Why are DIN regarded as better than RCA?

Posted by: Consciousmess on 23 March 2018

Especially when RCA are most common?  Surely if DIN are better, all manufacturers would use them - but they don’t. Why?

Posted on: 23 March 2018 by Richard Dane

You may find the answer to your questions in the forum FAQ. RCA phono was made popular to the point of ubiquity by the dominance of Japanese and far eastern hifi during the 70s and 80s. RCA phono is cheaper and easier to implement. DIN performs better (sounds better) but is costlier and more complicated as the DIN plugs have to specifically wired for purpose. 

Certain markets find DIN a bit scary or weird (US and far eastern markets) and so choosing DIN is seen by most manufacturers as automatically limiting your market appeal. Naim though put performance first and so have always championed DINs where possible. 

Posted on: 23 March 2018 by vintageaxeman

There's CHEAPO DIN and Naim (Freh) DIN, and the more expensive versions. No comparison between them. The good ones really are good.

Posted on: 23 March 2018 by The Strat (Fender)

Isn’t it do with the earthing?

Posted on: 23 March 2018 by MDS
The Strat (Fender) posted:

Isn’t it do with the earthing?

That's my understanding, too.

Posted on: 23 March 2018 by vintageaxeman

(By CHEAPO ones I mean thin cables terminating in plastic cased plugs, cheaply made from the 60s onwards and intended for Dixons music centres and cassette recorders.)

Posted on: 23 March 2018 by Adam Meredith
Richard Dane posted:

You may find the answer to your questions in the forum FAQ.

But you may need to read it - https://forums.naimaudio.com/to...m-use-din-connectors

Posted on: 23 March 2018 by vintageaxeman
MDS posted:
The Strat (Fender) posted:

Isn’t it do with the earthing?

That's my understanding, too.

I remember reading that Naim's tests on their Din plugs proved that they made better contact than RCA plugs. 

Personally, I would have thought that earthing methods, although crucial, would be very similar in both DIN and RCA plugs, for any given application. 

Posted on: 23 March 2018 by SamClaus

Does this mean that you shouldn't use a decent RCA/RCA interconnect (Rega Couple, for instance) between, say, a Rega Fono and a Naim amp, but an RCA/DIN one? I can't think of a phono preamp with a DIN out socket, apart from the Stageline/Superline, and RCA/DIN interconnects are few and far between, it seems.

Which RCA/DIN interconnect would you recommend? Chord, or ???

Posted on: 23 March 2018 by The Strat (Fender)

Chord supply RCA>DIN cables at a reasonable price.   That would be the recommended approach.  

Posted on: 23 March 2018 by Malazan

So would RCA>DIN be better or no different to RCA>RCA? 

 

Posted on: 23 March 2018 by audio1946

there must be 100s of audio manufacturers very few use din.  why would they use a degrading product.....,always power down when changing leads to avoid the issue with phonos ,disconnecting earth first

Posted on: 23 March 2018 by joerand
Adam Meredith posted:
Richard Dane posted:

You may find the answer to your questions in the forum FAQ.

But you may need to read it - https://forums.naimaudio.com/to...m-use-din-connectors

I read it and it raises a question for me regarding audio signal voltage; the output from a phono stage or CDP where RCAs are commonly used. I thought these outputs were DC voltages.

Richard states: "The phono plug, or RCA connector, as best as anyone can remember, was designed decades ago as a direct current (DC) power connector. Its design properties do not lend themselves to transferring music signals that have very low voltages (less Than 5 volts) of alternating current (AC). This is true - no matter how good the RCA plug is or whether it is made with gold, etc."

My question is where in a system do RCA connectors carry alternating current?

Posted on: 23 March 2018 by Richard Dane
joerand posted:
Adam Meredith posted:
Richard Dane posted:

You may find the answer to your questions in the forum FAQ.

But you may need to read it - https://forums.naimaudio.com/to...m-use-din-connectors

I read it and it raises a question for me regarding audio signal voltage; the output from a phono stage or CDP where RCAs are commonly used. I thought these outputs were DC voltages.

Richard states: "The phono plug, or RCA connector, as best as anyone can remember, was designed decades ago as a direct current (DC) power connector. Its design properties do not lend themselves to transferring music signals that have very low voltages (less Than 5 volts) of alternating current (AC). This is true - no matter how good the RCA plug is or whether it is made with gold, etc."

My question is where in a system do RCA connectors carry alternating current?

Technically, the analogue audio signals are AC. 

Posted on: 24 March 2018 by joerand

Ok thanks for clarifying Richard. I never knew that. As a follow up question, is the current from the power amp to the speakers AC or DC?

Posted on: 24 March 2018 by Simon-in-Suffolk

The FAQ talks a lot about reflected signals which occur at impedance mismatches, I do suspect at audio frequencies and variables of differeing cable characteristics the effect here is absolutely minimal, and reflections more likely to occur, in my opinion, from the electronics behind the connector, but at video frequencies and SPDIF  I can see this becomes more of an issue.

