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….

Romy the Cat wrote:

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 Rgs, Romy the caT

el`Ol wrote:

I am not ideologic, and if a driver that can be used from 1kHz up is only state of the art from 5kHz up I won´t hesitate to cross it there.

There is a difference between “can be used from 1kHz” and “a driver sound at 1kHz  as good or better than other diver”. It is not about where to cross but how good it sounds before you cross it. I my book the lower ribbon goes the more compromised it sounds.

el`Ol wrote:

Maybe it has something to do with developer´s pride to extend the frequency range as far as possible. I never heard a RAAL, but I believe Alex is also not free of that when he claims the natural x-over frequency for a large ribbon is 1.5kHz.

Alex and I have major disagreement about it. I believe that quality of sound from ribbons is back proportional to frequency. Alex feels that it is a bogus believes and he considers that if ribbon is properly implemented for a given operation mode then it might be an effectible wide bandwidth driver. Certainly he has more foundation to support his believe but I’m still willing to maintain my view. Even if Alex is capable to make a decently sounding MF ribbon then… why do not use 2 ribbons: one is optimized for MF and another is optimized as a tweeter – to serve HF only. It is like you need two different channels to best produce 30Hz and 300Hz you need two different channels (transducers) to best produce 1kHz and 12kHz. Perhaps it is my ignorance but I never heard any seriously-sounding MF-HF transducer - nor I ever have seen a need for it…

Ending up re-amping my MF channel, I found myself at unexpected situation that I am not completely compostable with Macondo HF. It is not that the HF are bad but they were made to serve the interest of older, slightly softer operating single-stage MF channel but with some extra “zap” of  the deep-idling MF channel  my current teeter underperforms in my view. I would like to get more “zap” this time from tweeter.

The Water Drop tweeter in the way how I use is doe not play aggressive and does not go rough. Also, it is very dynamic and it show itself off ONLY when it being g called upon, otherwise it sits in shadow. It does not produce the stupid audiophile “air” – it produces HF if they are needed. Adding the HF of amplitude at HF, even for 1 db make it worse but I would like not to have more HF but to have no more "aggressive" HF, aggressive  but clean. In a way I would like to use not the 175:1 transformer that I use currently (from plate to ribbon) but let say a virtual 400:1. Sure this transformer would not work and the 6E5P have no gain to driver such a ratio.

I kind of think what options are on a table and what might be done. The leading option is to put back a regular ribbon transformer that RAAL made with the original Water Drop and to drive the tweeter with some kind SS devise. Alternately it would be nice to find some kind of SS amp that will be able to drive my Water Drop direct coupled. The Water Drop has 0.2R impedance at 16R, if I am not mistaken. Are any SS buffers that can drive the thing?

The ribbons surely do lack "qualities", but we are talking about serious "HF" in this case, and who says real HF actually wants "qualities"?  I really doubt that any "tweeter" that can do "stuff" can also do what the ribbon does best - in a class of its own, for that matter.

Yes, the ribbons are lacking in bite, traction, texture and color, so maybe you want that stuff from, say, 4 - 5k or so on up to your RAAL X-over at 10 - 12k, and maybe paralleled for a ways up there?

The best way I know of to supplement a "real" HF tweeter is with a nice silk dome; but I think "they" stopped making the good silk domes quite a while ago, and in any case you will probably never find one anywhere near your insane efficiency ratings.

I will eventually try the cheap Selenium phenolic tweeters, which "look like they might sound OK", and they can be had up to around 104 dB, I think, or maybe more.

But I still see the idea here as being supplemental rather than replacing the "Real HF" ribbons.  In other words, maybe the "problem" with the "HF" is not the Water Drops but it is actually lower down the frequency range, or it might be effectively dealt with in this way?

Best regards,
Paul S

Actually the S2 above 8Khz, or what ‘nl’ calls the “breakup range”, is something that I absolutely certainly would like do NOT loose. I very much like what S2 at it’s 10-12Hz. It might be a bit brutal in some cases; I reported it at the beginning of my years with S2.  Now I have no problems and I know how to play S2 to take advantage of all lucrativeness of it’s upper region. There is a few other reasons why I I would like do not truncate HF from S2 but do exactly opposite: to feed it more.

