Paul S wrote:

Based on previous trials, I have avoided putting resistors on my new ribbons so far.  Finding decent caps and coils has been enough of a problem already, since everything comes through so clearly.  Maybe a variable inductor...  probably hear the wiper...  Any ideas?

Specialty for the “Water Drop” Alex designed a very slick coil with variables indictor. Interesting that the way he did the coil was so cool that it even theoretically was not different then a fixed inductor. However, be advised that you might not use it “in fly” as change of inductance affects time aliment.

Do not repeat my stupid mistakes:

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=2790

cdwitmer wrote:

I'm probably revealing my ignorance by even asking this, but I'm curious to know if a field coil ribbon tweeter could be practical. It occurs to me that if one could be made, it would be a lot safer since it wouldn't be a black hole for magnetic objects -- at least when the power is turned off

I proposed the electromagnetic as an option purely for Alex’s benefits, but I personally with my objectives did not have a strong desire to go there. If you read my examination about the electromagnet-converted Vitavox S2 driver

http://www.goodsoundclub.com/LatestPosts.aspx?ThreadID=1929

then you would know that I am a not such a huge and undutiful supporter of the field-coil idea. I am not saying that electromagnet is bad but it is as good as anything else: has own merits and own problems. The field-coil, if to drive it very hot and dissipating a lot of stray flux, might give extra 2dB to the “Water Drop” but it is absolutely unnecessary as my Macondo’s horns channels are calibrated for 109dB, and the 109dB is exactly what the “Water Drop” does. Also, do not forget that the “Water Drop” is line source and working with point source (horns) it has already a few decibels advantage at listening position. It should be also considered that to make the critical core size for the field-coil the “Water Drop” back should be much larger and I meant to keep the water drop shape as small as possible in order to minimize diffractions, the  bouncing back etc, and make the tweeter as much as possible optimum for the HF-type-only tweeter. Furthermore, with more (unnecessary) magnetic force we would not be able to make the cheeks of the gap as they are as we would need to change the entire magnetic shape of the tweeter. The tips of the cheeks are currently completely saturated and we would need to make them bigger… that would not be optimum for the given narrow gap of the small ribbon.  So, we went with perm neodymium magnet, conceding also the fact the Alex had practical knowledge what would be best magnetic force in the gap vs. the worthless stay filed and considering that the force of neodymium perfectly fulfill our objectives.

I am very much not saying that electromagnet tweeter would be a bad idea, we juts decided to do what we know already know and go to the direction where Alex has proven and predictable relationship between actions and the actual sonic result of the actions. You see, above 12.5K there is no sound in a normal science but rather a stream of noises that are should be viewed differently then sound. With the introduction of the new type of ribbons in “Water Drop”:

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=4259

we got that “crispy softness” that makes me see no needs to think about other magnets. Still, the only direction that I would like to explore is to try making ribbons to go all the way up in dynamic range like the compression drivers do but it has nothing to do with magnet. Currently Alex is working on a new type of transformer that I presume might be able to deliver what I expect. I will report it is it. So, the need for electromagnet tweeter is not on my radars. I feel that is a lot of other prominent things that should be taken care in a HF-only tweeter that I feel might make the type of the magnet to have very secondary meaning. Anyhow, if I had a second change to do the “Water Drop” again with an objection for a different magnet then, considering what I know about HF and magnets, I would go for Alnico magnets but not for the electromagnets.

Romy the Cat wrote:

I had today a conversation with RAAL’s Alex and he pinched to me a very interesting idea. He feels that I attenuate the outpit of my “Water Drop” too much. I have no doubts that I attenuate it as much as necessary and Alex proposed that I do too much attenuation because some unknown to me HF anomalies. What Alex proposes is that those anomalies (coming from amps, cables, alignments of from whatever) force me to attenuate my tweeter for 5-6dB more then he would expect… I have to say it is very interesting idea and from my point of view it is very cogent thinking… I have to investigate it further…

... and from  http://www.GoodSoundClub.com/TreeItem.aspx?PostID=4563

Romy the Cat wrote:

Got today home, turned the playback on and realized the electricity got better. Not as god as it should be but much better. At lest each ambient sting instrument did not surround surrounded with a cloud of white noise and the woodwinds do not sound like coppers - is huge freaking accomplishment!!!

