Topic: Soundboard Patches and Attenuation

[wbrisette]

I understand that I won't need them for a signal coming via-RCA, and that I may well need them for a signal coming from XLR.  My questions are basically as follows:
1- Do I need attenuators (my recorder is a iRiver H120)

Maybe. It all depends on where the output is coming from on the board and if the FOH engineer is nice enough to turn things down if they are too hot or up if not hot enough (assuming he or she has control of this).

2- Where do I buy them

Any pro audio shop, ebay, guitar center, you name it they probably have them. Loads of mail order houses have them. There are two that I highly recommend, either the Shure model or the AudioTechnica versions. Both are XLR only though.

3- How do I use them (how do I know how far down to turn the signal?  Is an attenuator just turning down the volume or the electricity-- or are those the same?)

The AT and Shure models use a switch. -20, -15, and -10 dB or something similar. As you monitor your recording, you'll know when you have padded the signal properly.

Wayne

[Roving Sign]

There are also some level shifting devices on the market...

http://www.sweetwater.com/store/detail/LLS2/

[Church-Audio]

There are also some level shifting devices on the market...

http://www.sweetwater.com/store/detail/LLS2/

Your better off with an actual attenuator then a converter this thing is just a pad with a few resistors. I think I might end up having to make a product because there seems to be a lot of confusion about this subject. It safe to say that you should have in your kit a way to reduce the signal at least 20db I think the best way to do this is with a pot not a fixed resistor. The reason being is with unbalanced connections you need to maximize your signal to noise ratio in other words attenuate as little as possible. Because the more you attenuate the more you may have to boost on the recorder end. That being said most recorders can only handle about -10 db at the line input before they run into distortion this distortion can not be fixed by the control on the device it self because its a digital control. So you need an external control of the level so you can knock it down to -15 or so and have about 5 db of headroom A simple 10k pot for most applications would work fine. A fixed pad will work too but you might end up cutting more level then you need too and increasing your signal to noise ratio in the process. So I think an interface with a VU meter and a volume pot would be in order so the user could see the incoming level before his or her recording device and pad it down accordingly maybe have a pre pot and post pot switch for the VU as well so they can see the difference?? what do you guys think?

[120db]

I dont know anything about mixing in stereo, VCA, subgroups, UM100P's, 10 650P's, 10 MSL4's, 8 UPA1P's, or the Allen & Heath GL2400-24....

But 

I do know that the Sony D8 7 pin cable is digital interface - and useless unless said console has a built in A/D section with a SPDIF output - you'll need to find another cable...

I'd bring a 1/8 stereo mini > L/R RCA cable...and some RCA > 1/4 adapters...

Thanks for all the tips, I guess RCA is going to be my best bet since the 7pin might not be useful.
I do have a RCA > 1/4 adapter that plugs in to my line in jack. So, my question now is I can just accept the signal as is? I would have to use headphones to monitor and ask politely to adjust if possible? I dont have a 1/8 stereo mini, will I be ok with just RCA > 1/4?
Thanks for all the helpful advice guys.

[gratefulphish]

Wow, I started this thread, and it took off into a virtual shooting war, and has now calmed back down to some useful answers.  In my case, I was able to successfully deal with a hot board patch, as the R-4 Pro's sensitivity settings allowed me to take the signal down by 20 db or so.  I also found out from Edirol, (after asking their tech, and having him call Japan for the answer) that the R-4 Pro (I don't know about the R-4) actually shows you if your analog input is clipping, as well as also separately showing digital clipping.  I wasn't sure what it was at first, but by lowering the sensitivity levels, the clip indicator stopped, and I could use the trim controls from there. From that perspective, I love the features on this machine.

[gratefulphish]

Thanks for all the tips, I guess RCA is going to be my best bet since the 7pin might not be useful.
I do have a RCA > 1/4 adapter that plugs in to my line in jack. So, my question now is I can just accept the signal as is? I would have to use headphones to monitor and ask politely to adjust if possible? I dont have a 1/8 stereo mini, will I be ok with just RCA > 1/4?
Thanks for all the helpful advice guys.

If you are going to be coming out of the board, be prepared to deal with XLR jacks.  You can get any variation of cables from someone here on the board, such as L & R XLR> 1/8 stereo mini, and then, if you need to, you can get attenuators.  Monitoring is not the issue, if the signal is too hot, nothing is going to help the situation, except attenuating it.  Your meters should make that pretty clear.  If you are planning on doing this more than once, I would just get the cables you need, so that you can handle as many likely configurations as possible, including RCA, 1/4" and XLR.

