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  »  New  Vitavox’s S2 Survival Guide...  A typical convention......  Horn-Loaded Speakers Forum     123  924909  07-16-2004
  »  New  An ultimate transformer for narrow bandwidth?..  Re: ...apply similar tactics to the power supply......  Melquiades Amplifier  Forum     14  85415  02-03-2005
  »  New  Ultimate HF output transformer?..  Leads to further air core heads...  Melquiades Amplifier  Forum     7  70849  07-14-2005
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  »  New  Incorporating active crossovers into DSET..  Thanks...  Melquiades Amplifier  Forum     2  29742  07-22-2008
  »  New  LF Amplifier in biamping...  DSET is tricky....  Audio For Dummies ™  Forum     10  51859  08-05-2005
01-25-2008 Post does not mapped to Knowledge Tree
mark
Posts 20
Joined on 01-25-2008

Post #: 1
Post ID: 6430
Reply to: 6430
Entry level DSET Melq?
i am currently gathering parts for a pr. of full range melq.i would like to have the option to add a single stage to do 550 hz and up.then to switch the full range to do below 550hz.what transformer do you suggest for the high pass(i am ordering transformers from kandk now)? also what changes do you suggest to do the highpass/lowpass function?
01-25-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,538
Joined on 05-28-2004

Post #: 2
Post ID: 6433
Reply to: 6430
Familiarize yourself with Milq full-range sound.
Mark, what loudspeakers are you planning to drive in this configuration? The single-stage amp is 2W and the full-range Milq is 6W -7W. Anyhow, look at my replies to others in this forum. I always advise before thinking about DSET around Milq to familiarize yourself with Milq full-range sound, even in its prototype version.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-25-2008 Post does not mapped to Knowledge Tree
mark
Posts 20
Joined on 01-25-2008

Post #: 3
Post ID: 6434
Reply to: 6433
Entry level dset milq?

i have vitavox S2 and also altec 288c.i am trying to source the fane studio 8m,just missed a pair by 1 day on uk diy.until i get the fane and make a horn for it,i will use altec 515c in vot.i also have jbl 2405.yes i will definitely build the full range first,that is common sense.but i want to be able to switch the full range to low pass at 550hz and high pass a single stage from 550hz up.eventually i might follow the full 4-6 channel setup eventually but for the next year this is as far as i want to go.since the sourcing and shipping is a pain for such small quantities i am going to order sufficient quantity of the smaller harder to get parts(diodes,950 caps etc.) to last me for several units.right now i would like to know what transformer you would reccomend for the single stage 550hz up as i am ready to order the LL1627a from k&k and would like to get the single stage transformer ordered and shipped together.as soon as i get the full range done i really want to experience the dset midrange.one step at a time.

01-25-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,538
Joined on 05-28-2004

Post #: 4
Post ID: 6438
Reply to: 6434
Learn if the full-range Milq worth you attention

Well, the LL1627A is very good universal transformer with phenomenal flexibility (properly done - with section not with tabs) to load the output stage. It might be a good choice for a full-range amp at 200mA, though I would still prefer to have a transformer gaped for 300mA – so you would need a larger core and they do not do it. I do suggest to by one LL1627A as you would need to know how to load your 515c, your S2 and how Milq might sound all together.

For LF transformer you need nothing fancy but juts with a lot of core mass. In my case Jack from ElectraPrint did very well, it is else very inexpensive but there is a catch in there – you do not know what kind ration you would need to damp your 515c driver properly (do not forget –Milq is no feedback amplifier). You might use the LL1627A to investigate your bass channels’ needs – that what I would do. Alternatively you might try to do what I am trying to do now with my 1Ohm (amorphous?) bass transformer – to make the secondary interchangeable. It has some complexity as the coils would not fill up the core as they use to and the person who would wind the thing would need to make the necessary corrections in order to hit the target impedance.

I have a left over bass transformer from my project but it would not be useful to you primary because my transformer dies at 800Hz and it would be too low for you. If I was you I would go for top roll of at minimum 2000Hz as 550hz is very high crossover point.