Also, did I mention that today I was able to run the Water Drop not at minus 9dB as at the time of bad electricity but flat at 0dB? I did not experience a lot of discomfort. I think it was it. I have the same experiences in the beginning when I got the Water Drop (it was winter).

Let see what this will lead me to…

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=4480

Over the course of the last year I have been gently harassing my transformers-savvy surrounding trying to evangelize them into amorphous core. They stubbornly and perhaps stupidly resist. Some of them not… 

During the last few months I was talking with a number or people with objective to have the HF channel of my 6-chennal Super Milq to drive RAAL’s “Water Drop” directly. The requirement was to use amorphous transformer. Two people bid for the job but after a conversation with Alex, (the RAAL guy who made the “Water Drop”) I gave him the project as I fell that he has better experience with the Ribbon’s needs then any other person I know. I got the new transformers a week ago from Alex and put them today into the play.

Lately I spent a LOT of efforts with finding a right solution for high-pass filtering for my HF and MF channel and nothing give me the sound that I found acceptable. That why I did not put the WD into the game right the way – was waiting for the right crossover solution for HF channel.  However, yesterday I have found a VERY good sounding solution using RL filter in MF channel (superbly!!!)  and an air capacitor on the “Water Drop”, both of course at line level.

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=5288

I deseeded do not go for RL filter in tweeter channel as it would even further increase the restive chain in the driver’s grid. I would like to keep it relatively high as the 6E6P is VERY fast tube but still I would like do not go too for too high resistance. Also, the air cap demonstrated phenomenal sound at HF, so I let it be. Then there were a lot of efforts with shielding, assembling, calibrating and… now the 6E6P with 30mA on plate drivers directly the “Water Drop” via 175:1, amorphous torpid, foil-to-wire.  (The transformer sits on the tweeter side and connected via cable caring plate voltage – I use regular hoop up wire at this moment)

Paul S wrote:

As a certified non-expert I wonder about 1st order XO with the tweeter, because of the phase issue.  Probably stupid, but I always figured that at 180 degrees you could just switch the wires... Do I remember reading somewhere on your site that you pretty much dismissed the "90 degree" issue, at least for LF?

Do not think about amount of degrees what you think about crossovers – it is very deceptive thing and I never take under consideration. Think about synchronization of MF an HF channels in the SAME period and do not worry about degrees.

Paul S wrote:

But I have not tried 1st order on a ribbon for a long time.  I have tried the 3rd order that everyone recommends fairly recently, however, and it was bad in my system.

Romy the Cat wrote:

Over the course of the last year I have been gently harassing my transformers-savvy surrounding trying to evangelize them into amorphous core. They stubbornly and perhaps stupidly resist. Some of them not…  During the last few months I was talking with a number or people with objective to have the HF channel of my 6-chennal Super Milq to drive RAAL’s “Water Drop” directly. The requirement was to use amorphous transformer. Two people bid for the job but after a conversation with Alex, (the RAAL guy who made the “Water Drop”) I gave him the project as I fell that he has better experience with the Ribbon’s needs then any other person I know. I got the new transformers a week ago from Alex and put them today into the play.

“Finished development of Amorphous C-cores application in our ribbons. Some years ago, we were the first to introduce large gap approach in bulding ribbon transformers and now we are the first to use AMCC's in ribbons for absolutely uncompressed high power transient transfer and, at the same time, even further improving already the best low-level performance in the world today, by decreasing the width of hysteresis compared to HF ferrite cores. For direct coupled tube SE-ribbon, we succesfuly developed 175:1 ratio, -3dB at 120kHz Amorpous C-core transformers that can carry DC idle current of SET. Impedance conversion is about 30000:1, bringing the 0.1 Ohm ribbon up to 3kOhm, good for plate loading of most triodes in HF. AMCC's are available as an option to both OEM and DIY.”

