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Recording SVT output transformer comparo...stock vs. Heyboer

Discussion in 'Amps and Cabs [BG]' started by JimmyM, Apr 11, 2017.

  1. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    So yesterday I got a second Heritage SVT rig:


    Yeah, I know.

    The new one is bone stock while the old one from 2013 has a Heyboer output transformer spec'd on an original Blue Line transformer. I got the Heyboer after a couple discussions on here and some consultations with Ampeg employees who were very big on it. Been a great tranny and the price was right so I'm glad I got it. But since this new one is going to be a house amp at a couple venues we play regularly and available to other acts when we're not playing, I skipped the Heyboer. Of course, I AB'd them rigorously by ear for an hour when I first got the new one yesterday. I'm not so sure I hear any differences between the stock OT and the Heyboer (both have the stock JJ tubes all around), but then with the lag time between switching them out, sometimes I think I do hear slight differences but then I forget what the other one sounded like. All I can tell is they're very very close in tones and the stocker is no slouch at all.

    So tomorrow I'm going to record them to try and get a better fix, but I have a couple questions about the best way to do it.

    1. I'm going to record them with a Type 85 DI between the heads' speaker out and cab, but I'm wondering if I should also mic the cab. Seems to me to be rather pointless when the goal is hearing the amp as plainly as you can, no? I'm going to record samples both clean and with power tube distortion, but even for them, I think I'm better off recording them straight into my DAW. What do you all think?

    B. Of course I'll let each amp warm up fully, but is it better to let them warm up for a couple hours vs doing it after about 15 minutes of warmup? Does it make much of a difference? We've pretty much decided that an amp is going to get about as warmed up as it's ever going to be after about 15 minutes, right?

    Thx in advance for answering questions I should have known the answers to already :D But it never hurts to double check yourself when doing something this important.
    slugger, High Camp, Mik75 and 15 others like this.
  2. Long time coming! I would just A B them myself, but t.i.a for recording them so I can live vicariously for a few minutes.
    JimmyM likes this.
  3. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    I'd say if you want to be semi-scientific here you're going to have to do some work. Record a pass with a looper or direct into your DAW and use a reamp box. Track a pass with the countryman and a mic on one cab with one amp. Swap all the tubes from that amp into the other amp and set the bias, run again with the same cab, same mic/placement, and use the looped/reamped sample into amp two.

    Or set them both up and just A/B between them for fun.
  4. +1 for using the mic and a/b the amps. Although hearing the naked 85 would be interesting also.
  5. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Oh, intercourse the penguin!


    Somewhere in the middle is the answer.
    GregC and rodl2005 like this.
  6. Arthur U. Poon

    Arthur U. Poon

    Jan 30, 2004
    SLC, Utah -USA-
    Endorsing Artist: Mike Lull Custom Basses
    And I was (and still am)jealous of your your first Heritage atack.....Times that by two now. :woot: :D :bassist:

    If it were me I run them both just to experience the power!! :hyper:
    rodl2005, Lvjoebass and JimmyM like this.
  7. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Already did, Senor Poon! Let's just say it's everything you'd expect and a couple things you wouldn't :D
  8. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    What an awesome dilemma to have!!!!!

    Sweet pair man.
    Lvjoebass and JimmyM like this.
  9. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    OK, decided to mic the cab. Doesn't take much extra effort and it'll give me another perspective.
  10. callofcthulhu


    Oct 16, 2012
    At least use the same cab for both heads.

    The looper idea is good too, if you've got a Ditto or some such lying around.
    GregC, HolmeBass and JimmyM like this.
  11. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    I don't. But I'm pretty consistent in my playing, and besides, I'd rather hear what it sounds like directly from the bass. Will use the same cab for both heads, though.
  12. Gizmot

    Gizmot Supporting Member

    Mar 22, 2009
    Nashville area
    Don't forget to match the levels as precisely as you can - not just the control settings.
    JimmyM likes this.
  13. Nickweissmusic

    Nickweissmusic Knows all intervals from one Fred, to Juan octave Commercial User

    Jan 26, 2014
    San Diego, CA
    I teach lessons and perform live music in and around San Diego CA. Sometimes I even make money doing it!
    First of all, bummer you have to spend a day recording 2 awesome giant amps, rough gig.

