SYN 50 => Little Labs Redeye 3D Phantom (DI/reamp) => UAD Apollo => Computer results in huge high pitch squeal!

[BTMagnus]

Hi

I have a disturbing problem with my setup and I've tried for a month to fix it and I've now reached a dead end. The problem is most likely not the Syn50 so I hope it's OK that I post my question here anyway cause I'm really lost at this point. Please help??

I recently bought a Synergy SYN50 amp and a Little Labs Redeye 3D Phantom (DI/reamp).
The purpose is to record the DI signal and the amp and that way having the option to reamp.

As soon as I connect the DI/Reamp box to my interface theres a huge squeal. If I then lift the ground on the DI/Reamp box the squeal goes away but the guitar tone doesn't sound great...thin and almost "electrified".

The problem seems to happen when the computer and the interface are connected to power at the same time which makes me think there's an ground loop issue. I've tried to connected the interface and computer to different power outlets, or the same outlets, lift the ground also on the SYN50, tried other cables etc but no luck. I've found a few people on different forums describing similar problems and relating it to ground loops but what seems to have been the solution for them hasn't worked for me so far. Anyone has any idea what I could try to fix this issue?

If anybody takes the time to respond to this - huge thank you in advance. Happy 2023
// M

 

[Mike P]

With all due respect, I have no idea what you're trying to accomplish.

If you're recording Direct because you're using a DAW Amp Simulator like Guitar Rig, et al, the front input of your Apollo should suffice but if you don't like the tone, the DI might be an improvement.

One solution would be to use a switcher like a Radial ABY. One output to your DAW and the other to your amp. If you're trying to record your amp, plug directly in and use a reactive load box like a UA Ox (which also has cabinet simulation) or a Two Notes or any number of reactive load boxes on the market.

But a DI has no place in that signal chain. Good luck!

 

[buddachile]

Did you try using the Redeye 3D in both passive and active modes? Was their a difference in the noise?

 

[Katash]

To help you find the issue I'd need more info on the exact signal chain. Guitar > Redeye DI > Amp In? What else is connected to the amp?
And how exactly is the DI connected? What cables what in Out goes where?
What interface?
I have the same DI in my setup and guess we can find a solution

With all due respect, I have no idea what you're trying to accomplish.

If you're recording Direct because you're using a DAW Amp Simulator like Guitar Rig, et al, the front input of your Apollo should suffice but if you don't like the tone, the DI might be an improvement.

One solution would be to use a switcher like a Radial ABY. One output to your DAW and the other to your amp. If you're trying to record your amp, plug directly in and use a reactive load box like a UA Ox (which also has cabinet simulation) or a Two Notes or any number of reactive load boxes on the market.

But a DI has no place in that signal chain. Good luck!

With all due respect Mike, a DI can have a place in this signal chain and it's not up to you to tell him/her otherwise, just because you have a different workflow or don't understand what the OP wants to accomplish.

Git > DI > regular signal chain is basically daily business for rock and especially heavy music in studio. Reamping is one of the main reasons to split the DI to DAW before everything else.

Redeye DI is perfect as it has good transformers, buffer, built in reamp box capabilities and easy level matching.

My guess is it's not connected right, as ground lift shouldn't change amp tone, but without knowing the setup it's just guesswork.

Cheers,
Max

 

[jwin615]

Yep. More info needed.
Are you trying to record di and amp at the same time, with the instrument out of the red-eye into the input of the syn50?
A high pitch sequel likely isn't a ground issue but instead a feedback loop. First step is to try headphones and double-check your routing.
So mic out of the redeye should go to mic in on your Apollo. The redeye should be in *DI mode*, not reamp mode. It's only input should be your guitar. No need to feed it the output of the DAW. When live tracking. If you were and we're in reamp mode, that was likely your feedback loop. The other likely option is monitor to mic feedback(hence, try headphones).
Good luck.

 

[Katash]

High pitch squeal could also be impedance and or ground related, had that problem 1 week ago in my own rig. I don't understand why, but a buffer before my loop switcher solved it in the test rig and a buffer plus iso transformer did it in the big rig.

 

[Katash]

Isn't it ugly?
Anyway - OP can you tell us your exact cabling?

 

[Mike P]

To help you find the issue I'd need more info on the exact signal chain. Guitar > Redeye DI > Amp In? What else is connected to the amp?
And how exactly is the DI connected? What cables what in Out goes where?
What interface?
I have the same DI in my setup and guess we can find a solution


With all due respect Mike, a DI can have a place in this signal chain and it's not up to you to tell him/her otherwise, just because you have a different workflow or don't understand what the OP wants to accomplish.

Git > DI > regular signal chain is basically daily business for rock and especially heavy music in studio. Reamping is one of the main reasons to split the DI to DAW before everything else.

Redeye DI is perfect as it has good transformers, buffer, built in reamp box capabilities and easy level matching.

My guess is it's not connected right, as ground lift shouldn't change amp tone, but without knowing the setup it's just guesswork.

Cheers,
Max

LOL

 

[BTMagnus]

Did you try using the Redeye 3D in both passive and active modes? Was their a difference in the noise?

Hey Buddachile!