I can not objectively assess the benefit of “Direct Ride” as my specific application has 4 new major changes:

1)     The “Direct Ride” transformer from plate to ribbon

2)     The Amorphous core transformer

3)     New Single Stage Amplifier

4)     Use of air-capacitor in crossover

I did not evaluate the contribution of each change incrementally but I might report that the whole package works extremely differently-positive.  I think the next step for Alex should be design own custom amorphous core size-shape, imbed it into his production transformer and introduce a “relax” version of his products. The only thing is that I am concerned that the Morons out there use RAAL’s in 2-way systems, driving them all the way to 1.5kHz-3kHz and this application (completely bogus from my point of view) would have some issues with the amorphous core size for RAAL’s production models…

Romy the Cat wrote:

I did not evaluate the contribution of each change incrementally but I might report that the whole package works extremely differently-positive.

drdna wrote:

I am kind of disappointed, since you typically advocate a very careful and systematic way of proceeding.  What do you mean by extremely different positive?

So, when I approached different manufactures I was asking amorphous transformer between a ribbon and 3500 Ohm – 3 people offered me different design. I knew exactly what is necessary to accomplish I have absolutely no idea HOW.  The RALL’s Alex, also proposed to render the projects and he suggested that he has very clear vision HOW to do it properly.  He coursed the amorphous cores, did all circulation and built a less successful prototype and then the more successful final version of the transformers. I feel that considering that since he specializes on ribbon transformers generally I feel that he has more credentials to do this project successful then many other competitors… I very pleased with result; even though the transformer has a relatively high insertion lost.

So, this new 175:1 transformer could be used with a regular Milq and might be used only in context of a single-stage amp with a high-pass (the requirement for transformer was to roll of at 4K-5K) with objective to use the “Water Drop” above 13K, second order. So, it all came together as one unified solution.

The air cap? There was not better rechargeable practical cap, I made this experiment many time in many applications. In fact I will be trying in a week or so vacuum caps in there…

What is extremely differently-positive? The sound from the tweeter. I will comment on the Sound differences sometimes later when I feel comfortable to do it.

Romy the Cat wrote:

The HF Range “F” channel: The 6E6P-DR at 30mA connected at tetrode. The filter is second order with Sowter 9858 Pultec MEQ-5 EQ Inductor 420/277/145/108/61/34 mH) and variable air cap. The variable inductance and capacitance allow me to write any prefer Bessel curve against any frequency I wish and I have now much more gain on in tweeter then I need. The driver is tetrode strapped to defeat the insertion loss of the 175:1 transformer and to have more then necessary gain to run the “Water Drop” Tweeter on transition slope, crossed at 30kHz-40kHz with second order. The shortcomings of the tetrodes (loosing of damping, increase of output impedance and so on…) are absolutely not applicable in my case as the ribbon tweeter care less about the damping. In fact if I have a tube with more transconductance then 6E5P-6E6P (30-35ma/V or 30.000mS in Western scale) that has >3-4W on plate and more then 2-3V of bias I would stick it in. I might use something like 7788 pentode only with more power and more bias. If you know any of them then please pitch it to me as to have too much gain on tweeter do not hurt. Do not forget that the chennal will not do “sound” but rather the “space noise”. Still, even what I have now is ~ 12dB more then I needed and it is already is very good.

I have been asked by a number people who monitored my progress with RAAL’s “Water Drop” tweeter: “Romy was it worth it?” Well, I think after a year of leaving with tweeter, learning and satisfying it’s little habits I might pass some generalizing observations. Before I go there let me to be crystal clear – it is not a consumer persuading site. The Morons in audio use to that if anyone talk about audio then it should be some kind of encouragement of discouragement to buy or peruse something. Trust me: I absolutely do not give a damn about your tweeter purchasing intentions not to mention that RAAL would hardly do the same type of tweeters again. My objective in this post are very broad and has more to do with experiences of HF in the realms of “Abstract Audio” then with the  specifics of RAAL tweeters.

As the readers of my site know the quest stared in 2006 with my thoughts to escape a horn-loaded HF driver.

http://www.romythecat.com/Forums/ShowPost.aspx?postID=2974

The presumption was that HORN is a LF equalization devised and if my objectives are only HF then horn-loading is contra-objective as any horn EQ LF much more then HF. The second objective was to found a tweeter that would be able to keep up with transients and tone of Vitavox S2 diver. One way of another I get in touch with RAAL and the custom project of “obnoxious tweeter” was in a way. Since I started to use the “Water Drop” there was a number of changes made to the tweeters, and the “Water Drop” used in different applications – it all was very educational. Was it worth it? Well, the answer had 3 dimensions: cost, results, value.