The channel above the S2 is a different matter. The idea to have another small diaphragm driver is fine. I do have a number of tweeters including my beloved TN51. What I would like to find out why the Water Drop does not do it for me anymore. The Water Drop is unique in Macondo’s’ context as it has wide horizontal dispersion (Macondo is installed across a wide wall) and it has narrow vertical dispersion (as it shot in the opening between MF and Fundamentals horns).

The car people say that if an engine does not start then there are only two reasons: no sparks or no gasoline flow. I think the very same with my tweeter. If it does not do what I want then it is ether a problem with the tweeter or with the amp that drives it. Since the tweeter was not change I need to review the amp that drivers Water Drop. I do have theoretical criticism for this amp, primary by the fact that it does not follow my rule of “open top” (similar to the idea of “open bottom” in LF sections). The design of the HF amp itself contains a well-defined HF limit, what I would like to see ONLY high pass filter with  no low-pass at least for 10x. I need to experiment with this more to see what is doing on.

I kind if cycle my attention on the notion of compression and it is not accidental. When a few years ago I used the hugely dymick NT51 tweeter in my car I experienced problem to set the right volume and I run the volume control 10  times more frequently then I would usually do. When the NT51 played low it was too loud and in soft passages it was way beyond the rood noise.

Now with Wetter Drop I have in a way the same effect. What I add a DB to my reference level then I feel that it too brought but generally I feel that there is a room for more tweeter output. I described it as luck of “compression” but not the compression in normal sense but rather tweeter non-compression – or inappropriately set relation between tweeter and MF. What I think I would need to do is not to add tweeter HF output but rather to add it’s MF output that would add the relevant amount of MF relative to HF and therefore make my HF more “compressed” in relation to the rest sound.

RAAL’s Alex advised the same but for different reasons. He feels that my tweeter shall provide more leading edge to the MF driver's impulse response. I just a bit concern that a bit overlay hygienic tone of the ribbon driver might override the tonal quality of the S2’s upon knee. Well, I will try to do go too low; let sat to 10K from 13K, and will see how it goes.

If it were not enough to add harshness then I will convert the 6E5P stage that drives the Water Drop to cathode bias and will “inject” the “harshness” by use of the cathode capacitor.

The caT

What kind of futzing would it take to work an attenuated T350 or something like that back in there, just to check it against massed strings and the other impossible-to-achieve standards that tell everything about the "mid HF" qualities?

All that x/o wants is a cap, right?  Well, there's the "cap" you were talking about...  just put it on the "voice tweeter" rather than at a cathode...

Can you work something like this with your present channels?

I woulld think that if you mess with your amps to get "sound" from the ribbons, then that "sound" will turn into noise after a while.

Best to leave the correct ribbons to make umami with the drivers that should do sounds, and to help with the space.


Best regards,
Paul S

Romy the Cat wrote:

Hm, interesting, I did drop the crossover frequency but I do not like the result. I was driven in different configurations and experimented from the current 13kHz to 7.5kHz. As soon I drop below ~ 11.8kHz then the overly clean and would say sterile influence of the Water Drop become to dominant and ruin the very fine texture of the Vitovox S2’s upper range. Also, during my standard “sit-down test” the WD and S2 sounded not like slightly different drivers and the WD was bit too soft - I did not have it before. I need to make the WD slightly harder and slightly more hostile. Then I will think how to integrate it with my updated S2. So fae, it is not there…

In fact it is not just better but it is truly perfect.

I made a number of experiments over the last two day but it was no good. Dropping the crossover made the Water Drop to take over Vitavox and it was not what I liked. I began to think that I need to “tweak” the amp that drives the Water Drop, making it somehow “harder”. I did not like this idea – the single stage the drives the Water Drop in theory shall be the best imaginable amp – a single stage with only single resistor in path. Still, something needed to be done.