Sorry for taking so long to get back.
Yes I did and it's the same problem. I don't think the problem has to do with the DI/reamp box itself.
What I've also found out is that the squeal seems to happen in relation to volume. So when the DI/reamp is connected to the interface - if I then lower the volume on the to lets say 9 o'clock it works. This is quite low though, AND, if I just disconnect the DI/reamp from the interface I can crank the amp as much as I want without any issue. My guess is there is some kind of power related issue but I just can't figure out what.

Thanks for your response Buddachile

 

[BTMagnus]

Yep. More info needed.
Are you trying to record di and amp at the same time, with the instrument out of the red-eye into the input of the syn50?
A high pitch sequel likely isn't a ground issue but instead a feedback loop. First step is to try headphones and double-check your routing.
So mic out of the redeye should go to mic in on your Apollo. The redeye should be in *DI mode*, not reamp mode. It's only input should be your guitar. No need to feed it the output of the DAW. When live tracking. If you were and we're in reamp mode, that was likely your feedback loop. The other likely option is monitor to mic feedback(hence, try headphones).
Good luck.

Thanks a lot for your response jwin615, I truly appreciate it

I agree, this doesnt sound like a ground loop issue. Yeap - because of the di/reamp button, when in DI mode, the box only passes through the guitar signal to the amp....the signal from the DAW shouldnt then be an issue. I also doubled checked this and turned it off and the problem is still there.

I belive there's some kind of power related issue because when the Redeye is connected to the interface and the interface and the computer is connected to power at the same time that's when I have the problem. If I disconnect the computer from power but the interface still have power it works and I can crank the volume as much as I want.

I can also get around the problem by lowering the volume on the amp quite much, to like 9 o'clock, but then I'm not close to cranking it.

My UAD interface is connected to the computer with firewire 800 that sends power, I don't know if this could possibly be the problem?

// Cheers, Magnus

 

[BTMagnus]

To help you find the issue I'd need more info on the exact signal chain. Guitar > Redeye DI > Amp In? What else is connected to the amp?
And how exactly is the DI connected? What cables what in Out goes where?
What interface?
I have the same DI in my setup and guess we can find a solution


With all due respect Mike, a DI can have a place in this signal chain and it's not up to you to tell him/her otherwise, just because you have a different workflow or don't understand what the OP wants to accomplish.

Git > DI > regular signal chain is basically daily business for rock and especially heavy music in studio. Reamping is one of the main reasons to split the DI to DAW before everything else.

Redeye DI is perfect as it has good transformers, buffer, built in reamp box capabilities and easy level matching.

My guess is it's not connected right, as ground lift shouldn't change amp tone, but without knowing the setup it's just guesswork.

Cheers,
Max

Hey Katash

Sorry for taking so very long to get back, and thanks a lot for taking the time to respond to my post, I truly appreciate it.

This all seems to be power related somehow. I'm no expert on electronics so don't take my word for it though
I've spent many hours problem solving this by disconnecting everything extra in my chain - screens, monitors, pedals....everything...to end up with only the minimal necessary connected: the computer, UAD Apollo Quad interface, Redeye di/reamp, amp and iso box, nothing else. This is what I found:
1. If the minimal gear is connected as it should then I get the huge squeal. (Here I have the guitar connected to the active input on the DI that requires phantom power from the interface). Then I lift the ground on the DI/reamp box (as I should in a setup like this according to the manual) and the squeal disappears but the guitar signal sounds "electrified", broken.

2. When the ground is lifted so the squeal is gone but the guitar signal sounds broken I can actually get around this problem by lowering the amp volume quite much. Too much, like only 9 o'clock...which is not close to cranking the amp.

3. If I disconnect the computer from power it all works - I can crank the volume as much as I want without any problem and here the DI/reamp is connected to the interface and the interface to power. The computer and the interface is connected by firewire 800 that sends power...I don't know if this potentially could be the problem?
4. If I have the computer and interface connected to power at the same time it just doesn't work.

I've attached three audio files here as well.
File 1: This is a sound clip of when it actually works.
File 2: The squeal when computer, interface, di/reamp, amp, and iso box is connected together without the ground lifted on the di box.
File 3: The "broken" guitar sound when I've lifted the ground on the DI. This is the problem I can get around by lowering the volume on the amp drastically though.

Huge thanks again Katash and to everyone else in this thread.
// Magnus

 

[jwin615]

This is kind of a dumb suggestion but I had a noise issue with a new Chapman a few months ago that I went in circles over. Which leads me to ask...
Have you tried a different cable?
Both mic and instrument?

Also, does it happen when using the passive in on the back as well?

 

[BTMagnus]

This is kind of a dumb suggestion but I had a noise issue with a new Chapman a few months ago that I went in circles over. Which leads me to ask...
Have you tried a different cable?
Both mic and instrument?

Also, does it happen when using the passive in on the back as well?

I'm open to any suggestions at this point so there are no dumb ones
When I tried connecting only the necessary minimal gear (computer, interface, di/reamp, amp, iso box) I also tried changing the cables around without any luck. The only thing that really seems to work is to disconnect the computer from power which of course defeats the whole purpose.

Thanks a lot jwin615!
Cheers
// Magnus

 

[usrbin]

If the noise goes away when the computer is unplugged (assuming the red-eye and head are both powered), my guess is you have either EMF from the computer or a ground loop between the computer and the red-eye. Have you tried the same outlet for all 3 with a decent power regulator? Are you using balanced cables between the red-eye and computer? Have you tried to move any guitar gear away from the computer and monitor?