Is this a re-amp kit?

[natwalk]

Just a quick question for all the electronics bods for a relative new-by to electronics (outside of replacing pickups on guitars anyway). I was just browsing an online electronics store for interesting kits to try and expand my technical knowledge, and soldering skills to be frank and came across this,
http://shop.voltelectronics.com.au/new- ... v-kit.html
Could this be used as a re-amp box? Not great with terminology but from my limited knowledge it sounds like a very cheap pre-packed kit for a re-amp box.
If it is I'm really tempted to pick it up when they come back into stock before trying NYDaves version.

Thanks for your help in advance,

Nate

[ckeene]

A reamp box will take a line level signal and convert impedence to more closely resemble what's coming from a guitar (and sometimes will have the ability to attenuate the signal). Impedence conversion is something a transformer is naturally suited for, hence the name!

Another thing transformers are commonly used for is for converting audio from balanced to unbalanced, and vice versa. These transformers may or may not also provide impedence conversion, based on the number of windings on the primary vs the secondary.

The device here uses an op-amp to create a balanced signal. I presume this is for use with standard line-level audio and has no impedence conversion, and wouldn't be suited for reamping.

[natwalk]

Bugger, Thanks for the quick reply,
oh well I guess I'll start gathering components for the NY Dave/ Jensen re-amp I've seen here.

Thanks again for the help,

Nate

[???????]

This is a related question:

Would a passive transformer-based DI work in reverse as a reamp box? I always assumed it would (seems like it should) but I've never actually tried it.

[chris harris]

This is a related question:

Would a passive transformer-based DI work in reverse as a reamp box? I always assumed it would (seems like it should) but I've never actually tried it.

It's not the same. Some people do this, though...

A passive DI takes an instrument level signal and converts it to a signal similar to the output of a microphone. This is not the same as a line level signal. That's why you connect the output of your passive DI to a mic preamp and don't plug directly into a line level input on your tape machine or converters.

I've reamped through a passive DI (backwards) and it got the job done. But, I've also reamped with Little Labs boxes designed to do the job right. There's a big difference in the results.

[ckeene]

This is a related question:

Would a passive transformer-based DI work in reverse as a reamp box? I always assumed it would (seems like it should) but I've never actually tried it.

A DI xformer converts a really high Z load into a pretty low mic-level load, whereas a reamp starts with a line load and converts to a high Z instrument load.

Here's what i think the ballpark numbers are. Pls don't quote me on this, ok?

I think it's like 10K ohm to like 150/300 ohm for a DI and 600 ohm to 10K ohm in a reamp.

So the numbers are a little different. I think the deal is people do use DIs in reverse for reamping although it's not technically the best tool for the job.

There are a few other reamp threads recently that probably explain this better than I'm doing here.

[chris harris]

Yeah, you've still gotta attenuate the signal pretty radically coming out of your line level converter or tape machine and into the "DI in reverse". It's much more noisy than using an actual reamp box. And, simply turning down the signal going into the DI in reverse, will degrade the signal and affect the tone.

[???????]

thanks everyone.

[GooberNumber9]

Yeah, you've still gotta attenuate the signal pretty radically coming out of your line level converter or tape machine and into the "DI in reverse". It's much more noisy than using an actual reamp box. And, simply turning down the signal going into the DI in reverse, will degrade the signal and affect the tone.

I'm sure this is all true. In practice, I've never had a problem with using a Whirlwind IMP-2 backwards as a re-amp box. I do have to turn the output down a bit, but since I usually record the DI'ed guitar at a fairly low level, I don't have to turn it down that much. I haven't experienced a re-amped guitar sound be any noisier than a normal guitar sound into the same rig. YMMV.

[jonathan]

what happens when i do the line out of my 002 and put it directly into pedals, and
then back into a preamp using a 1/4 inch to xlr?

what horrible things does that do?

[ashcat_lt]

The device mentioned in the OP says it "can also convert balanced signals to unbalanced," which I would take to mean it uses the opamps to invert one leg of the balanced input and then mix it with the other, creating an unbalanced output. Likely, the input impedance is about what a line-level output would expect to see. The output impedance is probably really damn small, and will be perfectly happy connecting to anything, whether it be a low-Z mic preamp, a line input, or a high-Z instrument input.

It would probably work fine, with 3 caveats.

1) It may not isolate the ground between input and output the way a transformer would, and therefore might cause a ground loop.

2) It probably will need some attenuation, either before the input or after the output.

3) An active circuit with this many components is far more likely to cause noise and/or coloration than a straight wire. Have you tried that?

[jv]

what happens when i do the line out of my 002 and put it directly into pedals, and
then back into a preamp using a 1/4 inch to xlr?

what horrible things does that do?

Try it and see. It would probably work best if your line out of the 002 is a low level or run through an attenuator.
If you want to see exactly what is in a ReAmp, the patent is here:
http://www.google.com/patents?id=PqkXAAAAEBAJ
I built a reamp using the schematic from the Jensen website and a transformer out of an old DOD direct box and it works great.

[???????]

what happens when i do the line out of my 002 and put it directly into pedals, and
then back into a preamp using a 1/4 inch to xlr?

what horrible things does that do?

Try it and see. It would probably work best if your line out of the 002 is a low level or run through an attenuator.
If you want to see exactly what is in a ReAmp, the patent is here:
http://www.google.com/patents?id=PqkXAAAAEBAJ
I built a reamp using the schematic from the Jensen website and a transformer out of an old DOD direct box and it works great.

Looking at that patent, it appears that it's just a transformer, 6 resistors, and a cap.

Is this right?

[jv]

what happens when i do the line out of my 002 and put it directly into pedals, and
then back into a preamp using a 1/4 inch to xlr?

what horrible things does that do?

Try it and see. It would probably work best if your line out of the 002 is a low level or run through an attenuator.
If you want to see exactly what is in a ReAmp, the patent is here:
http://www.google.com/patents?id=PqkXAAAAEBAJ
I built a reamp using the schematic from the Jensen website and a transformer out of an old DOD direct box and it works great.

Looking at that patent, it appears that it's just a transformer, 6 resistors, and a cap.

Is this right?

Yes, it is.

[???????]

might have to be my next DIY project. All the part values are listed right there in the patent. I wonder if that's immoral.