watt F4 amp in this bi-amped system. And my room’s only 18 ft x14. I don’t see how the Altecs could ever come close to being clipped in this system.
LOL, I have converted most of my SET into headphone amps.
PP EL84 can be great on treble horns.Here is a tube amp that has "big" bass..
