PlanetZ forums - scopeusers.com

Hi there,

I have:

- 1 Pulsar II
- 1 A16Ultra
- 4 optical cables

Wiring them altogether, I want to get an audio signal in from a cd player, into the A16, into the Pulsar ADAT A, in SCOPE 4.0, out of the Pulsar ADAT A, in to the A16 and out the A16's analog output into a Mackie Big Knob. I wired everything up, flipped the A16 inputs to -10db 'cos the CD player has RCA outputs and hey presto, lots of crackly nastiness.

I fiddled with the A16 to get it to synch to the incoming ADAT (I think?!) and the crackling is gone, but it still doesn't sound right, almost like there's some distortion going on somewhere. Plugging the CD player straight into the back of the Mackie Big Knob gives a much better sound quality.

How can I find out what's going on here and fix it?

cheers,

Chris

Are the RCA outs phono unbalanced or SPDIF out?
Clicks sound digital to me,so I guess that A16 has to slave to cd.

Hope that helps

No, no, the CD player is just a normal boring old KAM twin deck from about 1994

The RCA's are analog, -10dB.

Think about it... the A16 only has analog jacks or ADAT lightpipe into it, if I connected an SPDIF out to one of the Analog Jack inputs, I'd get a lot worse than crackling

So, anyone else got any ideas?

On 2005-04-19 19:25, cjw1378 wrote:
Hi there,

I have:

- 1 Pulsar II
- 1 A16Ultra
- 4 optical cables

Wiring them altogether, I want to get an audio signal in from a cd player, into the A16, into the Pulsar ADAT A, in SCOPE 4.0, out of the Pulsar ADAT A, in to the A16 and out the A16's analog output into a Mackie Big Knob. I wired everything up, flipped the A16 inputs to -10db 'cos the CD player has RCA outputs and hey presto, lots of crackly nastiness.

I fiddled with the A16 to get it to synch to the incoming ADAT (I think?!) and the crackling is gone, but it still doesn't sound right, almost like there's some distortion going on somewhere. Plugging the CD player straight into the back of the Mackie Big Knob gives a much better sound quality.

How can I find out what's going on here and fix it?

cheers,

Chris

For syncing A16U to Pulsar 2 with your setup you would either have to set Pusar 2 as master and A16U as slave, or the other way around.

You can set master/slave and source for P2 under SFP:Set->Samplerate.
The A16U you either set to "master", or "adat" (if as slave), with the front sync-switch.
Make sure you do this correctly. If you are oout of sync you will hear this as repetitive glitches in your audio-stream.

Anyway, am I understanding you right when you say you want the signal to go like this?

CD player -> A16U -> SFP -> A16U -> Big Knob

Set all the dip-switches on the A16U to up (+4) except dip no. 1 (A in) which should be down (-10).
Output 1-16 and input 9-16 will now be operating at +4 nominal level/balanced, except input 1-8 which will be operating at -10 nominal level/unbalanced.

You should now be able to hook your CD player up to two of the eight inputs on strip A. I take it you use RCA->jack plugs for this.

To send from SFP to Big Knob, hook two TRS jacks to any of the 16 outputs, lets say output 1-2 on strip A, and then to any _balanced_ input on the Big Knob.

Route correclty in SFP.

Now, if you have set Pulsar 2 and A16U up correctly you should be able to process your input in SFP without distortion.

IF you do hear distortion, try lowering he output volume of the CD player, if possible.

If this has no effect, try hooking up some other equipment to the A16U to see whether this is not specific to your CD player.

Still no help? Check latency setings under SFP:Set->Settings->ULLI.

also check the pots in the back of the big knob

Well, bizarrely, I tried again the following day. Looks like it "just works".

Still, it has made me realise the A16Ultra has a bit of a flaw in that there's no analog trims on the way in, so if you have a "loud" device tha tdoesn't have a trim itself, you're kidna stuffed and have to go and put some kind of mixer in front of it. Exactly what I was hoping to avoid

the a16 is a +4 device...if you are overdriving that, it's an EXTREMELY hot signal.

Yeah, but I'm thinking of more like a "-9dB signal" - ie: too hot for the -10 setting, so you end up having to use the +4 setting, and ending up with a half strength signal :-S

hmmm,
my tangos don't have any gain pot either. most ad/das don't unless they also have mic pres. it's a problem, i guess, though it hasn't affected me yet.