Ampeg B-15 and DI Boxes and "Ext Amp" and etc.

Discussion in 'Amps [BG]' started by bluehevy75, Mar 15, 2014.


  1. bluehevy75

    bluehevy75

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    I have been reading the threads and doing some research but I still have some questions.

    The situation: I gig out with a 1969 B-15n blue-line. Often I just plug my bass into a DI (whatever the club provides) and that sound goes to the mains/house PA.

    Last night, Ted (sound man) takes the "Ext Amp" into the DI. "Great" I think. We'll get some tube-y goodness in the mains. But I have to crank the amp because the DI created an "impedance mismatch"

    In the future I'd like to get some of the tone of the amp in the mains but want to avoid the impedance mismatch and volume loss. In the clubs I'm playing in I really don't think any sound man is going to want to mic the cab.

    Check my ideas:
    1. "Ext Amp" gives you a signal from the pre-amp. There is no sure way or DI Box to avoid an impedance mismatch here when going to the mains?

    2. "Ext Speaker" gives you a signal from the power amp? DI's with a -30db pad will work here?

    3. I have a Whirlwind Director DI http://www.sweetwater.com/store/detail/Director/ . That should work with the "Ext Speaker" jack? I use an additional speaker cable? Sound guys will feel comfortable with this? This is similar to a countryman 85?

    4. Just in terms of tone, is there an advantage to having a pre-amp sound or a power-amp sound in the mains?

    Thanks,
    K
     
  2. JimmyM

    JimmyM Supporting Member

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    I've never used one at speaker level, but the Director has an inst/amp switch on it that should be turned to "amp" when going speaker level. It's a 30db boost/cut switch, and it should make up for the lost gain in the "amp" position. Also, don't go out of the ext. amp but out of the main speaker out. You will need adapters that switch from the 4-pin XLR to the 1/4" plug and back again, but www.fliptops.net sells them.

    I used to do that with a Countryman Type 85, and the difference between the DI by itself vs coming out of the speaker out is astounding.
     
  3. dlmaston

    dlmaston

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    My assumption is that with that vintage B-15N, you are only throwing a max of 30W. I am also guessing that you are using the original cabinet too.

    The thing about the B-15N BL that modern sound guys do not realize/stop to think about is that your tone comes as much from that cab as it does the amp itself. To get your "real tone" into the FOH mix, you really should mic your cab.
    When those amps were designed, nobody ran thru a DI.
    (The DI did not start gaining popularity until 1974 or 1975.) Trust me, no decent sound guy in North America or in Great Britain will have a problem running that mic line, regardless of the size of the club.
    And....do not go "cheap" on the mic. I recommend something like the EV RE-20 or a Sennheiser 421. These are good quality mics that will handle the low end well without getting muddy.

    To answer your question at the end about tone.....if you are using effects, then you want the post-amp tone going to the mains, otherwise....only you hear the effects. If you are running clean, then it really doesn't matter much.

    In truth, much of your tone is in your hands.....literally. Technique is everything.
     
  4. JimmyM

    JimmyM Supporting Member

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    Agreed to an extent, but if you ever heard a B-15 speaker DI'd through a PA, you'd understand why people do it. Sounds awesome and clearly makes a difference in tone.

    Not true. As early as the Motown era, people were DIing bass.

    Also not true, and I have witnesses ;) One in approx. every 5 gigs I did with an unfamiliar soundman resulted in an argument over the mic, even though I brought a very nice mic to do it (Heil PR40). And even with speaker level DIing, I would get into arguments when I'd change my amp sound, even though it was just a little change. That's why I finally broke down and got a REDDI. Nobody argues the REDDI, and if they do, it's big and heavy enough to cause cranial damage.

    Agreed, especially about the RE20.

    True, but the difference with a speaker DI'd tube amp vs the DI by itself is too astounding to ignore.
     
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  6. dlmaston

    dlmaston

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    With all due respect to you, that is a very common modern misconception....and not at all accurate.

    Thinking of today's modern DIs and comparing them to the ones available pre-1970s is, at best, an apple to oranges comparative.....and unless you can honestly say that you have used both (as I have), then you do not know the whole story.

    The original DIs that began showing up in the 1950's were nothing more than reversed mic transformers and not the DIs we know today. The modern DI was not even popularized with pros, let alone weekend warrior musicians, until the early 70's.

    Please....do not take my word for it. Do your homework and you will find that I am 100% correct.

    The original RMT-style "DIs" had a totally different tone pass through and the sound was nothing like what you hear from DIs today.

    As a multi-year owner and user of the B-15N BL (1968...and I bought it from its original owner in 1976 when I was 12), I have tried both on multiple occasions. I prefer the sound taken from a good mic off the cab. You make your statement as if it is undisputed fact. It is not.
    In truth, you are stating nothing more than a personal preference, just as I am. ;)

    Please note in my original quote that I said "no DECENT sound man". I did not say "any dude with a PA running sound at a gig". (ROFL! J/K!)
    No decent live sound reinforcement engineer will even blink at running a cab mic for a small bass rig.....and if they do, then they are probably a "guitar boy" that should be home practicing and not running sound in a decent live venue. HA!!
     
  7. JimmyM

    JimmyM Supporting Member

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    While that may be true, those homebrew DI's used in the 60's ate the later SS DI's for lunch. I'd MUCH rather plug into the Motown preamp than a Countryman.

