I can't wrap my head around this...


A very peculiar thing just happened to me. Back story - I have been rearranging my components the past few days, and ended up unplugging everything, and putting back together to help sort out my "rat’s nest" behind my rack. Once everything was up and running again, I tested each component to make sure they were sounding good.

Everything was working properly, until I noticed faint distortion from my speakers while using my turntable (in between records). After hours on seeing if the ground wire was connected, switching out ICS, isolating PCS, checking the forums, almost posting on here about the problem, and finally deciding to buy new ICS, I went to bed instead

This morning, with a fresh head (thanks coffee), this is what I noticed & I feel a little dumb about it.

Associated Gear: VPI Traveler, PS Audio NuWave Phono Converter, Parasound Halo Integrated

I had the OUTs on the Traveler connected to the OUTs on the PS Phono Converter, and the Phono INPUTS on the PS Audio were used as OUTPUTS to the Parasound. I was still playing records though, with a little bit extra distortion, but I’m not sure how sound was still being produced....and also sounding quite good. I’m not sure how long I have had the IC connected incorrectly, if it was before or after I unplugged everything.

Just thought I would share that, in perhaps someone may have an explanation... Was there an extra conversion in the Phono Converter???? Did it reverse it’s function because it realized the user error??

Very curious to see how playback was still functioning..

Everything has been adjusted to the proper setup now, the distortion is completely gone. For the record.
robelvick
@ robelvick
You should mark the cables. You should use a product like this to avoid any future mishaps !


https://www.cableorganizer.com/wire-marker/rite-and-wrap.html
@yogiboy, Thanks for sharing.  I am going to be fixing my 'rat nest' in next couple of weeks and this will come in handy. 
@yogiboy  that's a good idea.

Still trying to figure out how my phono stage still played music though.. 

I just reconnected the rcas the "wrong" way again, still plays...

Are inputs and outputs interchangeable sometimes?

 
@robelvick
The inputs and outputs are not interchangeable. I’m baffled why it works when you hook it up that way! Maybe someone with more expertise than me could answer your question!  
Yes, that’s certainly strange. It seems possible that there could be some degree of "crosstalk" (coupling of signals) between the RCA analog inputs and outputs, especially given that the corresponding connectors are right next to each other. What seems inexplicable, though, is that the sound would still be reasonably good, as you’ve indicated.

Is the volume level approximately the same when the connections are interchanged, for a given setting of the volume control? Also, are you using a high output or low output cartridge? Your system description lists both types. And what do you have the cartridge loading set to in the NuWave?

Regards,
-- Al

@almarg 

Volume level is the same.  Right now I'm using an Ortofon Kontrapunkt B LOMC.  Loading is set at 160.
The hum/distortion is also back, even though everything is connected as it should be. I have to put my ear close to the speakers to hear it, but it’s quite noticeable when the volume increases. This is when not playing a record.

Only with the input for phono stage as well. My TT and phono stage are not connected with a ground wire, as when I do this I get a loud hum.

Using AQ black mamb ICS. Tried switching to AQ golden gate, and Pangea premier. No luck fixing problem between the three. I believe all three are shielded, but perhaps that’s not the issue...

Also tried using XLR as the output, but same issue

any suggestions?
I'm no expert but your "condition" may occur if your circuits are not "buffered". I think buffering is done by inserting diodes into the signal path so the signal can go one way but not the other. An example: You have two active sources, both playing music, and you can hear both of them at the same time. This happened to me long ago but can't remember the precise circumstances. Hope I haven't added confusion.
Well, after carefully reviewing the NuWave's manual, description, and specifications, and a review in Audiophilia, and after searching in vain for a datasheet on the "THAT 1532 programmable input stage" that is described as being used for the phono input, I have no idea how to explain these findings.  But it certainly seems that something is unusual about the design of the NuWave's phono section, and perhaps a communication with PS Audio is in order.

Regards,
-- Al
 
I had the OUTs on the Traveler connected to the OUTs on the PS Phono Converter, and the Phono INPUTS on the PS Audio were used as OUTPUTS to the Parasound. I was still playing records though, with a little bit extra distortion, but I’m not sure how sound was still being produced....and also sounding quite good.
WOW!!! Fuse directional and a phono stage not!
I learn something new everyday
From PS Audio tech support:

"

Good morning Robert,

This is very odd, and I struggle to think is possible.

The mosfets on the phono input shouldn’t allow a signal to pass through.

The only thing I can think is possible here is if there is some kind of feedback carrying through the circuitry.

I hope everything is sounding better with it connected properly.

Bes

t, "


I’m wondering if this is the cause for slight distortion. In the meantime I’ve ordered a pair of AudioArt IC-3se RCAs with the Xhadow Precision connection, w/ 72 hour burn in (wanted to try these for a while, now have an excuse). BTW, Rob at AudioArt is awesome. Exceeds his reputation.

Will update on Friday when they arrive.

Are you sure that you didn't plug the phono into the "analog input" which is designed for line level sources such as tape decks, tuners etc.
If you had done this then you would get a lower level distorted music signal running into the integrated amp. This would explain your results.

@dover 

You may be on to something, but I was definitely using the phono inputs as outputs to my integrated, so no actual outputs on the phono stage were being used.  I set it up the wrong way again, just to double check, and sure enough it still plays. 

Right now I'm just trying to figure out why I'm still getting distortion with everything set up properly.
@robelvick

Why are you running the PS Audio? Doesn’t the Parasound have its own MM/LOMC phono section?

If you are using the Parasound’s phono input, and the PS Audio is driving that, you might have enough gain for the Parasound to equalize the phono signal. I would expect some distortion though.

Have you tried bypassing the PS Audio entirely?
@atmasphere 

I use the PS Audio to rip records to my computer.  It also  will convert the analog signal to digital and can be sent to a DAC, which sounds amazing when I go this route to my Wyred4Sound.  

But, I still use it as a straight phono stage most of the time, and it sounds considerably better than the Parasound's phono section, although the Parasound is pretty good in it's own right.

I have had the PS Audio connected to the Parasound's balanced XLR inputs, and all of the other 5 analog inputs via RCA.

Same issue with distortion.  I've also tried switching our various carts to see if one was the cause.  Not the case.

I'm thinking it's a problem with the PS Audio now.  I've been in contact with them the past few days, as well as VPI's tech support to figure it out.
@robelvickVPI is off the hook on this one.

I agree, the PS Audio is the issue. Does it still sound better than the Parasound? I suspect that if really is doing what you say, the answer is no.