Blue Jeans Cable Isolation Transformer Review

[DualTriode]

Hello All,

This device is designed to remove hum from a subwoofer.

Remember by definition at X-max a woofer is operating at 10% distortion.

Also by definition a sub-woofer operates up to 20% distortion.

With that said why are we testing this device above sub-woofer frequencies?

Why are we looking at a 1kHz FFT plot? What does that prove?

 

[Chrispy]

Hello All,

This device is designed to remove hum from a subwoofer.

Remember by definition at X-max a woofer is operating at 10% distortion.

Also by definition a sub-woofer operates up to 20% distortion.

With that said why are we testing this device above sub-woofer frequencies?

Why are we looking at a 1kHz FFT plot? What does that prove?

Also interested in an explanation along these lines. Just generally doesn't look to be a very good product for any application.

 

[amirm]

Remember by definition at X-max a woofer is operating at 10% distortion.

Also by definition a sub-woofer operates up to 20% distortion.

With that said why are we testing this device above sub-woofer frequencies?

I explained that in the review at the start. The bulk of testing was at sub frequencies including this dashboard at 40 Hz:

That is 54% distortion. It is going to be easily audible as evidenced by reports of heavy distortion:

"I just got one, and it really quieted my sub amps. I have four inuke 3000dsp with one ds4 per. With nothing playing through the speakers, I can hear a quiet hiss / hum noise. I have tried through cable management and a grounding wire to the avr from amps to quiet the noise, and it is almost quiet. Then I added this peice. Dead silence. But, now with heavy bass, my subs destort very badly like I've never heard before. So I removed it, and the bass is back to normal."

This whole hand waiving thing on bass distortion needs to stop. I hear bass distortion almost every time I test a speaker. Clip an amplifier and it too badly distorts bass. Even before full clipping that spray of harmonics stomps on low level detail and/or causes brightness.

 

[Rja4000]

And to put things in perspective, here is another transformer-based isolator measurement at 0dBu (0.775V) 40Hz

(See more here)
And this is not a crazy expensive device ($75/channel). You may find better, for sure.

So doing better with a transformer is possible.

 

[ronnzi]

I’m glad I dodged this one. Recently had to purchase a ground loop isolator for two of my subs and went with the Jensen unit here:

SUB-2RR | Jensen Transformers

Inside, a specially designed Jensen audio transformer with extended sub-sonic response delivers powerful and articulated bass for maximum impact. Even when being subjected to extremes, the SUB-2RR is able to gracefully handle low frequencies down to 20 Hz with less than 0.01% distortion and less...

www.jensen-transformers.com

I will say, I was surprised that I seemed to lose some output at the gain level I had the subs set to, but I simply added it back in my MiniDSP (I have plenty of headroom).

I know Amir already tested the Jensen transformers meant for main speakers, but hopefully he’ll get his hand on some of these subwoofer ones. I’m really curious if it holds up as well as the others (given their reputation, I’m hoping they should).

 

[RF Air]

Thank you Amir for this Review. I would consider this product a "wake up" for BJC. I discovered their products here in the Forum and have purchased, as well as recommend BJC to other Forum members.

A reputation is hard earned, yet lost in mere moments with an oversight or poor decision. It should be expected that BJC will respond to this Review, at least if they care to explain, maintain or defend their reputation or repudiate the tested product.

From a Tort perspective, BJC should at least take responsible action with it's supplier of the product, or make a decision to investigate these test results with the Product Manufacturer. Like any business, mistakes occur. Responding to a mistake or deficiency of any one product is very important to future sales of every product you offer.

We will see if BJC responds and reports back to the Forum. It's an opportunity to demonstrate character and a defense for their reputation. Even the admission of a mistake, if factual, has the underpinning of good character in a business community.

 

[sealman]

Maybe you should consider the concept of free will, it means you can vote however you wish.
Maybe you’d be more comfortable in North Korea or China, I believe it works the way you prefer over there.

I don't have an issue with anyone voting "great" for this product. I would however really like to know their reason why they think it is great.
That free will concept does indeed work both ways. I would like the ability to exercise my free will to put the trolls on my ignore list as they have nothing I am interested in reading.

 

[sealman]

So people can discredit them? Or for what would that be necessary?

I don't have the time or energy to attempt to discredit anyone. I would like the ability to just "ignore" them instead.

 

[fpitas]

Well, if you're BJC, coming on here and letting the peeps kick you will you're down is probably not a good idea. I don't see this tangent as being a problem with their longer reputation....which has been just fine.
Relative to some extremely goofy and ill-conceived audio products in the larger market, this is hardly even a blip on the radar screen.

