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  »  New  A littlie D-War: Bidat vs. Lavry Gold..  RE: the "New" DAC...  Didital Things  Forum     13  132973  12-18-2005
  »  New  Sansui TU-X1 Broadcast monitor...  Replace all audio coupling......  Off Air Audio Forum     46  316576  06-20-2007
  »  New  Recording options: Pacific Microsonics vs. Lavry Gold...  Pacific Microsonics vs. Lavry Gold in D/A mode....  Didital Things  Forum     24  179660  09-27-2007
  »  New  The Lavry Gold DA924 ++..  A new Lavry Gold?...  Didital Things  Forum     25  195678  03-28-2008
  »  New  Rohde & Schwarz EU-6201 Tuner..  The Schwarz runs from crystal oscillator!...  Off Air Audio Forum     34  242220  05-07-2008
  »  New  DC offset for A/D converters...  DC offset for A/D converters....  Didital Things  Forum     0  12048  03-13-2009
07-20-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,511
Joined on 05-28-2004

Post #: 1
Post ID: 7851
Reply to: 7851
Tuners and digital noise from DAW, A/D and D/A
Well, I have to admit that the stupendous sensitivity that Sansui TU-1X have after the Stereo Surgeons tune up to use the TU-1X is kind of complicated. With 0.8mkV this tuner picks the noise that my DACs radiate. I staffed all wholes of the Sansui’s with ferrite – it helps but still I need to shot down all digital in home to get good noise-free recording. Larry 924 is the worst. When this DAC is on it is Finita la comedia for good reception. With antenna is off and a piggy tail running near the Lavry’s DAC I can tune the tuner to the harmonics of the Lavry clocks (99.9Meg) and actually listen it via the speakers. Lavry A/D gold is better but still has some nose at lover frequencies (88-96Meg). The Pacific is the best, though not silent and it does have some HF noise injection. That is all with Sansui TU-1X, with Rohde & Schwarz EU-6201 is it very different story – this tuner is practically immune to nastiness of digital noise from DACs. Even when the Larry DA924 is on and is tossing the UHF with a force of an atom bomb’s electro-magnetic impulse the Schwarz’s shielding actually handles it. Well, I would like to have TU-1X to act in the same way, I do not know at this point how...

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-21-2008 Post does not mapped to Knowledge Tree
Antonio J.
Madrid, Spain
Posts 272
Joined on 08-16-2004

Post #: 2
Post ID: 7853
Reply to: 7851
I was concerned you hadn't commented on this before
So I thought my tuner weren't properly adjusted. It has not been serviced nor recently aligned, I have no proficient technicians around who I depend to let them put their hands into the tuner. The damn thing always picked up Bidat's and CEC's noise. In my case the most noisy of the two is the CEC transport and only can get rid of the noise by switching off both devices. When the Bidat doesn't detect a potential input, like when switching off the CEC, then the noise gets worse. In my case not ferrite nor ERS sheets have been helpful at all. Only placing the digital parts very away (more than 1m) from the tuner is a bit helpful.

Rgrds
07-21-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,138
Joined on 10-12-2006

Post #: 3
Post ID: 7854
Reply to: 7851
Digital noise psychosis
I have for some time unplugged digital gear that is not in use, and it's no happenstance that my DAC is tweaked to operate "off the grid".  Distancing the stuff is good, as noted, and it can also help to use a different circuit and/or ground for the digital stuff.  More annoying is that the digi stuff can interfere each with the other, leaving one to ponder separate circuits/grounds/locations for each digi piece.

Best regards,
Paul S
07-21-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,511
Joined on 05-28-2004

Post #: 4
Post ID: 7856
Reply to: 7853
Ferrite, ferrite , ferrite , ferrite ...
 Antonio J. wrote:
So I thought my tuner weren't properly adjusted. It has not been serviced nor recently aligned, I have no proficient technicians around who I depend to let them put their hands into the tuner. The damn thing always picked up Bidat's and CEC's noise. In my case the most noisy of the two is the CEC transport and only can get rid of the noise by switching off both devices. When the Bidat doesn't detect a potential input, like when switching off the CEC, then the noise gets worse. In my case not ferrite nor ERS sheets have been helpful at all. Only placing the digital parts very away (more than 1m) from the tuner is a bit helpful.
Hm, this is interesting. I my case nether neither CEC nor Bidat affect other of the tuners. Lavrys do but not Bidat. Try to put ferrite on ALL Sansui inputs: antenna, power cord, output cables. I have 3 bids on each leg of power cord, 4 bids on combined power wires, one bid on each combined analog output and 12 bids on the combined antenna cable on the cable between the input jack and the entrance to front end.

