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Mesa Boogie/GiO/Logic signal path Question(s)


~flipper

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I'm just a guitar player. I'm using Apple Logic, Native Instruments + Superior Drummer software, an old Mesa Boogie Mark IIB and a GiO board from Apogee that I use as a direct box into an Apple laptop.

 

My concerns are two-fold, first, how to safely use the Mesa (instead of the goofy NI Guitar Rig) with my current setup, and secondly, a few other Mesa Boogie-related questions.

 

The Mesa (my fourth Mark II) has a send/return on the back of the chassis. I'm in a phones-only situation. I'm woodshedding, big-time, for the next 12-18 months, so I won't be able to consider throwing a mike on the amp. The 'send' won't interrupt the signal path internally in the Mesa, but I am uncertain about the safety of running the send out to the GiO.

 

So, the first question, assuming there isn't a tried-and-true solution that is simpler, that I'm unaware of, is:

 

1 - Will the effects send signal from the back of the Mesa Boogie fry the input circuitry on the Apogee GiO?

 

[i learned, the hard way, that by the time you smell smoke, it's too late. I cannot afford to replace the GiO; I've talked to Apogee, and they're optimistic but "non-committal." I'm saving up for a Euphonix MC Control; it looks like Spring '11, and at that point the GiO will be the most bloated DI box on Earth (I hope). But it has to last until then. I need some seriously confident advice. Please.]

 

Here's a couple Mesa Boogie-related questions (they aren't rocket science, I know, but I've been totally away from guitars and almost all things 'audio' for 17 years or so, and see no point in pretending to know/remember things that I don't):

 

2 - The Boogie combo, in normal use, is an 8 ohm load. What, exactly, is the appropriate 'thing' to attach to the 8 ohm speaker jack on the Mesa Boogie when it is only being used as a direct box (with the internal speaker not plugged-in, in other words)?

 

[i'm not a gamblin' type, but if I was I'd be curious what the 'over/under' on the number of 'answers' that go like "Throw an 8 ohm resistor on it" would be. heheh]

 

3 - The Boogie has a second cab (w/an Altec, nice). Question is: What sort of cable is best for a short-run extension cab? I stopped gigging 20 years ago and forgot tons of stuff. Is a regular, short guitar cable okay, or do they need some sort of slightly-different twisted-pair thing?

 

Thanks for any help on these things.

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1 - Will the effects send signal from the back of the Mesa Boogie fry the input circuitry on the Apogee GiO?

 

I have no idea. :idk:

 

I've successfully run amp signals direct into other audio interfaces, but I don't want to assume that what worked for me will not end up turning your GiO into a puddle of smoldering goo.

 

2 - The Boogie combo, in normal use, is an 8 ohm load. What, exactly, is the appropriate 'thing' to attach to the 8 ohm speaker jack on the Mesa Boogie when it is only being used as a direct box (with the internal speaker not plugged-in, in other words)?

 

I'm not even sure what you're asking here.

 

3 - The Boogie has a second cab (w/an Altec, nice). Question is: What sort of cable is best for a short-run extension cab? I stopped gigging 20 years ago and forgot tons of stuff. Is a regular, short guitar cable okay, or do they need some sort of slightly-different twisted-pair thing?

 

I don't have a clue. But best of luck on all this stuff, and welcome to the forum. :thu:

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Thanks Jeff - regarding that one question, in the old days, Mesa Engineering used to say "Always run the Boogie with either a speaker, or speakers, or a proper load resistor." I'm certain they meant that for cases, like mine, where we wanted to run the amp as a pre-amp out only, or use the slave out, or the effects send loop, and not drive the internal (or any) speaker.

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The Marshall Power Brake and other examples of load resistor exist, most of which weren't exactly cheap, last time I looked. Do note, you will cook your amp if you run it without a proper load. If you search "power brake" and "dummy load" with guitar, amp, etc, you'll get relevant info on that subject.

