Tekton Double Impacts
Folks I’m still baffled as to how an octal small tube such as the 6SN7 has the capacity to successfully manage a legitimate full range speaker. How is this tube able to provide sufficient current for a 4 ohm impedance load? I believe the listening impressions of Teajay and Allan but this outcome is highly outside expectations given known specifications of both products. Fascinating results in my opinion. I’ve been a long time advocate for high quality lower power amplifiers ( particularly DHT SET types) and higher sensitivity and easy load efficient speakers. But! I must admit to being surprised by this unique scenario. Charles |
Charles1dad, if I were an EE maybe I could scratch the surface of explaining David Bernings designs but they are very complicated. These amps are unlike any other tube amp I have ever owned and they also seem more powerful than conventional tube amps. David Berning's ingenus impedance conversion tech is behind this. http://davidberning.com/technology |
Hi Charles,
Your question is of course a logical and very valid one. After thinking about it a little, I believe I can explain how the 1 watt MicroZOTL amp can drive the DI to levels in the vicinity of 100 db at the listening position. Three things need to be considered: Output impedance, current capability, and power capability. I’ll mention first that the amp is rated, somewhat counter-intuitively for a tube amp, to be able to deliver more power into 4 ohms (1 watt) than into a higher impedance (0.5 watts into 14 ohms). And its output impedance is specified as a usefully low 2 ohms. How is that possible with a 6SN7, which like just about any small signal tube operates under relatively high voltage/low current/high impedance conditions? The key to the answer is that the ZOTL amps are not true OTLs in the traditional sense. As I know you’ll recall from discussions in other threads here, between the output tube and the output terminals of the amp is a transformer that operates at RF (not audio) frequencies, as well as some solid state switching devices. That circuit converts the high voltage/low current/high impedance condition under which the tube operates to a much lower voltage/higher current/lower impedance condition, while presumably being efficient enough to not sacrifice a significant amount of power in the process. (For a resistive load power = voltage x current, and when a transformer transforms voltage and current the product of the two cannot increase, since it is a passive device). So that takes care of output impedance and current capability. Regarding the 1 watt power capability of the amp: The speaker is rated to produce an SPL of 98.82 db at 1 meter for an input of 2.83 volts. Let’s call it 99 db. 2.83 volts into 4 ohms corresponds to 2 watts. So the 99 db becomes 96 db for a 1 watt input. Assuming that falls off with increasing distance at a rate of 6 db per doubling of distance, which is typical for non-planar speakers, at a typical listening distance of say 10 or 12 feet the 96 db would be reduced to about 86 db. If both of the speakers that are present are supplied with 1 watt, the overall acoustic power that is radiated into the room would increase by 3 db, relative to the output of a single speaker, but the increase would approach 6 db if the listener is approximately centered. That brings us to 92 db. “Room gain,” i.e., the effects of reflected energy in the room, would conceivably add something like 3 db or so. That brings us to 95 db. And probably another few db would be added as a result of some combination of dynamic headroom, conservatism in the 1 watt spec, and a small amount of clipping that would not be perceivable as such. Voila! Best regards, -- Al |
Hi Al, Well, once you explain it that meticulously it does begin to make considerably more sense. That RF transformer is doing some serious work 😊 My amazement is the 6SN7 is used in this manner so apparently effectively. In my pre conditioned mind that tube is thought of as one of the iconic small signal tubes and not a device used to drive speakers (especially of the 4 ohm variety). Again, fascinating. Charles |
@mac48025 ; @klh007 ; @corelli If I go with the Herbies Audio 'Giant Threaded Stud Glider' product, do you recommend going 1/4" 20 in the 1/2 inch length so that the sliders are flush with the speaker base, or would you go with a slightly longer length to offer up some advantages...like elevation and angling, etc.? I haven't looked underneath the speakers.... @mac480245: you mention that the bass leaks from the screw holes... if they are open ended I would not want to damage anything with a long screw. If I do a hybrid approach and use the Soundcity Outrigger that @corelli recommends, do you feel that placing Herbies Giant Fat Gliders (not the screw in type) under the Soundcity auto leveling / rubber feet versions would offer further benefits in isolation / sound quality? This approach (I think) allows me to easily move the speakers because of the gliders and provide (I think) the additional stability outriggers might bring vs going with the Herbie Threaded Gliders alone. Thoughts? Thanks! |
