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How to go best way from XLR to RCA and vice versa.


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I plan to put my Underground Jubilees back up in a few weeks. First I have to transport them back to Cologne. In advance I bought and restored the amplifiers. Especially I had to replace many electrolytic capacitors (22 in the pre) because they are 32 years old and should not expire soon with the consequence of aggressive leak. From 2008 to 2017 there were different power amplifiers with different input sensitivities on the Jubilees. And one of the two power amps had only RCA inputs. My DSP/Xover is a Yamaha SP2060 which has only XLR. 
The now "new" amp system is a Quad 34 pre amp and two Quad 306 power amps. They sound fantastically smooth on horns and they are very good transistor units, the power amps with an extraordinary "current dumping" circuit which is characterized by the fact that the quietest signals are very distortion-free, quasi a kind of "first watt" from the 1980s.

Now to my point. It is not so easy to make good transitions from RCA to XLR...and vice versa. So, I go from RCA to XLR in the input of the Yamaha SP2060 and I go in the output from XLR back also RCA of the two power amps.

I found a good text here. It is in German but you can either just turn on the google translator immediately if you are interested or, for a better translation use deepl.com.

What I want to say with this thread, it is worth considering how to switch the best connection. Accordingly, prefabricated adapters are unsuitable because they always connect ground and cold together.

 

Perhaps you have your own experiences to contribute and a fruitful exchange will develop. Here is the link to the German thread (first post is relevant) which is helpful from my point of view.

 

http://www.hifi-forum.de/viewthread-42-58.html

 

 

 

 

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I have to use a single ended to a balanced connector from my preamp to the xilica, and then balanced back to singled ended from the xilica to the tube amps.

 

I dont have any issues. There is a rolled off sound to my jubilee system that I can not seem to diagnose,  but I think it's only a matter of time before I find what's causing it.

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26 minutes ago, Schu said:

I have to use a single ended to a balanced connector from my preamp to the xilica, and then balanced back to singled ended from the xilica to the tube amps.

 

I dont have any issues. There is a rolled off sound to my jubilee system that I can not seem to diagnose,  but I think it's only a matter of time before I find what's causing it.

May be the article could be of help, e.g. if earth of the RCA pre amp output should go only and without a connection of XLR 1 to cold which is XLR 3, just to mention one of several possible issues.

 

At the output of the DSP (whether Xilica or Yamaha) I first try it so that I switch XLR 3 to ground of the RCA, even without a connection with XLR1 because otherwise it could happen that the differential amplifier at the output of the DSP could be shorted. In the article the suggestion is made that XLR 1 could be connected to chassis ground in case my circuit suggestion could cause hum.

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Good evening Heinz , do you think about a diy solution , than use symmectric raw cables ( 2 seperate or twisted stranded wires AWG 22 ) with a seperate shield 

 

cinch to xlr

 

2014949079_cinchaufxlr.jpg.be7153986da91ec73bf6804d63c7ff8e.jpg

The major part of the interference suppression capabilites of balanced audio systems is ofered by the diferental input side. “Unbalanced to balanced” wiring should be designed in such a way that it takes optmal advantage of these qualites. This means that the negatve signal should be connected to ground at the unbalanced transmiter side.

 

 

 

 

 

xlr to cinch

 

1832257791_xlraufcinch.jpg.591653e0b328410c9ae164c4311d79ff.jpg

 

 

Mark that pin 3 of the 3-pin connector is not connected. If it was connected to the ground of the 2-pin connector, it would short the signal. Since pin 3 is not used, this type of 3-pin to 2-pin connectons is effectvely completely unbalanced, just like a 2-pin to 2-pin connecton. And like in the later case, the small capacitor ( usually 1 pF )makes sure that the audio signal fows through the inner twisted wires while the shield stll conducts RF and thus keeps the ‘cage of Faraday’ closed.

 

 

If you do not want to built them on your own, have a look at Mogami Cables or Sommer Cables, they offer a wide range of adapters cables .

 

just my two cent .

 

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12 minutes ago, MicroMara said:

Good evening Heinz , do you think about a diy solution , than use symmectric raw cables ( 2 seperate or twisted stranded wires AWG 22 ) with a seperate shield 

 

cinch to xlr

 

2014949079_cinchaufxlr.jpg.be7153986da91ec73bf6804d63c7ff8e.jpg

The major part of the interference suppression capabilites of balanced audio systems is ofered by the diferental input side. “Unbalanced to balanced” wiring should be designed in such a way that it takes optmal advantage of these qualites. This means that the negatve signal should be connected to ground at the unbalanced transmiter side.

 

 

 

 

 

xlr to cinch

 

1832257791_xlraufcinch.jpg.591653e0b328410c9ae164c4311d79ff.jpg

 

 

Mark that pin 3 of the 3-pin connector is not connected. If it was connected to the ground of the 2-pin connector, it would short the signal. Since pin 3 is not used, this type of 3-pin to 2-pin connectons is effectvely completely unbalanced, just like a 2-pin to 2-pin connecton. And like in the later case, the small capacitor ( usually 1 pF )makes sure that the audio signal fows through the inner twisted wires while the shield stll conducts RF and thus keeps the ‘cage of Faraday’ closed.

