Tripp Lite IS250 Isolation Transformer Review for Audio (Video)

[amirm]

Follow up review of my Tripp Lite IS250 Isolation Transformer for audio fidelity applications.

 

[AdamG]

Making a face like that, no words are really necessary. Your expression says it all! Meme worthy stuff.

 

[Ismapics]

Lets proclaim that the main rule in audio accessories should be: Never solve a problem that does not exist. Now say yours.

 

[Jim Shaw]

Lets proclaim that the main rule in audio accessories should be: Never solve a problem that does not exist. Now say yours.

For me, the first rule is: An audio playback system, first and foremost, should not be annoying.

 

[Anthony101]

But what manner of audiophools would contemplate paying $140 for this device!

 

[Jim Shaw]

Well, using this item for general audio applications is a misapplication of the term 'isolation,' as well as the device. Yes, it might swallow up some spikes and whatnot in the power lines, but the audio system components' power supplies should do that. This should be the central premise of any tirade against this hardware. Likewise, if you voluntarily use a separate diesel engine generator to power/purify your audio system, it's another misapplication. Any fool would know that, but not some audiofools, apparently. As to the ground pin on the outlets, what in hell would you hook it to? The goal is to have an isolated and balanced hot and neutral connection, not an isolated earth. How would you isolate an earth ground? [Hint: with another earth ground, never none.]

I have used isolation transformers in labs for decades and they serve a purpose -- a purpose that a mere music listener would find hard to understand. Explaining this with a series of measurements is like handing a calibrated micrometer to a Chimp: he will use it to beat others about the head.

Similarly, I don't blame Cummins gasoline engine company for selling gasoline engines; I would surely blame someone misguided enough to use one to drive a vinyl record turntable or a tape capstan. I would blame them if they told you to do it.

 

[DualTriode]

@amirm,

Thanks for the review.

That is an interesting thing about the green or bare wire safety ground being bonded to the Neutral, Grounded Current Carrying Conductor back at the service entrance panel.

So things are not so isolated after all.

Thanks DT

 

[jameslab]

Follow up review of my Tripp Lite IS250 Isolation Transformer for audio fidelity applications.

Since I am a cheapskate I buy old used equipment and keep stuff for a long time. One thing that plagues me is noise from transformers, particularly toroidal transformers, especially when they start to delaminate. But also, apparently DC offset, even small amounts, can cause toroidal transformers to hum. So while an isolation transformer will not reduce signal output noise in a Topping D90, it may be useful to reduce mechanical noise in a power supply itself. I expect this is not an issue with the Topping D90 (and I don't know if it has a SMPS or a linear one). But one function of an isolation transformer that was not mentioned in the review, or tested, is that it blocks DC. If this device uses an EI transformer, and I expect it does, it will be less sensitive to DC offset than a toroid. I have a preamp with a noisy toroid that might benefit from this isolation transformer. It won't reduce noise coming out of the speakers, but if it reduces noise coming from the stereo cabinet that still lowers the SINAD that reaches my ears and could very well be worth the money. Please consider actual use cases and test for them before concluding something has no value.

 

[amirm]

Please consider actual use cases and test for them before concluding something has no value.

Did you not watch the introduction of the video?

 

[Lambda]

Please consider actual use cases and test for them before concluding something has no value.

The video actually makes this very what is scope of the review and what not.

The transformer as is without modification is not very us full

it can be modified but i would not advice to do so if you don’t know what your doing.

 

[DualTriode]

Hello All,

Also interesting about large EI transformers is Mains Leakage or radiation. That hum and harmonic series gets into everything and is one of my worst complaints about vacuum tube circuits.

First you have your B+ voltage supply, then you have your H+ supply. Even with high quality filters and regulators that transformer radiation gets into everything.

Thanks DT

 

[DonR]

Hello All,

Also interesting about large EI transformers is Mains Leakage or radiation. That hum and harmonic series gets into everything and is one of my worst complaints about vacuum tube circuits.

First you have your B+ voltage supply, then you have your H+ supply. Even with high quality filters and regulators that transformer radiation gets into everything.

Thanks DT

Thus toroids.

 

[DualTriode]

Thus toroids.

you might think.

but no such luck

 

[DonR]

you might think.

but no such luck

Toroids should only emit magnetic energy on the axis of the hole. It should be minimal elsewhere unless it's poorly constructed.

 

[DualTriode]

Toroids should only emit magnetic energy on the axis of the hole. It should be minimal elsewhere unless it's poorly constructed.

You might want to think.

But no such luck.

Remember; 1ppm is -120dB.

One drop poisons the the well.

 

[DonR]

You might want to think.

But no such luck.

Remember; 1ppm is -120dB.

One drop poisons the the well.

But how would you know in a tube amp?

 

[DualTriode]

But how would you know in a tube amp?

This is a FFT of a 12B4A Headphone amplifier built by me with shunt regulated B+ and H+ voltage regulators.

The FFT was mostly done to view the noise floor.

One reason that I know.

to view

 

[DonR]

This is a FFT of a 12B4A Headphone amplifier built by me with shunt regulated B+ and H+ voltage regulators.

The FFT was mostly done to view the noise floor.

One reason that I know.

View attachment 198825to view

I was only half-joking and by the looks of that second and 3rd harmonic maybe I wasn't. Are you sure the 60Hz isn't heater hum?

 

[DualTriode]

I was only half-joking and by the looks of that second and 3rd harmonic maybe I wasn't. Are you sure the 60Hz isn't heater hum?

Heater hum or B+ hum either or both I do not know.

Both the heater supply and B+ both had similar transformers, bridge rectifiers, capacitor, inductor filters and voltage regulators. The filters and regulators got rid of all the rectifier switching noise and a large part of the 60 hZ hum. Yet a few parts per million 60hZ hum remains. I blame it on the transformer / mains leakage.

The distortion series is classic Single End Triode distortion.

I have used operational amplifier correction to clean up the SET distortion but If you do that it is not tube tech any more.

DT

Even using the solid state power supplies and regulators is cheating a bit.

 

[hifiamps]

This is a proper isolation transformer. 3kVA.