Cost. The entire “Water Drop” project was somewhere above $2.600 that is somewhere a reasonable price for a custom-made driver of objectionable ambitions. In fact I would consider $2.600 is on a low side. If I make my custom MF driver then I would feel that I will hit 4000-5000. Considering that I got along with the drivers the RAAL’s support and very valuable education on the ribbons know-how I feel that it was financially very rewarding deal.

Results. Well, I use it in my playback – what else should I say. It has what I need – it has the right geometry of radiation, it matches my MF driver, it is properly integrated within Macondo. A moron would ask - is the best tweeter that I heard? I clearly have no idea and do not view the things in this way. A tweeter is not a self-contained element but it is an organic ingredient of the rest of installation. There is a lot in my playback that made to serve the interest of this tweeter. Would it be another tweeter it would be other set of efforts to make that other tweeter serve its best in context of the rest of playback. As now, I have no objectives to revise what the “Water Drop” does and I am HF-calmed. There are some HF “dilemmas” that I experience but they are not the subject of my tweeters’ performance.

Value. A ribbon was a big push forward. The higher crossover point the better ribbon works. In my case with 12.5K it does very nice perfectly fulfilling its topological advantages. The application with witch the ribbon is used in Macondo –Melquiades setting it absolutely wonderful and exactly fits my suppositions about of “how it should be”. Any value is expressed as a tradable commodity in reference to exchange the value for other tradable commodity. If not the HF-optimized ribbon then what else? Cone tweeter, horn-tweeter, dome tweeter, electrostatic tweeter, piezo tweeter, plasma tweeter? All of the options were well-conceded before I dived into the ribbon world.  I would like to see electrostatic tweeters with high dynamic capacity. I would like to see plasma tweeters that have tone’ structure that would be integrateable with other drivers.  Unfortunately I do not know any electrostatic tweeters or plasma tweeters manufactures of Alex Radisavljevic caliber who would be interested to peruse custom projects with aspirations and ambitions higher than just the “commodity tweeters”

Concussions:  what was done right?  No first order for ribbons. Minimization of the tweeter back chamber. Line-source to shoot between the horns.  Solicitation of Alex to use amorphous core. Driving the tweeter directly from the tube plate with single, HF optimized high-ratio transformer.  A single-stage amplification for tweeter. Use air-capacitors for tweeter filtering. The tweeter attenuation.  Use  of naked ribbon.  Sound

Concussions:  what was done wrong?  No opportunity to change the plate loading in case a different  ribbon type is used (though I might experiment with shunting of primary). The need to pressure for 109dB sensitively is arguable. No opportunity to manage the stretching of the ribbon. No dedicated PS with dedicated filtration for tweeter amplifier (it might be changed soon)

The beigest question: would I do it again if I do not have the “Water Drop”? Absolutely yes, but I would enforce measures in a new design to precise load the tweeter driving anode (even for a coast of interchangeable anode-ribbon coupling transformer) and   I would make a provision to prices tune the ribbon resonance frequency.

I have wondered about setting/tuning ribbon "tension".  Of course it can't be touched, but it shouldn't be difficult to rig it, and it might not take much, if taken into consideration from the start.

Best regards,
Paul S

Romy the Cat wrote:

A moron would ask - is the best tweeter that I heard? I clearly have no idea and do not view the things in this way. A tweeter is not a self-contained element but it is an organic ingredient of the rest of installation. Rgs, Romy the Cat

el`Ol wrote:

I know the PAC tweeter of the WLM has the best transients and transparency of all tweeters I know and so is the best tweeter above 5kHz I know, although I hated the implementation (crossed far too low, harsh-sounding upper midrange, lower midrange not anywhere as precise, weak bass, etc.), and I would appreciate to hear it in combination with a good midrange compression driver. Of course I am not 100% sure it works, but close to that figure.

el`Ol,

I never heard PAC tweeters; in fact I do not think I never heard WLM speakers. I do not even know what principle the PAC tweeters use.  However in what say I think there is two major “bloopers”.

