OK, I was looking today at the par of the new Melquiadeses posted above and realized they are too ugly to sit them in my room over the 4th July holydays. So, spending another fey hours I designed to end the project and put it behind me. I still do not have in my hand the final plate resistor for the driver stage but it would be no big deal to change later on.

So, I put the final bypasses in their places. The powers supplied were measured, bleeded where it was necessary, the final damping was eddied, the time delays were tuned, the main chasses was sealed, the top cover was inhaled (took 2 hours!) and the game officially was decaled over.

Actually the entire ceremony was much less annoying then I anticipated. It took approximately 40 hours, one working week, to make too monoblock, including testing and debugging the second unit (had some issues). Each monoblock end up to be 81 pounds but it is manageable as it is relatively small.

I look forward to get next week my new “fundamentals channel” 250Hz horn and to put the new Melq init the game.

Rgs,
Romy The Cat

PS: I juts conducted the most critical Koshkabilety test. It looks like my fussy pussy loves the new Milq...

A few days ago I decided to learn how the new Melq sound and made a quick speaker level crossover for one of my Macondo’s channels, putting the new built Melquiades to drive the acoustic systems that the SET meant to drive (Before it was 82dB and 88dB sensitive speakers). To my surprise it did not sound good. The sound was “large” but not delicate, detailed but not minute, colorful but not tonal. Even bass was lager and “puffier” but not as articulate as I would like to. Furthermore it little puzzled me the frequency sweeps that I have posted above was not as interesting as in the first Melquiades.

I was wondering what it might be. There are a number of minor differences between this new Melq and the original about none of them should crate problems, but in contrary be better. I really did not know….

I hypnotistsised that the only REAL difference between the old and new Melq was that the new one I decided to drive this new Melq fool force, burning the 6C33C at 60W. Since I am limited with the current on transformer I jack up voltage and run the output stage at 230V-240V. Theoretically the exercise power should truncate the frequency range but how could I confirms it and drop the voltage in output stage?

I was trying to put a larger R22 resistor, burring voltage but it increase the impedance of power supply and was not good. Then I trued to put another 40V transformer in out of phase with the B+ transformer. It dropped the voltage but did not sound well as well. Well, I took a rheostat and drove the B+ transformer with lover voltage then I have in mains. Actually the result was stunning. Ass soon I was entering domain of 105V I was getting sub 200V on plate and the sound completely changed. It was like coming back home: I lowered the voltage, wait for a few seconds until the tube cool down and then suddenly the sound begun opening up and blossom with the dazzling fertility and richness of the original Melquiades. Surprise, surprise… now the 6C33C was driven at 40W… exactly like the original Melq...

Now, I am in trouble as the B+ transformer is mounted and connected. I need now another transformer with 80V less voltage. I thought it was it but apparently it was not…

Rgs,
Romy the Cat

Jim, I did try the anti-phase transformer in the secondary but I felt that it did something to sound. I can not do it on primary as I have the pate coil for the first stage sitting on the same transformer. Regarding the sweet spot of the 6C33C - I have a half of the site dedicated to this subject :-). The 6C33C is tricky little bastard and it’s best operation point vary form man y different thighs. In context of the given amps I have limited transformer of 200mA and I drive the second stage with 185mA. The first Melq was using 200V on plate and it sounded very good. The 200V was found after many-many days of experimenting and listening with all imaginable voltages, currants, dropping resistors, OPT sections configurations and so on… However, it was all I context 200mA gap in the transformer as Lindale has not enough core to hold masonry inductance if I go for higher current. Still, Dima and I were experimenting with the Melq sound truing the tube do not manifest sonic deficiently nether neither in current nor in voltage. It looks like at 200/200 it slicked very well… In the super Milq where I have no limits in the transformer core and what I have no demands for inductance the story was different…

BTW, Jim, did you view my question about the crazy swinging input shock that I've sent you another day?

