Xlr to phono buffer

[Peterbean]

I made a big step up on dacs recently _ OKTO research dac8;

the Dac arrived yesterday and I’ve realised that the only analogue out is Xlr. My pre is all analogue, but solved problem by buying a phono to Xlr cable. Or so I thought. 
it transpired that the manual says that’s a nono due to earth problems, and I need a buffer or equivalent…aaargh

 

so I’m wondering if anyone can assist- do you have a spare or is there some e-wiz here who can knock one up?

 

[frankn]

Input 1 x XLR 600 ohms to Output 2 (stereo) x RCA 10k ohms

Balanced 600 Ohm 3 pin female XLR to unbalanced 10K Ohm 2 x RCA with level control. +10dB max signal gain.
Steps up input signal by factor of 16, ie 20mV in = 320mV out.

This unit can be used:
a) for unbalancing a line level signal (converting a balanced signal to unbalanced)
b) as an isolation unit to prevent hum loops in audio systems

[surprisetech]

2 hours ago, frankn said:

Input 1 x XLR 600 ohms to Output 2 (stereo) x RCA 10k ohms

Balanced 600 Ohm 3 pin female XLR to unbalanced 10K Ohm 2 x RCA with level control. +10dB max signal gain.
Steps up input signal by factor of 16, ie 20mV in = 320mV out.

This unit can be used:
a) for unbalancing a line level signal (converting a balanced signal to unbalanced)
b) as an isolation unit to prevent hum loops in audio systems

 

Neat little units and I'm sure these represent very good value like most Selby products. 

I assume that there's a transformer inside to maintain the integrity of the balanced connection and provide the impedance matching and voltage gain.

However, at that price, while they might be worth a try, I'm not sure the quality of the transformer or level control would be great.  Frequency response is listed as a 6dB envelope from 20Hz to 20kHz which might not do the new DAC justice.

These are intended for PA systems rather than hifi systems.
I would be inclined to look at an active converter.

[frankn]

There are lots about on the interweb . 

[andyr]

7 hours ago, Peterbean said:

I made a big step up on dacs recently _ OKTO research dac8;

the Dac arrived yesterday and I’ve realised that the only analogue out is Xlr. My pre is all analogue, (do you mean 'RCA'?) but solved problem by buying a phono to Xlr cable. Or so I thought. 

it transpires that the manual says that’s a nono due to earth problems, and I need a buffer or equivalent…aaargh

 

RCA to XLR converter cables are pretty commonplace in hifi systems - so I can't believe that they can't work.  

 

Why don't you ask someone who makes cables - like, say, Mark ( @SonicArt)?  Then, when he comes back with a schematic of how the cables are wired ... you can send that to Okto and ask them why it wouldn't work.

 

Like @surprisetech, I would suggest not using a PA item on a high-priced DAC like your Okto.

 

[Peterbean]

14 hours ago, andyr said:

 

RCA to XLR converter cables are pretty commonplace in hifi systems - so I can't believe that they can't work.  

 

Why don't you ask someone who makes cables - like, say, Mark ( @SonicArt)?  Then, when he comes back with a schematic of how the cables are wired ... you can send that to Okto and ask them why it wouldn't work.

 

Like @surprisetech, I would suggest not using a PA item on a high-priced DAC like your Okto.

 

From the manual 

H

[andyr]

You seem to have found your answer (in the manual)!

 

Lundahl LL1584-3FXPHM Balanced to unbalanced converter

 

See here:

 

 

 

 

[Peterbean]

1 hour ago, andyr said:

You seem to have found your answer (in the manual)!

 

Lundahl LL1584-3FXPHM Balanced to unbalanced converter

 

See here:

 

 

 

 

Yes but they are very expensive so I was looking for something cheaper-at that price I could almost get a

 balanced pre 

[andyr]

Or you could sell the Okto, keep your current pre ... and buy an RCA-connectable DAC!    Like, say an Abbas.