For above 550hz you might use the same LL1627A if you wish, for MF the 200-250mA gap will be fine. Yes it would be reasonable to desire less inductance in the transformer, mean less turns but honestly I personally did not detect that it very much affects sound, at least in context of the S2 bandwidth.
Well, Mark, there are a number of manufactures out there who made amorphous transformers, I did not try them, I am sure you will found a lot of people out there who had more exposure then I did. I kind of had an easy ride with LL1627A.

For a single stage amp you would need a transformer with ~40mA and the inductance enough to care 2-3 octaves under your crossover point. Here is fragment of email that I was sending to transformer manufactures when I was searching my MF transformer.

1) Amorphous 'C' cores (there is different type of amorphous material, I
would need with higher permeability)
2) Ratio 15:1
3) Minimal amount of turns on primary, juts enough to built up inductance to support high-pass roll off at 500Hz.
4) Gaped for 40mA
5) The most minimalist phase shift above 10Khz.
6) 300V on primary.
7) Lowers DCR on primary
8) <5w carrying power.
9) Inclosing and appearance of the transformers are irrelevant
10) The secondary sections (>7 sections)go out (with marked polarity) allowing secondary remapping
.

Still, if I was you I would not think about the transformer for a single-stage amp or about anything else. Get a single LL1627A if the equivalent amorphous, it will cost you $350. Build a single mono Melquiades around this transformer, powering it from your bench PS but with the Milq biasing schematics. It would take you one evening to do as Milq is very simple amp. If you found the full-range result worth you attention then you might think further. While you do so you will see how you bass channel react to 8H of the LL1627A’ inductance.

Rgs, Romy the caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-26-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,538
Joined on 05-28-2004

Post #: 5
Post ID: 6444
Reply to: 6434
Milq’s amorphous core and Vitavox S2 driver
 Romy the Cat wrote:
For above 550hz you might use the same LL1627A if you wish, for MF the 200-250mA gap will be fine. Yes it would be reasonable to desire less inductance in the transformer, mean less turns but honestly I personally did not detect that it very much affects sound, at least in context of the S2 bandwidth.
I had to be said: “…but honestly I personally did not detect that it very much affects sound, at least in context of the S2 bandwidth and in context of the right S2 driver” .

Mark, one more think that you mostly likely do not know now but should consider and be aware. When you go with MF amorphous core with reduced amount of turns then that transformer will be lightingly fast, capable to handle tremendously articulate transients.  The Vitavox S2 driver is a very transiently venomous driver itself and it is highly possible that your S2 driver with you Milq MF transformer mighty be too much. I said “mighty be” not “will be” because there is catch in there.

Vitavox S2 driver is available with different type of magnet (I think it was 5 different Alnico types) and with 3 different diaphragms.  You will not be able to use any other diaphragms then plastic-suspended with your amorphourised Milq and you will need to spend a LOT of efforts to align those diaphragms. However, you have no control on knowledge what magnet you get in your driver. Here is the ketch - with some magnets S2 driver and amorphous Milq is just not throw absolutely unmanageable sound as it will be too fast and too incorrect.

So, beside dong over the troubles to pay the exuberant amount of money for those idiotic vantage S2 drivers you very much could come to observation that YOUR given S2 does not do well for you. From this perspective the 288 or 2440 are well more stable and secure chooses. Let me give you an illustration. I own 12 Vitavox S2 drivers and only 3 of them are able to work with Milq’s MF channel and to sound as I would like then to.

Rgs, Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-26-2008 Post does not mapped to Knowledge Tree
mark
Posts 20
Joined on 01-25-2008

Post #: 6
Post ID: 6446
Reply to: 6444
Vitavox s2/amphorous core interaction/idiosyncracies
well i never thought i would be opening such a pandora's box with this combination.firstly,the drivers have the plastic surrounds(whew,lucky!i know the diaphragms are potentially harder to source than the drivers)what indicators or criteria would make my particular drivers more or less amicable with amphorous cores?(with reduced inductance only?)is it strictly an issue of varied lots of alnico used throughout  decades of production?and what about the magnetic flux level of these vintage alnico drivers??? i just had an altec 288c come  from great plains audio(good guys) and was pleasantly surprised to find out that they routinely check all alnico magnets with a high quality tester.i hear that some may need recharge. have you done this with your s2's?or can you do this by ear?in reference to the potentially venomous output of the s2 is this only for mf or fundamentals as well.with regards to aligning s2 diaphragms,the altecs have locater pins and are not adjustable.i suppose the s2 does not have these.how do you adjust these; roughly by eye and then finely by ear?details?as you know my plan is to source fane studio 8m use the s2 from 550hz to 12khz.i want to focus on these 2 drivers to start.it is interesting that spectral plot i saw on your site of a classical piece that shows the concentration of energy 80hz-8khz.and last i remember reading about the problems with s2 in midrange which i believe is what motivated you to split the 550hz-12khz between 2 s2s,would you mind elaborating on that topic?once again thanks for sharing this interesting experience
01-26-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,144
Joined on 10-12-2006