Al, youre a marvel. Thanks yet again for explaining something I couldn't previously conceive in a manner that I understand. Charles, teajay mentioned he is using the holy grail of 6sn7 tubes. Maybe that accounts for him being able to drive the microZOTL to its extreme without any harsh results? Just a thought. David, I'm using the 1/4/20 giant gliders with 1 1/2 studs for greater lift off the carpeting and more distance for leveling as my basement floor isnt real level. No issues with the threaded studs entering the speaker cabinet. |
david_ten If you use the studded glider directly to the speaker, agree with mac at 1.5". If you use the outriggers, the steel is 1/4" and you would need another 1/4" for a brass acorn nut/washer on the top of the outrigger and then another 1/4" to adjust for uneven flooring, then the jam nut---so you will need the 1" 1/4-20 glider. Also, I opted for the knobs from soundocity--they are only $3 each and look nicer than the acorn nut. I attached the outriggers with hexhead SS bolts/washers, 1 1/4 length 1/4-20. Either way ought to work well. I would keep the speakers vertical. Not a fan of self leveling footers. Way to much wobble for me. I'm a believer in a solid/stable footing for speakers to avoid "micro wobble" induced by the woofers which in my mind might slightly add some element of haze. But I'll be the first to admit I have not spent hours, days, or weeks comparing all the many options out there. |
Teajay, The tungsol round plates are very nice tubes, but aren't the only game in town. I have a big collection of 6sn7's. IMS, I think the 1952 Sylvania bad boys are better. They have a bottom getter and 3 holes in their plates. Give them a try, if you can find them. Big bass, dynamics, and beautiful tone. In my preamp they are much better maybe not in the LTA, but worth a try. The tungsols are overrated and overpriced imho. Joe |
Almarg, As always thank you for the stellar explanations regarding the microZOTl driving the DI. This thread has really made me re-think what is possible. I've been a fanboy of Eric Alexander for some time now and still own the Tekton original Lore as well as Micro Lore which are very good speakers. Not long ago I also acquired my brother's DeVore 0/96 and Harbeth HL5's. Both are phenomenal speakers in their own right; but I think I must try the DI with the MicroZotl stuff. Best, mikirob |
Hey snopro, I too have had virtually all the highly regarded 67SN7's in my collection, including the Sylvania 1950's bad boys, and for my taste I still greatly prefer the TungSol 1940's tube. I fine them to the most natural/real sounding in their tone and unbelievably 3D in their imaging with an overall liquidity from top to bottom. Yes, very expensive these days, but not over rated in my opinion. |
Hi Charles, Everything is good, thanks! Hope all is well. Yes, I am still using the Hornings and Franks and the pairing is wonderful. Real music makers. Sorry for going off topic. The LTA and DD sound like great bargains and really good performers. It's nice to see companies where you can still get great sound for not so much money. Audio prices have been getting crazy in the last several years. I applaud these companies for keeping prices reasonable for people with tighter budgets. Joe |
Hi Joe, I find this thread very interesting for the same reason. What apparently are truly high performing audio products at honestly obtainable cost with seemingly little if any compromise. It appears that the Tekton DI with the LTA ZOTL electronics or say a Line Magnetic SET amplifier will yield serious high end sound quality far below Uber price levels. That is noteworthy in my opinion. I’d eagerly move in this direction if I weren’t so thrilled with my present audio system. Charles |
Charles, Funny you mention Line Magnetics. This was another amp I was reading about--the 518 integrated to be specific. Thought it might be a good match for the DI's. Plus in the winter it could function as a space heater (: Have you ever listened to this amp? Glad you are so happy with your system. "Upgradeitis" can be an expensive affliction that never gets us to an endpoint. Sounds like you knew what you were after and achieved that goal. |
Hi Corelli, I haven't heard the Line Magnetic SETs but I've gotten enough feedback from people I trust that the 518 ia, 219ia and 508ia are really quite special amplifiers. Yes I am very content with my system (going on 8 years). I was after a very natural sound and a system that brings out the sol and emotion of music. I never pursued "perfect" sound, that leads to frustration IMO. Charles |
@corelli: I did a three hour store audition of the Devore O 93/96s driven by Line Magnetic components in NYC. The pairing was excellent and I was very impressed with the Line Magnetics performance and price points. I unfortunately don't remember the component numbers, but the integrated as well as separates were in the chain. @mikirob : Interesting! I thought I was going to move ahead with the Devore O/96s or the Harbeth HL5+ or M 40.2. Was holding off until the house was completed and I knew for sure which room was going to serve as our audio/media room, specifically which Harbeth would be best in it. And then, along came the Double Impacts. The third option / route was going with a Spatial Audio Open Baffle. |
