Unbalanced to Balanced Converter Build?

[bob p]

instead of wearing a HALO, you could just use a pair of headphones.

[bob p]

Darn it Enzo -- now you've convinced me to hijack my own thread.

And frankly, I don't recall ever in my life just sitting there actively "listening" to the music, unless i was trying to pick out the lyrics. My listening was always an adjunct to relaxing. No sitting in perfect posture with my head in the "sweet spot." No listening room for me either.

I like to think of recorded music as being the background to a more important event -- sort of like the soundtrack to my life -- rather than having recorded music be so important that it demands the focus of my attention. My time is more important to me than its ever been, and I'm trying to accomplish more now than ever before, so I just don't have the time to do what audiophiles call "critical listening". I hate to say it, but for me 99.99% of the time music is a background event while I'm giving my attention to accomplishing something that's a lot more important and requires the majority of my attention. I just can't afford the production downtime that goes with "critical listening". But I have to admit, when I do get a chance to sit down for a while in a "properly" designed room, i find it to be a very enjoyable experience that doesn't last very long. I just can't let my brain stand still and i get bored and want to start doing something else. there's too much workaholic in me, i guess.

To the audiophiles, my objection to the whole straight from CD to speaker thing is the false notion that that somehow would sound "just like real life." They never watched recordings being made, never watched the recording engineer adding a little this, correcting a little that, compressing some of this, and adding a little pitch tweak here, and panned delay there. Sorry, but it won;t sound like the real thing, it will sound like what the engineer wanted to hear.

I'm in 100% agreement when it comes to pop music. Every popular recording, whether it be rock, pop, jazz or whatever, has had its signal molested in ways that audiophiles might find horriffic. But i'm not sure that's the case with symphonic music. I think that when it comes to symphonic recordings, chamber music, etc., there's a lot less manipulation that goes on. that is to say, that George Martin stuff is all over the pop recordings, but I don't think its so prevalent in the classical recordings. There I think they are a lot more rigid and "pure" in their approach, where Mic placement is standardized and the interventions are limited to necessary evils, like limiting and EQ.

its never made sense to me that the HiFii nuts fuss so much about cables and interconnects, when the recordings were all made with plain old studio-grade Belden cables. and cable capacitance? who worries about that? most microphones might have had 100 feet of cable between them and the mixing panel.

the comment about engineers and panning reminds me of an experience that I once had at a high end audio store. this was a long time ago, back when the huge Acoustat 2+2 electrostatic panels were in production. It had to be n the 80s. I was listening to a Shostakovich symphony on those large electrostatic panels and i thought the sound was marvelous. then some guy walked in like he owned the place and burst my balloon when he started carping about how the speakers weren't aligned properly and the imaging was just awful. he complained that the store's owner was a friend of his but he didn't know how to set up the speakers to properly focus of the music. he complained that the focus was crossed, so that it sounded like some of the people in the orchestra weren't sitting where they were supposed to be.

so he spent a minute re-aligning the panels and then he stood in the sweet spot. he made several iterations in re-aligning the speakers by a miniscule amount, and then he pronounced the setup as being properly aligned and commented about how the violias and cellos were now in their proper locations on the stage, yada, yada, yada...

i thought this guy was nuts. when he left the owner of the store told me that he was John Nelson. he was the conductor of the Indianapolis Symphony Orchestra at the time. he's one guy who really knows what music is supposed to sound like when you're standing in the sweet spot.

[bob p]

Enzo, back to that 6dB business -- we were only considering the 6dB loss that you have with balanced vs. unbalanced signals. if you also consider that consumer grade audio is referenced to -10 dBv and pro audio gear is referenced to +4 dBu, it looks like there's about 12dB difference in signal level. that can be huge.

AFAICT the blurry schematic that I have says that the amp requires a balanced input of either 1.67 or 1.87 VRMS for the amp to make its rated 100W output power. i don't know whether or not a consumer grade unbalanced preamp that puts out about 300 mV will have enough reach to bring the amp up to its full rated output or not. if not, i may have go with an active electronics.

[Enzo]

And that conductor always listens from the ONE place in the house that NO ONE else can ever listen from, so he might notice the soundstaging was off, but how would anyone else know? It would be like you and I discussing what it would be like to sit in the driver seat of the space shuttle. (Which has a bitchin' sound system, I hear...)

yes, the symphophiles - how's THAT - like to say they are getting the thing exactly so, but does it sound EXACTLY like the symphony at the Hollywood Bowl, or at Carnegie Hall, or perhaps like at the Kennedy Center?

Which thing exactly are you installing? The head rest or the dummy?

[bob p]

i've already got the dummy.

[tedmich]

Bob, you have checked out Rod Elliott's site right? Very useful stuff on bal/unbal, I especially like the cheater circuit in fig 4

Balanced Transmitter and Receiver II