Series Passive Cue Feed Boxes

[StarTrucker]

I was at Columbia Studio A in Nashville and their cue feeds are series fed passive boxes and I am curious how to do this.

The cue mix comes from the console and out through an XLR into a passive cue box. On each box, there is a headphone jack and volume control, as well as a pass through to the next musician's cue box. The boxes are chained along this way.

What kind of attenuator do you use to do this without the first musician's volume control dragging down the signal of every other musician's cue box farther on down the chain?

 

[ruffrecords]

If the cue mix was from a small loudspeaker amplifier capable of driving a few watts into 8 ohms then all you would need is a series resistor followed by something like a 100 ohm pot. I did something similar many years ago when I sent the output of a small loudspeaker amp to a box sitting on top of a monitor speaker in the studio. In the box were four resistors connected to four headphone jacks. There was also a relay in the box operated from the control room which disconnected the speaker when recording.

Cheers

Ian

 

[thomasdf]

I have been thinking about this a lot, because Cue sound is often not that great in many studios, and cue boxes can be really ugly and cluttering the space with cables.

I wanted to try 7 pin XLR carrying various unbal signals + power supply for great quality headphone amp.

But the system you are describing looks very interesting for sure. XLR 3pin ? So unbal stereo signal ?

 

[ruffrecords]

I have been thinking about this a lot, because Cue sound is often not that great in many studios, and cue boxes can be really ugly and cluttering the space with cables.

I wanted to try 7 pin XLR carrying various unbal signals + power supply for great quality headphone amp.

But the system you are describing looks very interesting for sure. XLR 3pin ? So unbal stereo signal ?

The system I described I built back in the 70s. In those days most cue sends were mono only and this one was too. In principle it is straightforward to convert it to stereo - just a matter of doubling up the signal connections and feed resistors. It was definitely unbalanced because it was the output of a little transistor power amp of about 12 watts. You could use a 3 pin XLR but someone would be bound to plug it into an input which might well damage something. Probably best to use a unique connector for it - maybe a 4 pin XLR


Cheers

Ian

 

[kags]

Many studios do this. We use crown and Hafler power amps that go out to Redco Little Red Cue Boxes. They have like 100 ohms on each input channel so you can daisy chain (which makes parallel connections) and the amp load stays reasonable with a handful of boxes. Volume pots are stereo 2w 2k or 5k pots.

Furman, Redco, Hosa, and many others make the boxes if you don’t want to roll your own…

 

[ruffrecords]

Many studios do this. We use crown and Hafler power amps that go out to Redco Little Red Cue Boxes. They have like 100 ohms on each input channel so you can daisy chain (which makes parallel connections) and the amp load stays reasonable with a handful of boxes. Volume pots are stereo 2w 2k or 5k pots.

Furman, Redco, Hosa, and many others make the boxes if you don’t want to roll your own…

Looka like one area has not changed from the 70s!!!!

Cheers

Ian

 

[Brian Roth]

The passive cue box system was used by hundreds/thousands of studios from the 1970's (when I began working) well into the 90's and later. It used a standard power amp (like a Crown D-60 or larger) and fed multiple cue boxes in the studio.

I attached a diagram showing the most basic version. Many variants added switching for different purposes. Back then the boxes were DIY. It was common that the wall jacks in the studio for the system to be XLR male to differentiate them from the female mic XLRs.

Besides the boxes kags mentioned, I've seen lots of Simon Systems boxes.

Other discussions on this topic are here:

https://groupdiy.com/threads/4-way-headphone-box-need-help-with-circuit-design.47920/#post-604168

https://groupdiy.com/threads/help-with-passive-headphone-box-stereo-mono-switch.81884/#post-1057121

Bri

 

[kags]

Many studios have switched to Aviom, or the like, which sound nowhere as good as the cue mixers of the 90s, like Manley’s or PrivateQ and others. Aviom have networked connections and memory and lots of features, but the amps kinda suck. Some people claim to notice the latency, too, but I don’t find that an issue.

I hear Paul Wolff makes a good box now.

 

[Brian Roth]

@kags Someone recently mentioned to me that Wolff was selling a system. I just searched and quickly scanned the info and need to read more about it.

Cue systems are a crazy subset of a studio design. I began engineering sessions in the early 1970's at a couple of studios with MCI JH-416 or 428 (blackface) desks. Two mono cue sends! Fed into a Crown D-60 amp and DIY cue boxes built in various heavy-duty steel boxes ("gotta make 'em Picker Proof!" lol) from the electrician supply wholesalers. Two Allen-Bradley Type AB pots (one level control for each ear), a toggle switch for cue 1 or 2, and maybe two TRS jacks so two players could share one box.

Fast forward....Furman cue systems which used a 25-pair telco cable to each box, Hearbacks with Cat 5 cables, etc. Those gave the players their own mixing "mini console" but less experienced guys in the studio would get befuddled with the controls. I'd have to go out and put on the headphones and correct the mess with the mix on the "pods".

Another thing....the pods are pricey and not always durable. Just ranting now! <g> I don't do much session work anymore so I'm kinda out of the loop.

Bri

 

[kags]

@kags Someone recently mentioned to me that Wolff was selling a system. I just searched and quickly scanned the info and need to read more about it.

