XLR questions. AR Ref 3 preamp questions etc.

[Athalwolf]

Putting together a system upgrade ( my first tube system! ) and have several questions about XLR plugs.

The previous owner changed out the stock tonearm wire on my Thorens 520. I notice that there are only two wires going to the XLR's. Is this pseudo XLR and not true XLR? Is there a purpose for this? I recall he used a separate phono preamp for each channel.


A different angle shot:

Here is the other end:


That stock arm was removed and replaced with an SME with RCA's but that leads to another question. I just bought a used AR Ref 3 preamp. It's 600 miles away in Calgary and I'm throwing on some winter skins and heading out in a few days to pick it up. There is also a AR Ref 75 amp for sale. The Ref 75 only has inputs for XLR. The Ref 3 preamp has plenty of both in and out.

If I run single ended from the turntable into a phono stage or SUT and then single ended into the Ref 3 and then XLR into the Ref 75 will the Ref 3 convert the signal to balanced for the Ref 75?

My tech says the entire system has to be XLR to properly utilize the Ref 75 and he can convert the SME tonearm but would that involve rewiring the entire tonearm from the head shell to the XLR ends? I'm trying to figure out how that is possible when there are only two leads per channel at the head shell. Where the heck does the third wire shield/ground come from? My tech speaks very little English and I have no idea what he is attempting to tell me so I am asking here.

If I was to have XLR's replace the RCA's on the SME in the same manner as the above pictures then run those into a phono preamp or SUT with XLR's in and out then XLR to the Ref 3 preamp and on to the Ref 75 would I have true XLR? What are my options? Thanks AK!

 

[twiiii]

If the two wires are connected to pins 2 and 3 then I would suspect a balanced configuration at first glance. The ground wire of the TT and tone arm being connected to the ground post eliminates the need for a third wire in the XLR connector pin 1. But you know what happens when you assume something. Making an ass out of u and me.

But then there is the matter of the shield, hope fully its connected at the tone arm. If not then if the ground of the chassis is connected to the 1 pin of the XLR, then you will have to connect the shield. Remember you can't have two grounds. Only one. How you configure your wiring to get the lowest path way resistance to ground will give the best result. If the chassis ground is floating then you will have to try different combinations to get the best results. C-28 Mc pre amps the chassis connection of the RCA pins was floating, but you got the best performance with the pre-amp grounded to a ground stake, with the TT and arm connected to earth ground with shield isolated and connected to chassis ground. With MM cartridges there were really no issues, but with MC cartridges using transformers that was the best solution.

I notice from reading later posts with pictures your pre=amp uses a 3 wire AC cord. Which means the chassis should be tired to earth ground in which case connecting the shield may or may not give the best performance. when all is said and done if you still hear a hum. You are going to have to call an electrician to verify if you have a good ground at your wall out let. I don't, so I use a ground stake with a #8 AWG wire connected to the chassis of the the TT and tone arm and satellite dish with floating shields tied to the C-34V pre-amp or to the MP 100 Pre-preamp. MC cartridges can be a pain.

 

[Athalwolf]

If the two wires are connected to pins 2 and 3 then I would suspect a balanced configuration at first glance. The ground wire of the TT and tone arm being connected to the ground post eliminates the need for a third wire in the XLR connector pin 1. But you know what happens when you assume something. Making an ass out of u and me.

Thanks for your reply. I'm hoping it is as easy as that. I contacted Audio Research to ask them if it's possible to run single ended into the Ref 3 preamp and then XLR to the Ref 75.

 

[E-Stat]

If I run single ended from the turntable into a phono stage or SUT and then single ended into the Ref 3 and then XLR into the Ref 75 will the Ref 3 convert the signal to balanced for the Ref 75?

Balanced operation exists at different stages. Regardless of the input, the connection from the ARC REF3 to the REF75 will be balanced and afford lower noise. I do same with a SP20 into VTL monoblocks.

My tech says the entire system has to be XLR to properly utilize the Ref 75

Nonsense. Have you ever looked at the back of ARC's current $14k REF3 Phono preamplifier?

 

[Athalwolf]

Balanced operation exists at different stages. Regardless of the input, the connection from the ARC REF3 to the REF75 will be balanced and afford lower noise. I do same with a SP20 into VTL monoblocks.

That's the answer I was hoping for. Thanks for taking the time to reply.



Nonsense. Have you ever looked at the back of ARC's current REF3 Phono preamplifier?

View attachment 1329828

 

[Athalwolf]

Follow up question. Is it possible to safely run the Ref 3 preamp through the auxiliary inputs of an Akai AA-1200 receiver? There would be balance and volume controls on each unit. Thanks!

 

[E-Stat]

Follow up question. Is it possible to safely run the Ref 3 preamp through the auxiliary inputs of an Akai AA-1200 receiver? There would be balance and volume controls on each unit. Thanks!

Via tape output, yes.

 

[Athalwolf]

Via tape output, yes.

Thanks for your reply. It turns out the Ref 75 is no longer in Canada. It is still for sale but it is now in the US so I will find something else and use the Akai in the meantime.

 

[E-Stat]

Thanks for your reply. It turns out the Ref 75 is no longer in Canada. It is still for sale but it is now in the US so I will find something else and use the Akai in the meantime.

No problemo. Wifey and I love the Seattle area and are planning a trip next month. I'm looking into taking a seaplane to Vancouver to spend the day. Take in the aquarium and park area, Granville Island, enjoy some good sushi ???

 

[Macaroonie]

Standard XLR convention is Pin 1 Gnd
Pin 2 Hot or +
Pin 3 Cold or -

Should you continue to need to use the XLR's I would check that the Gnd is hooked on to pin ! that way at least you are getting some shielding.

 

[Athalwolf]

No problemo. Wifey and I love the Seattle area and are planning a trip next month. I'm looking into taking a seaplane to Vancouver to spend the day. Take in the aquarium and park area, Granville Island, enjoy some good sushi ???

Oh that's great! We appreciate your tourist dollars especially in the off season. If it's too rainy that day there is also The Vancouver Art Gallery. And there is good sushi to be found. Have you visited Vancouver before?

 

[E-Stat]

Oh that's great! We appreciate your tourist dollars especially in the off season. If it's too rainy that day there is also The Vancouver Art Gallery. And there is good sushi to be found. Have you visited Vancouver before?

Thanks for the tip. Not to Vancouver - we took the ferry to Victoria one year around Christmas and thoroughly enjoyed the trip. Toured the BC Parliament, visited the museum, took in an IMAX film and walked around Beacon Hill park.

Never visited Vancouver before. Would really like to spend a week there and take in some skiing.

 

[Athalwolf]

Thanks for the tip. Not to Vancouver - we took the ferry to Victoria one year around Christmas and thoroughly enjoyed the trip. Toured the BC Parliament, visited the museum, took in an IMAX film and walked around Beacon Hill park.

Never visited Vancouver before. Would really like to spend a week there and take in some skiing.

Lol that's amazing that you just mentioned skiing. As I was walking back to my PC I was thinking that I would like to ski Marmot at Jasper since I am now going to go to Edmonton either before or after Calgary. It's a big circle from here and I can go either way. Marmot opens in two days and they have 17cm in the past 8 days but I'm not sure what the base is like as it's early. Nice local skiing here but I’m ashamed to admit that I have never skied Whistler/Blackcomb.

Found a nice demo MC275 MK VI in Edmonton. It’s on hold for me so yahoo road trip!