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  • Jazzer2020
    started a topic Direct from guitar amp?

    Direct from guitar amp?

    I need to make a quick decision and am hoping for some advice here that might guide me.

    First I'd like to know if it is generally preferable to record a guitar direct from amp to software
    or mic-ing the amp?
    What are the pluses and minuses of each in a nutshell?

    I'm having a tube amp made and need to decide between having an extra speaker out vs.
    a line/recording out from the amp.

    TIA!


  • Danhedonia
    replied
    Most the information above is technically accurate but woefully out of date.

    Get the direct-out option. Actually, it bugs me that you have to choose -- why? It would be nice to have both and many amps do (several of mine do). Anyhow, the ones built today are purpose-built and won't require dummy loads, etc. They simply provide a line-level out on a balanced jack.

    Tons of people use DI as a recording option, from the Beatles to QOTSA; it's simply a choice, mostly having to do with whether or not you wish to color the sound with the ambience of miking your amp.

    Leave a comment:


  • onelife
    commented on 's reply
    Thanks for the tip. I don't record that way anymore.

    My main amp is a Yamaha DG80 which has a digital preamp (with a 'Master' volume that emulates power amp overdrive) and seperate Output controls for the 80 Watt amplifier that drives the speaker and for the speaker emulated balanced line out - very convienient.

    Recently I have been recording guitar with a Boss ME-25 - plugging the stereo headphone output directly into a Yamaha mixer - and getting surprisingly good results.

  • WRGKMC
    replied
    Originally posted by onelife View Post
    I used to use a Peavey E.D.I. (Equalized Direct Interface) which is a transformer based unit with a Timbre control that produced a balanced mic level signal. I used it with a Twin Reverb and with a Fender Montreaux and was very pleased with the results for both live and recording.

    I connected eleven 47 Ohm 10 Watt resistors to a long terminal strip to give me a 4 Ohm load capable of absorbing 100 Watts.

    The E.D.I. worked exceptionally well with a SF Champ, the dummy load and one of those XLR to quarter inch inline transformers into a Tascam multitrack tape machine. I remember reading an article by Craig Anderton several years later talking about the role of transformers in the signal path.
    Personally I wouldn't use a fixed resistor as a dummy load. Speaker impedance is AC not DC and varies impedance with frequency. You often hear stories about tone sucking with purely resistive solutions. Most old fender amps have durable transformers so you may not hurt it but long term use can be a cause of premature power tube failure or fatigue.

    What you want is a reactive load using an inductor like a speaker coil provides. The simplest would be a cheap high wattage speaker like this for $10. http://www.parts-express.com/pyramid...round--290-260



    They have a low SPL level and don't produce allot of sound to begin with. You mount it flat against the inside of a side sealed box and pack the cone and box with foam so the speaker is virtually silent. You can then mount that circuit I posted to tap a line level signal and you're good to go for maybe $25 total.

    If you use a fixed resistor like you were I'd used the old light bulb trick. Measure the resistance of the bulb, subtract the difference from your load resistor and put it in series. This will allow the power to be dissipated in the form of heat instead of backing up through the transformer and cooking your tubes. Heck, use a colored bulb and use it as a light show gimmick. Might help you maintain your dynamics when playing.
    Attached Files

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  • WRGKMC
    replied

    I remembered to get this out of my Home Computer archives. This isn't a dummy speaker load. You'd still need to run a speaker. Its a low voltage line level tap off the speaker which has a cap to remove the harsh high frequencies.

    I've added a 500K pot here so the level can be varied. In the first pic, the level could be adjusted from an adequate line level for a 50W amp with the 500K pot bypassed to a 100W amp full up.





    In this diagram I put the pot across the output so you could tape down the output if the signal from a 50W head is too strong. You'd likely need to use a linear taper so the pot gradually shunts the volume down. Having a higher wattage 470K resistor might be needed too.



    As far as adding a through jack you'd simply wire a second jack in parallel to the top one.

    If you need a balanced output to connect a mic cord you can simply use one of these.
    If you're going to run it into a Mic input you'd want to flip the attenuator switch to -20 ~ -40dB so you don't over power the mixer. These also have a ground lift which is often needed with tube amps.

    You can pick these boxes up cheap. I bought a couple for $10 each and a stereo version for $20. Most have enough space inside to drill a hole for and extra jack or two. You could easily add the circuit above to a normal DI like this so you can plug it into a speaker jack. Then you'd have a multi purpose unit to take care of many issues.






    Attached Files

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  • onelife
    replied
    I used to use a Peavey E.D.I. (Equalized Direct Interface) which is a transformer based unit with a Timbre control that produced a balanced mic level signal. I used it with a Twin Reverb and with a Fender Montreaux and was very pleased with the results for both live and recording.

    I connected eleven 47 Ohm 10 Watt resistors to a long terminal strip to give me a 4 Ohm load capable of absorbing 100 Watts.