Cue systems are a crazy subset of a studio design. I began engineering sessions in the early 1970's at a couple of studios with MCI JH-416 or 428 (blackface) desks. Two mono cue sends! Fed into a Crown D-60 amp and DIY cue boxes built in various heavy-duty steel boxes ("gotta make 'em Picker Proof!" lol) from the electrician supply wholesalers. Two Allen-Bradley Type AB pots (one level control for each ear), a toggle switch for cue 1 or 2, and maybe two TRS jacks so two players could share one box.

Fast forward....Furman cue systems which used a 25-pair telco cable to each box, Hearbacks with Cat 5 cables, etc. Those gave the players their own mixing "mini console" but less experienced guys in the studio would get befuddled with the controls. I'd have to go out and put on the headphones and correct the mess with the mix on the "pods".

Another thing....the pods are pricey and not always durable. Just ranting now! <g> I don't do much session work anymore so I'm kinda out of the loop.

Bri

yeah - I use the old cue boxes way more than Avioms unless the client asks for the Aviom (Hearbacks are similar)

The Fix Audio headphone stuff looks great but is a bit unclear if it’s intended uses.

https://www.wolffaudio.com/collaborator

 

[Brian Roth]

I saw this one at first:

https://www.wolffaudio.com/memore

It seems both require a rat's nest of cabling for power and analog audio connections. Something to be said in favor of Ye Olde passive boxes....1 mic cable per box.

Bri

 

[thomasdf]

The studio I started in fed the cue boxes with Crown D75, straight from the patchbay so most often the stereo cue from the SSL 4000. Sounded great ! In the future I'll go for something like this but maybe with 4 channels because nowadays musician are used to make their own cue mix... which is not always a good thing haha.

Aviom sounds like crap ! And yes, I noticed some phasing issues ...

Interesting things on this thread Thanks all !

 

[soapfoot]

For many years I've been accustomed to Mytek PrivateQ-style personal mixers (some studios even had small Mackie-type mixers w/ faders at each station).

It's interesting to consider going back to a single cue mix monitored by multiple players--particularly with experienced musicians, I see a lot of merit to that.

We have PrivateQ systems at our NYC place, and what I notice is that, when a group of experienced session players is in, the cue mixes look substantially-similar at the end of the day. You only really encounter weird stuff on the cue mixers when someone is new to recording.

I've been doing a few sessions at an older legacy studio in Memphis that still has an old-school cue system like the one described in the OP.

With the sessions I've been doing there (as a player) I find I don't really miss the fine-grained control over my cue mix. I mainly get to hear what the engineer is hearing in the CR, and I like that. And none of the other players seem to mind/object, either.

And while I can't prove it, I suspect it's at least a little bit meaningful that all of us are monitoring the same thing. It's just that tiny bit more like "playing together" (as opposed to "playing individually, but at the same time")

I wonder if we may start seeing a trend back toward simpler cue solutions (at least as an option) even in some of the bigger rooms.

 

[JimJhn]

Hi! Brian could you specify the values in your schematic? I'd like to build some of these. Thanks!

 

[JohnRoberts]

As has already been shared many studios roll their own cue systems.

I looked at developing a dedicated active box last century while at Peavey and never came up with a concise single definition. Everybody seemed to have different feature demands. We did make one passive headphone splitter box that could be driven by a modest power audio amp and daisy chained in series if more than 4 cans were needed.

JR

 

[Brian Roth]

Hi! Brian could you specify the values in your schematic? I'd like to build some of these. Thanks!

I am going from 50 year old memory here. The pots were definitely Allen-Bradley Type J which were 2 Watt carbon. The value was 500 or perhaps 1000 Ohms. They were linear taper since those were readily available.

The series resistors were 150 Ohms (?) and likely 2 Watts as well. One of the main reasons for them was to act as an isolator in case there was a short between the "hot" and "common" of the headphone cable or plug.

The selection of the pot and resistor values is a bit of a "dance" when it comes to the apparent taper of the controls vs the impedance of the phones.

Bri

/EDIT: The two "real" studios here in town have passive cue systems. One uses Simon Systems boxes and the other has DIY. I'll try and remember to open boxes at each place and get the component values.

 

[kags]

This thread has some good info and schematics: https://groupdiy.com/threads/passive-headphone-splitter-with-volume-control-per-headphone.19416/

Or buy this and reverse engineer it
https://reverb.com/item/83601227-redco-little-red-cue-box

 

[Spiritworks]

From around 1980 to 1983 I worked for Audiotechniques, who were the precursor to Redco Audio. One of my many tasks was to assemble the Little Red Cue Boxes. Working there was the start of a lifelong relationship with the current owner of Redco and, as an electrical contractor, I have done most of the electrical work at their current facility in Monroe, Connecticut.

 

[JimJhn]

Hi thank you so much Brian!

 

[Brian Roth]

I did peek inside of a Simon Systems CB-4 today. Dual gang 1K pots (forgot to check taper) that I believe are Clarostat 53 series which were 2 Watt conductive plastic. 330 Ohm 2 Watt (perhaps higher since I didn't recognize the brand) wired in series with the top end of each pot.

Bri