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[Steve Shafer]

First off, I have noticed that Lundahl transformers show up in a lot of studio gear and are highly regarded.  However, they do not seem as popular (at least in the US) as Jensen transformers.  What are the differences between these two prominent transformer brands?

Secondly, has any one had hands on experience with the Cable Factory DI's?  Has any one done some side by side measurement/comparisons with some of the well known DI's such as countryman, radial, BSS ect?

Steve S

[Mats Fagerkull]

Can't really say what differances there are.....but usually the biggest differance use to be freq. spectrum, especially in the lower regions.

But my gut feeling is that if there isn't a Jensen transformer then the only other acceptable brand to me is Lundahl.

And as usual you have to look at the whole package, thus it might be possible some products with Lundahl transformers would actually be better than those with Jensen.....

Ie, if Radial suddenly stopped using Jensen and changed over to Lundahl I think there shouldn't be any reason to stop buying your DI from Radial.

And it probably doesn't matter which ever brand Behringer uses either.....

/mats

[John Roberts {JR}]

Steve Shafer wrote on Thu, 01 June 2006 10:15

First off, I have noticed that Lundahl transformers show up in a lot of studio gear and are highly regarded.  However, they do not seem as popular (at least in the US) as Jensen transformers.  What are the differences between these two prominent transformer brands? Secondly, has any one had hands on experience with the Cable Factory DI's?  Has any one done some side by side measurement/comparisons with some of the well known DI's such as countryman, radial, BSS ect? Steve S

One should be careful about reading too much into brand associations. Deane Jensen RIP was a great transformer designer and shared his wealth of knowledge in clear specifications and sundry published applications notes. Several other transformer makers have taken this published information and made decent product.

If you are trying to consider transformers as black boxes, you will rarely go wrong just plopping a Jensen into the application but you pay a premium for that comfort level.

Most manufacturers with even a modicum of price sensitivity will look beyond the brand mojo. OTOH if I were trying to position a "transformer using" product high end, there's a temptation to pay the premium and flog it as a benefit.

I'm old enough to remember when Alps faders were cheap, then when they were good, now they're back to ho-hum.

If you don't know how to read, look at the book cover. If you know how to read, see what's inside the book.

JR

[Bruce Gering]

I'm trying one out this weekend. I'm not going to A/B it with anything, but the band is one that I've worked with many times  before. I'm just going to see if I like what I'm hearing compared to the past. I usually use the same rig for these guys and it will be in a familiar venue.

[Cliff Rosenberg]

Hello-

I have a CableFactory DI-PRO-P1 DI box, I got it a few months back.  As a side note, the guy who answered the phone at CableFactory was very fast and friendly to deal with, which is becoming less and less common these days, and they shipped my order same day (express was cheapest option) which is even more rare. The DI-PRO-P1 uses the Lundahl LL1530 transformer. Since I have several well known pretty good quality DI boxes to compare it to, I'll try to do that here, un-scientifically, "by ear"....

Units Compared to:

BSS AR-133
Countryman "Type 85"
Radial "JDI" passive DI
Radial J48 active DI
Whirlwind "DIRECTOR" passive DI
ProCo "DB-1" passive DI


DI-PRO-P1 pluses:

-Simplest design of the whole bunch with one (recessed) switch only, for "ground lift"
Single piece anodized aluminum casing, very rugged
-Entire box contains ONE very thick printed circuit board with super-fat traces for all signal paths
-All components securely fastened to P.C. board, will last through the most severe poundings with ease
-Switches and jacks look to be very high quality, will last very well
-Passive, so no 9V batteries or phantom power problems
-No one has a DI this cool looking, so it's harder to steal than usual  

DI-PRO-P1 minuses:

-No "input attenuation" settings, so very high input levels could distort; the LL1530 is rated <1% distortion @ 50Hz with a +16dBU input (800ohm source imp.) per www.lundahl.se
-No filters for high or low cut functions
-No Phase invert switch
-Can load down certain piezo pickups and negatively affect output and frequency response
-No well-known "brand name" to impress all the audio "techies" around your gig  

The DI-PRO-P1 held up under the most demanding signal sources. I think that there are two ways to test how good a DI is: high level low frequency signals like active bass pickups and keyboards and very fussy "piezo" instrument transducers like  used for violins and acoustic guitars (impedance "loading" effects). As expected, the non-active DI's produced the usual low-end "cut" and overall level drop on the unbuffered piezo pickup due to impedance mis-match.  A > 1Meg ohm input impedance is usually Ok to avoid this, and the active DI's with JFET designs easily provide this.  No "passive" DIs usually have more than a 1K ohm primary impedance, so the LL1530 is a good as it's gonna get at 10K ohms. I don't have the gear to test this claimed spec. accurately, so mfg. numbers are all I had to reference.