 

I would suggest trying the send output (jack) first and try to get a workable signal. Start with everything turned down and work up, so you don't overload anything. I've used a send jack in this manner, but the signal level coming out is anybody's guess. But, it should be somewhere in the ballpark.

One thing to remember is if you do this (on most amps), you will only be getting the preamp section in the equation, and the send jack tone isn't exactly all that. (Sure, my Metal Zone Pedal sounds cool, but The Champ 30 running it through a speaker is what makes it. Run that same pedal into a direct box and it won't even compare.)

 

The reality is (imo) that the majority of killer guitar tone happens in the speaker. You can take a combo and swap speakers and have a completely different sound. So, what I was thinking is:

 

I'm wondering if your best bet is a POD, or some other similar device, that can provide you some good workable tone, without any volume issues. If you are trapped in headphone-ville, and I've been there (and yes, it sucks), you do what you have to do. I used a H&K Red Box for years, but it still isn't a full fledged load resistor, and it's got a basic sound and you work with it. They were a popular item in the days before speaker emulation was not an oxy-moron. I always just ran various distortion pedals into it and used it for the cab emulation, since I was trapped in headphone-ville. But, it still didn't give you the tone you really want. ;)

 

These days, some good solutions are out there to give you these killer tones. I'm not going to say an amp sim/speaker emulator or a POD/etc is going to be the same as inserting a dynamic mic (without lube) into a speaker cone at maximum vibratory potential, but I sure wouldn't mind having a POD or similar, because I've heard some killer tones come out of these boxes anymore.

 

You mentioned the "goofy" NI rig and that makes me think a dedicated box would be much better, and you'd get a whole range of tones, from Mesa, to Marshall, to Fender and Orange, Vox and all the rest...for what? What's a good POD type device go for these days? You mention cost, so I'd suggest selling your TV and getting what you need. ;)

 

So, here we go:

 

1. Patch a cable into the send loop on your amp and then send that to an input of some other device (not the Apogee), so you can test the signal level coming out of that send. If it seems good, then you can make a safer guess as to whether it will work.

 

2. If it worked, make sure you return all the levels to zero before you try it and bring them up slow.

 

3. You will be working the preamp section only and won't be getting any speaker emulation. Perhaps you can use software after the fact to get the speaker cab effects. It's a big part of guitar tone, so even if you were using the speaker out into a dummy load, you still wouldn't be getting the benefit of the speaker and the resultant air moving.

 

Test it out on an old cassette deck or something and see if it works. Then come back and tell us what you figured out. We've been hanging out in here for years just waiting for somebody to come in here with an actual question.

 

We used to be "Expert Forums", but now we lurk in one of the dark segregated corners of HC, waiting anxiously in the hope they don't do a software upgrade.

 

:)

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3 - The Boogie has a second cab (w/an Altec, nice). Question is: What sort of cable is best for a short-run extension cab? I stopped gigging 20 years ago and forgot tons of stuff.
Is a regular, short guitar cable okay,

 

Absolutely not. A guitar cable is 24 or 22 gauge vs a speaker cable which is 16 or 18 gauge. It's a "kink in the hose" and could damage your amp. You're exceeding the maximum rated level of amps that wire can carry.

 

or do they need some sort of slightly-different twisted-pair thing?

 

Get regular old speaker wire. The best bet is probably some lamp cord. Ultra cheap and you can get some good connectors. Or just buy a speaker cable.

 

This whole subject is an issue I've ranted about. How many guitar cables and speaker cables look just alike? Who could blame even somebody who knows. I've got a whole wall of black cables with 1/4 inch connectors. Could you tell me which are which? ;)

 

Speaker cables should be anything but a 1/4" connector. Half the guitar players out here are probably using a guitar cable for their amp! ;)

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Stranger's advice is excellent. Along with the search terms he mentioned for speaker load boxes, also try "power soak."