All true, but this may be a wake-up call if they didn't realize how this thing performs.

 

[dasdoing]

they should do a recall for these lol

 

[elmoe420]

Better than silver soldered? No. World's Best can provide good components for the same price and don't push BS that Blue Jeans has gotten into of late. Basically you can no longer trust them. They'll sell you stuff like this broken design to accommodate sensibilities of audiophiles that aren't based upon reality.

Here is a quote from a World's Best product detail page on Amazon:

"With an industry-leading total of 4480, 99.99% Ultra-Pure Oxygen Free Copper (OFC), 0.08mm ultra-fine strands, this heavy gauge cable will effortlessly deliver deeper lows, sweet mids and higher highs without any fear of signal loss. Satisfying all the most stringent requirements of the most demanding audiophile."

Sure sounds like the typical audio cable marketing nonsense to me.

I also wouldn't write home about World's Best prices. Their products are all assembled in Sri Lanka so they are making very large margins at those prices. Many of the cables I buy from BJC are assembled right here in Seattle, WA. Big difference in labor costs, let alone working conditions, from Sri Lanka.

As for the product tested in this review, clearly it's awful and a big thanks to Amir for objectively establishing that fact. Hopefully BJC will engage with him on the data and offer a working alternative in the future.

 

[Billy Budapest]

Here is a quote from a World's Best product detail page on Amazon:

"With an industry-leading total of 4480, 99.99% Ultra-Pure Oxygen Free Copper (OFC), 0.08mm ultra-fine strands, this heavy gauge cable will effortlessly deliver deeper lows, sweet mids and higher highs without any fear of signal loss. Satisfying all the most stringent requirements of the most demanding audiophile."

Sure sounds like the typical audio cable marketing nonsense to me.

I also wouldn't write home about World's Best prices. Their products are all assembled in Sri Lanka so they are making very large margins at those prices. Many of the cables I buy from BJC are assembled right here in Seattle, WA. Big difference in labor costs, let alone working conditions, from Sri Lanka.

As for the product tested in this review, clearly it's awful and a big thanks to Amir for objectively establishing that fact. Hopefully BJC will engage with him on the data and offer a working alternative in the future.

Agreed re Worlds Best Cables. American company, utilizing internationally sourced cables and jacks, with connectorization in Sri Lanka. I’d rather have the same cables and jacks assembled in the USA, like BJC and others are doing.

 

[BoredErica]

So it's possible for ground loop isolators to cause performance issues. Could same be for DC offset blocker? Different product for different situation but I wonder. EG my iFi SilentPower DC Blocker.

 

[fpitas]

So it's possible for ground loop isolators to cause performance issues. Could same be for DC offset blocker? Different product for different situation but I wonder. EG my iFi SilentPower DC Blocker.

A DC offset blocker has no obvious way to contribute audible distortion.

 

[fpitas]

He did voltage and frequency sweeps: see the last graph.

 

[frogmeat69]

what your favorite album from them?? im torn between twisted into form being great all around and fairly progressive, but forbidden evil has their best songs.

Twisted Into Form is what turned me onto them,so I would pick that, but I like pretty much all of their stuff.
I would always discover bands with their 2nd album releases for some reason back in the 80's and early 90's, including Forbidden.

 

[Chrispy]

Back to the WBC stuff for a bit as to whether their marketing is more a poke at audiophilia or not, more about their pricing. They use good construction, materials and connectors and the value in that respect is very good, the manufacturing location not so much but what's new in consumer products in that respect?

 

[beeface]

BJC had built up so much good will, but between this and the Iconoclast Cable they're definitely starting to squander it

 

[JSmith]

From a Tort perspective, BJC should at least take responsible action with it's supplier of the product, or make a decision to investigate these test results with the Product Manufacturer. Like any business, mistakes occur. Responding to a mistake or deficiency of any one product is very important to future sales of every product you offer.

I agree and I'd suggest it's most likely BJC had no idea about the quality of this product and were simply buying/selling it, rebadged with their brand... still, they should remedy the situation as much as possible to protect their reputation. What would be interesting is to ascertain which company made this device and under what other names it is sold.


JSmith

 

[Sal1950]

This is a major miss for a company like Blue Jeans Cable which produces very good cables at very reasonable prices. Whoever thought of this product clearly had no understanding of what transformers do to signals other than isolation they provide.

Wow, another stab at BJC's prior high integrity rating.
I don't know what's going on over there but its not good.