Since my B2 ULF power amp will be long time to fix then being a compulsive person fully suffering from Dostoevsky Complex I bought another B2 amp to keep the blood flooding in my playback. Surprisingly it was no my decision but I got advise from Wagner.

Before the amp blew up I was listening Das Rheingold from mid 50s. It was celebrated recording by Georg Solti /Wiener Philharmoniker. Besides very good performance (George London and Kirsten Flagstad to name a few) it has phenomenal sound. London (the label) recorded the opera in studio specifically with objective to demonstrate the capacity of new stereo medium and to convince the consumers to buy stereophonic equipment. Before the B2 blew up I was playing the first act and it was let say ”loud”.  The people who were in my house know that I generally play loud – because my playback can – and the Rheingold that was playing was very loud – how else can you play Wagner. In a few hours the amp blew up and the next day I was playing the Rheingold again.  Now the loud play was not as much fan – without ULF Sound was dry and was more like Verdi Sound instead of Wagner

I realized that I need to bring my ULF back ASAP and that I have no patience foe experiments with other amps.  I also found a technician who most like will look at my burned B2 and will try to fix it, otherwise I will keep it for spare parts… So, my infatuation with audio lately turned into me sitting at my driveway and hallucinating about  coming UPS truck with my new B2 power amp. It’s it, unit I get my B2 replacement I will be wearing brown underwear…

This is kind of funny. I got another B2 amp a few days back. It was near new condition, at least inside. As I plug it to drive my ULF I felt that it produces some kind of strange bass. I did not like it at all and it was very different then what I got from my broken B2. I looked at the scope what my second B2 does with 5V input signal. I had some odd distortions. Sucks, the amp need to send to fix it….

I pull from basement another cheap consumer amp. I did test it on a bench and it was working very fine, clipping with 10.6V and running flat down to 12Hz. I figured out it will be fine as a temp solution and I put it in the system. It worked fine but the character of ULF was not even closed to B2 and very far from where I would like it to be.

What however took my interest was that this new consumer amp, along with B2 had very precise meters and they do not run even at ¼ of the full power at the new amp. On B2 they did not run even at 1/6 of full power. The new amp it 50W SS Hitachi or something like this. So, I asked myself how much power do I need for my ULF?

The question is very much important. I am under presumption that I need over 100W, preferably more to drive my LILF line arrays. Back in the Milq forum I have couple threads dedicated to an idea how to get a lot of power from LF DSET:

http://www.goodsoundclub.com/LatestPosts.aspx?ThreadID=2136

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=5200

Still, if in reality I need only 20-30W then I am very much in the realm of paralleled 6C33C that would be very easy to do. I reality I do not know how much power I need in my new room.

In my old room I knew that my Milq LF run securely in A1 but then room was much smaller my woofer array were larger.

http://www.goodsoundclub.com/Forums/ShowPost.aspx?postID=6057#6057

I need to do the same test with my new room. Frankly I feel that if wood be able to beef up my woofer towers with 8 drivers per channel and to use a dual 6C33C out then I will be able to make a phenomenal ULF  DSET. I just need to evaluate how much power I would need and would 35W-40W that I can get from a pair of 6C33C enough.

Ok, I did try the 4th order filter and it did not sound as I wanted. The 3^rd order is right slope foe my room but I need to go for custom filters separately dedicated for right and left channels. The problem is my right channel with the attached to use equipment mini-room create a huge 10dB inflow at 65Hz that screws up output of my midbass horn. My midbass horn still in my estimation produces the “proper bass.” The ULF does offer a LOT of very important benefits but it compromises my midbass. If I will be able to defeat let say narrow 6dB at 65Hz then I will be able to get great and proper sound.  As now I have phase butterfly effect – this needs to be addressed.

Maybe the short cut to customize-able LF curves these days is DSP, at least until you figure out exactly what you want in the way of attenuation?

Best regards,
Paul S

For a casual observer it might appear that I am constantly fought with my ULF, finding and loosing better and worse configurations.  It might be so but I have a very strong sense of objective of what I would like to accomplish. I want to reinstate that Sound in my room what I was injecting +20dB at sub 20Hz in my room. However, I would like to do it in a way that under any circumstances would smear my midbass.