FerriteOnTuner.jpg

My TU-1X do not acknowledge Bidat at all, ether the DAC is it locked of not.

The caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-21-2008 Post does not mapped to Knowledge Tree
peter foster
Australia
Posts 40
Joined on 02-16-2006

Post #: 5
Post ID: 7857
Reply to: 7851
Lavry DA-924 + Sansui TU-X1 ~ Noise and interference
Dear Romy,

I performed the following tests:

Test 1.

Digital CD source OFF;
Digital Domain DD-2 processor OFF;
Lavry DA-924 OFF;
Sansui TU-X1 ON and set to FM output;
Custom tube amplifier ON volume HIGH;
ESL-57 speaker arrays ON;
Result: no interference and no noise detectable at 99.9 MHz or at 88-96MHz.

Test 2.

Digital CD source ON;
Digital Domain DD-2 processor ON;
Lavry DA-924 ON;
Sansui TU-X1 ON and set to FM output;
Custom tube amplifier ON volume HIGH;
ESL-57 speaker arrays ON;
Result: no interference and no noise detectable at 99.9 MHz.
Result: interference and noise detectable at 95.9 MHz but not at other frequencies between 88-96MHz.
Signal source: the interference and noise detectable appears to be an AM frequency.

Test 3.

With the interference and noise detectable during Test 2 then switch OFF the Lavry DA-924 and the interference and noise immediately disappears.

Notes:

I have high quality, directional FM and AM antenna system that allowed me to identify the interference and noise as an AM broadcast, even though the Sansui TU-X1 is set to FM output.

Is it possible that you do not have a high quality AM antenna system and that is masking the interference and noise making it difficult to identify as an AM broadcast?

Either way, one would hope that such noise and interference did not happen.

Test 4.

With the interference and noise detectable during Test 2 switch OFF the digital CD source so that the Lavry DA-924 begins its cycle to locate a digital source and interference and noise becomes immediately audible not from an AM broadcast but instead matching the cycling of the Lavry DA-924 trying to identify a digital source.

In summary, this is the first time I have run such tests.  When all components are switched ON and the Sansui TU-X1 tuned in to a FM signal with FM output or tuned into an AM signal with AM output there is no interference or noise.
07-21-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,511
Joined on 05-28-2004

Post #: 6
Post ID: 7858
Reply to: 7857
The radioactive Larvy and the fragile FM

Peter, I do not know what is doing in with AM, I do not use it and all my experiments are in FM range. You might do the following: take FM antenna out of tuner and use instead a few cm of local wire. Defeat the noise causation on Sansui and run the tuner from I would say 95.0 to 101.0Meg. You will have a few stations and a lot of nasty air-noise that will be more or less homogenous. Then turn the Larvy 924 on and run the tuner across the range again. You will see some heavy MF signals and regions of complete exclusion of air-noise (that is interference too). Turning Lavry on and off will show up very indicative how much Lavry tosses out noise. Wight down the regions of max MF signal the come from Lavry. Put antenna back, turn Lavry off and tune to a station in the written regions. Attenuate the signal for Sansui for a given station. Listen the background noise – you shell have no hiss of any kind. Then tune the Larvy on. Listen the HF hiss that will be coming…

Sure the result might wary upon many conditions. In my case Larvy 924 and FM reception are not compatible. It does not bother me BTW too much as there is no need to run Lavry DA while I do recording. However, I need to run my A/D machines… That is why I put a lot of ferret in my Sansui… In fact I am contemplation to disengage the Pacific D/A section and use it only as A/D processor… Pacific is WAY quieter from tuner interference then Larvy 924 of 122. Perhaps if I turn all my recording to Rohde & Schwarz (that made at very different pro standards and actually was designed to work in very heavy noisy environment) then it would be less hassles but at this point I am hesitant to give the duty to the Schwarz as it is not ready yet to perform at its full bloom.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-21-2008 Post does not mapped to Knowledge Tree
peter foster
Australia
Posts 40
Joined on 02-16-2006

Post #: 7
Post ID: 7859
Reply to: 7858
Lavry DA-924 + Sansui TU-X1 ~ Noise and interference

Dear Romy,

My tests showed 2 separate types of noise/interference being caused when TU-X1 & DA-924 were switched ON while the TU-X1 was set to OUTPUT FM: -

First noise/interference, the Sansui TU-X1 was passing an AM broadcast on VARIABLE OUTPUT FM and on FIXED FM OUTPUT at a number frequencies 87.0 - 87.8 MHz, 92.2 MHz, 95.9 MHz, etc.  I did some more investigations and found that the wire from an adapter (AC to 12V DC) to my AM antenna tuner was a source of this interference.  Moving the wire affected the interference.  So the cause of this interference was a combination of: -

~ DA-924 being switched ON;
~ TU-X1 tuned to the particular frequency or frequency range; and
~ AM antenna tuner adapter's wire being in a particular position too close to another cable (I will investigate further).

