Line level to mic level attenuation

[Bjørn Felle]

Hi everyone

I’ve just ordered a Roland VT-4 vocal effects unit. It takes a mic level input and outputs at line level. I want to use it in conjunction with a Boss VE-500, which requires a mic level input. Will I need an attenuator, and if so what type? I have tried to contact Roland but you can’t call them, and their stupid online case logging thing has allocated my question to a person who is not available for over a week, which seems highly questionable.

[RealReasonHead]

I don't think so. As far as I understand, a mic pre amp is just there to bring the mic level to line level so if you leave the gain at the lowest setting (which should be 0 dB gain), it should work just fine.

[Bjørn Felle]

I don't think so. As far as I understand, a mic pre amp is just there to bring the mic level to line level so if you leave the gain at the lowest setting (which should be 0 dB gain), it should work just fine.

Thanks so much for your reply dude. When you say mic pre amp, do you mean the one in the Boss VE-500?

[RealReasonHead]

Thanks so much for your reply dude. When you say mic pre amp, do you mean the one in the Boss VE-500?

Yeah, sorry, should have specified that.

[Bjørn Felle]

No apology needed dude, I appreciate your reply and just wanted to make sure I understood before I followed up. Ok so the pre amp in the Boss is responsible for bringing the mic input to line level, but what will it do if the signal coming in is already at line level? Would that not harm the preamp?

[Bjørn Felle]

Right, I was a brave boy I just quickly soldered up an XLR to 1/4" mono jack cable. I connected the jack end to my Microbrute, and the XLR to the mic in of the VE-500. The brute was on minimal volume. To my surprise the VE-500 handled it just fine, and I was able to increase the level of the brute and it did not distort. It also didn't actually increase the output level FROM the Boss, so I think there is some limiting going on on the input bus. Actually yeah this is probably part of the mic sensitivity/feedback limiting circuitry. So it would seem that a line level input to the VE-500 will be just fine and apparently not cause any distortion or damage! Thanks again for the replies dude

[Bjørn Felle]

Just to follow up - the VT-4 has arrived and it works perfectly with the Boss using the line out from the VT-4 to the mic in of the Boss. I was getting really poor signal to noise ratio at first, and then when checking the input threshold on the Boss I realised I had phantom power enabled. I turned it off and it's all working perfectly. Live terrifying formant fuckery is a go.

[Kalm]

Usually these things is all voltage unless and the preamp adds significant distortion to the signal. The preamp in the unit could distort only if the nature of the input level your unit is expected to receive is too high or impedance mismatch. You could always borrow a DI box from a friend or somebody to check for a quality difference but I don't think it'll make much of a difference. Then main thing to worry about is the rest of the chain if it's longer.

[Bjørn Felle]

Usually these things is all voltage unless and the preamp adds significant distortion to the signal. The preamp in the unit could distort only if the nature of the input level your unit is expected to receive is too high or impedance mismatch. You could always borrow a DI box from a friend or somebody to check for a quality difference but I don't think it'll make much of a difference. Then main thing to worry about is the rest of the chain if it's longer.

The chain is pretty short actually. This is a live rig built into a flight case so the interconnecting cables are short. The only source of noise seems to be the USB power to the VT-4, which doesn’t happen if I power it from batteries. But it should be a fairly simple fix with a proper regulated power supply. The actual connection between the VT-4 and the VE-500 seems to be problem free. The VE-500 is an excellent piece of kit and it wouldn’t surprise me if the mic pream has been specifically engineered to handle line level input even though this isn’t documented.

[Kalm]

Usually these things is all voltage unless and the preamp adds significant distortion to the signal. The preamp in the unit could distort only if the nature of the input level your unit is expected to receive is too high or impedance mismatch. You could always borrow a DI box from a friend or somebody to check for a quality difference but I don't think it'll make much of a difference. Then main thing to worry about is the rest of the chain if it's longer.

The chain is pretty short actually. This is a live rig built into a flight case so the interconnecting cables are short. The only source of noise seems to be the USB power to the VT-4, which doesn’t happen if I power it from batteries. But it should be a fairly simple fix with a proper regulated power supply. The actual connection between the VT-4 and the VE-500 seems to be problem free. The VE-500 is an excellent piece of kit and it wouldn’t surprise me if the mic pream has been specifically engineered to handle line level input even though this isn’t documented.

Sounds like you should be all right then