Tranfiguration Orpheus description

I think it unlikely that Nick would post on a thread as pointlessly contentious as this one. Unlike many of us, he actually has a life! ;-)

Neither Andrew nor I have anything to apologize for, and it's a waste of time responding to people who don't read what we wrote before posting criticisms. For example, I've stated at least three times that we played the O with slightly positive SRA, but I'm still being told that we should have done what we did, or how to do what we did. Has everyone gone blind?

Nsgarch launched this thread to discuss the Orpheus. I have nothing more to add unless I hear one again, and I'm unlikely to share it here if I do.

Doug

Dear Doug: Sorry to disturb again. My last post was only to state that there are differences in what Andrew think was the O set up and in what you state about. This Andrew post confirm it: +++++ " We did not evaluate a broad range of VTA in Doug's system . Paul tried several setting within a small range but I beleive all of the settings put the arm lower than parallel. Although, I preferred one of these settings, we did not make large enough changes to evaluate the cartridge with a parallele or slightly elevated arm. " +++++, I can tell you I'm not blind and I'm not doing criticisms only for doing that but for trying to help to understand the results of that cartridge test: that's all !!!!

Btw, those three subjects: precise volume gain, frequency response with changes in volume gain and RIAA accuracy, are crucial in any two cartridge test and are very important to understand the results and if you can it will be nice that you share the info with us.

Doug, it is normal the reaction of all the people ( including me ) in this thread when the test's results are controversial like this ones, be patience.

Regards and enjoy the music.
Raul.

All,

I've been experimenting with VTA/SRA on my setup. Using a maginifying glass I inspected the SRA with the tonearm completely parallel to the record surface and determined that the SRA was slightly negative. Approximately ~ -1 degress (stylus tip pointed away from tonearm base). I had to raise the tonearm approximately 4.5 mm to achieve an SRA of approximately 0 degrees.

This improved bass extension, tightness and detail as well as high frequency extension and dynamic attack. I also hear a little more record wear noise which probably suggests it's tracking the grooves more precisely.

I suspect the system might now sound better at 100 or so ohms. I think Nsgarch may be right on compensating for high frequency losses by increasing loading to 47K. I'll try reducing loading next and report back.

Andrew

Andrew,

I think you may have my comment about 47Kohm loading and negative SRA backwards. Let me explain it this way: If you have a MC cartridge at the correct SRA (stylus nicely locked into the forward-slanting groove undulations) and you set the load at 47Kohms, then you are feeding a perfectly wonderful signal (from the cartridge's output) into a perfectly horrible impedance mismatch. The effect of this particular kind of mismatch is to roll off the bass response more and more starting from about 1kHz on down -- leaving the highs (apparently) dominating.

Now, if you leave the load at 47Kohms, then the highs you are getting are essentially normal, but the bass is attenuated due to the impedance mismatch. The only way to (artificially) reduce those perfectly normal highs, so you can hear whatever piddling bass is still left after the impedance mismatch, is to severely disengage (unlock) the stylus from the groove, setting it to negative SRA in order to reduce the cartridge's HF output. And you wind up with a tonearm that slopes to the rear!

Talk about bassackward!!

47Kohms is ideal for MM cartridges. The Shure "V" series coils have an impedance of 1400 ohms! Times 25 that equals 37Kohms! So naturally a default preamp load of 47Kohms would make perfect sense. Similarly a little 2.5ohm MC coil only needs to "see" an impedance about 25 times its own resistance in order to transfer its energy. If you try driving a 47Kohm load with a MC, all those low frequency bass notes start to look like direct current at the preamp input and get dissipated as heat (if I still remember my electonic theory correctly ;--)
.

Nsgarsh is right,once again(what else is new).He has proven,time and time again,to me,that it's OK to be open minded.I have always felt the 47k load was just fine,with my set-up,and my friend has been absolutely adamant about keeping his set there too!This has always influenced me,but when some folks go on a binge,enough times,even though you don't necessarily agree,it can influence some tinkering.Here,my not being so pigheaded has been a gain in sound.And,thanks to guys like Neil,I have alot to learn,still,and am now getting FAR superior sound,at 100 ohms.Thanks Neil!
Best!
Mark