Hey david_ten, If you have not read my review on HTR on Tekton's very innovative Sigma OB speaker, which is an absolutely wonderful sounding speaker, and I gave a PRODUCT OF A YEAR AWARD, to get the details how Eric figured out how to avoid any electrical EQ to get the bass frequencies right. I love planar speakers sound-staging except for how they sometimes enlarge individual images and lack focus in location on the sound-stage and how OB designs can create a planar like sound-stage without these difficulties. However, I believe the DI's do everything an OB design can do plus many more virtues that are talked about on this thread. |
Hi teajay, I have read it. And Eric had terrific pricing on them as part of his "royally ticked off" campaign! : ) After discussing it over the phone with him, he steered me right towards the Double Impacts. I still see them as an option for surround duty, if I ever get to my HT needs. Right now, I'm considering other component upgrades to squeeze the most out of the DIs..... |
I was considering either the OB Sigma or the Pendragons but when I called Eric to place an order he asked if I'd be interested in a new speaker that was still just a twinkle in his eye at that time......the Double Impacts. While I knew nothing about them, being the first to get them, I didn't have any apprehension at all as I totally trusted Eric's ability. I never expected anything as good as the DI's though! I can't imagine how much one would have to spend to do better. Now, if the LTA MZ2-S is equally as good ( and I'm sure it is) I'll be in audio heaven. |
As I said earlier, while I loved my Magnepan 1.7's, I would not go back to them after owning the DI's. The DI's just have too many strengths, too much balance. I feel that I actually lost detail (perhaps from rear wave interference) with the 1.7's. Things were less precise with the soundstage. As teajay said you do get a larger than life image which is fun but not always accurate. When you look at voicing, sounstaging , dynamics, frequency response, quality of bass, this is a terribly hard speaker to beat. So while I enjoy open baffle/planar approaches, I have no urge to back in that direction. |
I have been reading this thread with interest in the Double Impacts and then I read someone is powering them with the one watt MZ2 so Just for the heck of it, I hooked up my older Micro ZOTL2 amp and MZ2-S as preamp together to see what kind of SPL I could get with my 93db sensitive Decware Radial speakers in my living room. I'm playing at levels as loud as I want surprisingly without clipping. The sound is as good as I've ever heard these speakers sound. A small notch above the Berning ZH230 I use. It is no surprise this little 1 watt amp will drive the Tekton's. |
Hi Guys! It was teajay's review and the value of the DI's that made me order a pair. I have to laugh about the WAF comments though. I was met with "these speakers look so much better", no doubt because they are replacing 6 ft high Dunlavys. I haven't received the spikes or the grills yet. Are stock spikes included? I'm really enjoying the speakers, but want to get the most out of them, so I'm considering ordering the MZ2 and hoping I can run it without the amp as that not only saves money but sounds like the hot setup. Teajay, what configuration (which MZ2 and which tubes) is recommended when ordering the MZ2? I'd like to get it right from the start. Thanks for a great thread! |
Cmss2000, The spikes are in one of the styrofoam end caps......they're easy to miss and the speakers will sound much better with those threaded holes filled. Congrats on your new speakers, you're in for a treat. I'm going to go with LTA MZ2-S also. Terry mentioned using the 1940's Tungsol black oval plate 6SN7's. That's what I'm going to go with also. A hot set up indeed.....the 1 watt still boggles my mind though! |
Congrats cmss2000, As mac48025 mentioned the spikes are to be found in one of end caps and you really don't know what your speakers can sound like with out them. If you did not special order your pair with grills, there are none to find. Concerning the Micro-ZOTL the one I purchased was the review demo with the stock tubes. It sounded very good with stock tubes, but nothing like the level of performance after rolling in a pair of Sylviana NOS Gold Brand 12AT7's and the TungSol NOS Black Glass oval plate 6SN7's. |
@cmss2000: Congratulations on your purchase! Keep us posted on your impressions and experience. I nearly missed the spikes as well. I did order a pair of grills but I think they are vaporware.... : ) @ everyone -- it's looking like the DIs are not the bargain we say they are. Everyone is on the upgrade or add warpath... myself included.... Said in jest of course! |