1)    Whatever it is, in the WLM speakers the PAC driver is not tweeter but a MF driver. My definition of tweeter is that it is a driver that covers frequency range AFTER a MF channel. There is no dedicated MF channel in WLM speakers and therefore the HF transducer that they user could not be caped as a tweeter. As least a tweeter that is understood in context of this thread. I have expressed many times before that “bad people” love to drool about the quality of tweeter but they do not look tweeter in context of a devise that continue duty of MF driver. I disregard a tweeter itself and my primary attention ONLY how a tweeter compliment the well-defined specifics of MF driver. I my mind, if there is no MF driver, or a crappy MF driver used, then there is no way to judge tweeter

2)    In 2003 I experimented a lot with large tweeters. At that time I had a notion of “HF radiation field”.  What I learned was that no matter what I did I was with a large tweeter actually smearing the transients. (Wilson WAMM used the same concept with large injection panel). If you look at the simple geometry of a MF driver and a large HF panel then you will see that juts based upon the size of the tweeter is also will have time differences between beginning of panel and end of pane in relation to single-point MF driver. That smudge a leading edge of the wave, though I have to admit the in a nice way. Still, this approach could hardly be called as “the fastest transients”. They might be pleasantest transients, perhaps even “best transients”, the Quad  people would argue this point favorably, but they are not challenging in transients competition. 

mark wrote:

just would like to clarify the cost of this ribbon,xfmr. etc.the figure of 2600us$ is that for tweeter pr. only or complete with the xfmr.?i got a quote of 4000 euros +300 ship in jan./08.has the material cost risen dramaticly since you got yours what was it 1 and a half years ago? i emailed alex to get clarification.

Mark, yes my cost was just above two and half grands.  Is Alex changing nowadays more? Well, good for him, why would I care. He runs business and as anyone in business he is a subordinate of supply demands. If he feels that his drivers should cost 4000 Euros then it is the way how he feels, there is nothing that we customers could do with it. There is another factor that you might consider: I personally have a tendency to aggravate people when they do custom work for me. I have very specific idea what I would like to have and the people who run production business when they are engaged in custom products with me they not always understand what they are stepping into. I have seen a number of the cases when manufactures undertook custom jobs with me, giving to me very low prices because they would like me to sponsor the project that they had interest themselves. Then, going over the projects, obsessing the amount of labor and amount of annoyance from my side they told to themselves that if they do it again it will be MUCH more expensive. For instance John Hasquin when he built my upperbass horn asked me $1500. They looking at all pain in ass that he experienced doing my project  the very next upperbass horn (in a few month)  that he did to a friend of mine (and the hone was sampler - 150Hz) I believed he took $8000. So, what Alex dose is not out of the realm of something that I would consider as non-predictable pricing policy.  There is one pain in ass aspect of Alex that I perfectly share with you but it is not his fault – his shipping charges. In his city the only reliable shipping method is FeDex and they have only expedited overnight service in there. It is kind of pricy but it is what it is…

mark wrote:

i do not think i would want to try anything less than a tweeter of this caliber to go with the s2, but the price quoted recently is staggering.

I do not know what “caliber” are you taking about and what all those notions come to you head. Reading a bunch of Morons, including me, blabbing on-line about different tweeter solution you have built in your head a stupid hierarchy of the tweeter’s calibers and feel that the “Water Drop”- like tweeter is the only that might be worthy.  It is absolutely wrong way to look at the things. I, with all my writings, might be just another online idiot or just a person who has very low reference points about sound of tweeters. If you so like your S2 (and you will go over it) then why do not try different tweeters and defile for yours what is better. If you found that my notes correlate with your own findings then you might use some of my paths. However, if you do your homework and conduct own research on the subject then you will be able to read my comments differently and will able to acknowledge some things that you are blind now.  I said that “a need for 109dB sensitively is arguable”. A person who juts blindly read words in my site will discard it as my another malapropic opus but for the an individual with a sense of specific and HF objectives  and tangible  experience it might open a pandora box for some considerations or perhaps serves as a warning…

Anyhow, my point was that before paying exuberant amount of money to Alex or to anyone else you need to define to yourself what type and what kind HF you are looking….