[Russ White]

LOL, doh, yes. I just was not sure if his Opus still had them in place or not.

 

[fran]

I think the guy mentioned something about upgrading the output caps to blackgates, so I reckon there should be something there.

Thanks for the help

Fran

 

[fran]

Thanks Russ for the help. The module arrived today and I have it connected up and running AOK. Took a little figuring out on the dip switches to get sounds, but after a little scouting on the support forum I got the answers and now she sings!

I have it USB module>>I2S>>opus and then the SE outputs to a aikido amp. Bass is very deep without being over blown. I'm impressed, I thought there would be a bigger penalty to pay for running it off the USB PS, but while I do have some noise in the background, sonics are very good. Its really handy to not have to plug it in - makes it very portable.

I was watching for the DC offset. When I first powered it up the offset was big (>200mV) but very quickly ran down to nothing. That was without any load. Once warmed up the offset was zero. As it will be plugged into the USB port all the time, it won't matter.

Thaks guys for the advice.

Fran

 

[manaox2]

Quote:

Originally Posted by fran /img/forum/go_quote.gif I have it USB module>>I2S>>opus and then the SE outputs to a aikido amp. Bass is very deep without being over blown. I'm impressed, I thought there would be a bigger penalty to pay for running it off the USB PS, but while I do have some noise in the background, sonics are very good. Its really handy to not have to plug it in - makes it very portable.

Opus and aikido sounds pretty sweet.

 

[slowpogo]

I'm considering the Opus as my external DAC, to be run from my Juli@'s SPDIF. Did some searches in this thread but there's too much to wade through.

A few questions...the Opus offers balanced stereo output. Do I need to configure it differently, or get the IVY stage to use unbalanced equipment with it (my Millett Max)?

My Juli@ has balanced outs, but I just plug in my Max and it works fine. I'm hoping the Opus is the same way.

And, the kits offered on Twisted Pear include the Opus, in my case the S/PDIF receiver, and a dual power supply. Does the power supply run both items, the DAC and receiver? I had thought all I would need apart from this package was an enclosure, but I wanted to check.

 

[Beefy]

Its been a long time since I read about Opus, so all of this is from memory...... take with a grain of salt!

Quote:

Originally Posted by slowpogo /img/forum/go_quote.gif A few questions...the Opus offers balanced stereo output. Do I need to configure it differently, or get the IVY stage to use unbalanced equipment with it (my Millett Max)?

You will need IVY or Ballsie for single ended outputs. IVY may be better because you can then remove/jumper the output coupling caps on the Opus.

Quote:

And, the kits offered on Twisted Pear include the Opus, in my case the S/PDIF receiver, and a dual power supply. Does the power supply run both items, the DAC and receiver? I had thought all I would need apart from this package was an enclosure, but I wanted to check.

You realistically need the Opus/Receiver/LCDPS combo plus a IVY(or Ballsie)/LCBPS combo. Five modules in total, plus two separate transformers.

LCDPS powers both Opus and receiver, LCBPS powers IVY or Ballsie.

 

[rodentmacbeastie]

OK, I own a Julia too and if you have single ended inputs on your headamp and balanced output configuration on the Juli@ you are only getting half the signal. The proper way would be to switch the outputs to SE on the Juli@ so you could get a properly summed SE channel. This will have nothing to do with the DAC though as you will use S/PDIF when it arrives.

Another option will save some money and likely make it sound better is to mod the Juli@ to get I2S direct to the DAC. If you are only using it at your computer, you would not need the digital receiver board and you would get a bonus in performance! However, if you want to move the DAC more that a foot from the computer this will not work as well. I don't know how stong the I2S signal is from the Juli@ and it may need a buffer to go longer distances. The guys at Twisted Pear have their I2S/DSD leads 4 or 5 feet long and are pleased. Think shorter is better. As for the mod to the Julia, you attach three wires to the large pins, it is as easy as that.

If you want to hook up another source you will need the receiver board anyway but you could still bypass it for the Juli@. This would avoid the whole conversion to S/PDIF and then back to I2S. For this all you would need is an OTTO switch for th I2S from the Juli@ and the I2S from the reciever board. Best of both worlds.

