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In the Forum: Melquiades Amplifier
In the Thread: Valve Preamplifier for Macondo/DSET
Post Subject: It is simple and not.Posted by Romy the Cat on: 4/21/2019

 anthony wrote:
Exactly that, my sources do not play loud enough through the Melquiades or DSET.  Like your OPPO, they only put out about 2V RMS which seems to be the modern standard and I need more.  Can you remember what input voltage DSET needs for maximum volume?  I can measure this, but just need some time.  Some sources these days have less than the nominal 2VRMS output, and my favourite source (which is my dac) I believe will only give a little over 1VRMS

 
Oh, good, why did not you tall it before. How the hell can you listen if it you DAC outputs 1V?! No wonder you have no volume. Also if you have no voluble you do not “get” one of the most advanced feature of multi-amp topology multiplied with one of the most advanced feature of Milq design: an ability to absolutely effortlessly to walk over dynamic contracts, particularly at high volumes. Most of the amps out there change sound as volume rise, not multy-amped Milq. This is all together a big subject that requires a separate explanation. Anyhow, with 1V from your front end you are nowhere. My front ends have 3.1V at 0dB digital. Many of Milq’s ideas were very much formed around the input Milq tube that ruin with 4.5V bias and that can naturally (with no feedback injected into cathode as Lamm does for instance running 12AX7) can handle the whole input voltage swing. My phonostage pushed over 4.5V and it will drive the Mil on A2 but it will be at the volume where the wind will be flying out on my listening room. With 3-4V at input we still at the perfect window where the driver tube not stressed by input voltage and the output tube is still not clipped by power:
 
http://www.GoodSoundClub.com/TreeItem.aspx?PostID=6057
 
I do not know what your fav DAC is but if it is operational amplifier basedDAC then you can easily get more gains out of it by lowering the op-amp feedback.



 anthony wrote:
The SS pre that I am building fits these parameters...and sounds very good in other systems...but the DSET is a very specific load to master and it will be interesting to see how it performs against the Placette.  Like all my audio projects, it has taken a long time to finish and at the time all I wanted was a unity gain linestage and I almost did not start the project because of the 4x (from memory) gain but thought if it did not work out that I could task it as a headphone amplifier.

DSET has no specific load demands the input passive filters are. All that you do in the preamp you make, from the Milq perspective, make sure that it has as low output impedance as possible but to be stable at the same time.


 anthony wrote:
Motivations!  Yes, the murky world of why we do what we do.  The further I have progressed in this DSET/Macondo project the more personal meaning it has accumulated.  Some people have a mid-life crisis and buy a Porsche or a yacht, some guys quit their high paying desk job to go and build a house in the scrub or the beach or use their hands on some large and introspective projects that bring an ongoing associated sense of relief or calm or achievement.  Well, I have the satisfying professional work plus I am still lucky enough to be hands-on at the farm so I am not suffering so much the urge to quit either nor do I need a tree change to balance my life's ambitions...everything is calm and plain sailing at the moment and has been for some time. 

What started out as a project to "get good sound" and "learn new stuff" has morphed into a little of a meaningless semi-philosophical tangent.  To me, DSET/Macondo is about many things including shunning the modern axioms of convenience and instant gratification and taking the path well trodden.  I am very proud of myself that the first DSET was powered up and is in operation without electrocuting myself or letting out any smoke (other than one potentiometer that went off the end of its track and stuck) and that I got the grounding scheme right first time.  The gear is huge and heavy and imposing and much of it is older than I am and it all uses amplifier topology that went out of fashion before my father was born but at the same time it is also relatively unique and of course "I made it".  To say that "I made it" is not some small factor influencing my thoughts about the valve preamp would be an untruth.

Plus, the valve pre would fit into the general vintage styling of the entire system and of course would be heavy, hot, large, difficult and all the things I have come to love about this project.

But, the sonic reasons remain the same as when I started this project, I want good sound.  At the moment I have a partially finished acoustic system and I am trying to pick the best path forward.  I definitely need more gain but am resolved not to alter the output of my sources but instead to put some gain into the preamplifier.  That is the first hurdle:  loudness.  I would love to build it myself and if possible do it with tubes but if SS is necessary then SS will be used.  If I end up sending my Placette over to Guy to get beefed up like yours Romy then that is what it will be.  At the moment, however, I will need more volume to make meaningful judgments about what I hear.  And of course I need to finish building the horns!

Anthony, I do understand all of it but the sentient you expressed has, in my view, a self-defeating and self-limiting fallacy. A desire to have “good sound” is abstract and never fulfilling. It is not different from the famous emperor’s comment that Mozart’s music has too many notes. Your parley in audio as a substitution for mid-life crisis is not something that I have problem with. I do have a problem that very frequently in audio people get taken by ability render differences (by building or buying)   and do not recognize that they keep moving irrelatively- latitudinal or lateral. A true progress in audio and better audio come with observation of system owner longitudinal or amplitude progress. I do not see in anything you say, at least publicly, any factoring of any listening objective and this is a bit concern you. Not that I worry about you too much, you do not need  my worry, but I also know a lot about machine- humans interaction, in this case machine are audio methods.  I do not want to bother you with all of it but I juts share you with my presupposition that you might take under consideration or might discard it as a stupid nuisance. If after a period of time listening you playback you detect that you move in your listening preference from whatever you are listening to Bach, Beethoven and perhaps Brahms then your playback “works” probably and you are getting “good sound”. If during you practicing audio your listening inclination do not move altimetry toward to Bach then you need to start changing tubes, voltages, cartridges, cable elevators etc….

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