Ironically to raise the order of ULF filter and to add volume does not work. It has to be, for some reasons, 18dB per octave and the key is to control the slop of that roll of. This is what I will be experimenting now, I know that I will find the solution as I have very strong visualization of what I need to get as the result.

I have much option on the table. The DSP is one of them. I have Velodyne SMS-1 and I need to do the action only on one channel, so I might use it. I have another digital parametric EQ that I might use. I might implement notch filter and correct the slope’ bump. (Here is a homework for you: why I religiously against notch filters but feel that it will work fine in my case). There is a few other options, I will examine them.

Actually the bigger question to me is why I like the Sound after my tube active crossover more than with line-level passive filter. The ULF IS better quality with line-level passive filter – I can testify it. But the ULF after the 4 stages of active tube filter make the ULF to sound that same as it come from the rest of the system – lash, measured and super polite. It does not have that thrilling ULF slam but it does not exist in real life ad well and I am trying to run as far from it as I can.  The ULF after that tube crossover is very pleasurable and listening I would quests that I have SS amp doing bass.  In way the tube crossover as my SS Yamaha B2 amp make the ULF amp to sound more similar to Milq. I personally feel that it has to do with characteristic distortions of 12AX4 in tube crossover – I happened to LOVE it in my “End of the Life Phonostage”. It will be VERY funny if I decide to stay with this tube active crossover as final version.

For now, after a few day of listening with line-level passing I voluntary took it off and switched to tube active. It gives me a feeling as I am sitting at the table and do something and somebody performs a foot massage on me…  I am listening now the live broadcast from Symphony Hall with full production of Berlioz‘s Roméo et Juliette, Charles Dutoit leads BSO and Tanglewood Festival Chorus. I did not have time to calibrate my active crosier and set it up by pure intuition. I know that upperbass a bit eaten by my phase bitterly on right channel but the whole sound of the Symphony Hall is amazing.  With this ULF injection the whole room is breathing with sounds and I have absolutely no feelings of bass excessiveness. Just wonderful! I raise my glass to Karl Leonhard!

Romy the Cat wrote:

For a casual observer it might appear that I am constantly fought with my ULF, finding and loosing better and worse configurations.  It might be so but I have a very strong sense of objective of what I would like to accomplish. I want to reinstate that Sound in my room what I was injecting +20dB at sub 20Hz in my room. However, I would like to do it in a way that under any circumstances would smear my midbass. Ironically to raise the order of ULF filter and to add volume does not work. It has to be, for some reasons, 18dB per octave and the key is to control the slop of that roll of. This is what I will be experimenting now, I know that I will find the solution as I have very strong visualization of what I need to get as the result. I have much option on the table. The DSP is one of them. I have Velodyne SMS-1 and I need to do the action only on one channel, so I might use it. I have another digital parametric EQ that I might use. I might implement notch filter and correct the slope’ bump. (Here is a homework for you: why I religiously against notch filters but feel that it will work fine in my case). There is a few other options, I will examine them. Actually the bigger question to me is why I like the Sound after my tube active crossover more than with line-level passive filter. The ULF IS better quality with line-level passive filter – I can testify it. But the ULF after the 4 stages of active tube filter make the ULF to sound that same as it come from the rest of the system – lash, measured and super polite. It does not have that thrilling ULF slam but it does not exist in real life ad well and I am trying to run as far from it as I can.  The ULF after that tube crossover is very pleasurable and listening I would quests that I have SS amp doing bass.  In way the tube crossover as my SS Yamaha B2 amp make the ULF amp to sound more similar to Milq. I personally feel that it has to do with characteristic distortions of 12AX4 in tube crossover – I happened to LOVE it in my “End of the Life Phonostage”. It will be VERY funny if I decide to stay with this tube active crossover as final version. For now, after a few day of listening with line-level passing I voluntary took it off and switched to tube active. It gives me a feeling as I am sitting at the table and do something and somebody performs a foot massage on me…  I am listening now the live broadcast from Symphony Hall with full production of Berlioz‘s Roméo et Juliette, Charles Dutoit leads BSO and Tanglewood Festival Chorus. I did not have time to calibrate my active crosier and set it up by pure intuition. I know that upperbass a bit eaten by my phase bitterly on right channel but the whole sound of the Symphony Hall is amazing.  With this ULF injection the whole room is breathing with sounds and I have absolutely no feelings of bass excessiveness. Just wonderful! I raise my glass to Karl Leonhard!