 

 

If you do not want to built them on your own, have a look at Mogami Cables or Sommer Cables, they offer a wide range of adapters cables .

 

just my two cent .

 

 

I have made many of these in the past using Mogami wire.  This is the way to do it.  Very easy to do. 

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32 minutes ago, MicroMara said:

Good evening Heinz , do you think about a diy solution , than use symmectric raw cables ( 2 seperate or twisted stranded wires AWG 22 ) with a seperate shield 

 

cinch to xlr

 

2014949079_cinchaufxlr.jpg.be7153986da91ec73bf6804d63c7ff8e.jpg

The major part of the interference suppression capabilites of balanced audio systems is ofered by the diferental input side. “Unbalanced to balanced” wiring should be designed in such a way that it takes optmal advantage of these qualites. This means that the negatve signal should be connected to ground at the unbalanced transmiter side.

 

 

 

 

 

xlr to cinch

 

1832257791_xlraufcinch.jpg.591653e0b328410c9ae164c4311d79ff.jpg

 

 

Mark that pin 3 of the 3-pin connector is not connected. If it was connected to the ground of the 2-pin connector, it would short the signal. Since pin 3 is not used, this type of 3-pin to 2-pin connectons is effectvely completely unbalanced, just like a 2-pin to 2-pin connecton. And like in the later case, the small capacitor ( usually 1 pF )makes sure that the audio signal fows through the inner twisted wires while the shield stll conducts RF and thus keeps the ‘cage of Faraday’ closed.

 

 

If you do not want to built them on your own, have a look at Mogami Cables or Sommer Cables, they offer a wide range of adapters cables .

 

just my two cent .

 

 

Does this mean that Mogami offers differently constructed cables depending on the running direction?

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3 minutes ago, KT88 said:

 

Does this mean that Mogami offers differently constructed cables depending on the running direction?

You can discuss this with the company that makes them for you , before they build them for you according to your specifications

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1 hour ago, KT88 said:

My DSP/Xover is a Yamaha SP2060 which has only XLR. 

 

I too have this Xover and use monoprice RCA to XLR cables (Stage Right series) between my Marantz AVR and the Yamaha. My amps utilize balanced phoenix connectors so I bought monoprice XLR to XLR (again, Stage Right series) and cut off one end for the interconnects between the Yamaha and amps. Absolutely no issues whatsover.

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Does anyone know if the minus output (pin 3) on the XLRs of the Yamaha 2060 are a driven signal of opposite polarity to pin 2? Or is it just an impedance matched signal to ground? If the latter the input and output cables can be made the same (cinch to XLR i.e. input cables in drawing above) and the performance will be theoretically better.

On Xilica XP series crossovers the minus output pins are just impedance balanced. It is the cheaper way to go but Yamaha maybe not be done the "cheap" way.

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33 minutes ago, babadono said:

Does anyone know if the minus output (pin 3) on the XLRs of the Yamaha 2060 are a driven signal of opposite polarity to pin 2? Or is it just an impedance matched signal to ground? If the latter the input and output cables can be made the same (cinch to XLR i.e. input cables in drawing above) and the performance will be theoretically better.

On Xilica XP series crossovers the minus output pins are just impedance balanced. It is the cheaper way to go but Yamaha maybe not be done the "cheap" way.

Thanks for your question, babadono. I think this is part of the issue that the way how to design an adapter depends on the circuit of the XLR unit in question. Here comes a link to the service manual which is beyond my understanding. Perhaps it helps to answer your question and also how to connect the cables in the best way.

 

 

https://elektrotanya.com/yamaha_sp2060_sm.pdf/download.html#dl

 

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Yes so the minus outputs are actively driven so the input and output cables will have to be made different.....or a line input transformer or ISO MAX box could be used.

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22 hours ago, babadono said:

Yes so the minus outputs are actively driven so the input and output cables will have to be made different.....or a line input transformer or ISO MAX box could be used.

 

Thanks for looking at the service manual. Now I know that the input cables and the output cables must be configured differently. But I still do not know how exactly. With the input cable nothing can break, if it is wrong it will hum or not sound good. But with the output cable I obviously have to be careful so that the amp that switches to XLR 3 will not be not damaged.

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@KT88

 

 *****correction of my post yesterday******

 

the SP 2060 is pro gear. It has a cross coupled output stage. So it CAN be used in a connection where the minus output gets shorted to ground of the input it is driving. AFAIC this is not good practice and has potential problems. Google "cross coupled output stage" if you want to learn more than you ever wanted to know.

Personally I would use an ISO MAX on the SP 2060 output to unbalanced amplifier input. You will be fine with the "cinch to XLR" cable that @MicroMara posted for your pre amp output to SP 2060 inputs.

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17 hours ago, babadono said:

For what application? The Monoprice cables are wired like the "cinch to XLR" in diagrams above.

what would be the effect of doing it one way versus the other when going from a pre to the xilica or from the xilica to an amp... or both applications?

 

the reason I ask is because I am still struggling with some performance issues based in and around the Xilica when using these and the Jubilee... not that it's the fault of the cables alone.

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