The Construction Process of Racks

[Terri]

In the past, I have been asked to document how I go about doing what I do...

 

I don't have a "rack tech" or a guitar tech for that matter. I am a kind of hands on type of girl. I like to know what is going on. I need to know how it works. So, after many years of research, working around in the 'biz' and eyeballing the 'other guys' rigs this is what I have come to...

 

I hope it helps those that are just starting out.

 

This first pic is after I have decided the order the units. I prioritize by importance and what needs to be accessable. Also the "heavy stuff" ALWAYS GOES ON THE BOTTOM!!!!" (in my book anyways).

 

 

Note the MESS. The bulk spool of Mogami cabling and stuff... Yeah, the 35watt soldering iron and what not.

 

 

Here is the next stage. Trying to figure where to split the power and signals off to. I decided power to the left and signal to the right, based on the shortest distance each of the pieces.

 

 

Things are starting to get a little tiddier. Zip ties are starting to clean up the wiring "rats nest" as I go along.

 

 

 

Mind you that this process was last year and I was a bit in a hurry to get the system up and tested. As I dressed the cables I constantly asked myself about the signal chain and tried to find the shortest possible distances between connections without making it look stupid.

 

 

Well, there you go. I hope you enjoyed this little "Discovery Channel's 'American Rackshop'".

 

As always, I'm here if you need me. (This is the time of the season when things are slow and I'm not swamped and out.)

 

Cheers!!

[THJams]

OK..... 2 questions (for starters)

 

1 - Is that an isolation transformer mounted on the bottom of the rack ?

 

2 - Do you bolt everything straight to the rack rails, or do you try to isolate each unit from the rails and from each other ?

 

Looks nice by the way!

 

Thanks

Tony

[Terri]

1) No, it's a drop down transformer. Some of the voltages in the rack require 220 volts.

 

2) I isolate. I subscribe to the star ground philosophy.

 

Thanks.

 

PS: If the photos stop coming up, that's because the daily bandwidth limit was hit and will reset the following day. Sorry if that is the case. I only have a 10MB daily limit with my hosting site.

[THJams]

Thanks Terri,

 

I fully understand the star grounding method, I shield and star ground every guitar I own.

 

But how exactly do you isolate each unit from each other when building a new rack?

 

Some type of insulating material between the rack ears and the rails ?

 

And between each units case?

 

What about the mounting screws? wouldn't these even create a common ground between all of the units through the rails?

 

Do you use HumFrees ?

 

Sorry for all of the possibly redundant questions, but I am currently rebuilding my rack, and I'm trying to get the best tone and the least amount of noise possible.

 

Thanks,

Tony

[Terri]

1) I isolate the rack rails with electrical tape.

 

2) Non metallic spacers front and back of the rack ears.

 

3) Insulation between units. (Anti-static foamcore sheets sandwiched between the units)

 

4) #2 acts similar to humfrees.

 

It's tougher to do this, but in my opinion cleaner and preserves the integrity of each piece of gear. (How would you like to buy a ground down piece of gear?) Not me.

[THJams]

Thanks again terri,

 

I'll try those tips on my current rack project.

 

One last question....

 

Do you have any links to your music? I would like to either download or purchase some of your artistic work. Your gear looks awesome, and I would truly enjoy listening to the tones you have created, as well as your playing and musical styles.

 

Later,

Tony

[devilboy]

Cool beans Terri. I'm a floundering rack newb and can use all the help I can get...would you mind putting together a fyi post like this with regard to controling multiple amps and proper integration via a switcher and mixer or whatever works best?

 

I'd like to be able to midi control a/b/y operation between my jmp-1/9200, my dual rec and effects while leaving the system modular so that I could take either my head or rack or both on the fly by just pulling the cables that run to the head...possible?

 

thanks

[Tisca]

Is it common to solder/make your own cables for racks? Is that the only way to get some proper lengths?

[Terri]

Originally posted by devilboy ... with regard to controling multiple amps and proper integration via a switcher and mixer or whatever works best? I'd like to be able to midi control a/b/y operation between my jmp-1/9200, my dual rec and effects while leaving the system modular so that I could take either my head or rack or both on the fly by just pulling the cables that run to the head...possible? thanks

Best bet would be to use something like am amp switcher (Mesa builds one, Axxess and CAE also has one to offer) These are typically active (Buffered and isolated) keeping your signal path clean and properly loaded. Although you'll need a MIDI switch box like a GCX (by DMC) or a Rocktron Octopus controlling it.

