[jtwrace]

I've ordered two to try to get rid of the last bit of noise.  It's so slight but am really curious to know if it will solve my issue. 

http://www.jensen-transformers.com/

[Dan Banquer]

I use one in the SPDIF coax line from my computer sound card to my DAC.
The sound card has a small transformer on the output of the SPDIF line which I found to be inadequate.

Regards;
Dan Banquer

[ctviggen]

They may or may not work.  I used one for a subwoofer that had some hum, and it did not help at all.  I then put the sub on the same phase as the rest of the system (that is, the electrical phase at the breaker), and that fixed the hum.   

So, in that case, the hum was not caused by whatever the Jensen transformers correct (typically DC/low frequencies on the coax cable). 

[jtwrace]

They may or may not work.  I used one for a subwoofer that had some hum, and it did not help at all.  I then put the sub on the same phase as the rest of the system (that is, the electrical phase at the breaker), and that fixed the hum.   

So, in that case, the hum was not caused by whatever the Jensen transformers correct (typically DC/low frequencies on the coax cable).

I only use one dedicated line for all my equipment.  I should be ok in that dept I think.

We'll see..

[NagysAudio]

jtwrace- Where will you be putting this transformer, between line-in, line-out? What sort of noise do you have in the system? Hum? The transformers will introduce significant distortion if you use them for low lever signal.

[Speedskater]

Many of the world's best mic pre-amps use Jensen transformers. If the proper Jensen transformer is chosen for the task at hand, no distortion will be added. 
But Jensen makes lots of transformers, make sure that you get the correct ones.

[jtwrace]

Many of the world's best mic pre-amps use Jensen transformers. If the proper Jensen transformer is chosen for the task at hand, no distortion will be added. 
But Jensen makes lots of transformers, make sure that you get the correct ones.

Thanks for the tip!  Yes, I spoke with David from Jensen and he helped me pick them out.  They arrive tomorrow.

[Norman Tracy]

For the record this statement "transformers will introduce significant distortion if you use them for low lever signal" is nonsense. 

Of course bad transformers are, well bad and do bad things. Jensen transformers are good (very good actually) and do good things chief among these good things are isolating the grounds of the gear they are placed between. The author jtwrace did not mention if he is getting just the transformers or the packaged and connector-ized ISO-MAX product. If the former when you install the transformer follow Jensen's recommendations to achieve the desired result of galvanic isolation.

Also jtwrace nice enclosures you are offering. If you are using the Jensens in a system using the class-D amps you designed the case for you will enjoy the added benefit of additional filtering of the switching noise one must control to reap the many benefits of class-D.

To read up on this topic a good start is to Google "pin-1 problems". Most of the articles that will return as hits will be discussing professional gear with XLR connectors. Keep in mind in our consumer gear with RCA connectors it is worse as different components share grounds and the noise currents therein.

[panomaniac]

I like the Jensens.  Hard to beat for the price, or any price.  They work well.
They do NOT add distortion if you use them as they are meant to be used.  Over driving anything will add distortion.

I've auditioned and measured  a lot of transformers.  The Jensens are very nice.

[jtwrace]

I like the Jensens.  Hard to beat for the price, or any price.  They work well.
They do NOT add distortion if you use them as they are meant to be used.  Over driving anything will add distortion.

I've auditioned and measured  a lot of transformers.  The Jensens are very nice.

That's great to hear!     People seem to have good luck with them or they don't solve the issue at hand.  Nobody until the post above has mentioned that they add distortion and don't sound good.  There have been many happy users / manufacturers.  Thanks for the reassurance.

For the record this statement "transformers will introduce significant distortion if you use them for low lever signal" is nonsense. 

Many people have told me they don't as well.  In fact, it's the complete opposite.

Of course bad transformers are, well bad and do bad things. Jensen transformers are good (very good actually) and do good things chief among these good things are isolating the grounds of the gear they are placed between. The author jtwrace did not mention if he is getting just the transformers or the packaged and connector-ized ISO-MAX product. If the former when you install the transformer follow Jensen's recommendations to achieve the desired result of galvanic isolation.

Dave from Jensen recommended the PI-2XX for before my active crossover and the PI-XX at each mono block (Clayton Audio M-300).

Also jtwrace nice enclosures you are offering. If you are using the Jensens in a system using the class-D amps you designed the case for you will enjoy the added benefit of additional filtering of the switching noise one must control to reap the many benefits of class-D.

Thanks for the compliments.  It was just something to help out the diy guys so they would have something really nice.  I will certainly try them on the Class D as well. 

To read up on this topic a good start is to Google "pin-1 problems". Most of the articles that will return as hits will be discussing professional gear with XLR connectors. Keep in mind in our consumer gear with RCA connectors it is worse as different components share grounds and the noise currents therein.

Yes, I have read about the pin 1 problem to tears.  Unfortunately that doesn't seem to be the issue.  That would've been waaay to easy.   

[FullRangeMan]

Just look in the Jenses site, I was surpridsed, seems they do not made output transformers for tube amps.

[Bill Baker]

Like anything else, when used properly, transformers will provide the results you are looking for. I have used Jensens in signal applications with exceptional results. I have also seen them used in application where they did not belong or not used as they were meant to be and abvioulsy the results were not up to par.

 Use them properly and they will provide the intended results.

[jtwrace]

I have also seen them used in application where they did not belong

Such as?

[art]

Distortion will rise at very low signal levels. It is clearly shown on the distortion graphs, if you look at them. It may not be much, but it does happen. You have to pick the right one for the application. (Since when would you not do that?)

Pat

[Bill Baker]

Such as?

By that I only meant that they were not used with a circuit that would allow them to perform properly.

[face]

I wish someone would come out with a HDMI isolation transformer.

[jtwrace]

Distortion will rise at very low signal levels. It is clearly shown on the distortion graphs, if you look at them. It may not be much, but it does happen. You have to pick the right one for the application. (Since when would you not do that?)

Pat

Of course it's always prefered to put less in line...there are times that there is no option.     There are just things that can't be controlled...

Being that David who is the V.P of Op and has been there for 30 yrs, I'm fairly confident that I got the proper ones for my application that may help.

[Speedskater]

Distortion will rise at very low signal levels. It is clearly shown on the distortion graphs, if you look at them. It may not be much, but it does happen. You have to pick the right one for the application. (Since when would you not do that?)
Pat

On the Jensen graphs that I see, they chart THD + NOISE.  So the total would increase at low signal levels.

[G.Michael]

I have a Jensen Iso-Max model.

  http://www.jensen-transformers.com/ci2rr.html

I had problems with 60 Hz-related noise at the speakers, and it seemed to be caused by interaction btwn preamp and power amp (ground loop, maybe?).  I put the Iso-Max between the two components, and noise was almost entirely eliminated, and with no noticeable degradation of the signal.  Impressive  .