Long RCA interconnects from phonostage to preamp

[newlash09]

Hi all.

Iam considering moving my turntable from the present rack to the center of my right side wall. This will entail running almost 4 mtr long interconnects from my Big bottle mk3 phono stage to my MFA passive preamp. Will there be any degradation in sound quality or hum issues from the above.


Alternatively I also have a active preamp in storage. I read somewhere that the MFA passive preamp can convert a incoming RCA input to balanced via its XLR outputs. I really don't know if that's really possible. However if that is so, can i feed the RCA output from my phono stage to RCA inputs of the MFA. Then use the MFA with its volume at max position to send the signal via 4 mtr long XLR cables to my active preamp.

I know it sounds like a lot of faff. But iam really cramped for real estate at the moment. Thanks in advance for any suggestions.

 

[newlash09]

Found the answer to my above question on the MFA website

The passive does convert unbalanced RCA to truly balanced XLR. And long XLR runs of even 10 mtrs, are apparently fine. As the MFA is transformer coupled and doesn't suffer from impedence issues, even on long runs.

Just thought I'd share the above for the benefit of others

So I will be moving my turn table after all

 

[audio_PHIL_e]

Good luck with the re-organisation

 

[newlash09]

Bummer

My active T+A P1260R preamp doesn't have XLR inputs

But it's not a deal breaker as I will use XLR to RCA plugs for sometime, till I replace the T+A with a DEQX Pro 8 HD active processor cum preamp.

 

[newlash09]

Good luck with the re-organisation

Thanks sir

 

[bencat]

Using a standard passive I would say that long ic cables would be not a good thing . However as the MF is transformer coupled then it should be able to cope with the long ic cable and still work fine . Sadly all of that is just theory in my head and of course the only real way to tell is if you try it . My suggestion would be to look for a decent quality but cheapo set of ic cables and give it a try . If they work okay then you can either leave it at that or get a better quality level of cable that will satisfy you .

 

[audio_PHIL_e]

My active T+A P1260R preamp doesn't have XLR inputs

hmmm ... can you get a box that has XLR/balanced in and RCA/unbalanced out so you can put it near your preamp and still have the advantage of a balanced long-run from your source?

 

[audio_PHIL_e]

Bummer

My active T+A P1260R preamp doesn't have XLR inputs

But it's not a deal breaker as I will use XLR to RCA plugs for sometime, till I replace the T+A with a DEQX Pro 8 HD active processor cum preamp.

hang on, didn't you say you were using a passive pre?

 

[newlash09]

Using a standard passive I would say that long ic cables would be not a good thing . However as the MF is transformer coupled then it should be able to cope with the long ic cable and still work fine . Sadly all of that is just theory in my head and of course the only real way to tell is if you try it . My suggestion would be to look for a decent quality but cheapo set of ic cables and give it a try . If they work okay then you can either leave it at that or get a better quality level of cable that will satisfy you .

Thanks sir....since I have two preamps already at hand, I can even try using the T+A from the phono stage and then use XLR's to the MFA. Does anything like a sheilded XLR even exist...just curious.

 

[newlash09]

hang on, didn't you say you were using a passive pre?

Yes sir

I actually have 2 preamps at hand. A passive MFA and a active T+A. The MFA has both RCA and XLR inputs and outputs. But the T+A only has RCA inputs, but one each XLR and RCA outputs, and it has the option to enable either or both of the outputs.

 

[dave]

If you are running a 4 meter line level cable I am not sure you would get much benefit from going balanced apart from the potential gain of electrical isolation. But there would be a cost of including a transformer, (although some people like that). Primary concern would be HF loss caused by the potentially high output Z for the bottle head, which balanced shouldn't help with , and / or the dreaded ground loop, which balanced isolated could help with.

 

[bencat]

Thanks sir....since I have two preamps already at hand, I can even try using the T+A from the phono stage and then use XLR's to the MFA. Does anything like a sheilded XLR even exist...just curious.

Because of the construction of XLR balanced cable they do not require any sort of shield as they split the signal in to three and each has its own separate run which makes them almost impervious to any interference . This was needed for their true home which is studio and concerts were very long 50ft + lines are used and need to be strong and distortion free . I will admit I do not know if there are any XLR cables made with shields but any XLR balanced will be much better than any RCA shielded or not . That is for resistance only and not a comment on the sound quality of either sort of cable .