Then I printed my comments about my dissatisfaction of the Water Drop and read them a few times, paying attention to the language. I was looking for aggressiveness and hardness from my tweeter but I did not want to spoil what I got from my MF.  Then it suddenly occurred to me: I needed a shaper filter on the tweeter.

So, I went for 3rd order and it was immediately clear that it was very right direction to go. The standard “sit down” test made Water Drop and S to sound absolutely undistinguishable – very very impressive! The Water Drop got it’s “hardness” and did not wrecked the S2. The 18dB roll off was it, now the key was to find the right new crossover point. Obviously I needed to drive the cut off lower. I was at 13kHz and I dropped to 11 kHz and then to 10kHz. At 10kHz it is incredibly good with S2 and not I ma debating against 10kHz and 9kHz. The 10kHz better talks with S2 but if I use 9kHz then the Water Drop lower the acoustic vertical center, allowing the Macondo Injection to run 2dB harder. Both have own positive aspects and I do not know what I would lend yet.

However, regardless if I select the 10kHz or 9kHz the third order with lower crossover is it and it will be the solution to integrate the Water Drop with more idling MF Vitavox driver.

The Cat

PS: Just for my own future reference:

I got it!

I realty have got it this time and it is exactly what I was craving for and shooting for. I converted both channels for 18db/octave on tweeter and recalibrated the whole Macondo, in a slightly different manner this time. After I finished the recalibration this afternoon I got the sound that I literally heard in my dreams – the upper MF are think and saturated but at the same time they are different with each touch of sting, with each blow of winds or with each soprano note. That was so interesting and play and SO INTERESTING to fine-tune the injection amount, the  MF attenuation, the HF attention, the type of the MF tube  and the current of HF tube that was completely caught up into this and had so much enjoyment the I even canceled my female engagement tonight. The result I got incitingly wonderful and I truly, truly pound of it.

The RAAL’s Alex asked me to let him know where I lend with my Water Drop application. This morning I spoke with him and listening my feedback about the positive result I got with 3rd order he advised to go 4th order. I see a lot of rational in following his advise but honestly it is so good that I would like do not spoil it for now.

The configuration I end up is following: the MF runs at minus 1.75dB and using type 45 tube. Other tubes do well as well but among the tubes that I own only 45 runs “straight”. The tweeter runs at 25mA and at 4dB down with 9kHz on left and 10kHz on right. (I know it is stupid but I did not decide yet where to lend in term of crossover point). The Injection runs at incredibly high level – minus 10.5dB. I never was able to have such a high level of injection but the transient from semi-idle Vitavox S2 and Water Drop looks like hold the vertical offset of Sound to the Injection channel. The result is very very sexy – it is fast and super clean but it is tonally rich to a psychotic madness. Where is my Bruckner with those colors?

Now, the only think that I feel might be left is to push the MF driver a bit higher, not more transient and not more idle via a transformer but high higher. I am planning to get read the wirewound attenuator from the transformer’s secondary. The wirewound LPAD has two coils in path, each of them is a series inductance that I do not need as it acts as low path filter.  I have spoke with right people to build a .5dB stepped attenuator with non-inductive resistors…

Ok, this game is over with VERY encouraging results. I am off to my Bruckner and then will be inflating my date tonight…

Hello everyone:

I exchanged a couple of emails with Romy, and since the topic may be of interest to everyone, I am posting the emails here. Just in case anyone wonders, of course I checked with Romy to see if he was alright with his reply to my email being posted here.

My email to Romy earlier today:

"Hi Romy:
 
I fear I may again have to trouble you for advice. I have been talking to Aleksandar of Raal about the Lazy Ribbon, and have dicussed its specs on paper with a friend who is more knowledgeable than me and is rather impressed.
 
Nonetheless, I have a couple of concerns. One is whether the sloping off at 20KHz and bump thereafter are a cause for concern. Alex suggests, and I would agree with him at least theoretically, that it should not be.
 