    I stated no preference, but since you asked, I actually do prefer the mic on a B-15. I only gave it up to stop the arguing I'd get from wanting a mic or a speaker level DI. But now that I'm using the REDDI, all of us are happy.

    100% agreed with that! The one thing that the soundmen who would argue about the mic had in common was that they all kind of sucked ;)
     
  8. dlmaston

    dlmaston

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    ROFL! All true! Nice to find an older "thumper" to talk gear with!!
     
  9. bluehevy75

    bluehevy75

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    You guys are great.

    We all know I can't afford a REDDI. I will try rocking the Whirlwind Director out of the "Speaker Out." Don't need an adapter cause my amp had been converted to 1/4" sometime before I got it.

    Yeah, "decent" sound man is key. I play in the city and even the good sound guys probably see so many hacks (I include myself here) in the course of a week that they are nervous to mess with mic'ing stuff. If I was running sound for a club I don't know how much I'd trust someone else's idea of how I should run "my" room. Especially someone who I will see for 50 minutes every few months--at the most.

    Maybe for more specialized shows I might try for mic'ing. Can't afford a mic right now though. How many venues will have the kind of mic I need available?

    Also will continue to work on technique. The more I play the more I find that cutting of the notes at the right times makes a HUGE difference in tone and the amount of space I take up in a mix. I use foam under the bridge and flats but trying to tame the boom on that E string will be some of my major technique work in upcoming weeks.

    Looking for that old school thump that moves people and moves the beat but doesn't take up more space than it needs to.
     
  10. JimmyM

    JimmyM Supporting Member

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    A couple random thoughts for you, Hevy:

    ---Don't know how it is with the Director, but in every other DI I've done speaker level, you have to use speaker cables.

    ---You probably know this, but the DI doesn't substitute for a speaker load, and you still must have a cab plugged into it.
     
  11. dlmaston

    dlmaston

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    Big Time +1 to Jimmy's last comment.

    Blue....that is why I stopped gigging with my Portaflex years ago. (And c'mon....you mean to tell me you can't afford a $700+ DI? ROFL! J/K!)

    I still have it (it is my home practice rig) but she does not go out on the road anymore. I tend to play larger venues so I use a B500 and an SWR 8x10 cab.

    Might I make a suggestion? I know you love that classic tone...but if ease of use, sound guy friendly, small footprint gear is what you need, then you might think about making a change in rigs.
    If you are an Ampeg tone guy like myself, then I have a potential solution for you.
    The most recent redesign on the Ampeg BA-115 now features a re-designed kick back/angle wedge cabinet housing (set up to angle like a stage monitor).

    The tone is solid modern Ampeg, weighs only 48lbs, has a small footprint, and has a good direct out w/ground/lift. It also allows you to send either the pre or the post signal, as you wish.
    It's 150w, highly portable and, makes a really nice, small venue rig.

    There is also the Markbass 2x10 combo. Lightweight, durable, good tone controls, and it is a solid combo with very good low end response (for its size).
     
  12. bluehevy75

    bluehevy75

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    All good reminders. Those are expensive things to overlook. Thanks.
    k
     
  13. bluehevy75

    bluehevy75

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    I'm good for now. But will keep these in mind if there are any changes on the horizon. For now I am still enjoying the journey.
     
  14. beans-on-toast

    beans-on-toast Supporting Member

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    There's some B-15 DI related notes here that you might find helpful.

    Although there were transformer based DI that were used to tap off preamp signals (I had one on a VOX amp), people also had tube based units. There were console amps with inputs that you could plug instruments directly into. One thing about the early days, people new how to design good sounding tube studio equipment. DI as we know it didn't take off till the late 60's early 70's. I saw dummy loads on tube amps, with and without the speakers connected, with line level outputs in the mid 60's so people were trying it.
     
  15. bluehevy75

    bluehevy75

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    Yeah, I did read that. The part that puzzles me is that no one seems clear on what DI avoids the impedance mismatch at the "EXT AMP" jack.
     
  16. beans-on-toast

    beans-on-toast Supporting Member

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    That depends on the B-15 revision (weather or not is has a cathode follower before the EXT AMP output) and the model of the DI (some have a switch which helps match the impedance).

    I have heard good reports of both the Radial DI and the Countryman. You might want to contact JvN and compare notes. He looked into this did a lot of tests combining a mic and a Radial DI with his B15. This way he gets a blend of power amp/cab tone as well as pre-amp from the EXT AMP.
     
  17. bluehevy75

    bluehevy75

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    Ok. I'll reach out. Thanks so much.
    k
     
  18. bigbottomend

    bigbottomend

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    Please post if you find a DI that works as i'm after a solution too for my Herritage B15.
    Very tempted to go for a Radial JDX http://www.radialeng.com/jdx.php between amp and cab to get the whole amp tone, but really unsure what to do for the best.
     
  19. JimmyM

    JimmyM Supporting Member

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    That's exactly what you do for the best. DI between amp and cab.
     
  20. bigbottomend

    bigbottomend

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    Cheers Jimmy, i'll go for one of those then :)
     
  21. bluehevy75

    bluehevy75

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    How different is that Radial than my Whirlwind Director? How much difference is there in DI boxes that are over $50.00 and under $200.00 for this application?
     

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