Pulsar 1 as HTPC's audio interface?

[JRDG Fan]

Hi everyone!

Just connected my DAW to hi-end rig (Jeff Rowland Concerto int., T+A speakers) through Pulsar 1's analog RCAs. It lives! One problem - lack of low and mid bass. Amplifier's volume is 85 of 99 instead of 55 of 99 when using my Audionet CD Player (with no problems). Pulsar 1 outputs' level is too low for that or what? Any thoughts, gentlemen? Thank you in advance.

Regards, Alex.

[Fluxpod]

The rca (analog outs) on a pulsar 1 card are terrible.Noisy and undefined sound.For that kind of system you should get a high end DA converter like this one.
http://www.lavryengineering.com/productspage_da_10.html

Remember Pulsar 1 cards are becoming close to 10 years old.

[winger]

Sounds to me like an impedance mismatch. Not sure what the output impedance of the pulsar is but rca is usually a high impedance. Plug that into a low impedance input like a 600 ohm line or 150 microphone preamp or something like that and the usual results is like running it through a 6db per octave high pass filter and a week output levels.

[garyb]

the speaks inputs are likely +4 balanced. there may be a switch to -20 which would fix the level mismatch.

do you have an sp/dif input on that system?

[winger]

I did not say level mis-match, I said impedance mismatch. Check the input impedance of you +4 db input. Probably 600 ohm. I dont have the specs of the rca analog output of the pulsar, but I would guess high impedance say 10k. If the output impedance of the pulsar card is higher than 600 you will get a low end drop. The larger the impedance difference, the higher the high pass filter cutoff would be.

If I am right, you will need an impedence matching circuit like a matching transformer, direct box or line driver type of thing to match the impedance.

In general, you can connect low impedance to high with no problem but connection of high to low impedanace is a problem.

[Neutron]

pulsar 1 makes a great active crossover with phase compensation, baffle step compensation or whatever you like. much nicer sound and more versatile than that popular behringer crossover thing.

put it with a decent ADAT converter and it makes a really nice system. and 16 outputs to use as you please. even 5x tri amped speakers + sub for Home theater overkill.

just dont use any pc(long) delays or reverbs if you dont want the evil stuttering of death.. as if you would for audio reproduction.

[JRDG Fan]

The rca (analog outs) on a pulsar 1 card are terrible.Noisy and undefined sound.For that kind of system you should get a high end DA converter like this one.
http://www.lavryengineering.com/productspage_da_10.html

Remember Pulsar 1 cards are becoming close to 10 years old.

I think that you are right, I already heard some bad things about Pulsar's analog RCA outs here and there. Just thought about something like this http://www.stereophile.com/cdplayers/10 ... ndex1.html or german Accustic Arts Tube DAC. Meaning the "age" criteria I will possibly move to some current Sonic Core internal solution (Classic or Plus).

Sounds to me like an impedance mismatch.

My tech told me the same thing today. Thanks for confirmation, Mark!

do you have an sp/dif input on that system?

No, I don't by now. But I think that I'm coming to it so very close

pulsar 1 makes a great active crossover with phase compensation, baffle step compensation or whatever you like. much nicer sound and more versatile than that popular behringer crossover thing.

put it with a decent ADAT converter and it makes a really nice system. and 16 outputs to use as you please. even 5x tri amped speakers + sub for Home theater overkill.

just dont use any pc(long) delays or reverbs if you dont want the evil stuttering of death.. as if you would for audio reproduction.

Gosh! It seems to be too complicated for my poor brains! But I thank you, Neutron! You are great!

Summing up. Will some digital connection (S/PDIF or AES/EBU) save the day, gentlemen?

[garyb]

sure, with a highend da...

[Fluxpod]

If you move to a Pulsar 2,the analog outs are way way better than on a Pulsar1.
If you decide on a outboard stereo da converter..the lavry black da 10 is the real deal.

[astroman]

... I dont have the specs of the rca analog output of the pulsar, but I would guess high impedance say 10k. ...

no, it's a 5532 driver at 300 Ohm, nominal level -10dBV, max level +2dBV

...In general, you can connect low impedance to high with no problem but connection of high to low impedanace is a problem.

in this case if the stage following the Pulsar had a (significantly) less than 300 Ohm input impedance, right ?
btw I also noticed a (fairly) muddy sound from my Pulsar One recently - in particular through an (admittedly aged) NAD Preamp, but not as much with the Boss RC50 Loopstation.
But then I suspect the whole thing doesn't work properly on a Core Duo board. No errors or crashes, but sounds like sh*t frequently.
I'll put it back on it's ols ASUS PIII companion soon and report the result - if nothing changes I'll probably have to sack the board... what a drag...

cheers, Tom

[winger]

Just because the output stage is a 5532 does not mean the impedance is 300 ohm. Not sure about the 5532 but most opamps have an impedance of 100 ohms are less. However, there is coupling capacitor use on the output. If the deistination impedance is say 10k you can put a small cap for the coupling cap and it will work great. But connect it to a 600 ohm input it will sound awful.

Need to see the schematic.

[astroman]

not at all... the specs are printed on page 106 in my Pulsar manual
I mentioned the 5532 only if someone wanted to compare to a more recent io-plate
probably the output stage is identical, though - even the Pulsar One had a 24-bit output converter

cheers, Tom