Post #: 7
Post ID: 6448
Reply to: 6446
The can, the worms, and the whole enchilada
Mark, what is it exactly that you have heard from the S2s that attracted you in the first place?  This is important, I think, because this is what you have as a starting point, to work from and to use as a reference point as you develop the sound of your drivers.

No, I am certainly not the guy for S2 info or advice; but I am touched by your situation.  For reference, my own very limited experience with Vitavox was with the old 2-way theater systems, which were bad beyond belief, believe me.  I have been both amazed and delighted that Romy heard something special in the typical stock S2 howling and growling and that he has been able to take it so far.  I literally could not stay in the room with them.

Romy's success notwithstanding, I am guessing that others will have a very rough go with these drivers, and this has been stated in so many words so many times at this site that IMO it is a wonder that people stay hopeful for their own S2-based projects.

Please don't get me wrong; I am NOT making any assumtions about you, personally.  For all I know, you will pull it off with ease.  But IMO, generally speaking,  aspirants should keep in mind that the list of S2 problems in the recent "negative" post is pretty much the half of it, at least according to what I have heard.

But Romy did throw out a fish,  as well, which I hope was duly noted.

To close, if I were to try horns again I would not use the S2s unless they literally fell into my lap; and even then I might take advantage of current S2 hysteria and sell them to buy something else, like...

Best regards,
Paul S
01-26-2008 Post does not mapped to Knowledge Tree
mark
Posts 20
Joined on 01-25-2008

Post #: 8
Post ID: 6449
Reply to: 6448
S2 pandora's box
truth is i took a risk.i bought the s2s on ebay,and have never heard them.i was motivated to experiment and explore the core of the mac/melq system.i have owned many horns and heard many more. one case in point;avantgarde duo,i have heard this speaker in some setups sound very dissapointing(most of the time)however one time  i heard them it was the best sound at the show.most reasonably well engineered horns are very revealing of what they are fed.all drivers have pros and cons.it will always be this way.the challenge is optimize the system.horns are very challenging.i doubt i will pull off s2 optimization with ease.i am willing to persevere if romey and others are willing to help and share.in the process i might discover some things that will be of benefit to others.worst case i sell them off.but i do take note of your comments and romeys.the thing that really hit me like a 2x4 was romey saying of 12 s2 only 3 were usable in his opinion.life is a journey,tough challenges build character.ideally it would have been nice to hear romey's system before investing the $ in this particular hardware.i do have a close friend in boston who has heard romey's system.i might be able to make it to boston third week of march.up for a listening guest romey?
01-26-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,538
Joined on 05-28-2004

Post #: 9
Post ID: 6450
Reply to: 6449
Without it any conversations are groundless.

Still, would like to keep the thread about Melquiades as it is a Milq dedicated forum. If you attention is only S2 driver then move to an appropriate thread about S2 – there are plenty of them at this site.

 mark wrote:
what indicators or criteria would make my particular drivers more or less amicable with amphorous cores?(with reduced inductance only?)is it strictly an issue of varied lots of alnico used throughout  decades of production?

Good question. I do not know the answers. I did matching of drivers to the amp channels not vice-versa.

 mark wrote:
the thing that really hit me like a 2x4 was romey saying of 12 s2 only 3 were usable in his opinion.

I would say 3 of 6 as the 4 of them I keep with metal and 2 with “old” plastic suspension.

Mark, generally in order you to have anything that I say in perspective of even better do not listen what I say at all and to use own judgment I proposed you to make/buy/borrow a full range SET (it might be a Milq prototype with AM core) and  to see how you driver will react to your expectations. Without it any conversations are groundless.

