XLR to RCA to XLR

Thanks Tvad and Almarg for the info. I've since looked into it a bit more with regards to the input and output voltages I'm dealing with and I may be OK just using XLR to RCA cables with the shields floating at the RCA ends. If that doesn't yield the results I want, I will pick up some transformers.

Hi Jedinite,

Regarding the Rane BB44X, which I see sells at B&H for $279, based on a quick Google search I didn't find much that would shed light on the sound quality it would provide in a high-end home audio system.

Looking at the datasheet, though, a concern would be that while a statement is made that the unit provides "wide bandwidth," the only spec that is provided is that frequency response is 20 Hz to 20 kHz +/- 2 db. The 2 db tolerance is very uncomfortable, IMO, and the fact that no margin is indicated relative to the audible frequency range is as well. Without a margin of 5 times or more (i.e. 4 Hz to 100 kHz), and preferably even approaching a factor of 10, I would not feel comfortable that audibly significant phase shifts wouldn't occur within the 20 Hz to 20 kHz range.

In contrast, Steve McCormack's unit is specified as having a 3 db bandwidth of 0.5 Hz to 150 kHz, and the frequency response graph shown in the datasheet for the Jensen PC2XR shows it as being in a similar ballpark.

Also, some cautions that would apply if any of these level converters were used to step UP "consumer level" to "pro level":

First, using one of these devices in that direction will increase the impedance seen "looking back" from the destination device toward the signal source by a factor of about 16 (corresponding to the square of the nominally 4:1 turns ratio), and will decrease the load impedance seen by the signal source by that same factor of 16. That will result in impedance incompatibilities in many cases.

Second, at 20 Hz the unbalanced input of the Rane device will reach its overload point at only 1.68 volts, with the Jensen PC2XR being only slightly better in that respect. So, as might be expected, one would not want to use one of these transformers to step UP the outputs of unbalanced signal sources which provide the 2 volt kinds of levels that are typical these days, especially with digital sources. And chances are that other components in the signal path would overload as well, if that were done.

These two cautions do NOT apply to 1:1 transformers, such as the Jensen PI models, and do NOT apply to the 4:1 level converter devices when used as step-DOWN transformers, i.e., going FROM "pro levels" TO "consumer levels."

Regards,
-- Al

FWIW...Steve McCormack uses Jensen transformers in his VRE-1, and I assume in his Flex-Connect unit as well. He's extremely particular and thorough in his evaluation of parts, so I have to assume he's done his homework and has concluded the Jensen products are the best sounding alternatives out there.

Jensen makes 1:1, 1:2, 1:4, 2:1, 4:1 transformers, and I suspect any of these could be built into their XLR>RCA or RCA>XLR converter boxes at a customer's request.

My experience with the Jensen XLR>RCA converters, and with the VRE-1C (and beginning with the VRE-1) is that the units just flat out work. I've experimented with enough XLR>RCA adapters and various grounding units to know that I would no longer waste my time with anything else. When something works well, the money is well spent, and in my view, the cost for the Jensen units is reasonable when viewed relative to the cost of equipment and tweaks in larger world of high end audio.

The Rane piece looks good. I like that it's totally passive. I wonder if it would work well just for balanced to unbalanced when -10 to +4 conversion is not a concern.
What's confusing is, it seems balanced doesn't always mean "pro" or +4 and unbalanced doesn't always mean "consumer" or -10. What does most high-end balanced home audio (not pro) gear operate at, +4 or -10?

01-23-13: Rdeckard
What's confusing is, it seems balanced doesn't always mean "pro" or +4 and unbalanced doesn't always mean "consumer" or -10. What does most high-end balanced home audio (not pro) gear operate at, +4 or -10?

The reference to unbalanced signal levels on consumer equipment being around -10 dbV lost whatever meaningfulness it may have once had when the CD medium was introduced, which was standardized with a full scale (maximum) level of 2 volts, for unbalanced outputs. 2 volts is +6 dbV, or +8.2 dbu. Some digitally based equipment will exceed even those numbers significantly, while phono stage outputs will usually be considerably less.

Each situation needs to be analyzed individually, although it is more common these days to have too much signal and too much gain, rather than too little, regardless of whether the connections are balanced or unbalanced.

Grant (Tvad), thanks for your always knowledgeable inputs.

Regards,
-- Al