 

The economical (non-MIDI) way would be to get a AB switch from someone like Whirlwind. The mixer comes in play with multiple FX's in a chain. I usually keep these in Parallel opposed to serial unless I want them in the delay chain. Then I would have the FX feed into a delay serially.

 

Don't forget that more you have going from one to the other just muddy's up you tone and sound, adding noise and hiss. One good quality box replaces a bunch of inferior boxes. (Less is more concept) unless you can't live without that single sounding reverb or chorus, etc.

 

Hope this helps?

 

Frequent problem is being strapped for cash. You can always piece it together slowly with your "eye on the prize". I know, it's hard but in the end the product would be worth your hard work and reward you with something that works for you.

[Terri]

 

Originally posted by Tisca Is it common to solder/make your own cables for racks? Is that the only way to get some proper lengths?

 

 

I use to have cables made by someone else but that got tedious. As you can see, when you have to redesign racks for different show lineups then you end up with cables that are either too short or too long.

 

If you're not going to change your setup (Highly unlikely if you ask me) and you don't trust your soldering skills, then I would recomend ordering custom length cables. (expensive and lead times can be long).

 

 

So I began to make my own and found it was far cheaper to do this then to specify whether a cable was a balanced to an unbalanced Nuetrik or balanced to balanced, straight guitar signal etc, etc, etc. When dealing with complex systems, you have to think on your feet. You have to remain flexible in your design. Sometimes what you think is going to work, doesn't and vice-a-versa.

[nickdahl]

 

Originally posted by Terri Frequent problem is being strapped for cash. You can always piece it together slowly with your "eye on the prize". I know, it's hard but in the end the product would be worth your hard work and reward you with something that works for you.

 

 

This is excellent advice. Another way to see it: "buy once, cry once." Good gear can get expensive, but the costs associated with buying and selling "temporary" gear can make the difference much smaller. If you've ever sold something online to someone, only to find out that it was damaged in shipment, and the shipper (UPS, FEDEX) balks at solving the problem, you know what I mean. Your cash is in limbo, and you don't have the pieces you need to make your music.

 

Nick

[devilboy]

 

Originally posted by Terri Best bet would be to use something like am amp switcher (Mesa builds one, Axxess and CAE also has one to offer) These are typically active (Buffered and isolated) keeping your signal path clean and properly loaded. Although you'll need a MIDI switch box like a GCX (by DMC) or a Rocktron Octopus controlling it.

 

 

So, use a buffered amp switcher that handles output load and trigger it with a GCX (type device)...no need for a mixer to match levels for Y operation? How about if it's into one cab? Would it be amps a/b-->switcher (recieving midi control from GCX)-->signal a/b/y-->mixer-->signal a/b/y-->stereo cab???

 

 

Frequent problem is being strapped for cash. You can always piece it together slowly with your "eye on the prize". I know, it's hard but in the end the product would be worth your hard work and reward you with something that works for you.

 

 

Copy that; I don't intend to rush it. I've got a fairly dope rig for the time being and don't mind waiting while I money up for the super-duper fly gear. It'll take me that long just to figure out what I actually want and how to rig it anyway...

 

thanks

[Terri]

CAE makes an amp switcher with a built-in load box so you can switch power amps into a single cab.

 

You can't dump your amp output into a mixer. (outputs are looking for 4,8,16 ohm loads) and typically the mixer inputs are 100K ohms. (Good way to screwup two perfectly good pieces of equipment). If you want to use two heads or amps the buffered outputs in a switcher will allow you to do that without signal loss. If you use the el-cheapo way you will have some degradation in signal.

[THJams]

Terri,

 

Do you use a buffer to drive your multiple preamps into a line mixer, or do you use a switcher to A/B single pre's to your power amps ?

[THJams]

Terri,

 

Do you use a buffer to drive your multiple preamps into a line mixer, or do you use a switcher to A/B single pre's to your power amps ?

[devilboy]

 

Originally posted by Terri CAE makes an amp switcher with a built-in load box so you can switch power amps into a single cab. You can't dump your amp output into a mixer. (outputs are looking for 4,8,16 ohm loads) and typically the mixer inputs are 100K ohms. (Good way to screwup two perfectly good pieces of equipment). If you want to use two heads or amps the buffered outputs in a switcher will allow you to do that without signal loss. If you use the el-cheapo way you will have some degradation in signal.

 

 

Understood, but it looks like the switchers (CAE & GCX) only offer a/b operation. How do I go about running both in Y operation with one cab?

