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NewBuyer
2007-06-29, 21:32
I see on the website description, that both the XLR and the RCA outputs on the Transporter can be used at the same time (which would be great for driving a separate powered subwoofer). But if this configuration was used, would you then lose the noise-rejection and ground-loop cancelling benefit of the balanced-outs? For example, electrically speaking, are the XLR signal lines, and the RCA signal lines, completely separated from each other within the Transporter?

haunyack
2007-06-30, 06:37
I see on the website description, that both the XLR and the RCA outputs on the Transporter can be used at the same time (which would be great for driving a separate powered subwoofer). But if this configuration was used, would you then lose the noise-rejection and ground-loop cancelling benefit of the balanced-outs? For example, electrically speaking, are the XLR signal lines, and the RCA signal lines, completely separated from each other within the Transporter?

My configuration includes using the Transporter unbalanced RCA out to my powered subwoofer along with the XLR out to my (2 channel) power amp.

Works fine ... no ground loop problem.
Transporter...it's a beautiful thing.

.

NewBuyer
2007-07-13, 16:16
Contacted SlimDevices directly, who told me that when using both balanced and unbalanced connections at the same time, the balanced output becomes unbalanced. Reason given, is that the RCA and XLR outputs are not isolated electrically within the Transporter.

Just wanted to share this, in case anyone else was wondering about this too.

haunyack
2007-07-13, 17:17
Contacted SlimDevices directly, who told me that when using both balanced and unbalanced connections at the same time, the balanced output becomes unbalanced. Reason given, is that the RCA and XLR outputs are not isolated electrically within the Transporter.

Just wanted to share this, in case anyone else was wondering about this too.

Thanks for sharing.
Interesting.

.

seanadams
2007-07-13, 17:29
Contacted SlimDevices directly, who told me that when using both balanced and unbalanced connections at the same time, the balanced output becomes unbalanced. Reason given, is that the RCA and XLR outputs are not isolated electrically within the Transporter.

Just wanted to share this, in case anyone else was wondering about this too.

That is completely wrong! They are separately driven and you absolutely can use both at the same time. I'll make sure the guys know.

haunyack
2007-07-13, 17:46
That is completely wrong! They are separately driven and you absolutely can use both at the same time. I'll make sure the guys know.


Thanks for that Sean.
My setup - Transporter
xlr out to amp
rca out to powered sub

S'ok?

.

seanadams
2007-07-13, 17:48
Thanks for that Sean.
My setup - Transporter
xlr out to amp
rca out to powered sub

S'ok?

.

yep


(the message you have entered is too short)

haunyack
2007-07-13, 17:50
S'wonderful!

.

NewBuyer
2007-07-13, 20:14
S'wonderful!

.

Agreed! Thanks Sean. This is great news to me, it means the transporter would fit and work perfectly in my system.

So just to clarify please: Within the Transporter, the output RCA signal lines, are electrically isolated from the output XLR signal lines?

seanadams
2007-07-13, 22:21
Agreed! Thanks Sean. This is great news to me, it means the transporter would fit and work perfectly in my system.

So just to clarify please: Within the Transporter, the output RCA signal lines, are electrically isolated from the output XLR signal lines?

I'm not sure exactly what you're asking there. Yes, they are separate insofar as each is driven by different op amp. Their shields of course go to the same ground.

NewBuyer
2007-07-13, 23:16
I'm not sure exactly what you're asking there. Yes, they are separate insofar as each is driven by different op amp. Their shields of course go to the same ground.

Sorry to ask and pursue such a geeky question!

I just mean that, within the Transporter: Is the RCA neg/shield line, electrically isolated from XLR pins #2 and #3 ?

(so any ground loop current riding on the RCA shield lines, cannot jump onto either of the two balanced XLR pin#2/#3 signal lines, but would instead be forced to ride through the XLR pin #1 shield lines).

seanadams
2007-07-13, 23:56
Sorry to ask and pursue such a geeky question!

I just mean that, within the Transporter: Is the RCA neg/shield line, electrically isolated from XLR pins #2 and #3 ?

(so any ground loop current riding on the RCA shield lines, cannot jump onto either of the two balanced XLR pin#2/#3 signal lines, but would instead be forced to ride through the XLR pin #1 shield lines).


That's right. The XLRs are proper differential, balanced outputs. The block diagram for each channel is:



- o----|\-+------|100R|----o XLR p2
|/ |
|
+ o----|\-|-+----|100R|----o XLR p3
|/ | |
| |
| | --o XLR p1
| | _|_
| | -
| |
| |
| |---|\----|100R|---o RCA center
|-----|/
--o RCA sleeve
_|_
-

NewBuyer
2007-07-14, 01:50
Thank you very much for your help and info Sean.

At every turn, the engineering and functionality of the Transporter describe as perfect an audiophile component as anything I've ever seen - a perfect fit in my system.

Well, with one (very minor) exception: I greatly wish the internal attenuation jumpers affected the balanced outputs too. Then it would be a truly perfect fit for me. Do you think such a feature, might be available in any future Transporter versions?

NewBuyer
2007-07-17, 00:41
About my last question, about whether the internal attenuation jumpers could affect the XLR outputs in a future Transporter version:

It would really help me to get some feedback to it please.

- If the answer is no, I will likely buy a Transporter right now.

- If the answer is yes, I will wait for the revision.

- If the answer is "can't say", then at least I got an answer :)

Regardless, thanks very much for the help so far.

NewBuyer
2007-07-18, 23:08
I guess Sean is now ignoring my question. I was getting spoiled by the attention. :)

Well thanks for the help in this thread so far though Sean (and other threads too), I do appreciate it.

The Transporter may well be my next audio purchase.

NewBuyer
2007-12-20, 02:40
Just wanted to update this thread with some great news (for me):

I've just had a chance to borrow and audition a Transporter in my system.

The unattenuated signal level from the balanced outputs is the *perfect* level needed by my downstream equipment. No need for internal attenuation jumpers after all - the Transporter is exactly right for my system, just as it is! All other balanced-output DACs I've tried have produced too hot of a signal from the balanced outs during musical transients - hot enough for instance to cause clipping from a downstream balanced processor. But not the Transporter - it is "right on the money".

Do I even have to mention that it also sounds, well, FANTASTIC?

Guess what my wife and I, are getting ourselves this year for Christmas! :)

(Thank you Sean and everyone at SD/L!!!)