    The E.D.I. worked exceptionally well with a SF Champ, the dummy load and one of those XLR to quarter inch inline transformers into a Tascam multitrack tape machine. I remember reading an article by Craig Anderton several years later talking about the role of transformers in the signal path.

    Leave a comment:


  • WRGKMC
    replied
    ^^^ Sure - The old school method of DI for guitar amps was a passive step down circuit using resistors and caps to give you a line level signal.
    All the circuit did was tap the speaker signal and drop it way down so it was safe to connect to a line level device.

    If you have an amp with only one speaker jack you can plug the box between the head and cab. It would be wired as a straight through connection as though it isn't there. Then the tapping circuit connects to a third 1/4" jack gives you a line level send. ( I left out mentioning to add the 3rd jack for this config which is probably why you're asking)


    I think the OP has two speaker jacks so the spare jack can be used with a box with a simple Speaker in line out, but while its being built you may as well add an extra speaker through in case you ever need it for some other amp.

    There is one other notable item when it comes to using a passive DI like this. You can have ground loops, especially with tube amps because of the higher currents. As a safety precaution, using a high value cap in series with the line level hot wire which will pass the full frequency AC signal and black the DC might be a wise move. You could probably add a 1:1 unbalanced to balanced transformer to it too or just use an additional passive DI to it.

    There are also some SS amps where the speaker ground floats. They don't use a common chassis ground for the guitar input and speaker out.
    They can be identified as having plastic or jacks insulated from the chassis. It may be OK to use the box because it steps the voltages down to less then a volt, but I'd look at the circuit diagrams just to be sure it wouldn't cause an issue. Again, these DI's were used for tube amps mostly with the typical common frame. I used one for 10 years playing out with my Ampeg V4B amp. The sound guy would get a direct signal and it was pure thunder,


    There's plenty of things you can do depending on the needs. One valuable item would be to add a pot so you could adjust the level. I've seen many that had rotary decade switch so you could change the resistance to match different amp wattages.

    The one I have in my Bassman is just about ideal for recording with that 50W head at normal volumes. If you had a 100W head you'd likely need to increase the resistor wattages from 1/4 watt and double the values so the line level signal level is better suited. If you had a lower wattage amp, you'd probably need a slightly lower resistance to get a stronger signal.

    I could figure out the values if I know the amp wattage. I did forgot to post the diagram again. I may be able to find it in my post history, I've posted it at least a dozen times over the years.

    Leave a comment:


  • onelife
    replied
    Originally posted by WRGKMC View Post
    A speaker out should only be used for an extension speaker...

    ... stick it in a box with a couple of 1/4 (inch) jacks and plug it into the spare speaker jack and then run a cable to a recorder or PA.
    I realize that you are being helpful but I find the above bits from your post to be a bit confusing. Could you please clarify?

    I'm uncertain and don't want to cause any damage.
    Last edited by onelife; 02-02-2017, 01:47 PM.

    Leave a comment:


  • WRGKMC
    replied
    A speaker out should only be used for an extension speaker. Its high voltage/current and can easily blow the recorder up used directly.

    you can use a special direct box which will step the voltage and current down to line level. I used to build them all the time for tube amps that had no line level outs so you could feed a PA mixer or recorder directly. Its a very simple circuit using two resistors and two capacitors. You stick it in a box with a couple of 1/4" jacks and plug it into the spare speaker jack and then run a cable to a recorder or PA.

    This is a speaker emulated line out unit that removes the harsh treble tones so it sounds more like you're playing through a cab. Because its connected to the speaker jack you capture any power tube and transformer saturation from the power amp. A regular line out is sterile sounding because you're only feeding the preamp at line level, not the power amp.

    You can mount this Speaker emulated line output into an amp too if you wanted. I did that on my Bassman head because I had a spare hole in the chassis after installing a grounded cord and removing the AC phase switch. That's you're option. If you make one for external use it might cost you a few more bucks for the box and extra jack. The resistors cost like $2, and a single jack another $2. A box might cost $5~10 and an extra jack another $2. soldering it together only requires a few soldering points and you're good to go. I can post a diagram if you want. I'd just have to do it in the morning when I'm on my home computer which I have the diagram saved on.


    If you use a regular line out the fix is very simple too. You can buy one of these AROMA ASR-3 Cabinet Simulators as cheap as $25. Thwy will let you input either a line level or guitar level signal and give you a cabinet voiced sound out. http://www.ebay.com/itm/TOMSLINE-ASR...IAAOSwo4pYhFt6




    You plug your amps line out (NOT SPEAKER OUT) into it then run a cord out of it to your PA or recorder.

    You select the cab type you want, then adjust the volume and tone. You'd swear you're actually playing through a guitar amp and you wont be able to tell the difference in a blind comparison. The volume and tone are handy too incase you need to tweak the gain or color.

    I been into recording direct since around 1980. There are few methods I haven't tried and though some can give you unique tones, there are some that are a sure bet. Since people have been able to record digitally in the past 20 years and the low cost of typical guitar boxes have come down, its very easy to find solutions that don't bust your wallet.