 

[newlash09]

hmmm ... can you get a box that has XLR/balanced in and RCA/unbalanced out so you can put it near your preamp and still have the advantage of a balanced long-run from your source?

I will have to explore that option sir. I've seen XLR to RCA plugs, and was under the impression that they did the same thing.

 

[karlsushi]

With a passive pre, I have found that a buffer can work wonders to resolve impedance matching issues. More of an issue with LDR or stepped attenuator type passives though. Like you say, perhaps not an issue with a Transformer-based passive.

The Musical Fidelity X-10D is a very good buffer and lets you have some fun with valve rolling if that's of interest. Pass Labs B1 is also a well-regarded buffer.

A buffer is unity gain (i.e. won't affect the volume), so you can place it before or after your passive.

But as ever with audio, I would still recommend the 'less is more' approach, so if you can live without one, then all the better.

 

[newlash09]

If you are running a 4 meter line level cable I am not sure you would get much benefit from going balanced apart from the potential gain of electrical isolation. But there would be a cost of including a transformer, (although some people like that). Primary concern would be HF loss caused by the potentially high output Z for the bottle head, which balanced shouldn't help with , and / or the dreaded ground loop, which balanced isolated could help with.

Iam sorry sir, but I couldn't understand your goodselves fully. Can you kindly please elaborate in more detail, as iam really dumb at electronics

 

[newlash09]

With a passive pre, I have found that a buffer can work wonders to resolve impedance matching issues. More of an issue with LDR or stepped attenuator type passives though. Like you say, perhaps not an issue with a Transformer-based passive.

The Musical Fidelity X-10D is a very good buffer and lets you have some fun with valve rolling if that's of interest. Pass Labs B1 is also a well-regarded buffer.

A buffer is unity gain (i.e. won't affect the volume), so you can place it before or after your passive.

But as ever with audio, I would still recommend the 'less is more' approach, so if you can live without one, then all the better.

Thanks for the advise sir

Will keep a unity gain buffer as a option for now. But to the extent possible I would love to retain the MFA in the chain directly if possible. As it's the most transparent one I've ever heard, and absolutely love it to bits

The problem is that my cheaper MFA beats way more expensive preamps I've had in my system. It took a 17K , 2 box karan preamp to beat it noticably. Thus, iam worried that the addition of a buffer ( especially if powered), might not stand up to the MFA's transparency.

 

[audio_PHIL_e]

Yes sir

I actually have 2 preamps at hand. A passive MFA and a active T+A. The MFA has both RCA and XLR inputs and outputs. But the T+A only has RCA inputs, but one each XLR and RCA outputs, and it has the option to enable either or both of the outputs.

so maybe what you want is a splitter with XLR in and XLR & RCA out. I've seen similar (1/4" mono jack in & out plus XLR out) used to send signal from electric bass to backline amplification and to the PA, so I'm sure it must be possible to get (or make) a stereo box with the required interfaces on it.

 

[newlash09]

so maybe what you want is a splitter with XLR in and XLR & RCA out. I've seen similar (1/4" mono jack in & out plus XLR out) used to send signal from electric bass to backline amplification and to the PA, so I'm sure it must be possible to get (or make) a stereo box with the required interfaces on it.

Thanks sir...will explore that option too.

 

[audio_PHIL_e]

Thanks sir...will explore that option too.

I've got (somewhere) a DI box like I mentioned, and while you can get battery-powered (active) DI boxes, mine is (iirc) passive. I learned that it was not a good idea to let it sit on top of the bass amplifier (or indeed ANY amplifier) as it would buzz like hell, so I used to put it on the floor next to the bass rig and use relatively short coax to get the signal from the box to the bass amplifier's i/p.

 

[zeta4]

Because of the construction of XLR balanced cable they do not require any sort of shield as they split the signal in to three and each has its own separate run which makes them almost impervious to any interference . This was needed for their true home which is studio and concerts were very long 50ft + lines are used and need to be strong and distortion free . I will admit I do not know if there are any XLR cables made with shields but any XLR balanced will be much better than any RCA shielded or not . That is for resistance only and not a comment on the sound quality of either sort of cable .

If it helps , 3 pin XLR cables are wired Pin 1 - cable screen, Pin 2 -signal positive or "hot", Pin 3 - signal negative or "cold". When a XLR cable
is converted to RCA Pin 2 (and sometimes pin 1) are connected to the RCA plug's ground connection. When this is done the connection is no longer balanced.