So the first problem could be solved by either turning the DA-924 OFF or shifting the wire.  I shifted the wire.  Note that I could affect the noise/interference by placing my hand on the DA-924 near the IEC connector when trying to switch it OFF.

Second noise/interference, the Sansuii TU-X1 was picking up noise of the DA-924 attempting to locate a digital source, i.e., AES1 -> AES2 -> IEC -> MUTE -> AES1 ... at 95.7 MHz through 96.0 MHz.  Shifting the wire makes no difference to the noise/interference.  Note that I could affect the noise/interference by placing my hand on the DA-924 near the IEC connector of the DA-924 when trying to switch it OFF.

I detected NO OTHER unexpected noise/interference in my tests.

07-22-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,511
Joined on 05-28-2004

Post #: 8
Post ID: 7860
Reply to: 7859
I am much less lucky in that.
Peter,

what is the relation in your installation between DA-924 and the tuner? Hey might not be sufficiently connected in order the HF dirt penetrate the tuner. In my case it is too much and the interference is very strong. In my case TU-X1 has no wearable outputs but two low impedance direst coupled outputs. One of them drives preamp. Another drivers A/D, then DAW, then DA-924 and to preamp. The second 924s digital input courses from my transport. I do admit that when I experience the 924’s noise and when break up the non-used connections to DA-924 then the character of the noise changes but it never goes away.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-22-2008 Post does not mapped to Knowledge Tree
peter foster
Australia
Posts 40
Joined on 02-16-2006

Post #: 9
Post ID: 7861
Reply to: 7860
Installation

The Lavry DA-924 and Sansui TU-X1 are on separate equipment legs/chains and only come together at inputs to the amplifier.  They also are on separate uninterruptible power supplies that are on separate legs of our wall supplies.  Also, amplifier has internal pre-amplifier section.

Leg/chain A.

Digital source #1 feeds the DD-2 processor.
DD-2 processor feeds the Lavry DA-924 (AES-1).

Digital source #2 feeds the Lavry DA-924 (AES-2).
Lavry DA-924 feeds analog output to the amplifier (inputs pair #1).
Amplifier feeds speaker arrays.

Leg/chain B.

AM tuner system (aerial, rotator and fine tuner) feeds the Sansui TU-X1.
FM tuner system (aerial array and rotator) feeds the Sansui TU-X1.
Sansui TU-X1 feeds analog output (OUTPUT-1 VARIABLE FM) to the amplifier (inputs pair #2).
Sansui TU-X1 feeds analog output (OUTPUT-2 VARIABLE AM) to the amplifier (inputs pair #3).
Sansui TU-X1 feeds analog output (OUTPUT-3 FIXED FM) to the amplifier (inputs pair #4).
Amplifier feeds speaker arrays.

Leg/chain C.

Microphones feed analog output to the Lavry 4496 (pre-amplifier + clock + ADC).
Lavry 4496 feeds digital output to the hard disc recorder.
Hard disc recorder (inbuilt DAC) feeds analog output to the amplifier (inputs pair #5).
Hard disc recorder (digital source #3) feeds digital output to backup DAC.
Backup DAC feeds analog output to the amplifier (inputs pair #6).
Amplifier feeds speaker arrays.

Thoughts:

1.  Lavry performs a power supply upgrade for DA-924 units marked as 'db technologies'.  Have you done that upgrade?  I wonder if that upgrade would help mask some of the noise/interference you are receiving.

2.  Does your Sansui TU-X1 have the AM section active or did you disconnect/remove it?  I assume that your Sansui TU-X1 has the AM section operational and that, as standard, the TU-X1 is supplying AM and FM output simultaneously.

3.  Do you have an external AM aerial attached to the Sansui TU-X1 or are you relying on the inbuilt AM aerial (which I found unusable in our location)?  In my case, I was able to use my powerful AM antenna system to clearly identify one of the noise sources as a very distant AM broadcast even though the amplifier was switched to amplify the Sansui TU-X1's OUTPUT-1 VARIABLE FM or the OUTPUT-3 FIXED FM.  Weird.