Rgs,
Romy

1000Hz

20.000Hz

40.000Hz

100Hz

20Hz

15Hz

OK, the first think first. The second and the their images from the tope that were marked 2000Hz and 40000Hz are in fact 20.000Hz and 40.000Hz. I just lost a zero when I typed it. I have corrected the labels

Jim, it is a good question about the input waveform? I have no idea now and I will post it later on tonight. I have quite rudimentary and not very well performing generator and perhaps it does not have a proper output (thought I doubt). From a different perspective, why should we not see a lot of 2nd order distortions in output? It is SET, it should be this way. Perhaps later on I will run my distortion analyzer against the Melq …

Regarding the power. 28.5V RMS is was into 12R, as I usually do. I measured it precisely at calibrated scale just once to have an idea about the power. When I was looking at the frequency response I uncalibrated the scare juts to starch the wave exactly across the 10 dividers on the screen and then, running the frequencies up and down, I used only time/div to view the valve. I know, that you might consider this way of viewing is quite barbaric and I might agree with you but I did not care when it hit 3dB and I was not concern about the absolute numbers of the response. To me it is more important to get a FEELING of dynamic of this process. I usually set the max outs voltage on generator before the wave get clipped at 1000Hz and then moving up I observe how dynamic  with whish amplitude goes down after 20Khz; and moving down, I observe HOW the wave get distorted under 30Hz. I had THAT feeling from my first excremental Melq and I was a little disappointed that this new Melq with 60W plate dissipation measure and sound so different and so poor. This current version with the lower plate dissipation (similar to the original Melq was) behaves and sounds and very similarly to the original Melq, although the original had very slightly more, 42W on plate.

Guy, yes, I post the 10K square wave tonight,,,

Rgs,
Romy the Cat

romy wrote:

I have quite rudimentary and not very well performing generator

Well, Jim, it is time to say “Oops!” I told to myself do not make any posts early morning unit I eat a bagel but this mooring I disobeyed the rule. Anyhow, I do not know how I come up with 28.5V RMS. Defiantly it was peak-to-peak on the scope and I remember that I intended to get a correct calibrated number, so I did but, or I think I did…. but it hardly looks like anything mindful. The amp should be in 12W region, slight less then the original was. I juts feed it with 2.4V into 12R and my “true RMS meter” Fluke 87 said that it is 9.22V. Also, here is the feed directly from my generator that you asked.

1000Hz

20.000Hz

100Hz

Here is I fed one channel from scope directly and another from amplifier. The wave that came form amplifier is located higher in all 3 pictures.

1000Hz

20.000Hz

Best amplifier is the one that you just built…

Yes, it is a common unfortunate law of Audio but the people who know me personally know that try do not behave according to this behavioral pattern. So, this weekend I decided to do try the new Melquiades on the crap that I have been using for a few weeks but quick-make form Macondo a suitable mono speaker suitable for this SET. It took literally 1/4 hour to make the speaker. A pair of 5.5R woofer towers connected in series with 65Hz low pass first order driven from one of the new Melquiades monoblocks.   The Macondo upper bass horn driven full-range juts for sake simplicity. The S3 channel from Macondo with unavoidable 3UuF and the Macondo’s tweeter atop. The horns are driven by the second Melquiades monoblock, full range with EVS attenuator in front to EQ the sensitively gap with the LF chants. The both Melqs eventually fed with new tubes and driven the 180V, 200mA.

What is that marvelous sound; it was exactly the Melq that I remember. It is not exactly even because the speaker is simplified but it is the very-very the same sound as Melq is need to do. It has stunning resolution and transparency but it never go further into hyper-resolution and artificial effects. It has fantastic speed and transient characteristic but at the same time it perfectly maintains something that I call “acoustic-like harmonic structure” and capable to produce very fluent and soft sound. I have written about it  and many other things during my “Melquiades discovery phase”….

