Does a tube amp need a load or can you record straight into a computer?

Discussion in 'Recording Gear and Equipment [BG]' started by bassmandudeguy, May 27, 2012.

  1. Ok here's my quick story. I'm trying to do a little long distance recording with my brother. I'm on bass, he's the guitar player. I just got him a Focusrite Scarlett 2i2 for his birthday because his sound clips sucked so bad so I was trying to help the both of us lol.

    Anyway we're on the phone and he mentions he's gonna plug his all tube guitar head into the Focusrite because he wants his amps sound and I freaked out on him cuz I'm pretty sure he might make an early fourth of July fireworks show that way!

    I told him he very well might blow something up doing that and that the tube head needed to see a load. I also told him to get a decent mic and mic his cab and send THAT into the Focusrite if he wanted to capture his TUBE amp sound.

    So did I give my bro bunky advice or is there any truth to that? I think I read about tube amps needing to see speakers here on TB but I'm not 100% sure but I figured it was safer to tell him NOT to do it just in case... until I got to the bottom of this anyways.

    Oh and since we're on this topic is there any HARM in running my signal through my BX1500 without speakers attached then to an interface>computer? I want to say no but I'm pretty sure you guys will say that's a dumb idea anyways for some reason? Help I'm a complete to recording!
  2. You did right, A tube amplifier always need to see a Load.
    I don't know about the BX1500 but usually SS or Class D amplifiers don't usually need to see a load, so you can use it without speakers.
  3. Thanks Hellbastard! I was pretty sure I was right but my bro started quoting some random sound engineer dude friend of his and he tried to argue with me and I told, look man if u want to fry your gear go ahead!

    There actually might be a way to do what he was stating, I don't know the veracity of the convoluted crap he was feeding me based off some second hand knowledge from a"soundguy" i didn't know... I told him my info was pretty solid cuz I know a bunch of PROS from TB tho and they have NEVER given me bad advice LOLZ!

    Props to you guys! Thanks again!

    P.S.- he was like "*** are these TB Pro guys anyways?" I was like... "you play bass now?" his response, "pffft no way dude!" me,"ya, don't even worry about it then dooder!"
  4. bongomania

    bongomania Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    IF the "convoluted crap" his soundman friend told him included a dummy load, or an actual speaker load of any kind, then he was probably on the right track. Otherwise, he probably misunderstood what he was told.

    Amps with an all-tube power section need a load in order to stay alive. A hybrid head with a tube preamp and solid state power section does not need a load.
  5. fu22ba55

    fu22ba55 Supporting Member

    Apr 16, 2009
    1) Unless on standby, tube amps ALWAYS need a load. (I prefer to keep a load connected even when on standby, just in case I mistakenly go off standby while recording...)

    2) Some tube amps will let you take a line-level signal (from DIRECT OUT out NOT speaker out) while amp is on standby. The Focusrite will like that line-level signal

    3) Some solid-state amps let you run without a load, but I don't believe in solid-state amps, so I'm no expert there.

    4) Speaker out from head --> into focusrite == BAD IDEA = a ruined tube amp, totally confused and bummed out Focusrite. You told your pal the right thing. Avoided fireworks display. Tube amps always need a proper load, and you maybe could have cooked the focusrite too.


    How to get the "speaker sound" your pal wants:

    a) mic the cab and warn the neighbors

    b) speaker-level DI (countryman DI or JDI added into speaker chain), but you still need a load to accept the brunt of the speaker out, and all impedances still need to be observed.

    c) dummy loads plus countryman or JDI:

    You can buy dummy loads that your amp will think are "close enough" to a real speaker load:

    Just be sure to put a grilled cheese or baked potato on top so you can cook dinner while recording. Those things will get hot.
  6. Ok thanks again Bongo and fu22ba55!

    Ya my bro didn't mention anything about using dummy loads although I can't say what that other soundguy told him. Probably somewhere along the chain they crossed some communication wires.

    Thanks for the detailed response man! It raises some more questions however.

    I'm not even sure what his amp is. I tried to get ahold of him but he works a lot and has 2 kids so... but I think it's an older model marshal or maybe a peavey and I'm not even sure it HAS a direct out. I think what my brother was GOING to do was like you said in #4 and plug the focusrite into the speaker out!!!

