Jump to content


  • Posts

  • Joined

  • Last visited

clyborne's Achievements


Newbie (1/14)



  1. I'm on a Mac or I certainly would have. Rob D.
  2. Hi-- Sorry if i missed an existing discussion. Claims to do .oma-> .wav among other file conversions.. Info at: http://www.dvdvideoconverter.com/atrac/ Thanks, Rob D.
  3. Hi-- A listen to this test I made could be useful: http://www.uwm.edu/~type/audio-art-tech-ga...es/page_38.html Eric Benjamin of the micbuilders list tested the Rolls PB-224 unit that I used in these tests and found that in a one-third octave spectrum noise test with Schoeps MK-2 mics, the Rolls came in at -120 dBV. The output impedance of the phantom supply is 6k81, so Eric surmised, "I don't think that the noise from the Rolls is a problem." The Rolls also output 47.6 volts. Rob D.
  4. Alan-- I just went over and hooked up NT-4-> Art-> NH900 and its working great (as it did ithe tests). Still showing the 13 dB increase in gain compared to NT4 (9volt)->NH900. Something odd is going on. Maybe take out the 9 volt battery, try other cables and then both recorders? Please do let us know what you discover. I use the Nt1A's outside (exclusvely) in DIY cut away PVC shock-mounts with big hairy zeps. No, nothing like a compact m-s rig, but workable. Lots of hours. I knifed the capsules where they join the posts in one pair and rotated them 90 degrees so they are front-facing. Then I mounted the bodies horizontally which looks more like a "field" mic, but both my vertical and horizontal sets have similar bulk and handability in the field. There's a litle less handling noise with the horizonatl set for some reason. As for the NT-5's, maybe look at the Studio Projects C-4's too? These mics are getting some very nice things said about them and they come with cardioid and omni caps-- and weigh only 3.3 ounces each. Rob D. = = = = =
  5. The Art and Rolls units are strictly mic level. Yes, previous wisdom said "line level" is better and you can judge the vaildity of this assumption yourself with the quicktime movie test. Practically speaking, no external pre is going to introduce less noise than the pre in the 722. Listen to the diference between the NT1A's going directly to the 722 and then through the Rolls or Art to the NH900 mic input. That's the best possible "improvement" I can think of that one could make instead of using the "lowly" HiMD mic level input. Gain wise, there's plenty with the mic level input too. There are folks who would prefer using another analog-digital converter rather than that built into the NH-900. We'd probably have to be using the exact same monitoring system to get into analyzing these differences. Rob D.
  6. Hi Alan-- Good to hear that the RH-10 mic pre is also compatible. You should be able to get the noise down to where the Nt4's self noise is loudest and covers all of the other noise sources. The NT1A mics in the test movie have 11dBA less self noise than the NT4. At that noise bed, it seems all of the contributing components are pretty much on par. Thank again for your pursuits. Rob D. = = = =
  7. Hi Alan-- Give it a shot and see. 24 volts might not silence it completely. Battery cost ~ new Art Phantom II? The Art and the Rolls seem to pull considerably less juice. I tried Schoeps MK-8/MK-21 mics->Rolls-> NH-900 mic input today. The owner, who swears by Lunatec V3 outboard preamp, said, "Sounds pretty clean to me." Let us know about the A/B test with your AD 20! Rob D. = = =
  8. Thanks Allan-- Some interesting clues from your tests. They are pretty consistent with what I found. The PS-2 would work much better using a hi current 9.6volt "RC" battery pack but would hiss and sputter on the standard 9 volt batery. Seems like you're getting even better performance on 12 volts because I could NOT get a fully clean signal out of 9.6 volts on the PS-2. I understand using a battery sled, the PS-2 I tested did draw-down a 9volt bat within 45 minutes. The Art and Rolls (no fizz etc) will run on the 2-9 volt bats or wth 12vdc inout plug option too. I Maybe the switching transformer puts out more noise with less supply current to work with? Its possible that you could find that an ART or Rolls could put out less noise,.. You can hear from my test that the NH-900 isn't contributing much noise at all (if any). Rob D. = = = =
  9. Unfortunately, I tried 33-100uf caps to block the PIP voltage but it didn't remove the fizz and line hum from the Denecke PS-2 unit for example. My best guess is the noise is from the switching power supply and the Art and Rolls use higher switching frequencies. The amount of noise may also be affected by the current load from the mic-- another reason we need to run tests on more condenser mics. Understandng what is happening, though, might help in making arguments to Sony/others for a better/more compatible future mic input design. Rob D.
  10. Its a pleasure to help if I can. Thanks for your kind comments. That's correct about the phantom conflict. I do not fully understand the nature of the conflcit between most portable phantom power supplies with the HiMD (and other) mic preamp "Power In Plug" (PIP) circuits. The bad result is a loud fizz and line hum. I've asked on a few lists, but no one has figured out why these two units work and others (even expensive ones) do not. I came across the discovery while trying to determine what the EIN (Equivalent Input Noise) of the NH-900 HiMD mic preamp is by trying to get a low noise mic to work with it. I was surprised as any one with the result! Klas Standberg (Telinga Microphones) has been stressing for years on the naturerecordist list that consumer grade mic pre chips have good specs but that something could be preventing them from working correctly. We owe Klas thanks. Another curious thing is that what ever is causing the PIP/phantom supply conflict might be related to the poor performance of some PIP "compatible" mics when used as recommended. The Rode NT-4 mic gaining 13dB of output when used with an Art/Rolls over 9 volt PIP is one example. If I owned a mic that had phantom power capability and an HiMD recorder, I'd drop $45 to try the phantom supply unit in a heartbreak. They're small enough so that you can "velcro" the HiMD recorder to it and still have a one palm recorder. Maybe one of the industrious MD accessory businesses out there will make a smaller unit soon! I do tests because one really can't believe everything dealers and manufs claim about their products. Its ridiculous, when you think about it, that no one tried what I tried before. I too spent a lot of money on pres instead of on better mics because I accepted the myth that one needs an external pre with consumer grade mic pres to get low noise performance with lesser expensive recorders. It is not that hard to borrow gear from each other and run simple comparison tests. _When_ manufs bother to provde manufs provide specs, they are an indication. What matters to us is how the components perform in combination, "mics with pre" in the field with high gain-- they way you use it, etc. I'm very curious to hear from folks who have older MD and DAT pres. Do they get the huge improvement in mic preamp performance with an Art or Rolls ? Seems to me that a recordist who is thinking about upgrading can rethink her/his mic options because that's where the noise limitation is now that the PIP circuit can be worked-around. There's a lot of field testing to be done on the large crop of low noise condenser mics out there. If you go to the usual HiMD accessory stores, you'll see a slew of mics with 22 to 41dB(A) self noise; there should be some lower noise options on their shelves. Perhaps Sony, Edirol etc. will address/fix the limitations of PIP if we apply some pressure like we did on the .wav conversion issue. Sony is now looking at HiMD as a professional replacement for DAT. I've not studied the history of PIP, but, as I recall, it was a stop-gap solution to cut down on recorder bulk. PIP performs with much lower quality than what most digital recordists know is possible these days. Low noise, inexpensive condenser mics did not exist when PIP was introduced. Rob D.
  11. I'm happy to report that there is no need to use an external preamp to get very, very good, low noise, high gain performance out of the Sony HiMD built-in mic pre. In tests I've been running using both the Rolls PB224 and the Art Phantom II portable phantom power supplies ($70 and $45) to enable the use of low noise, condenser mics, the EIN rating of the Sony mic is no worse than -118 dBu-- you'd have to spend a lot to get an external pre that's better. The trick turned out to be compatibility with the PIP circuit and these two phantom power modules can cope with it (many others I tested cannot). The preamp chip used by Sony has very low noise, it was a matter of getting around the PIP conflict. Below is a link to a QuickTime Movie that has 2 Rode NT1-A mics with 5.5dB(A) self noise first run through a Sound Devices 722 pre/recorder and then through the Rolls and Art phantom modules to the Sony NH-900's 3.5mm stereo mic input. http://www.uwm.edu/~type/Mic%20Preamps/Por...rtv01SorIMA.mov You can hear for yourself that the noise produced by both the $2200 pre/recorder and the lowly NH-900 pre/recorder is on par with the self noise of this extremely quiet mic. The good news, of course, is that recordists on a budget are no longer restricted to using PIP mics. With the addition of a phantom supply module to your HiMD recorder, you can try some of the many, new (phantom-powered) condenser mics that have come out in recent years. The Studio Project C-4 mics, for example, look interesting at 3 oz's each, with cardioid and omni capsules and 16dB(A) self noise. (The mentioned mic with 58dB S-N has 36dB(A) self noise in comparison.) The Rode NT1-A's are definitely an amazing match for HiMD recordists who want to bring home recordings from quiet settings. Note that the Sony mic pre has 5dB more gain than the 722's pre so even lower sensitivity mics (safely anything >10mv/Pa?) should work very well too. Almost all PIP compatible mics have fairly high self noise (and low output) but if your condenser mic(s) happens to also run on 48volts phantom, it will probbaly show as much improvement running through one of these portable phantom power supplies as through a $800 external preamp. In the test, a Rode NT4, acquired 13dB more gain after liberation from PIP compromise with a Rolls PB224 or Art Phantom II. The two portable supplies perform identically. The Rolls outputs only 48 volts and the Art has 12 volts as well. The Rolls has a nicer battery slot, but is a tad bigger. You can use a standard 2-xlr female->stereo mini plug unbalanced adapter cable to get from the box to the mic input. The phantom supplies might also liberate older MD's DATs.etc. Feel free to send reports to me at the email address in the movie. Rob D. = = =
  12. I suspected this. It would be great to know if anyone can confirm that SS 3.1 is transferring/handling long duration files reliably for them. I'm on mac so upgrading the PC would be primarily for transfers.
  13. My first post. I often make recordings in excess of 30 minutes in HiMD PCM mode with an early Nh-900. With Sonicstage 2.1->3.1, I'm getting *internal (system?) errors,* transfer and conversion stalls and even unreported omissions when transferring these larger (300mb+) files. Also, running a recording to the end of a hIMD disc (using autostop) seems to produce a much greater liklihood of the recording being untransferrable. I suspect some of the problems are tied to SS's 650 mb partitioning feature. Are others encountering problems with 300+ mb files? Can I assume they will be minimized if I use a faster platform than my 66Mhz laptop 32mb and windows 98se?! Thanks
  • Create New...