4.  Regardless of the above, there is still a source of noise/interference that the Lavry DA-924 generates on my system when it cycles looking for digital sources, i.e., AES1 -> AES2 -> IEC -> MUTE -> AES1 ... at 95.7 MHz through 96.0 MHz.

07-22-2008 Post does not mapped to Knowledge Tree
Antonio J.
Madrid, Spain
Posts 272
Joined on 08-16-2004

Post #: 10
Post ID: 7862
Reply to: 7856
That's much more ferrite than I've used
 Romy the Cat wrote:


Hm, this is interesting. I my case nether neither CEC nor Bidat affect other of the tuners. Lavrys do but not Bidat. Try to put ferrite on ALL Sansui inputs: antenna, power cord, output cables. I have 3 bids on each leg of power cord, 4 bids on combined power wires, one bid on each combined analog output and 12 bids on the combined antenna cable on the cable between the input jack and the entrance to front end.

My TU-1X do not acknowledge Bidat at all, ether the DAC is it locked of not.

The caT


Thanks for the detailed ferrite setup in your system. I'll try it that way and see what happens, hopefully I can keep the digital rig on (which is almost a requirement to have decent sound when starting listening to CDs) while listening to FM.

Rgrds
07-22-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,511
Joined on 05-28-2004

Post #: 11
Post ID: 7863
Reply to: 7862
Beter installation + more ferrete

Peter,

It is obviously that in your installation Lavry and FM are much more isolated then in mine. In fact if your power amp breaks both ground and central wire then when you switch you playback to “Leg B” then digital in not in the picture at all. Even your recorder that pumps to the amp directly is off when your amps are in FM mode. 

 peter foster wrote:
1.  Lavry performs a power supply upgrade for DA-924 units marked as 'db technologies'.  Have you done that upgrade?  I wonder if that upgrade would help mask some of the noise/interference you are receiving.

This update is worthless for the perspective of noise/interference. What I did it Lavry changed front panel and put better rubber under the power transformers. Since it cost me around $650 and Lavry stressed that that the change of the front panel was free I was asking was else was done. They told me that many changed in PS were done in order to make the unit to run cooler. I did not see any changed and asked them to name even one. They were not able to…

 peter foster wrote:
2.  Does your Sansui TU-X1 have the AM section active or did you disconnect/remove it?  I assume that your Sansui TU-X1 has the AM section operational and that, as standard, the TU-X1 is supplying AM and FM output simultaneously.

My TU-X1 has AM section active but I do not use it. BTW, the TU-X1’s AM section is a truly Rolls-Roys -like according to my tuner guys and it shell yield a very high performance. I juts do not care about the AM programming I have in Boston.

 peter foster wrote:
3.  Do you have an external AM aerial attached to the Sansui TU-X1 or are you relying on the inbuilt AM aerial (which I found unusable in our location)?  In my case, I was able to use my powerful AM antenna system to clearly identify one of the noise sources as a very distant AM broadcast even though the amplifier was switched to amplify the Sansui TU-X1's OUTPUT-1 VARIABLE FM or the OUTPUT-3 FIXED FM.  Weird.

So, you use AM section to identify the souse of interference? Interesting. The DAC it looks like tosses a lot of noise at wide bandwidth. I afraid that with AM region it might be different then in FM

 Antonio J. wrote:
Thanks for the detailed ferrite setup in your system. I'll try it that way and see what happens, hopefully I can keep the digital rig on (which is almost a requirement to have decent sound when starting listening to CDs) while listening to FM.

Not only that. I have all 6 active digital lines that come from my Linx card heavily ferreted as well.

FerriteOnTuner.jpg


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
Page 1 of 1 (11 items) Select Pages: 
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  A littlie D-War: Bidat vs. Lavry Gold..  RE: the "New" DAC...  Didital Things  Forum     13  132973  12-18-2005
  »  New  Sansui TU-X1 Broadcast monitor...  Replace all audio coupling......  Off Air Audio Forum     46  316576  06-20-2007
  »  New  Recording options: Pacific Microsonics vs. Lavry Gold...  Pacific Microsonics vs. Lavry Gold in D/A mode....  Didital Things  Forum     24  179660  09-27-2007
  »  New  The Lavry Gold DA924 ++..  A new Lavry Gold?...  Didital Things  Forum     25  195678  03-28-2008
  »  New  Rohde & Schwarz EU-6201 Tuner..  The Schwarz runs from crystal oscillator!...  Off Air Audio Forum     34  242220  05-07-2008
  »  New  DC offset for A/D converters...  DC offset for A/D converters....  Didital Things  Forum     0  12048  03-13-2009
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