For now, without going digital, I have settled with 3rd order filter on left and 4th the order on right. I also run the right ULF 2dB louder then left.  To use different filter on right and left channel sound logical to address the ULF asymmetry of my room but it was a bit strange sounding at beginning. Eventually, when I discovered the need to drive the channel with higher order hotter it straights itself up.

So, I am taking that I can run ULF 10dB up and down and had not much impact to sound and at the same time I am very picky about 2dB right channel to be louder then left. What I am talking about then?

Well, this is the tricky part.  ULF serves not only lower extension of my Sound but also is acts almost as a delay channels, extending the reverberation time in my room. If the contribution of ULF in auditable sound might be very much tolerated to a large degree then the moderation of reverberation time is in my view need to be set more or less accurately.

Listening how ULF deal with decays in my room requires totally different type of listening. The room might dissipate only so much bass and so much infra bass. Pumping the room with ULF a create a critical mass of infra bass and further increased of it has no positive effect to auditable sound. This ULF level of saturation is very important as my ULF channels is NOT true ULF but it has SOME touch in auditable bass. So, the objective is to set the right level of auditable lower octave but in the same time to pump the room with max amount of ULF, under the level of room ULF saturation. This is what the slope of the filters and volume controls at each ULF channel become the tools of action. It is VERY interestingly that the “right level of auditable lower” with tube crossover is flexible but the right level of ULF saturation is very picky. With line-level passive filter and only SS amp it was in reverse: the “right level of auditable lower” was very demanding but ULF saturation level was very flexible. It is very interesting phenomena, read again to understand is and do not ask me about the reason – I do not know the reason.

So, what to listen while adjust the critical level of ULF saturation, or effectively the reverberation time on listening room? This is very good question. You will not always will be able to do it by the ambient sound of recording, even if you know the recording very well. What I suggest to do is to use tempo as the reference for reverberation time. Get a good recording of a good organist that you trust playing let say Bach. Max out your ULF and play Bach. The room will be too “long” and soon you will feel ( if your organist is a good one) that Back is being played slower than it has to be for the sound of your room. Close your eyes and listed the tempo with witch the notes are opening up. Pretend that you are the one who play it. Continue music to play but stop listening it and set your own tempo in your head with the respect to the reverberation in your room. Not begin to shorten your ULF output db by dB until your own feeling of right tempo will be absolutely identical to the tempo your organist. You need to be able to spell out loud the Bach notes with no timing discrepancies between the expressed tempo of your organist and your own feeling of tempo in your listening room. If you have a mute switch then it is very convenient to mute the sound, to continue with Back in your own tempo and then bring sound back. If you have good listening expertise then you do not need mute switch and can do it by singing the notes louder then sound of recording, or juts do the exercise in your mind.

Your objective shall be your absolute agreement with tempo of your organist.  You might disagree with his tempo but you need to have your own reasons why you or him did what you both did.  You might use not organ but a well recording piano but with piano recording there is a danger. Many piano recordings are vandalized by idiots sound engineer who inject into recording artificial sound reverberations and a mix from microphones installed inside the piano deck. It is bad as it is but the idiots do all of it after the pianist played, so those recordings has no human-induced and artistically-measured relation between reverberation and tempo.  It looks to me that the idiots do not temper so much with recordings of organs.

I am not sure that I am at final stage of my ULF wondering. I do like the integration-free problem of my ULF via tube crossover. I am a bit concert that I am injecting now + 9dB at sub 20Hz and do not feel that I have too much bass. I am a bit more concerns that with use of tube crossover I lost “some” thump in lowest bass, particularly at very high volumes.  The softening of the very last pinch at the very low end in no way annoying or even noticeable in most cases but there are some moments where it is necessary. It is like walking in fog – you need some black object to see in order to recognize how dance your fog. Yes, I am taking about the 8 symphony, fourth movement of guess who?