 

To complicate more, it seems that I need to rewire my cab (mesa recto 4/12 w/8ohm v30s) to do this...right now it's 8 mono/4 stereo - fine for the recto head, but the 9200's outs are 8 or 16/side, leaving me with mono only.

 

Ideally, I like to be able to run the jmp-1/9200 as an independent rig and use both sides of the 9200 for stereo effects. On top of that, I'd like to be able to run from a switcher to the recto head for a/b/y. This way, rather than having this towering monster that's a pain to haul around, I can just grab the head and go or just grab the rack and go...am I making sense? Surely this is possible right?

 

I guess the last bit to add is that I'm considering a boss gt-pro for effects and pre models with the same thought in mind. There should be no problem running this along with the jmp-1 without a switcher allowing a/b/y operation between itself and any pre. Thoughts?

 

thanks

[H535]

Hey Terri great to hear from you! A couple of questions

 

1- What is the "Star Ground" methode. Google search is pulling up nothing but coffe

 

2- Anti-static Foam core is also a mystery. Anti static foam is all over but nothing on form core

 

3- I see a bulk roll of Mogami, black but your pics show different color cable runs. What type of Mogami are you using and where did the color cable come from.

 

Great stuff thanks for the run down. I am getting ready to re-wire my rig. We switched to IEM's and you can REALLY hear noise now. Just looking for ways to quiet everything. Thanks again.

[Terri]

Originally posted by H535 1- What is the "Star Ground" methode. Google search is pulling up nothing but coffe 2- Anti-static Foam core is also a mystery. Anti static foam is all over but nothing on form core 3- I see a bulk roll of Mogami, black but your pics show different color cable runs. What type of Mogami are you using and where did the color cable come from.

1)(Star ground is where you only have a singular point where all ground meets in a system. Like a star pattern, the center is where ground meets and eminates). Many studios prefer this system.

 

2)

You can see various sheets (pink, white stuff) on top of the various units (ready to be used.)

 

Do a search on anti-static foam sheet.

 

3) The other cables (some cables from a previous install salvaged) was, if I remember correctly, Audio Purity cables with Switchcraft 90 degree 1/4" males. The sleeves are colored transparent so you can see the shield braiding. (In case some of it gets kinked or opens up and you can inspect it.)

 

Hope this answers some of those questions.

[Terri]

Originally posted by THJams Do you use a buffer to drive your multiple preamps into a line mixer, or do you use a switcher to A/B single pre's to your power amps ?

My Amp Switcher is buffered and I can drive multiple preamps simultaneously if I so choose. I don't drive preamps into any mixers since I typically use separate amps that are mated to a specific pre. Sometimes a pre can share an amp but that's rare for me.

[H535]

OK, so about this star ground stuff. Can you go into a little more detail on that. Most of the stuff I read/hear when it come to grounding is the way too elaborate grinding of rails and internal lifts and such. Give me a link or a source if you can. I would love to read about it.

[Terri]

Originally posted by devilboy ...it looks like the switchers (CAE & GCX) only offer a/b operation. How do I go about running both in Y operation with one cab? ... I can just grab the head and go or just grab the rack and go...am I making sense? Surely this is possible right? I guess the last bit to add is that I'm considering a boss gt-pro for effects and pre models with the same thought in mind. There should be no problem running this along with the jmp-1 without a switcher allowing a/b/y operation between itself and any pre. Thoughts?

Give me a little time to think this scheme out. Anything is possible within rea$on. (Get my meaning?)

[devilboy]

Originally posted by Terri rea$on. (Get my meaning?)

 

yep, gotcha. again, I'm not sweating it too much - not that I have a fat account by any means, but I'm in no rush and don't mind saving up to drop large coin for quality products.

[devilboy]

on the "star ground" method - do you ground lift everthing into the power conditioner then use its ground to carry the whole system?

[Terri]

Originally posted by H535 Give me a link or a source if you can. I would love to read about it.

http://www.rane.com/note151.html

 

It's long, lengthy and chock full of technical jargon (get use to it, learn the lingo, if you have questions feel free to ask!) and stuff that may not apply but needless to say, it's really worth knowing and understanding. This article covers both signal and chassis grounding techniques. ABSOLUTELY NEED TO KNOW!!! I can't tell you how much Rane publishes to educate the public about proper installation. Drop them a line to thank them for the valuable lessons you're receiving for FREE!!!

 

Hope this helps.

[H535]

Thanks Terri!