    BUT if I understand you correctly, IF his amp has a DIRECT OUT he can keep the speakers hooked up and put the amp on standby and go DIRECT OUT to focusrite and be ok right? So even on standby the amp sees the speaker load but silently sends the signal out via direct out to the focusrite and then pc right? I know this is noobish but I'm to make sure his broke ass doesn't fry his gear!

    I don't quite understand how to hook up your suggestions in b & c with the speaker level DI's and dummy loads though so we'll probably avoid that since he's broke anyways and won't want to buy more gear. But thanks for the idea... just wish I understood how it works lol

    He'll probably end up micing the cab since that seems the simplest and the least probability of ruining gear. It's just the neighbor thing like you mention and most of his recording will probably be on the weekends so that MAY be problamatic hah!

    Thanks again guys!
  7. fu22ba55

    fu22ba55 Supporting Member

    Apr 16, 2009
    Maybe. Some tube amps will still send signal to direct out while on standby, some will not. But as long as you still have speakers connected to speaker out, and you're only trying the "direct out" with the focusrite, it's worth a try. (And you likely won't blow anything up).

    Double Plus +1

    This is tried and true, safest method, more fun, etc...
  8. stingray96191


    Jul 27, 2001
    Pittsburgh, PA
    Unofficially Endorsing Ernie Ball Music Man Guitars
    You dot ever turn on a tube amp if it is not plugged into a speaker or dummy load. The imprudence doesn't need to match. It just needs something to keep the transformers from blowing up.
  9. Thanks Stingray! Weird thing just happened, I had to reboot cuz I was trying to scan a picture my daughter made for a project and the printer wouldn't work blah blah

    so I come back to TB and I'm logged out now after the reboot and I read your post and there's a link for transformers so I click it and it brings me to ebay with a bunch of optimus prime transformers!!!

    Then I log in and the link is GONE! I'm not making this up bro! Weird!

    Oh and thanks for the reply! I was already pretty sure that was the case but just double checking!
  10. stingray96191


    Jul 27, 2001
    Pittsburgh, PA
    Unofficially Endorsing Ernie Ball Music Man Guitars
  11. seamonkey


    Aug 6, 2004
    Some older tube amps have a shorting 1/4" output jack. No load plugged in and they short the output. This is safe for tube and output transformers. It's only half idiot proof. You can't plug in a cable and leave the speaker disconnected.

    If the amp has speakons then chances are high that there's no automatic shorting with no load. The Manual or schematic would say in either case.
  12. Thanks for the reply Seamonkey. I'll pass this on. I wonder why the newer amps don't have this sort of "safety" feature. The amp is pretty old. I havent laid eyes on it in probably 12 years but I'm fairly certain the peavey is an early 80's model and the Marshall an even older roadworn hand me down from our uncle so they probably only have 1/4" right?

    Anyways I should be able to get ahold of my stupid brother later today. I think he's avoiding me cuz I've been pestering him about a review of the focus rite interface I got him for his birthday and he hasn't had time to play with it yet haha. Hopefully he hasnt blown anything up!
  13. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Many new Fenders still do. It's a fail-safe mechanism to keep the amp from blowing up when you neglect to plug in a speaker, not a feature to allow you to run it that way for long periods of time. And if you did run it that way, where are you going to derive your recording signal from? ;)
  14. John D

    John D Guest

    Dec 27, 2009
    OP, follow Seamonkey's advice at your own, or your brother's risk. Passinwind is giving you the proper advice.
  15. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Please get the exact details and post them. ;)
  16. BassyBill

    BassyBill Still here Gold Supporting Member

    Mar 12, 2005
    West Midlands UK
    Sorry - had to quote this purely for giggles. :D
  17. seamonkey


    Aug 6, 2004
    I'm assuming the OP knows more than you, and is smart enough to take the pre-amp out, or effects loop out.

    In the manual it would say if this cuts off the signal to the power amp.
  18. stingray96191


    Jul 27, 2001
    Pittsburgh, PA
    Unofficially Endorsing Ernie Ball Music Man Guitars
    That is an iPhone spelling "correction" the correct term is impedence.
  19. John D

    John D Guest

    Dec 27, 2009
    If he follows your advice, he apparently doesn't know more than I know.
  20. Stumbo

    Stumbo Guest

    Feb 11, 2008
    Your might want to take a look at this attenuator/power soak.

    It has a line out for recording that may be exactly what he needs.

    I bought one (w/o the line out) awhile ago and, for me, it does everything I need it to do. YMMV.
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