Author Topic: Isolation transformer on studio monitors?  (Read 2179 times)

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Offline drummerdimitriTopic starter

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Isolation transformer on studio monitors?
« on: November 14, 2019, 06:33:01 pm »
I would like to connect my studio monitors to isolation transformers to prevent any ground loops from occurring as I've heard them buzzing in the past on some occasions.

My question is whether or not that could deteriorate their sound quality somehow. I know there will be a lower PF as this is now an inductive load from the the mains but is there any reason I shouldn't do it?



 

Offline dom0

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Re: Isolation transformer on studio monitors?
« Reply #1 on: November 14, 2019, 09:07:03 pm »
Intense buzzing in bursts is GSM interference and will never be fixed by isolation transformers.

Quote
My question is whether or not that could deteriorate their sound quality somehow.

No, unless the transformers are too small for the monitors. Then it might cause excessive ripple in the monitor's power supply under load.
,
 

Offline Gyro

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Re: Isolation transformer on studio monitors?
« Reply #2 on: November 14, 2019, 09:38:55 pm »
Also compare the cost of audio signal level isolation transformers - but check the frequency response and impedance specs very carefully, otherwise they will degrade sound quality.
Best Regards, Chris
 

Offline Audioguru again

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Re: Isolation transformer on studio monitors?
« Reply #3 on: November 14, 2019, 11:35:41 pm »
Of course an audio coupling transformer will cut and distort low frequencies, mid frequencies and high frequencies like a 60 years old guitar vacuum tubes amplifier.
It also ruins the excellent damping factor of a modern amplifier.
 

Offline David Hess

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Re: Isolation transformer on studio monitors?
« Reply #4 on: November 15, 2019, 03:58:25 pm »
A power line isolation transformer used with an amplifier studio monitor will have no effect on the audio quality unless something is drastically broken.

But don't your amplified studio monitors have balanced inputs?  They should have considerable common mode rejection which makes your problem seem more like an radio frequency interference issue.

Of course an audio coupling transformer will cut and distort low frequencies, mid frequencies and high frequencies like a 60 years old guitar vacuum tubes amplifier.
It also ruins the excellent damping factor of a modern amplifier.

Those limitations do not apply at small signal levels.  Dampening is irrelevant into the high impedance input of an amplified studio monitor and a small signal audio transformer can cover the entire audio band with low distortion and loss although they are $50+ expensive.
 
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Offline Giaime

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Re: Isolation transformer on studio monitors?
« Reply #5 on: November 15, 2019, 04:08:05 pm »
I would like to connect my studio monitors to isolation transformers to prevent any ground loops from occurring as I've heard them buzzing in the past on some occasions.

My question is whether or not that could deteriorate their sound quality somehow. I know there will be a lower PF as this is now an inductive load from the the mains but is there any reason I shouldn't do it?

If you mean an insolation transformer on the MAINS, it will do nothing for the ground loops. Unless if you cut the EARTH connection, which you shouldn't do for safety reasons.
The best way would be using SIGNAL isolation transformers, on the audio lines.
Usually balanced connection* will solve this anyway.
Are you using the internal sound card of the PC?

* Unbalanced to Balanced adapter is not a balanced connection: a balanced connection is a real balanced source, a balanced cable, a real balanced reciver.
 

Offline drummerdimitriTopic starter

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Re: Isolation transformer on studio monitors?
« Reply #6 on: November 15, 2019, 09:32:25 pm »
I have no earth connection and yes I am talking about a mains isolation transformer.

The speakers are rated at 230 W so a 500 VA isolation transformer should be enough correct?
 

Offline David Hess

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Re: Isolation transformer on studio monitors?
« Reply #7 on: November 16, 2019, 02:45:53 am »
I have no earth connection and yes I am talking about a mains isolation transformer.

The speakers are rated at 230 W so a 500 VA isolation transformer should be enough correct?

Yes, that will be more than large enough.  The speaker rating is a maximum rating and average power levels are much lower.
 

Online langwadt

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Re: Isolation transformer on studio monitors?
« Reply #8 on: November 16, 2019, 03:24:24 am »
I have no earth connection and yes I am talking about a mains isolation transformer.

The speakers are rated at 230 W so a 500 VA isolation transformer should be enough correct?

makes no sense, the speakers already have an isolated supply inside
 

Offline Al3579

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Re: Isolation transformer on studio monitors?
« Reply #9 on: November 20, 2019, 09:05:05 am »
should need it  especially if your using balanced cables. A balanced cable signal cable will have a twisted pair and ground and can be on xlr or TRS 1/4". What most people end up doing is using unbalanced TS 1/4" cables or use the unbalanced inputs.

Then there is manufacturers that produce equipment with pseudo balanced inputs.

with short cables runs unbalanced is usually sufficient unless you living in ground loop hell.
 

Offline Electro Detective

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Re: Isolation transformer on studio monitors?
« Reply #10 on: November 20, 2019, 10:03:15 am »
There are different combinations of mains isolation transformer wiring, I would suggest trying the stock standard wiring first,
before doing any dangerous earth/ground cuts  :scared:

If that's a fail, then it's time to try a pair of input signal transformers

If that's a fail, then the electronics in the active/powered/amplified monitors need attention

and yes some Ground Loop Hell may be at play here too

fwiw before doing any of the above, check and test ALL the signal cables FIRST, in a medieval fashion if necessary,

i.e. pull the lot out and start plugging till you hear the offending racket  :horse:

 
 


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