Reamping Problem

[LowellWolfe]

I have a Tascam US-1800 interface and I'm trying to reamp a clean guitar signal which I recorded through the instrument input of the interface. There are 4 balanced output jacks on the back. In my DAW, I have given the output of the guitar track output 4, and then connecting output 4 through my pedals to my 5150 with a 1/4" cable.

I am getting a very loud and irritating buzz that won't go away, and I see people who are able to reamp very cleanly.

Is this because I don't have a reamp box or is it another problem I missed?

Thanks.

 

[deLuther]

Yes, it can be due to absence of reamper, you can try to use ground lift on amp (if exists), it can help or some isolate ground connector on power cord (it can act as gtound lift), ground lift on reamper is useful tool to get rid of ground loops problems.

 

[AHChris]

Yes, it can be due to absence of reamper, you can try to use ground lift on amp (if exists), it can help or some isolate ground connector on power cord (it can act as gtound lift), ground lift on reamper is useful tool to get rid of ground loops problems.

NEVER EVER EVER EVER EVER DO THAT!!! If you're killing the ground on the power chord, you're risking your life! If the amp malfunctions somehow you can have full mains voltage on your guitar strings! You can disconnect the ground wire inside of the audio connectors. This is equal to a ground lift switch.

 

[TheWinterSnow]

NEVER EVER EVER EVER EVER DO THAT!!! If you're killing the ground on the power chord, you're risking your life! If the amp malfunctions somehow you can have full mains voltage on your guitar strings! You can disconnect the ground wire inside of the audio connectors. This is equal to a ground lift switch.

What the...? No, that's not quite how grounds work. At no point will mains voltage ever be on the ground if it is not connected to earth. That would signify a catastrophic failure that would instantly blow the mains fuse even if ground on the amp wasn't connected to earth. The biggest concern with an amp that is not connected in any way to earth is static shock. Regardless though operating a Class II device without an earth ground connected is illegal.

Still by connecting an instrument cable to the amp to another device to earth ground, the amp still has an earth ground, its just through the interface and not the earth plug on the amp. You run the risk though if the cable shorts out at the ground (-) connection you might feel a little shock which is an indicator your amp has no earth connection which is not good.

Also when I was designing this DI here earlier this year I noticed that grounding through an interface/computer is much noisier because there is quite a bit of noise that rides on the ground of a computer or high frequency digital devices so its better to ground everything to the amp when possible. That means your best bet is to lift the ground at the instrument cable, its quieter and safer when it comes to ground lifting.

 

[Genius Gone Insane]

^For the sake of my life can someone please clarify the above? I am currently playing in a place that is not grounded. We are not jamming too often so I am not really concerned. Should I be?

 

[TheWinterSnow]

^For the sake of my life can someone please clarify the above? I am currently playing in a place that is not grounded. We are not jamming too often so I am not really concerned. Should I be?

No not really. My Band's practice space is like that too, three prong outlets, earth not connected. Its noisier. more likely to kill your tubes if you have power outages/fluctuations and may cause your guitar to give you a little zip.

 

[AHChris]

Of course this is not likely, but if you get a short inside of the amp involving the enclosure it is possible

 

[TheWinterSnow]

It will still pop the mains fuse if that happens. Even then since you or your guitar is no longer connected to earth ground, the only current draw you will feel is from the almost non-existent capacitance our bodies hold, you would feel it but since you are not completing a circuit you won't die and that is only up until he fuse pops which even for a slow blow is quick.

To anyone that is actually concerned about not having ground at their location, that is what earth lifting adapters are actually for (the 3 prong to 2 prong adapters). They have a hook on them so that you can move your earth to another location. If the screw that holds the outlet panel has a solid earth connection you can simply screw that adapter lug into that, if it doesn't have ground as in the case of really old houses pre 60s-70s and haven't been retrofited to three-prong or don't have the outlet casing connected to earth then all you have to do is get a length of wire, solder it and shrink wrap it to the prong adapter and to the other end solder/clamp/connect a copper rod and insert it to the nearest patch of moist soil and you have an earth connection. For both methods you can verify that by connecting a surge protector to that outlet adapter with it plugged in and switched on, if the surge strip has a ground indicator LED it should be lit, if not the soil isn't moist enough and/or the rod needs to be longer.

Back on topic, to the OP, just disconnect the ground connection at your cable. Easiest way to do that if you don't want to buy a DI is to get a cable that has access to the solder connections and cut off the ground connection on one side, any side will do. Conversely you could get a small hobby box that can hold two plastic 1/4" jacks (they must be plastic sleeve) and drill the box so that you can put the jacks inside and just solder the positive (tip) connections to each other, leaving the ground connections unconnected. Your amp's earth and your interfaces earth will no longer be connected. But you will need two cables instead of one.

 

[AHChris]

It will still pop the mains fuse if that happens. Even then since you or your guitar is no longer connected to earth ground, the only current draw you will feel is from the almost non-existent capacitance our bodies hold, you would feel it but since you are not completing a circuit you won't die and that is only up until he fuse pops which even for a slow blow is quick.

To anyone that is actually concerned about not having ground at their location, that is what earth lifting adapters are actually for (the 3 prong to 2 prong adapters). They have a hook on them so that you can move your earth to another location. If the screw that holds the outlet panel has a solid earth connection you can simply screw that adapter lug into that, if it doesn't have ground as in the case of really old houses pre 60s-70s and haven't been retrofited to three-prong or don't have the outlet casing connected to earth then all you have to do is get a length of wire, solder it and shrink wrap it to the prong adapter and to the other end solder/clamp/connect a copper rod and insert it to the nearest patch of moist soil and you have an earth connection. For both methods you can verify that by connecting a surge protector to that outlet adapter with it plugged in and switched on, if the surge strip has a ground indicator LED it should be lit, if not the soil isn't moist enough and/or the rod needs to be longer.

Back on topic, to the OP, just disconnect the ground connection at your cable. Easiest way to do that if you don't want to buy a DI is to get a cable that has access to the solder connections and cut off the ground connection on one side, any side will do. Conversely you could get a small hobby box that can hold two plastic 1/4" jacks (they must be plastic sleeve) and drill the box so that you can put the jacks inside and just solder the positive (tip) connections to each other, leaving the ground connections unconnected. Your amp's earth and your interfaces earth will no longer be connected. But you will need two cables instead of one.

Well I'm no electician, but I've been told this more than once. Don't know if there is a difference between US and EU electricity/ground systems, but let's just agree that it's not good and (as you wrote) even illegal to disconnect the ground on the power cable. Just do it on the audio cable and you will be fine.

 

[deLuther]

I`m forgot about other electricity systems, so proposal can be inappropriate for US/EU.