 

[glt]

The OPUS can be used single-ended or balanced. The IVY/Balsie is optional and it is used to remove the DC and some harmonic filtering. One single PS will power the receiver, the DAC and even other components such as the Toslink and Metronome. If you can get I2S out of the Juli@, then you won't even need the receiver, and feed I2S directly into the DAC.

 

[slowpogo]

Quote:

Originally Posted by glt /img/forum/go_quote.gif The OPUS can be used single-ended or balanced. The IVY/Balsie is optional and it is used to remove the DC and some harmonic filtering. One single PS will power the receiver, the DAC and even other components such as the Toslink and Metronome. If you can get I2S out of the Juli@, then you won't even need the receiver, and feed I2S directly into the DAC.

OK, so I assume in order to use the Opus as single-ended, you need to use different jumper switch settings or something like that? Is there any more specific or detailed documentation available on using it single-ended?

I only plan on using this with my computer...it would sit right on top of the case, so the I2S wires could be short. Maybe a little more than a foot, but short. Would there be a problem with terminating these wires with an XLR plug, and using XLR input to the DAC?

So sounds like if I went the I2S route, I'd only really need the Opus module, the low current dual power supply, and transformer? (plus enclosure stuff)

 

[slowpogo]

Quote:

Originally Posted by rodentmacbeastie /img/forum/go_quote.gif OK, I own a Julia too and if you have single ended inputs on your headamp and balanced output configuration on the Juli@ you are only getting half the signal. The proper way would be to switch the outputs to SE on the Juli@ so you could get a properly summed SE channel.

I've gotten conflicting information about this. I have used my Max with the Echo Mia, 1212m and Juli@ - all balanced outputs, and all of them sounded great, not weird at all. I also tried the Juli@ with the single-ended RCA outs, and it sounded almost exactly the same to me, just quieter (-10db nominal).

So some people say it's fine to do that, others say it's not. I'm confused..

 

[glt]

Quote:

Originally Posted by slowpogo /img/forum/go_quote.gif OK, so I assume in order to use the Opus as single-ended, you need to use different jumper switch settings or something like that? Is there any more specific or detailed documentation available on using it single-ended? I only plan on using this with my computer...it would sit right on top of the case, so the I2S wires could be short. Maybe a little more than a foot, but short. Would there be a problem with terminating these wires with an XLR plug, and using XLR input to the DAC? So sounds like if I went the I2S route, I'd only really need the Opus module, the low current dual power supply, and transformer? (plus enclosure stuff)

No settings. Just use the +output. Some people would put a high value resistor between the - output and gnd, but I think that is also optional. If you use it single-ended, the level is (I think) 6 db lower. Another function of the Balsie is to boost 6db on single ended output.

 

[rds]

It seems we could run the LCDPS from a wall transformer like this one:
553-WAU12-500
Does that sound right?

 

[slowpogo]

The Opus needs 7.5v for both digital and analog sections..so wouldn't you need at least a 15v transformer? That one is 12v.

 

[Beefy]

Quote:

Originally Posted by slowpogo /img/forum/go_quote.gif The Opus needs 7.5v for both digital and analog sections..so wouldn't you need at least a 15v transformer? That one is 12v.

No, 12V will be fine. 15V runs very hot on the regulators.

Now that my memory is refreshed, I remember that you can run a single Opus straight to unbalanced out, but you lose output voltage. But if it were me, I'd still run an IVY, and subsequently bypass the output caps......

 

[rds]

Thanks.
It seems that the 12V will also run quite hot since we're regulating from about 17V to 7V. If anyone can recommend a good 9V or 6V replacement that would be great. It's too bad those are hard to find.
It seems this guy might do the trick: http://search.digikey.com/scripts/Dk...name=MT7117-ND , but maybe 125mA is a little low.

Quote:

But if it were me, I'd still run an IVY, and subsequently bypass the output caps......

Yeah... I know. My idea here is to make the DAC as inexpensive as possible while not sacrificing too much. Also I want to have a switch that allows me to run it from usb power when necessary, and have it in a small case.

It's not for me. I'm going for the Buffalo since I have a little extra money.
I'll be very interested to see how the two compare.