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mats wrote:

Inspired in part by Romy's  results and excitement with FM, I wanted to try. Restricted by apartment living, I had difficulties achieving a quiet stereo signal. I was also concerned about the a/d conversion for digital recording. Having used the BW Broadcasting RBRX1 tuner for about 6 weeks now , I would like to share a few thoughts.  It is a complex device with many settings: "Adjustments are provided for over 50 parameters, including audio and IF bandwidths, de-emphasis, and  blending for stereo,HF and ultrasonic noise." http://www.fm-receiver.com/rbrx1.php?productarea=Manual I have been able to use it pretty much wide open, with minimal blend, and it is seemingly immune to the noise from various digital equipment that surrounds it. Right away this is a huge victory, since I had yet to achieve a quality low noise signal before. (Revox, Yamaha and Micro CPU.)  As I write this, WFMT is playing The Planets,  Sir Andrew Davis conducting the BBC Phil, and it is rather amazing. Complex passages resolved as I would expect were I using my Goldmund transport. I prefer the digital out, 24/48 is the maximum currently, and I believe that my Lavry DA-11 dac is the factor of sonic character.  It appears that the tuner responds to whatever it is being fed.  I can find no limitation from the RBRX1. The ULF  right now is just phenomenal thru my tapped horn. It is very exciting to listen to.  I can't describe any sound, except it does have some of that "FM-magic".  Of course it must be noted that I have not compared the RBRX1 to Super-Sansui's  or alike.  I will also admit that Romy's best shared samples are better than what I listened to today.  Perhaps not by that much though. Hopefully someone will be able to do a direct comparison. Meanwhile I am delighted, and have a new favorite source.

Regarding the tuner. I never had it and I do not know what to expect. David was threading me that I will get one to test but it never materialized. Perhaps you mats will be traveling to Boston and you would bring your RBRX1 in? Then we will be able to see how RBRX1 stands.

There are a few things that I am very interested. They keep talking about the adjustable bandwidth but they never published the bandwidth of the window. I have plenty of good tuners that can do from 100KHz to 650kHz. What I would be interested is to see how RBRX1 will perform again other tuner with good selectivity at the SAME IF bandwidth. It is not difficult to get a good reception by narrowing the IF window. The problem is that with narrowing intermediate frequency we truncate the side band and losing a lot of audio quality, not to saying the stereo quality. With the way how the stations are seeded in US FM dial I think the 500kH is more or less optimal IM bandwidth, at least in Boston where we have each 0.2-04Meg a deferent station.

Another thing is the quality of that digital multiplex decoder. There are no modulations in decoder any more but pure sound. How all of it DSP processing affect sound no one know. At this matter we do not even know how many bits that 48K out has. I hope it has 24 but they do not say…. I would rather to have them to run A/D not 24/192 but 32/352. They then would be able to output 88K and have highest bits that can be eaten by DSP.

Of cause it is all literature and the quality of sound altogether is something that interests me. All those “over 50 parameters” (or better to say some of them) are relevant to set the tuner in optimism receiving condition for a given signal. Then there is the actual quality of sound that tuner is potent to show.  This variable is not known to me so far. I have seen online audiophiles were trying to compare RBRX1 to different tuners and found that MR-78 was more preferable.  That is funny as I do not consider the MR-78 worth any attrition, it is not to mention that audiophiles are generally understand Sound as much as Sarah Palin understand multiplication table….

It would be also interesting to run RBRX1 into external DAC and to see if you will be able to get better result. I do not know what kind digital signal they output. Most like it is Mono right after decoder with 19kH defeated. Anyhow, you can compare it with your Lavvy and get some idea about the quality of RBRX1’s output stage.

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