 

Unfortunately, you seem to be between a rock and a hard place.    If you look at the other suggested option in the manual - the Neurochrome Universal buffer - including shipping, that's going to set you back about A300.  And that's only for the PCB!  

 

Then you need a +/-15v PS ... and a case to put it all in.  I can put it all together for you ... but you'd be looking at upwards of A$800, I'd guess.

 

[SonicArt]

Most XLR to RCA cables simply short out the - signal to the earth, its an accepted way of doing it with a lot of equipment.

My Electrocompaniet pwr amp (AW100DMB) has a pair of RCA's and an XLR per channel for the input, its a true balanced design, one RCA carries the + signal and ground, one carries the - signal and ground. To run the amp with single ended RCA cables you plug them into the + RCA and you use a grounding cap to ground the - RCA to itself. Same concept as grounded - in a cable.

 

I can certainly make you an XLR to RCA cable with floating - pin, can make it with any level of cable, whats your budget?

 

Edited November 27, 2024 by SonicArt

[Peterbean]

2 hours ago, SonicArt said:

Most XLR to RCA cables simply short out the - signal to the earth, its an accepted way of doing it with a lot of equipment.

My Electrocompaniet pwr amp (AW100DMB) has a pair of RCA's and an XLR per channel for the input, its a true balanced design, one RCA carries the + signal and ground, one carries the - signal and ground. To run the amp with single ended RCA cables you plug them into the + RCA and you use a grounding cap to ground the - RCA to itself. Same concept as grounded - in a cable.

 

I can certainly make you an XLR to RCA cable with floating - pin, can make it with any level of cable, whats your budget?

 

Thanks Mark I am persuing some other options st the moment, I’ll get back to you in a while 

[metal beat]

On 26/11/2024 at 11:46 AM, Peterbean said:

I made a big step up on dacs recently _ OKTO research dac8;

the Dac arrived yesterday and I’ve realised that the only analogue out is Xlr. My pre is all analogue, but solved problem by buying a phono to Xlr cable. Or so I thought. 
it transpired that the manual says that’s a nono due to earth problems, and I need a buffer or equivalent…aaargh

 

so I’m wondering if anyone can assist- do you have a spare or is there some e-wiz here who can knock one up?

 

 

What the manual says seems more a design flaw in the dac than anything. 

 

Did u try the xlr to rca cable or did the manual scare u off ?

 

 neutrik xlr to rca adapters are excellent - they are very transparent. 

Edited November 27, 2024 by metal beat

[Peterbean]

13 hours ago, metal beat said:

 

What the manual says seems more a design flaw in the dac than anything. 

 

Did u try the xlr to rca cable or did the manual scare u off ?

 

 neutrik xlr to rca adapters are excellent - they are very transparent. 

It scared me off 

 

[SonicArt]

An XLR to rca adapter is not rocket science,  Cardas has made them for years too, way too expensive though.  I have made them in the past using neutrik XLR with a quality female rca fitted into the back of the housing. 

I wouldn't be frightened about using a cable or adapter,  I'm sure there are many using the rca input on Electro amps and no shorting plug with no issue,  the guy i got my AW100 off didn't have the shorting plugs and I only found out from downloading the manual, finding the info and making some up!

Amp sounded fine without them.

[aussievintage]

2 hours ago, Peterbean said:

It scared me off 

 

 

Shouldn't.  Anybody who ever uses an RCA phono interconnect has potential earthing problems.  You may have noticed many discussions about hum and earth loops.   Doesn't stop nearly everyone using them.

[kffern]

How about this? Supposed to work both ways.

 

https://www.altronics.com.au/p/k5522-balanced-to-unbalance-conv.-kit/?gad_source=1&gclid=CjwKCAiAyJS7BhBiEiwAyS9uNR0nfYqVxzGeBLZGHlX2g1AKIPv10stBxS1bGFQJFGhXWFHBC-FGLRoCNIIQAvD_BwE

Edited December 21, 2024 by kffern