Rgs, Romy the caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-30-2008 Post does not mapped to Knowledge Tree
mark
Posts 20
Joined on 01-25-2008

Post #: 10
Post ID: 6496
Reply to: 6438
LL1627a gap 200,250 or 300ma?
with reference to the LL1627a as used in full range application in melq.you mentioned a good choice gapped at 200 ma but i would prefer 300ma but they do not do it.i had k and k check with lundhal and they will do it and at the same price 375.he mentioned that this would potentially drop the primary inductance  which could become a factor in  low frequency response.what are your thoughts on the pros and cons of using the 300ma gap in this case? i suppose a potential pro would be more headroom?
01-30-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,538
Joined on 05-28-2004

Post #: 11
Post ID: 6497
Reply to: 6496
Look outside the Lundhal if you need more current to drive.

 mark wrote:
with reference to the LL1627a as used in full range application in melq.you mentioned a good choice gapped at 200 ma but i would prefer 300ma but they do not do it.i had k and k check with lundhal and they will do it and at the same price 375.he mentioned that this would potentially drop the primary inductance  which could become a factor in  low frequency response.what are your thoughts on the pros and cons of using the 300ma gap in this case? i suppose a potential pro would be more headroom?

If you prefer 300ma gap, then you are out of the Lundhal’s realm as they do not have enough core mass. They can gap this transformers with any gap you ask them but you pay losing of inductance. What you want is a sensible balance between headroom for current and LF power that the transformer will be able to handle. It would however would deepens how you will be using this transformer.

Having both 200mA and 250mA LL1627A and listening and measuring both of them here is what I feel you options might be. If you willing to build a full range amp then I would go 200mA as it give enough inductance for good bass and it will allow you to drive the 6C33C at 180-190mA and moderate power. Charles from New Zealand just finks his Milq with 200mA LL1627A and he commented very positive about bass.

http://www.GoodSoundClub.com/TreeItem.aspx?PostID=5740

I personally run LL1627A with 200mA and it was nice. It was clipping approximately 3Hz above ML2 (~19Hz vs. ~22Hz) but subjectively it was incontestably better despite messured higher. I have no idea way Milq does it. The amorphous core should lose at bottom very rapidly but it does not sound like this subjectively.  The 250mA does subjectively have less weight at bottom.

From another perspective if you are willing to eventually for DSET and get a dedicated LF transformer then you should not worry about bass and lower inductance would not be a concern.  However, you might not need a lot of gap for HF transformer as you might drive only half of the 6C33C plate at 130-150mA. In this setting the 200mA transformer will be more than adequate,  even it will be too much as you will not be driving LF though it. You in fact would need to loose inductance using less turns.

There are no needs to go for 300mA gap in HF transformer; in fact you might need for HF transformer to stay with a gap close to the current you drive. For LF transformer 300mA gap is fine, I would go higher, but it obviously would not be Lundhal.

So, as you see it would be all depends to what would be your plans for your amp. I do not see a need to invest into 15H 300mA full range amorphous transformer if you plant to do DSET. From another perspective you have money to burn then a custom 300mA transforms for a full range Milq would be a very cool to try. Let me know if you found a good source and I might get it for my Injection Channel (full-range) if it were not expensive.

Rgs, the caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
Page 1 of 1 (11 items) Select Pages: 
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Vitavox’s S2 Survival Guide...  A typical convention......  Horn-Loaded Speakers Forum     123  924909  07-16-2004
  »  New  An ultimate transformer for narrow bandwidth?..  Re: ...apply similar tactics to the power supply......  Melquiades Amplifier  Forum     14  85415  02-03-2005
  »  New  Ultimate HF output transformer?..  Leads to further air core heads...  Melquiades Amplifier  Forum     7  70849  07-14-2005
  »  New  Dual channel SET..  Space exploration...  Audio Discussions  Forum     8  55124  04-17-2008
  »  New  Incorporating active crossovers into DSET..  Thanks...  Melquiades Amplifier  Forum     2  29742  07-22-2008
  »  New  LF Amplifier in biamping...  DSET is tricky....  Audio For Dummies ™  Forum     10  51859  08-05-2005
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