I subscribe to the point of view for audio frequencies that for Naim’s use of DIN the principle advantages are:

  • Common ground between left and right .. this preserves very low level signals.
  • for a stereo end to end connection there are 6 physical contacts with DIN  as opposed  to 8 coonnectionswith phono giving a 25% increase in relative performance. Physical electrical contacts are a weak point.
Posted on: 24 March 2018 by Simon-in-Suffolk
joerand posted:

Ok thanks for clarifying Richard. I never knew that. As a follow up question, is the current from the power amp to the speakers AC or DC?

AC... if it were DC your cones would move one way and stay there and possibly burn out...

Audio signals are AC signals... they are proportional to the air pressure variations which becomes sound we hear through air. If you gently touch a loudspeaker cone when playing audio.. you can feel it vibrate as it creates pressure waves in your room... this is because an AC signal is being passed through the speaker.

Posted on: 24 March 2018 by Joppe

I always assumed that the benefit was that in the din plug left and right channel share signal ground or “neutral” and have a seperate (also common) case ground. As I understand these two “ground” levels are cept seperate in naim designs (a design choice possibly not done buy other brands). With RCA signal and case ground are mixed for each chanel which are seperated in left and right, hence the preference for din conector with naim amps. Correct?

Posted on: 24 March 2018 by joerand

Thanks Simon for setting me straight. So I assume DC (battery powered) radios, for example, have to convert their output voltage to AC. Sorry to digress, but what is the purpose of a rectifier tube in a vintage AC powered radio?

Posted on: 24 March 2018 by Simon-in-Suffolk

Indeed, the DC powersupply powers the amplifier stages and radio circuitry... radio circuitry extracts and amplifies the radio signal which is also alternating and then the extracted audio signal is then increased in magnitude by the amplifiers such that it can then usefully drive a speaker etc.  The amplifiers here need a constant voltage source to power them such that the amplified signal is only the original signal. If the power supplies were modulating as well, then the amplified signal would be the original signal plus powersupply modulated signal and be therefore the original extracted audio signal would be distorted... perhaps you can see why in terms of SQ, having a clean powersupply is important...

A rectifier, whether it be a thermionic valve (tube) or semiconductor essentially converts AC to DC. Therefore if the device is powered my the AC mains it will be typically transformed down to a lower voltage and converted by a rectifier to DC..This DC voltage is pulsing or varying in sync with the mains, and so is usually  then smoothed by electrolytic or reservoir capacitors and then often regulated such that the voltage is held constant irrespective of current draw and provide a steady constant DC supply.

These days rectifiers are typically made up of semiconductor diodes (in combinations of 1,2 or 4 diodes) as opposed to using valve diodes.

 

Posted on: 24 March 2018 by Simon-in-Suffolk
Joppe posted:

I always assumed that the benefit was that in the din plug left and right channel share signal ground or “neutral” and have a seperate (also common) case ground. As I understand these two “ground” levels are cept seperate in naim designs (a design choice possibly not done buy other brands). With RCA signal and case ground are mixed for each chanel which are seperated in left and right, hence the preference for din conector with naim amps. Correct?

Not neccessarily. That is down to the design of the equipment itself as opposed to any intrinsic property of a DIN or RCA/phono plug and socket

Posted on: 24 March 2018 by Tabby cat
vintageaxeman posted:

(By CHEAPO ones I mean thin cables terminating in plastic cased plugs, cheaply made from the 60s onwards and intended for Dixons music centres and cassette recorders.)

That's the epitome of DNM plugs and they would't use them if they detracted from what they wanted to achieve with their amps as they don't like to use metal in their products.DNM certainly don't make shoddy products.A lot of their stuff over the years has been groundbreaking.

Posted on: 24 March 2018 by SamClaus
Malazan posted:

So would RCA>DIN be better or no different to RCA>RCA? 

 

Yes, that's what I would like to know... is a DIN plug at the amplifier end better than no DIN plug at all?

Posted on: 24 March 2018 by Simon-in-Suffolk

It should be better, albeit perhaps only marginally, as at least the grounds are commoner at one end, and there is one less physical connection....

Posted on: 24 March 2018 by SamClaus
Simon-in-Suffolk posted:

It should be better, albeit perhaps only marginally, as at least the grounds are commoner at one end, and there is one less physical connection....

Thanks

Posted on: 24 March 2018 by Simon-in-Suffolk
Tabby cat posted:
vintageaxeman posted:

(By CHEAPO ones I mean thin cables terminating in plastic cased plugs, cheaply made from the 60s onwards and intended for Dixons music centres and cassette recorders.)

That's the epitome of DNM plugs and they would't use them if they detracted from what they wanted to achieve with their amps as they don't like to use metal in their products.DNM certainly don't make shoddy products.A lot of their stuff over the years has been groundbreaking.

Indeed Denis Morecroft of DNM deliberately uses plastic as opposed to metal cases on his DIN plugs to eliminate loose coupling of the signal to the metal case which he believes detracts from the signal... DNM is another advocate of DIN. Further DNM has specialised in High Frequency termination units in their DIN connectors to stop out of band frequencies reflecting or otherwise flowing affecting the feedback characteristics of delicate audio circuitry...