[gratefulphish]

A simple 10k pot for most applications would work fine. A fixed pad will work too but you might end up cutting more level then you need too and increasing your signal to noise ratio in the process. So I think an interface with a VU meter and a volume pot would be in order so the user could see the incoming level before his or her recording device and pad it down accordingly maybe have a pre pot and post pot switch for the VU as well so they can see the difference?? what do you guys think?

Chris, This could be a useful idea, if it could be done, and kept small, and powered by a single battery.  If it could be a 10-30 db range, all the better.  How about building a real outboard digital meter, a la the SVU, but designed for the digital realm, with something like the Tascam meters, with a peak level readout?  I will pre-order immediately.

[Church-Audio]

Thanks for all the tips, I guess RCA is going to be my best bet since the 7pin might not be useful.
I do have a RCA > 1/4 adapter that plugs in to my line in jack. So, my question now is I can just accept the signal as is? I would have to use headphones to monitor and ask politely to adjust if possible? I dont have a 1/8 stereo mini, will I be ok with just RCA > 1/4?
Thanks for all the helpful advice guys.

If you are going to be coming out of the board, be prepared to deal with XLR jacks.  You can get any variation of cables from someone here on the board, such as L & R XLR> 1/8 stereo mini, and then, if you need to, you can get attenuators.  Monitoring is not the issue, if the signal is too hot, nothing is going to help the situation, except attenuating it.  Your meters should make that pretty clear.  If you are planning on doing this more than once, I would just get the cables you need, so that you can handle as many likely configurations as possible, including RCA, 1/4" and XLR.

I am thinking of building a transformer based input with xlr 1/4 and rca inputs and a stereo 1/4 output that can be adapted on the other end. I am thinking maybe I don't need a transformer as most of you guys are using battery power. I am still thinking about this I think I can build this for about $200 for a 12 step stereo vu + level control + headphone amp. for monitoring. I can get it to operate on a set of 9 volts.

I am still thinking any input would be appreciated.

[gratefulphish]

I am thinking of building a transformer based input with xlr 1/4 and rca inputs and a stereo 1/4 output that can be adapted on the other end. I am thinking maybe I don't need a transformer as most of you guys are using battery power. I am still thinking about this I think I can build this for about $200 for a 12 step stereo vu + level control + headphone amp. for monitoring. I can get it to operate on a set of 9 volts.

I am still thinking any input would be appreciated.

Pun intended?  On the serious side, keep it simple, and small.  I would go with just XLR in and out, as most people here work with those, and have the necessary adapters to deal with RCA and 1/4" if they need to. I would also jettison the headphone amp. as well, as people can listen upline.  In this arena (pun intended) small, lightweight, and low power requirements rule. Just my meager thoughts.

[Church-Audio]

I am thinking of building a transformer based input with xlr 1/4 and rca inputs and a stereo 1/4 output that can be adapted on the other end. I am thinking maybe I don't need a transformer as most of you guys are using battery power. I am still thinking about this I think I can build this for about $200 for a 12 step stereo vu + level control + headphone amp. for monitoring. I can get it to operate on a set of 9 volts.

I am still thinking any input would be appreciated.

Pun intended?  On the serious side, keep it simple, and small.  I would go with just XLR in and out, as most people here work with those, and have the necessary adapters to deal with RCA and 1/4" if they need to. I would also jettison the headphone amp. as well, as people can listen upline.  In this arena (pun intended) small, lightweight, and low power requirements rule. Just my meager thoughts.

OK I can do that. I was thinking the headphone amp would be a good thing but to be honest its kind of a waste of time. I think I will make it with xlr connectors and 1/4 I can use a Neutrik combi plug for that application and take up the same amount of space.

[gratefulphish]

OK I can do that. I was thinking the headphone amp would be a good thing but to be honest its kind of a waste of time. I think I will make it with xlr connectors and 1/4 I can use a Neutrik combi plug for that application and take up the same amount of space.

That is sounding like a good plan.  How small do you think it would be, and what range of attenuation were you planning on providing?

[Church-Audio]

OK I can do that. I was thinking the headphone amp would be a good thing but to be honest its kind of a waste of time. I think I will make it with xlr connectors and 1/4 I can use a Neutrik combi plug for that application and take up the same amount of space.

That is sounding like a good plan.  How small do you think it would be, and what range of attenuation were you planning on providing?

The range of attenuation will be from -00 or all the way off to Unity gain. I will put the Vu with a pre post switch so you can see exactly how much your attenuating. The box will be about 5x4x2