HELP!! Going insane....

[eirikur]

Hi...
I wrote a post earlier about how my soundcard inputs are unbalanced, and my preamp only has balanced outs. Now, I solved this (I thought) by getting an external A/D box, which would accept the balanced output from the pre and turn it into SPDIF, since my soundcard also has an SPDIF input....

That SHOULD work fine, in theory... In order to get this to work properly, however, I would have to set my souncard as the slave and let the A/D box be master, to get correct clock signals.

And HERE's the problem... I can't get my soundcard to sync reliably to it.
The problem appears to lie with the soundcard (A creamware powersampler card), since I've tried to sync it with other SPDIF sources, as well as using a different cable.

Regardless of what sample rates I use, it is unable to sync properly.
Has sync, loses sync etc.. And when it is able to sync, it accepts fragments of sound that I send from the A/D converter... But I would like to record more than fragments...

Now.... anyone else had this problem with creamware boards, and figured out a way to solve this?
Alternatively, any good ideas for a "analogue" converter that would convert a balanced signal to an unbalanced signal, without affecting quality of sound?

The preamp, as mentioned, only has balanced outs, and I want to be able to "push" the pres output, otherwise I could just decrease the output volume from the pre with 14 dB, and everything would be fine...

Therefore: brilliant analog "box" that would do this "conversion" from balanced analog to unbalanced analog well?

Cheers!

 

[Jim Y]

I think you've overdone it.
My mixer has balanced out (TRS jack) and the soundcard unbalanced RCA inputs. I use ordinary mono jack-rca phono cable. There are no significant problems with this (a little hum pickup audible if I turn the monitors right up).

Most balanced gear works well enough with either mono plugs or an adapter cable. If the output is XLR, then an adapter cable can be made or purchased...
http://www.northernsound.net/Sales/cableaudio/linemiclevel.html#CONFIGURATION
... see XLR to 1/4" TS jack.

S/pdif doesn't always work. There are some esoteric settings (pre-emphasis flags for one) that could upset things, but it's more likely the output voltage of the a/d is too low for your card. Roland made a digital mic pre with a similar problem.

 

[eirikur]

Thanks for your reply.
But, unless you have some other way of adjusting the output (using aux or whatever), you either have to use less gain or adjust the output level using your faders, right? (assuming you're using direct outs)
¨
My pre is very much like a channel strip, with gain, eq and output.
The difference between balanced and unbalanced is 14 dB, right? (-10dB unbalanced, +4dB balanced)

Less gain is probably not a good idea, since less gain means a radical loss of sound quality...
In my ears, the sound of the pre is also radically different if you have to lower the output stage signal with 14dB, in order to fit the unbalanced ins.

"Less gain" would be a suitable description, I think, although that's of course not what's happening... Overall it sounds duller and "cheaper" and with much less feeling of "presence"... In my opinion, it's very much like running a race car on half throttle.. Also, you never get to use that special effect analog equipment gives you when you "push"/saturate the signal using either lots of gain or lots of volume on the output stage.

Of course, balanced is preferred primarily because it's better for long cable runs/interference etc, but it is also better since it has larger dynamic range (+4dB vs -10dB). And the worst thing you can probably do is to mix balanced and unbalanced, since you won't get to use the analog parts of the balanced gear to its fullest.... And for some musical styles, that's fine, for other genres, that saturated signal is very much desired and (IMHO) something thats extremely difficult to emulate truthfully using some sort of plugin.

And, of course, if you buy an expensive pre with balanced outs, well, you would want to use it, wouldn't you? One might discuss HOW much better balanced is etc, but the fact remains that it IS better.. that's why I want to use balanced, if I can.. and i should be able to..

I have, however, figured out what the problem is... Apparently, my motherboard and my souncard aren't the best of friends, since the card works brilliantly in another pc I have, same configuration and everything.. (Made sure that there were no IRQ conflicts and did "standard" xp tweaking for tracking) So I will have to look into either switching motherboard or soundcard....

 

[boingoman]

¨
My pre is very much like a channel strip, with gain, eq and output.
The difference between balanced and unbalanced is 14 dB, right? (-10dB unbalanced, +4dB balanced):

No. Those numbers describe the average internal operating level of gear. Consumer stereo gear(and soundcards) run at -10dbV, and is pretty much always unbalanced. Most audio gear we all use runs at +4 dbu, and can be either balanced or not. The numbers are in different scales, and the difference is closer to 10db. Still significant. Running from balanced out to balanced in gives a 6db boost over unbalanced, but there is no gain change going from balanced out to unbalanced in. If your soundcard runs at -10, you will have to turn the gain on your pre down, so you don't overload your soundcard input.

In my ears, the sound of the pre is also radically different if you have to lower the output stage signal with 14dB, in order to fit the unbalanced ins.

See above. You are probably right, +4 outputs don't get a long too well with -10 inputs. -10 inputs overload too easily.

There are boxes out there which will convert +4 outputs to -10 so you can use the gear together.

Ebtech line level shifter

"Less gain" would be a suitable description, I think, although that's of course not what's happening... Overall it sounds duller and "cheaper" and with much less feeling of "presence"... In my opinion, it's very much like running a race car on half throttle.. Also, you never get to use that special effect analog equipment gives you when you "push"/saturate the signal using either lots of gain or lots of volume on the output stage.

Again, the problem comes from the -10 input not being able to handle the +4 output, or the noise in the -10 output being raised by the +4 input.
Attenuating the output to the extreme degree needed to go from +4 to -10 will indeed affect the sound. Another issue is that if you don't hit the A/D converters with enough signal, or the converters don't have a lot of dynamic range, the lower bit depth that results will affect your sound as well.

Of course, balanced is preferred primarily because it's better for long cable runs/interference etc, but it is also better since it has larger dynamic range (+4dB vs -10dB). And the worst thing you can probably do is to mix balanced and unbalanced, since you won't get to use the analog parts of the balanced gear to its fullest

Dynamic range is seperate from operating level. Dynamic range is the difference in db between the smallest and largest signal the gear can process. Any problems come from incorrectly interfacing the different levels. The only problem with unbalanced runs is the potential for more noise, and in the case of instrument lines, loss of high freq content in very long (over 50 feet) runs from instrument to amp or direct box or POD or whatever.

And, of course, if you buy an expensive pre with balanced outs, well, you would want to use it, wouldn't you? One might discuss HOW much better balanced is etc, but the fact remains that it IS better.. that's why I want to use balanced, if I can.. and i should be able to..

Again, signal quality is unchanged whether you use balanced or not. You just have the chance to avoid some noise.

I have, however, figured out what the problem is... Apparently, my motherboard and my souncard aren't the best of friends, since the card works brilliantly in another pc I have, same configuration and everything.. (Made sure that there were no IRQ conflicts and did "standard" xp tweaking for tracking) So I will have to look into either switching motherboard or soundcard.... :confused.

I can't help with that, but you got it working! Excelllent!!!