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Tube Amps, Best Connections, Ripping Music

Scott Wilkinson  |  Aug 25, 2010

More Power!
How is it that tube amps only produce, say, 25 watts of power, and yet they provide enough output to drive speakers rated for hundreds of watts?

Steve Norene

It all depends on the speaker's sensitivity, which defines the sound pressure level it can produce when fed an audio signal with 1 watt of power as measured on axis at a distance of 1 meter; it is specified as decibels per watt per meter (dB/W/m). Typical home speakers have a sensitivity somewhere between 80 and 90dB/W/m or so, whereas high-sensitivity speakers can reach 105dB/W/m or more. The higher the sensitivity, the louder the speaker can play with a given amount of power. Thus, tube amps, which typically generate relatively little power as you point out, are best suited for high-sensitivity speakers.

Interestingly, high-sensitivity speakers are often capable of accepting lots of power, which seems counterintuitive, but there it is. Also, most people don't realize that the vast majority of their listening is done with only a few watts of power from the amp.

The Impossible Dream
I recently purchased a Sony EX400 HDTV (four HDMI ins), Sony BDV-E570 Blu-ray home theater in a box (one HDMI out), and Optoma HD20 projector (two HDMI ins). I have a cable TV feed without a set-top box. I would like to be able to watch TV and Blu-ray on the TV and projector. Any suggestions on how to connect them? I'd prefer all HDMI if possible.

Slavisa Zimonjic

I see no way to do what you want with the equipment you have. The BDV-E570 has no HDMI inputs—it's a closed system that outputs audio and video from Blu-ray, DVD, or CD—so you can't use that as a switcher. The TV has no HDMI outputs—in fact, it has no video outputs at all—so you can't use that as a switcher. And without a cable set-top box (STB), you can't watch cable on the projector at all.

You could do what you want if you get a cable STB and a 2-in/2-out HDMI switcher. Plug the STB and BDV-E570 HDMI outputs into the switcher's HDMI inputs, then connect the switcher's HDMI outputs to the TV and projector. I recommend getting a switcher with more than two inputs so you can add source devices later.

Like Father, Like Son
I was raised on Magnepans by an audiophile father. Now I am a new father, and I look forward to raising my son on quality audio. I can't afford Magnepans this year, but I want to start compiling a music collection for my son now. In your opinion, should I rip music to high-bitrate MP3, Ogg, or AAC file format?

Alan Howell

Congrats on new fatherhood! I'm touched that you want to raise your son on high-quality audio, in which case, I would rip music to uncompressed WAV files. Hard-disk space is very cheap these days, so that's not the issue it used to be. Once you have uncompressed files, you can then compress them in whatever format you need for any given device now and in the future—just be sure to retain a copy of the original uncompressed files to use as masters. Who knows what devices your son will have at his disposal when he grows up? If you follow my advice, you and he will be ready for anything the future holds.

If you have a home-theater question, please send it to scott.wilkinson@sorc.com.

COMMENTS
Dave's picture
Submitted by Dave (not verified) on August 26, 2010 - 1:26pm

I would sell the kid and use the funds to buy the Maggies. That way your next spawn will have Maggies to listen to.Only other alternative is cutting the wifey's shoe budget.

Corey's picture
Submitted by Corey (not verified) on August 26, 2010 - 4:25pm

Although Scott's suggestion about ripping music to WAV files is heading in the right direction, WAV files cannot be "tagged" with all the artist and song information, nor CD covers, lyrics, and other information attached.I would therefore recommend ripping the music to FLAC which is a lossless compressed audio which does allow extensive tagging.Then if you needed to send the audio to a portable music player etc, you can easily do a conversion to whatever format you like (Ogg, AAC, MP3 etc), including the tags which the player will need to "organise" the music.The ripping, encoding to FLAC, tagging, and transcoding, can all be done with one of many free piece of software available on the internet. The Hydrogenaudio forums are a good source of information on software and methods of ripping and encoding audio whilst retaining maximum quality.

Barnops's picture
Submitted by Barnops (not verified) on August 28, 2010 - 11:26am

I agree wholeheartedly with corey. Flac, or alac are two lossless audio formats that offer a bit perfect reproduction of the music at often half the size of a Wav file.

RALLEN's picture
Submitted by RALLEN (not verified) on August 28, 2010 - 5:57pm

I remeber experimenting with Windows Media Center and ripping to .WAV and it tagged the songs. I now rip with WMA Lossless, but am I missing something.I'll try again but I'm sure the .WAV files were tagged.

K. Reid's picture
Submitted by K. Reid (not verified) on August 28, 2010 - 8:41pm

Can anyone tell me where I can get more information on tube amps. I don't know much about them but would like to learn more about the basic of them before I consider a purchase. thank you

CJLA's picture
Submitted by CJLA (not verified) on August 30, 2010 - 8:55am

Slavisa, I know I'm reaching here, but any chance the Sony HTIB is new and you can return it or place it in another room? Personally, I think separates are always best, and as an example the Integra DTR-40.2 has multiple HDMI inputs AND 2 HDMI outputs that run simultaneously, so you could hook up both the projector as well as the flat panel, and maybe you have a Sony PlayStation with BluRay that you could use as well?

Kenny Kraly Jr.'s picture
Submitted by Kenny Kraly Jr. (not verified) on August 30, 2010 - 11:54am

Scott I need a little help here I have a Sony KDF rear projection tv the KDF-55E2000. Which picture settings do I use to get the most out of my tv> I use the custom mode. Any help here whould be great.

CJLA's picture
Submitted by CJLA (not verified) on August 31, 2010 - 6:36am

At K. Reid, here's a good to place to start to learn about tubes.http://www.hometheaterhifi.com/component/content/article/185.html

Scott Wilkinson's picture
Submitted by Scott Wilkinson (not verified) on August 31, 2010 - 12:43pm

Kenny, unfortunately, the best picture settings for any TV are unique to each sample, so I can't give you a definitive answer. I looked for a review of the E2000 on HomeTheatermag.com, which would have the settings we used on that particular sample, but HT did not review that model.The best basic approach is to get a setup disc like HDTV Calibration Wizard on DVD or High-Definition Benchmark on Blu-ray and set the user controls yourself. Alternatively, if you can afford it, hire an ISF or THX certified tech to do a full calibration.

Kenny Kraly Jr.'s picture
Submitted by Kenny Kraly Jr. (not verified) on August 31, 2010 - 4:17pm

Thanks Scott I allready set the tv up with the HD Basics blu-ray test disc and that worked prefectly for me I also put the tv on the warm 2 setting on the Sony RPTV. Thanks Scott and keep up the good work with the home theater geeks podcast.

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