Thanks guys! Does anyone know of a good source for those tubes? I previously looked in one endcap for the spikes but it could have been a top endcap. I'll go down in a bit and check the other endcaps. And yes, I did order the grills but I think they are shipped separate as they definitely weren't in the box and I remember someone else mentioning it took a while to get the grills after they received the speakers. That's when I thought the spikes would arrive too. I'm really getting excited about audio again, I thought I was done with it because of the skyrocketing prices of good gear. It's nice to hear there are still some great finds for a decent price. I want to thank Teajay and everyone else for sharing these little "secrets". |
Regarding the spikes I didn't find them till a couple weeks later when I was ripping the boxes up to go in the trash. They are not obvious at all! In the meantime I had gotten some 1/4-20 bolts which I cut the heads off and sharpened as a temp solution. Could have saved me a burned finger if I had found them sooner🙄 |
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Thanks for the tube sources! I'll be checking them out. Well, I finally unburied the spikes. I thought they were going to be much bigger for some reason but they work. I also pulled the speakers together a little more (I had them at 8 ft apart originally, now a little less than 7). And yes Teajay, the sound is definitely better with the spikes (and probably because of the spacing). Noticing a more stable center image. All notes are a little more defined and the bass is more solid. The speakers have disappeared and the sound is really nice! Can't wait to hear them with an MZ2. Keep the suggestions coming, much appreciated! |
For those having a difficult time locating spikes here's the video instructions: https://www.youtube.com/watch?v=4rQR3NNp-Q4 |
For immediate release April 19th 2017 Tekton Design LLC - We've prepared 8 Ohm versions of the patented Double Impact and Electron models. The new 8 Ohm version has been ideally optimized for lower wattage SET tube amplifier typologies, all tube amplifiers lacking 4 Ohm taps, and vintage solid state amplifiers. Eric Alexander - Designer |
Hello everyone, I have been looking for a speaker upgrade the last couple of months,I have been involved in this wonderful hobby for about 30yrs,So I owned a fair amount of speakers. About the only type I have'nt had is OB'S I was seriously considering the pap with the vox full range or the spatial M3 turbo s. Now that I have read this entire thread and all other info about the DI's,I decided to give Eric a call this morning and ask a few questions,he is a very busy guy but was accommodating. I ended up buying a set that are gloss metallic black and have all the internal upgrades.I'm looking forward too receiving them and trying them out with my equipment and room. I haven't heard any of the Tekton speakers and I don't know anybody in my area that has a pair. |
I see a pair of 8 ohm DI's in my future! I'll be getting a pair of LTA MZ2-S that will be bridged and run as Monoblocks which will provide 70% more output than a single MZ-2S. I'm sure that will be fine with my 4 ohm DI's but the 8 ohm version should be better yet. I wonder if teajay had any influence into that decision since he's the one that realized just how good the DI's are with the MZ. I applaud Eric for making this possible. Congrats kdude, you're in for a real treat! |
Last week I had the privilege of swinging by teajay's house to give the DI's a listen. I'm a bit late to share my thoughts on this thread, but wanted to offer my humble opinion... Wow! "Jaw-dropping..... especially for the money" is what's still resonating with me a week later. How can Tekton build and sell speakers of this quality for $3k shipped? Amazing. We listened to a range of music types and the DI's handled each with aplomb. There was a relaxed sense of ease with these speakers. They released the notes effortlessly. Excellent timbre and the sense of decay was palpable. The "air and space" was appropriate for each each recording - they had a sense of scale for larger recordings and an intimacy on classic audiophile-female-voice recordings. The speakers disappeared too - with a wide soundstage. Excellent low-level detail and a strong sense of slam/macro-dynamics. While we didn't push them too hard, my feeling is these speakers will ROCK. One could have lots of fun rotating through supporting electronics (1 watt!?!?) with the DI's not being a limiting factor in associated equipment selection. Of course teajay's reference-grade equipment, room, and set-up contributed to the overall experience, but in no way did these $3k speakers seem like a weak link in the chain. They are pretty large speakers. Pound-for-pound just jaw-dropping for the money and sonics. I can't imagine these will stay at $3k for long. Couple the sonics, frequency range and sensitivity with the price-point and they add-up to a value equation unique in the hifi industry. |
