![]() Regarding using this as a reamp box, which I appreciate is not simply the reverse of a DI and there will be tradeoffs taking this approach:įor now I only foresee using this to cancel interference over long runs to amps/getting more appropriate signal levels to use effects pedals as outboard. Anyway, I have a few questions if anyone is able to chime in:ġ) What is the purpose of C1 and C2 on AS066, is this to block unwanted DC components across the input, or something else? Are these strictly necessary?Ģ) On AS007 there is a 6.8kΩ resistor across the input, is this to ensure the transformer always sees an impedance > 6.8kΩ? If so, on AS066, when the pad is not engaged, is there anything lacking with this resistor not being present?ģ) AS006 has an optional AC coupling block - is this worth considering for connecting synths which may exhibit some DC components, or is this over-engineering? Basing this off the AS066 design, I don't need the -10dB pad or high-cut at the input, so I will omit these going forward. I've looked over the Jensen schematics - 'typical' ( AS007) and 'full-featured' ( AS066) DI boxes, and the reamp box ( AS092) - and have a couple of queries to improve my understanding and inform design considerations. I see there are a few threads on passive DIs already, but thought it may be helpful to combine my questions in the same place. Since we still have more than enough signal, a potentiometer for each amp will do what we need.Hey, this is my first post on the forum - looking for a little guidance with Passive DI / Reamp Box design. However I suspect that the amps do not all distort at the same input so will want different levels. ![]() In some markets, a "transistor radio" 10k:2k transformer is readily available, and will give a small drop of level (still plenty to beat-up the guitar amps). Three 10k:10k transformers seems a happy solution. More if you recognize that a guitar amp needs MUCH less signal than a console can deliver. A console output can drive hundreds of feet of cable and up to 80 guitar amp inputs. > To split the balanced signal that will come from a console and to send it to 3 transformers you need buffers that will make the job. There's a link on that page to the "open source" project details if you don't want to buy the kit. (not an endorsement - never used it).įor DIY balanced conversion and isolation check out (not an endorsement - never used it). You're in luck because you need three outputs, so to isolate them all you only need two channels of isolation, and those are common e.g. If you need output isolation, they are passive, and you can find them commercially for probably a lot less money than you could build them. ![]() The buffers are used to handle impedance considerations just like buffers in pedal circuits.įor a home studio setup, you might not need the output transformers - all gear could be plugged in to the same AC in the room and not have problematic ground potential differences.įor the same reason, you might not need the input transformer, and your DAW might have an unbalanced output so you don't need balanced conversion either.īut you will need buffers, and those are simple. Ground isolation avoids noise from ground loops, which can be a big problem when long cable runs connect multiple powered devices with different ground potentials. The JD7 uses one transformer for balanced conversion and isolation of the balanced re-amp signal and device, and a bunch more for phase inversion and isolation of the outputs and devices/amps. The main purpose of the transformer is not impedance matching - it's balanced to unbalanced conversion and ground isolation (although both can also be done without a transformer).
0 Comments
Leave a Reply. |