Anyhow, I juts listened on this my temporary playback a very complicated peace and mine the very favorite performance of Rafael Kubelik leading Berlin with Dvorak's Ninth Symphony. It is scare how good it is and how good the new Melqs handled it with … almost smile.

Good! I am very glad now with the result.

I was replacing transformers in the Super Milq HF channels and while I was doing it I decided to perform a minor maintenance on the amp.  One of the amp’s fans developed a “flat” in it bearing and created a very minor “step”. I order a replacement fan, also this time I decided to mount it differently. I ordered the very same fan that I used before, the most silent that I was able to fine 2 years ago.

To my surprise the very same fan tuned out to look very different: the same price, the same box packaging, the same model of course only slightly differently looking blades. It was SilenX 120x120x25 12V fan with 1100RPM at 11dBA. So, I put the new fan next to the old fan on my table and tune them on. The new one is twice more silent! Hm… how little I need to be happy!

Also I abandoned to mount the fan with screws and fan rubber gaskets. This time I just dumped on the amp’s wall the black silicon that I used everywhere (mentioned above) and glued the fan to the amp via 3/8” of the silicon. The result of the new fan and new mounting is fantastic. When the fan is on, at full 12V (never happen) then my stethoscope pick absolutely no events on the Milq’s chassis. Very-very cool!

The caT

Hello, loudcloud,

The Milq’s meters are by Hoyt (link). You might look at

http://www.hoytmeter.com

and from theer your might customize it in any direction wish. They are not dirt-cheap but I fine them reasonable for what they do. Here is the picture of the same meters in the Super Melquiades.

It, looks like the problem with the steel chassis picking up stay magnetic fields from my Super Milq’s power supply is about to be gone. With the introduction of the 3 extra single-stage channels I needed more current for 6.3V filaments and slightly other voltages for B+…. I was thinking to make it in half-ass, using my current magnetic, but then, since it will me my last amp, I decided to go for the set of the new transformers. Sure, opening the Pandora Box I opened it wide open and eventually I went for a new set of custom toroids for everything, including the potted chokes and so on… Since they will be hanging outside of the chassis in L-brackets (like the bunny ears) it will be no more with-chassis talking….

Two: 12,6V – 10A, center tap, 6.3V – 10A center tap

Two: 440V – 350mA, no center tap, 440V – 150mA, center tap

Two: 220V – 3A, no center tap, taped primary with 240V out

Six: 10H 400mA

Romy the Cat wrote:

.....it is scare how good it is and how good the new Melqs handled it with … almost smile.

Over the last 2-3 years the full-range Milq begin to loose it’s importance as it paved the way for a Super Milq DSET. The full-rage Milq was sitting in my room, sitting, sitting and sitting, driving the Injection Channels, driving some other thing and eventually, since the new 6-chennal Super Milq has a built-in full-range channel I decided to decommission the pair of my full-range Milq monoblocks. I dumped the Milqs to my car and drove it to my storage… So long, the Melquiades.

It was certainly not an “emotional” moments but I had “special feeling” as the Melquiades had became my past. I still feel that I was not completely “done” with it as I would like to hear the full-range Milq with 350mA transformer, driving the 6C33C at 55W. I’m not willing to do it myself, partially because I do not have good speakers with which I would be able to listen such a full-range amp and partially becose I have no need in that.

The last question that was cursing in my mind when I was driving the Milq to the graveyard was how much in the sound of my today 6-chennal Super Milq I recognize the sound of the original Melquiades. I would like to be able to tell you/myself that very well researched and investigated sound of the original Milq is essentially the same as the sound of the new Super Milq. However, it would not be a right observation. The 6-chennal Super Milq has different sound. The 3-chennal Super Milq has slightly different sound and the 6-chennal Super Milq has even more differences. The character of the sound is similar in a way but there are many other things that make both sounds not exactly comparable.

So, the Milq went to sleep with fishes. It is kind of sad and happy event… One door open another door close…The life is going on. Bye-bye the Melquiades. You were a good ride…