    I bought one of these things thinking it might be some cheap piece of garbage that uses passive circuitry to simply color the sound like an EQ pedal does. To my surprise I found out this mini pedal is gem. I thought I'd try it between a standard guitar pedal and recorder to give the pedal some guitar amp cab modeling and it worked out better then I expected - enough so that I turned around and bought a second one so I could record my stereo pedals and set up different cab voicings for each channel.

    Its not the only cab modeling I have but it can do many jobs including the trick of using it between the amps line out and recorder/PA.
    My Marshall Valve state has a cabinet emulated line out so I don't need to use one of these with that one (unless I need more tone options)
    I've recorded my 1960 Marshall cab with numerous mics and used the Emulated line out recording many times and 9 times out of 10 the Emulated out tops the miced tone (in the studio) If it were live a mic would capture the rooms reflection which is something that might be favorable.

    I usually record two amps, one miced and one direct but I could easily use one or two of these to get even more tone options. The switch is direct bypass so its taken out of line too.

    I suspect you'll see the price on this particular one go up as soon as people find out how useful they are. You can even put one on a pedal board to record direct from your pedals with no miced amp or line level direct from it. You just take a tap off any pedal at the end of the chain that has a stereo out like an echo or chorus and feed this box and your amp and you're good to go. You wont get your amps saturation of course but if your tones come mostly from pedals you should be good to go.

    You could probably re-amp through one too. If you did record the amps line out and it did sound harsh, play the signal out through the interface and loop it back into a new track. It will save you a butt load of time trying to do the same things the sound with an EQ. you can add some other pedals before it too if needed. The pedal compensates for that raw tone and adds some cabinet impulses. If you play one song that requires you to have a small combo tone playing through an 8" speaker just flip the switch, If the next requires a 4X12 cab marshall tone or a 2X12 Vox tone or a Rolland Jazz amp or a Fender Brown tone, again just flip the switch.

    This pedal doesn't produce overdrive its simply like plugging your amp head into different cabinets and adds that cabinet tone.
    Attached Files

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  • Jazzer2020
    replied
    Thanks WGR for the tips.
    It sounds like direct/line out recording from the amp is not a very popular route used these days.

    What are the uses for an extra speaker out on an amp?
    This would be the other option for extra amp output.

    TIA

    Leave a comment:


  • WRGKMC
    replied
    You can do either. Both have they're challenges. I can say from many decades of recording you'll need to work hard getting the best results using either. If you have a multi channel interface for recording - you can record both and see which you like best or comply combine the best of each when mixing.

    There are more methods too.
    Heres the list.

    1. Recording guitar straight into the recorder using a Direct Box (or an interfaces guitar level input).
    The signal will be 100% dry so it sucks for playing that way for most stuff. You can use software amp emulators to gain it up when mixing without a problem but it takes allot of tweaking. You can also re-amp through a miced guitar amp using this.

    2. Recording guitar straight into the recorder using a Direct Box using guitar amp software.
    This can work is you have a really fast computer and interface which has super low latency. Software manufacturers make a big deal out of selling these software packages but the latency in most computers and interfaces is too high to make this a good method. The computer takes time to process the signal.

    3. Recording straight into the recorder using a Preamp. There are many older rack style preamps designed to record direct that do a wonderful job. Many have cabinet emulation to make it sound like you're playing through a cab. You can use echo and reverb usints too but whatever you add cant be undone mixing so keeping it fairly dry is usually advised.

    4. Recording straight into the recorder using guitar effects boxes.
    You have an impedance issue here but many interfaces have guitar level inputs. There's no cabinet tone but even there you can buy a cabinet emulator to put at the end of the chain and sound just like you're playing through an amp. Works good too, I do it all the time.

    5. Recording straight into an recorder using a Modeling effect pedal. This is one of the best for solo work. I do this all the time, its actually my preferred method. You can dial up different amps, cabs, drives, tones, and effects. The units usually have a switch to toggle between direct recording or using it with an amp.

    6. Recording from an amps line out or effects loop send
    This signal comes direct from the preamp and has no power amp or speaker coloration. Its often harsh sounding and needs major EQing and coloration to get right when mixing. It works great for bass because you want that kind of sound but guitar can be tough to manage. Again, one of those amp modeler pedals for $25 will do the job nicely between amp and recorder so you can dial up the type of cab you want.

    7.Speaker emulated line out
    Many guitar amps have this feature built in now. The one in my Marshall sounds fabulous. The old method was to use a speaker emulated DI boxes that tap the speaker cable and give it a speaker emulated tone. You can build one for a few bucks using a couple of caps and resistors.

    8. Recording from a Miced amp.
    This one needs a good room and micing techniques. You still have to do allot of mixing to get it to sound right.

    You can use any or all of these and I do suggest you try them all and see which work best for you.

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