 

If you're willing to have the speaker connected, then this will do the job: http://www.peavey.com/products/browse.cfm/action/detail/item/117097/SDI%20Speaker%20Level%20Direct%20Interface.cfm

 

An expensive, but damn-is-that-good solution, is the Two Notes Engineering Torpedo. Here's a video of a demo that happened a little over a week ago at AES:

 

[YOUTUBE]petpRu90HVg[/YOUTUBE]

 

Personally, I have a Peavey Windsor amp because it has a power soak-type feature built in, as well as a DI out, and you can swap various tube types around for different sounds. I wouldn't take it out for playing live, but it's effing great in the studio.

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1 - Will the effects send signal from the back of the Mesa Boogie fry the input circuitry on the Apogee GiO?

 

The simple answer is "no." But there are some considerations. Since you mention "fry," I'll tell you that it's pretty rare that the signal from an audio output (which the Insert Send is) can overload an input (the guitar jack on the GiO) to the point of doing some actual damage. Here's why this is so.

(In regard to your question about questions, I'm explaining this so that you'll understand the mechanism and won't have to ask the same question about a Digitec or a Roland or some other pedal)

 

Since:

If it's indeed a short run, 6 feet or so, an ordinary guitar cable will work. There are speaker cables with 1/4" phone plugs on both ends which are made from heavier gauge wire than instrument cables if you have a longer run, or if you really want to do it right. But you won't blow anything or sacrifice tone except at top volume (which you aren't going to use for practice) by using a cable that you probably already have.

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Speaker cables should be anything but a 1/4" connector.

 

A 1/4" phone plug isn't all that great a connector for high currents. An XLR is considerably better (I think they're rated for about 20 A) but you don't want some idiot to connect a microphone to an amplifier output by mistake. That WOULD be harmful to nearly any microphone. Speakons are best, but it'll be a while yet before they're universal. 1/4" plugs and jacks are just so inexpensive, a criteria for 90% of all instrument amplifiers.

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I'm on a 'break' here, and am amazed at all the replies. I'm re-reading everything, and will reply to specific posts shortly, but for now, I am just a combination of impressed and grateful.

 

I still have my old Mesa manual. They say, "Always run the Boogie with a speaker or load resistor (8 to 20 ohms, 50 watts)." i pretty much already knew that part, minus the 'numbers', so I've been looking, online, at Marshall and H&K attenuators and whatnot. A little pricey, and 'unavailable' in many locations. Anyway, my responses and questions will follow in a few minutes.

 

Thanks a million, everybody.

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I still have my old Mesa manual. They say, "Always run the Boogie with a speaker or load resistor (8 to 20 ohms, 50 watts)." i pretty much already knew that part, minus the 'numbers', so I've been looking, online, at Marshall and H&K attenuators and whatnot. A little pricey, and 'unavailable' in many locations.

 

You can buy five 2-packs of 100 ? 10 W resistors from Radio Shack for $20 and make your own dummy load by connecting them in parallel. Of course you might have to visit three Radio Shack stores in order to find the ten resistors, but it'll save you a bunch of money.

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1. Patch a cable into the send loop on your amp and then send that to an input of some other device (not the Apogee), so you can test the signal level coming out of that send. If it seems good, then you can make a safer guess as to whether it will work. ... 2 ... 3. ... Test it out on an old cassette deck or something and see if it works. Then come back and tell us what you figured out.

:)

 

As 'lame' as this might sound, I don't have any other device that could stand in for an input. But, later on the thread here, whether in one of your posts, or another, there is an idea (with the logic of it all spelled out) that looks real workable.

 

The POD idea is interesting. I have one Line 6 thing, a modulation modeler, that works really well. But, for the time being I am "okay" with the, ahem, 'goofy' Guitar Rig. It's workable.

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The simple answer is "no." But there are some considerations. Since you mention "fry," I'll tell you that it's pretty rare that the signal from an audio output (which the Insert Send is) can overload an input (the guitar jack on the GiO) to the point of doing some actual damage. Here's why this is so.

