Taperssection.com
Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: Charliebrm on May 27, 2021, 06:53:26 PM
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I have 4 of these Radio Shack 274-017C adapters. Frankly I bought them ages ago expecting I'd be handling more small band recording but my path didn't go that route, with direct cabling, so I've never used them.
Now I'm more involved with recording from various lavalier mics – typically 3 mm TRS needing plugin power – into a variety of portable devices, particularly Tascam DR-40, Tascam DR-70D neither of which are friendly to 1/8" plugin power and unbalanced lavaliers. I'm aware of the Rode VXLR Pro as a resort but I've got boxes of components and parts looking for something to get soldered to them.
Any thoughts on what the internals or the complete adapters could be applied to in this age? Are the transformers even considered passable for audio? I hate throwing out things that can have another kick at the can if I knew what they'd be good for.
(https://blackrivermedia.ca/wp-content/uploads/2021/05/Impedance-adapter-diagram-800px.jpg)
(https://blackrivermedia.ca/wp-content/uploads/2021/05/Impedance-adapter-XFR-800px.jpg)
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I patched out of a friend from CT. for the Dead shows at Autzen stadium in 1994, he and another taper would use converters like this to run long cabling from one side of the board directly facing the stacks to another taper on the other side of the board. This gave us direct straight shots to the speakers, one taper on one side with his deck and one on the other side. Great sounding set-up, I've run at Autzen throughout the years, this was prob. the best sound I've got from there. They used equal cable lengths for both channels. This is a good use for these, I believe. Bob
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Those adapters are a good safe option anytime you need to interconnect unbalanced and balanced gear, providing/accepting a true balanced and isolated signal on the 3 pin XLR. Using them, you don't have to worry about the particulars of various direct-wired conversion schemes specific to different pieces of equipment.
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Quick question- is the other end 1/4 inch female?
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Quick question- is the other end 1/4 inch female?
Yes. The "input" end is 1/4" female. Tip Sleeve 1/4"
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Interesting. Used these before to isolate gear.
I wonder if cutting the middle wire (pin 1 on the XLR) would avoid ground loops.
I think this is the way "ground lift" works on some boxes.
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These are designed, I think, to let you plug a guitar or keyboard into a balanced microphone input on a mixer. I don't think they're 1:1 isolation devices (which certainly exist) but instead, the transformer may be wired to step the voltage down by 20 dB or more.
Also, audio transformers that small are hard to make well. These may be fine for casual use and for speech applications, but I would want to measure and listen carefully before trusting them for any music recording that I cared about.
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Essentially same as a transformer coupled direct box, but in a barrel with no ground lift option. Hi-Z 1/4" to 600Ω balanced, probably 50K hi-Z. Not meant for significant source level, more like hi-z mic or instrument. A hot keyboard could overload it in the bass. You can put an xls gender revers inline and plug a 1/4" cable into it to use it the other direction, low-Z step-up to hi-Z.