I would like to have that prodigious slam of that drum but at the same time it looks like the amp that can deliver it do not have the harmonic intelligence that I need from ULF. Well, I need to live with my current ULF for a while. Perhaps I need to re-tube my crossover as I do not think anything is left in it to modify…. If perhaps I need a deferent power amp. I am feel sadden that I sold my Lamm M1.1 amps – for high power they delivered very good bass – it would be interesting to try the M1.1 now in my ULF.

Still, I am a bit wondering why I am so attracted to that soft version of ULF.  I wonder how other people would react to it – to the high power ULF channel with, soften by tube crossover. I do not think that audio people generally hear something like this. Tomorrow an audio guy that I know will be arriving in Boston to hear my new playback results. I wonder what will be his reaction to my new ULF implementation.  I wonder become it is different. Pit is this way my ULF is “softer” then the sound the rest of Macondo, this mostly never happens with playbacks and to hear this type of setting a bit strange but interesting. I wonder what will be his reaction and if he will be able to understand of what is going on.

The playback with ULF doe not sound bad but the elective softness of ULF makes the feeling from this sound a bit different. It reminds me walking across a swamp or deep snow. First you spend efforts to pull your legs from swamp but as you get use to then you can walk and do what you do without paying too much efforts to the fact that each of your step is an effort. With my overly soft ULF it is in way the same:  listening,  you need first to get that feeling of that excessive in size but warm and fuzzy ULF. You need then to learn how to ride that ULF, literally how to lie relaxed atop of the bubble of ULF and let the ULF to drift you. Then mind observers that cloud of ULF is not only thing in the room and that there is a lot of more sounds in the room. The cloud of ULF acts as a metaphysical sustained pedal-point above which all the rest music grows. The softness of that pedal-point is key in my mind as the ULF cloud  is not auditable in normal sense. An interesting effect indeed…

It did not last long….

Just a couple days back I was thinking that I will live with my current lower bass for a while and now I feel that I will not.  I do not feel that my current ULF is wrong. In fact I feel that it is truly superb but I would like to add to it one character, still without losing what I have.  I do not want to change my lower bass but I would like to a very very very very very very minor degree to add some SS hardness, still preserving all long and beautiful LF harmonics that I have now. I am sure that no one would recognize it but I do. I do have some kind of nostalgia to my bass in old room. Even though in my current room I have in a way better a sound and better lower bass but I need to deLamminise my lower bass. My lower bass now has the quality that I did not like in Lamm ML2.0. With all phenomenal integrity of Sound in that amp it did not sound hard when it called upon. I was forced to idle the Lamms output stage very aggressively but then Lamm has no power when it drove 32R with 4R tap. Even in that configuration it was too polite. Milqides and then DSETing long change it but now with 4 stage Modified Marchand tube crossover and B2 amp I find myself in the same boat. I have very-very good bass but if music is called to rock-hard stress of the very leading edge then my ULF handle it a bit overly elegant.

So, What I am planning to do it to revise my Marchand crossover further. Here is the plan:

1)      Get rid of input stage and let my preamp to drive the filters directly.

2)      Get rid of output stage, moving the attenuator to the power amp.

3)      Slightly add current to the remaining 2 tube, dropping grid resistors from 180K to 160K

4)      See what happened then

I will get rid of half of the tubes and it might do the trick. I also consider using 6N6P instead of the 12AX7 as they might be better in cathode followers. They have the same ping and just need 6.3V, since I will have just two tubes left then I might connect them in series and to use the default Marchand  12V power supply…

Romy the Cat wrote:

It did not last long…. Just a couple days back I was thinking that I will live with my current lower bass for a while and now I feel that I will not.  I do not feel that my current ULF is wrong. In fact I feel that it is truly superb but I would like to add to it one character, still without losing what I have.  I do not want to change my lower bass but I would like to a very very very very very very minor degree to add some SS hardness, still preserving all long and beautiful LF harmonics that I have now. I am sure that no one would recognize it but I do. I do have some kind of nostalgia to my bass in old room. Even though in my current room I have in a way better a sound and better lower bass but I need to deLamminise my lower bass. My lower bass now has the quality that I did not like in Lamm ML2.0. With all phenomenal integrity of Sound in that amp it did not sound hard when it called upon. I was forced to idle the Lamms output stage very aggressively but then Lamm has no power when it drove 32R with 4R tap. Even in that configuration it was too polite. Milqides and then DSETing long change it but now with 4 stage Modified Marchand tube crossover and B2 amp I find myself in the same boat. I have very-very good bass but if music is called to rock-hard stress of the very leading edge then my ULF handle it a bit overly elegant. So, What I am planning to do it to revise my Marchand crossover further. Here is the plan: 1)      Get rid of input stage and let my preamp to drive the filters directly. 2)      Get rid of output stage, moving the attenuator to the power amp. 3)      Slightly add current to the remaining 2 tube, dropping grid resistors from 180K to 160K 4)      See what happened then I will get rid of half of the tubes and it might do the trick. I also consider using 6N6P instead of the 12AX7 as they might be better in cathode followers. They have the same ping and just need 6.3V, since I will have just two tubes left then I might connect them in series and to use the default Marchand  12V power supply…

They I played a bit with multiple 12AX7 tube that I have. When I had Lamm ML-2.0 I accumulated a Lot of 12A7 for Lamm’s first stage. Properly I have 30 different types. With Lamm I very much preferred Telefunken with smooth plate for MF and ribbed plate for bass channels (I multi-amped with ML2). Since it is ULF channel then the ribbed plate was the obvious candidate.  All Telefunkens are different, even of the same contraction and party by party sound different. All my tube were marked by sound (in context of ML2) and I find that it was no correlation how they sound in my crossover and in ML2. The best for bass tubes in Ml2 were too aggressive for my crossover; still it is nice to have it as an option. All together I turn out to like Russian made 12AX7WA. They are a bit muddy but it turns out works very nice with the plate current that I have settled.

Hm, I migh not need 150W DSET after all…

A few days back a local audio guy come to my place, heard some music and I played and said something that did not expect from his level of audio intelligence. (I wonder if it was the same guy who advised me to write a handbook “How to make friends 101”). He said that one of the most surprising things for him in Macondo Sound is that playback produces looks like a lot of bass but never go overboard.

Over the duration of the last year among the people who visited my room I have 4 individuals who expressed the very same sentiments in the very same words: they were surprised that with amount of bass Macondo is able to care it does not produce too much bass.  I think this requires a bit explanation.

We do judge bass upon I mistakes: the moments when it hits some kind of ugly distortions or too high output volume. If bass across the board too much but if it stays still accurate and even then it looks like we do not experience as much problems. Macondo does not output too much bass, in fact it is flat compare to MF. If some kind of wild things do happen in music then here is where Macondo’s bass accuracy takes control. What does it mean “bass accuracy”?

The bass accuracy is a tricky thing and it is very seldom achievable in the listening room. The “bass accuracy” implies the amplitude flat distribution of bass at the listening location with on relatively slow reverberation time. Most of the playbacks have just “bass”. It means a single channel that traduced LF, the channel in most of the cases is located right where he MF channels are. Since the bass amplitude at sub 150Hz is hugely depended from influence of listening rooms then it is self-explanatory that he bass results in listening rooms are very random. There are zillion ways to different degree to control bass, some of them more and less successful. Let take a look how Macondo deal with it.

Macondo compartmentalize the whole dangers bass on 3 individual channels: upperbass, midbass and ULF. Each channels has own amplification, own filter, own volume and own topological way to interact with the room. Then manipulating by each of the 6 bass individual channels Macondo made the total bass picture in the listening spot loaded but only to the point that “if it was extra ½ db then it would be too much”.  The most important that it is done by very natural means.

Sure one can very save even load across the entire bass by using digital room correction systems. Yes, some women prefer to deal with dildos instead of dealing with men. Still, I do not know any men who prefer to deal with a rubber woman…  The accuracy of bass in my view need to come along with tonal sophistication of bass notes and here is where digital room correction systems slip.

Anyhow, I would like to point out that compartmentalized bass to 3 individual channels give a LOT of advantage. I would like in fact it to be 4 individual bass channels but it will be probably in my next life…