(In regard to your question about questions, I'm explaining this so that you'll understand the mechanism and won't have to ask the same question about a Digitec or a Roland or some other pedal)

 

Since:

    of practicing at full volume. Ha ha, right. Unfortunately, when I was working as a musician for about 15-20 years, I was very dumb. I now have about a 60 db 'pad' built right in to my own head. Sort of like a reverse-Bionic Dude! I know, not funny, believe me. At least the 60 dbs are straight across the board.
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That's really funny and sadly true at the same time.
:)

The old saying was " ... Everything except what you're looking for!" right? My needs have been pretty mundane, so I tend to find whatever it is there, actually.

 

On the subject of major brand slogans that coulda-woulda-shoulda been, who could forget: "No highs, no lows ... it must be Bose!"

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Hey flipper, the Mark IIB is a fantastic amp and the first Boog I ever owned back in the very early 80's. I really don't think you're gonna get the sound of the amp out of the effects send, I'd be more inclined to just play it at conversation volumes and put an sm 57 on it. That said, if you do want to try the dummy load, check Parts Express or MCM. One of em I remember had a 50 watt 8 ohm load resister for techs to load amps with on the bench.

 

You might also think about selling your amp and getting a Mesa Mark IV which is what I did. The Mark IV has this fantastic feature called 'silent recording.' Basically you have a recording out jack that you plug into your sound card and you pull the master volume out (switch) and it turns off the speaker but keeps a load on the amp so it's safe. The sound that comes out of the recording out jack sounds almost exactly like your amp sounds miced up.

 

It's an old habit of mine; unscrewing 1/4" phone plugs to see if it's a tiny wire and shield or two equal size wires inside. The later (unshielded) is what you want to hook up speakers.

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Hey flipper, the Mark IIB is a fantastic amp and the first Boog I ever owned back in the very early 80's. ... I'd be more inclined to just play it at conversation volumes and put an sm 57 on it. That said, if you do want to try the dummy load, check Parts Express or MCM. One of em I remember had a 50 watt 8 ohm load resister for techs to load amps with on the bench.

 

Thanks a million; I found the 8ohm/50 watt resistor at MCM. When I get to 'real' recording the SM57 on the speaker is the way I'll go.

 

You might also think about selling your amp and getting a Mesa Mark IV which is what I did.

 

I hate to sound so obviously un-sensible in the face of such sensible advice ... But, I sold a pair of MarkIIs about 18 years ago (a 75-watt simul-class, and one of the 60/100 combos) and I will never sell this one. I just can't do it.

 

re: Extension cabinet cabling:

 

The later (unshielded) is what you want to hook up speakers.

 

That's great; much appreciated.

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1 - Will the effects send signal from the back of the Mesa Boogie fry the input circuitry on the Apogee GiO?

 

It's possible -- I fried an input to a computer sound card doing something similar. Turned out, after I chased down the cause, that there were different 110VAC power breaker circuits powering each device, and there was enough voltage difference between the two separate neutral lines (due to differing amounts of load current on each circuit) that it blew the brains out of the sound card input. If you want to be safe, put an audio transformer with no connection from the primary to secondary between the two.

 

2 - The Boogie combo, in normal use, is an 8 ohm load. What, exactly, is the appropriate 'thing' to attach to the 8 ohm speaker jack on the Mesa Boogie when it is only being used as a direct box (with the internal speaker not plugged-in, in other words)?

 

Get an 8 Ohm power resistor with a wattage rating of roughly twice the amplifiers rated power.

 

Something like this would work for up to maybe 30 watts. But bolt it down to a good sized piece of metal to carry away the heat.

 

Here's another that should handle 50 to 6- watts with no problem (again, if bolted to some metal).

 

3 - The Boogie has a second cab (w/an Altec, nice). Question is: What sort of cable is best for a short-run extension cab? I stopped gigging 20 years ago and forgot tons of stuff. Is a regular, short guitar cable okay, or do they need some sort of slightly-different twisted-pair thing?

 

Some 16 or 18 gauge stranded power cord (two conductor) wire would work.

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