Secondly, what are the ideal specifications, in terms of the transformers, to be aimed for in a system which to all intent and purposes, in terms of topology is indistinguishable from Macondo, in this frequency range at any rate? To recap, as I do not expect you to remember, I have exactly the same complement of S2 drivers, with a choice of aluminium or plastic diaphragms, as you have and I am hoping to pretty much emulate what you have done, if you do not mind. It would be used with exactly same channel of Melquiades as you are using presently (according to the schematics). I would be grateful if you could be precise if there are any departures from specific options being suggested by Alex.
 
Maybe I shoud add a third matter that I have been thinking about. I do like the shape of the Water Drop for very functional reasons (minimisation of reflections), but the WD itself has proven such a pain for Alex that he does not even want to consider it as an option. But is there any benefit to having the Lazy Ribbon fitted in a Water Drop shape enclosure? Either I can ask Alex whether he has Water Drop enclosures which render this possible or I could have it built out of wood and drop the Lazy Ribbon in such an enclosure. What do you you think?
 
I am reluctant to post these questions on the forum at the moment as I feel that it might look like I am questioning Alex's judgement. That is not at all the case but I would love to have your opinion to make sure I do not miss opportunities which are at this early stage still open to me. Of course do not hesitate to comment on any other matters (surely many) that may be eluding me that would improve on my solution for the high frequency range and it goes without saying, assuming you have a moment to consider my concerns.
 
Regards
Rakesh"

Romy's response:

"I do not see this email as something that would be prohibitive for open forum. You  are do not questioning Alex's judgment but you are looking for a second opinion. I think in this correspondence here is a lot that might be useful for public. Since Alex is the manufacture and his opinion is conditioned I feel it is perfectly reasonable to look what other data might be at the table.  In fact I think it would be good idea to inform the public that this driver is available as there is no data at RAAL web site.
 
The bumps or anything else at 20KHz are absolutely irrelevant. In fact any linearity or lack of it above 12K-13K is more or less irrelevant.
 
The transformer is a different subject.  What kind transformer you have in mind? The Milq’s transformer directly coupled to the ribbon or ribbon en own transformer? If you go for directly coupled to the ribbon then it automatically implies multiamping. If you have a full Milq dedicated juts for the ribbon then I think it might be a bit too much.
 
Regarding the same.  The Water Drop shape is great and this was what I was looking for went I approached Alex. However, I was in a different situation. At that time Alex was  a small manufacture with little exposure or publicity and I proposed to him to do something that he never did but something the he always wanted and never had customers who would pay for it. So, run my enthusiasm wave knowing that I get a great deal just  for the abuse of the Alex’s own passion. As a result I had my Water Drop for extremely low price, high quality and I remember that I did tell to Alex that in 5 years what he will be riding in Mercedes and had overvaluing amount of order it would be much more difficult to get that “push envelop” products out of him.
 
So, is Water Drop shape necessary? I do not know. I know that baffles are bad for HF devises and I would like my tweeter to stand alone with no baffles. If I buy this Lazy Ribbon then I would ask Alex to have the front plate no wider than  the body or the ribbon and to make the mounting provision under the bottom. Alex is very resourceful man and very much willing to use his inventiveness to benefit custom solutions. I feel that in out systems his tweeter need to be treated like a piece of furniture – you need to like how it looks and fells  in context of your own setup and your own speaker frame. I think Alex has no a lot of customers who use his drivers in standalone configuration – so you need to navigate his and to get from him what you want
 
The Cat"

PS: Lazy Ribbon data: http://www.goodsoundclub.com/PDF/RAAL+The+Lazy+Ribbon+specs.pdf



 

romy wrote:

So, is Water Drop shape necessary? I do not know. I know that baffles are bad for HF devises and I would like my tweeter to stand alone with no baffles. If I buy this Lazy Ribbon then I would ask Alex to have the front plate no wider than  the body or the ribbon and to make the mounting provision under the bottom. Alex is very resourceful man and very much willing to use his inventiveness to benefit custom solutions.

romy wrote:

I feel that in out systems his tweeter need to be treated like a piece of furniture – you need to like how it looks and fells  in context of your own setup and your own speaker frame. I think Alex has no a lot of customers who use his drivers in standalone configuration – so you need to navigate his and to get from him what you want