The bass freq. response was very accurate and un-distorted for the DI-PRO-P1 even with very hot "slap bass" signals, perhaps more so than any of the other passive DI's.  The cheaper Whirlwind really fell apart here, lots of distortion and pretty much bad sound overall. Almost anything except a average level passive pickup made this happen on the "DIRECTOR" box.  But it was about half the price of most of the other passives with "fancy" transformers inside.  The DI-PRO-P1 produced faithfully accurate transient response also, it definetly was less "smeared" than the non-Jensen equipped passive units. Overall I prefer this DI to a Jensen on the custom Hanewinckel bass (Bartolini P/U) I used to test them out. The BSS-133 is my favorite on violin pickups, the gal that plays for us has a ZETA "Strados Modern Violin" as well as a normal one with a Barcus-Berry 1320 piezo bridge. Still, the DI-PRO could be used to get the job done if needed, without a big fuss at all.

Summed up, the DI-PRO-P1 audio quality didn't dissapoint at all, and the no-goof controls (or lack of controls to goof up   ) would make it a lifesaver at crucial moments like "festival" gigs with lots of changeovers. The LL1530 is different sounding to my ear than the Jensen JT-DB-EPC that finds it's way into these applications. I didn't do "transfer functions" via SMAART or any other DSP measurements other than trading various DI's in and out of the circuit. All "subjective" judgements on audible differences were made by me listening to the "soloed" input channel on Sennheiser HD 25-1, Beyerdynamic DT-770, Ultrasone HFI-650 and Sony MDR-7506 headphones through a DiGiCo D5 console, on a rare "slow day" around work.

There you go, hope this helps somebody!

[Kosh]

  I have no idea why people are so hung up on Jensen transformers.  We all know the same old song of mass production vs personal attention.  The difference between transformers is the way they are made.  Is Jensen using a digital winding machine??  Why does Cadac choose Lundhal as the Hi-End option on the input of their consoles.  The proof in this DI Pro is when you do not use an amp and play your bass through the monitors, then try the neck to bridge tonal difference and I am sure you will be surprised.  I have had fiddle players refuse to leave the festival without taking my Di Pro with them. I never leave home without at least four in my tool box.

[John Roberts {JR}]

Kosh wrote on Thu, 15 June 2006 17:49

I have no idea why people are so hung up on Jensen transformers.  We all know the same old song of mass production vs personal attention.  The difference between transformers is the way they are made.  Is Jensen using a digital winding machine??  Why does Cadac choose Lundhal as the Hi-End option on the input of their consoles.  The proof in this DI Pro is when you do not use an amp and play your bass through the monitors, then try the neck to bridge tonal difference and I am sure you will be surprised.  I have had fiddle players refuse to leave the festival without taking my Di Pro with them. I never leave home without at least four in my tool box.

I'm afraid I don't know that "same old song".  

Jensen was head and shoulders better than competitors a few decades ago. Deane was the first or one of the first to computer model and measure actual transfer functions of audio transformers and tweak the designs based on that knowledge. He was also very open about publishing his specifications so other transformer makers could pretty much get similar results if they followed his recipes closely and used similar quality materials.

I don't dispute that many people may specify Jensen rather than doing the homework to make sure a given transformer is properly engineered for their requirements. For one-off projects it's probably worth the premium. Transformer design doesn't stop at the turns ratio... Metallurgy, winding geometry, lots of subtle details beyond just the physical process of how they are fabricated.

JR

[Andrew Broughton]

Do they still have those terrible 1/4" jacks on the DI-Pro? Cables practically fall out of those connectors on their own!

[Lee Brenkman]

[quote title= Why does Cadac choose Lundhal as the Hi-End option on the input of their consoles. [/quote]


Possibly because compared to Jensen, the manufacturer is on the same side of the Atlantic Ocean and the per unit cost, all applicable specifications being equal, from a more local producer is lower.

They are both makers of  some of the highest quality audio transformers available, Different designers and manufacturers might favor the "flava" of one or the other.

[Teri Hogan]

I've had the opportunity to A/B the Cable Factory Pro-DI against many high-end active DIs, including Countryman, BSS, Fishman, L. R. Baggs, Radial, and others.  In 100% of cases, the artist chose to use the Pro-DI.  It's an amazing device and as someone else said, we can't keep them in stock.

If I could describe this device in one word, it would be "honest".  What goes in is what comes out.  I almost never have to EQ anything at all, unless the instrument has an inherent flaw to begin with.

We've used the Pro-DI on acoustic guitars, fiddles, bass, mandolin, banjo and other instruments and it always, always comes up smiling.  This is the first DI I've encountered that simply gives the response you were looking for in the first place, with no outside assistance.

[ProSoundWeb Community]