    1) probably just the DI, and I'll bet there's almost no difference, other than an expected slight differrnce in amps. I bet neither is "better." Can you do a blind Poll on talk bass? As in, can you take poll answers but not let people know the results until it's all over, so as not to influence their decision?

    I asked a guy at Radial once how much better the Jensens were than the fine Chinese ones they put in their lower cost gear. All he did was silently shrug his shoulders. Nuff said. Obviously OT's are operating on a much bigger scale but my prediction is the poll gets split pretty much down the middle.

    B) no idea. I'd just turn em both on in the morning and let them stew for a while, think about what they've done.
    AlexanderB and JimmyM like this.
  14. Session1969


    Dec 2, 2010
    After reading all these posts, I can't hear a difference either.
    smogg, okcrum, DaveDeVille and 5 others like this.
  15. DD Gunz

    DD Gunz

    Jun 18, 2015

    I think it's a good call to mic the cabs. In a live setting, that's what you are getting so any tonal difference would need to be noticible emitting from the speakers.

    IMO the FOTH will color any diffence pushed out of the head anyway. I think the real story here is what's coming out of your speakers.
    Nickweissmusic and JimmyM like this.
  16. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    I could do a blind poll, yes. Was debating on even posting my clips at all, but I guess some folks might be interested in it.

    And regarding those Jensen transformers, Tony Levin did some recordings a few years ago with a bunch of different DI's, and two of them were Whirlwind Directors, one with a Jensen, one with a stocker which I assume was from China. I couldn't tell the difference.

    Yeah, I'm probably overthinking that part. I just get impatient.
    Nickweissmusic likes this.
  17. Lvjoebass

    Lvjoebass In Memoriam

    Jan 19, 2017
    Once opened for a headliner in the Midwest..4 of those batboys..simply heaven in an old theater early 70s!
    High Camp, JimmyM and Arthur U. Poon like this.
  18. I look forward to not hearing a difference. .. but
    saying one sounds better...stating that it's the stock / modded one then going back and saying 'upon further listening thru better headphones. .....the other sounds WAYYYYY better'
    But. ..seriously. I look forward to it.
    JimmyM likes this.
  19. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Warm up the amps with standby off for at least half an hour. Use your ears to dial them in to sound the same at a lower volume. An RTA spectrum on a phone or pad will allow you to visually see any differences in EQ. You would be surprised to see what is going on. An app like this one, see the last segment in the video: Spectrum Analyzer for iPad, iPhone and iPod touch. The built in mic is fine in this case because you are using it to compare two amps relative to each other.

    There are way too many variables to make this scientific. Test equipment would help identify differences. The app can help here. As Corey said, reamping will provide consistency. Normalizing the tracks within the DAW is important as even a slight volume difference can make one sound better than the other. There will be differences due to component tolerances, even with two identical amps and perfectly matched tube sets. Do the best you can with your ears.

    When testing an output transformer, you want to listen carefully to the clean notes. How distinct they are, the quality of the notes, the harmonics. Listen for low end distortions. Then play chords and listen for distinct notes, smearing indicates distortion. Do some slapping using upper registers, listen for how the impulse is handled. Then repeat with the amp pushed into distortion.

    The speaker cab affects the performance of the transformer. Adding a mic will create a whole new set of variables, exact placement on each cab is important. But since you can gather the data with a mic'ed cab, why not include it. Using the same cab for the tests would be ideal but this is the real world. Maybe swap the cabs with one head just to see if there are any sonic differences.
    Last edited: Apr 12, 2017
  20. Michael Schreiber

    Michael Schreiber Commercial User

    Oct 14, 2014
    Kassel / Germany
    First fo all: @JimmyM Congrats! \m/

    One question about the OT comparison: That would require to have it played quite loud, right? Or does an OT have hearable coloration/influence on the sound at lower volume?

    Just asking, since my first thought was A/Bing the live, as well; one rig to the left, one to the right - at reasonable volume. But at certain volume, I guess, the room would take over coloring the sound, masking any OT influence. Is that right?
    JimmyM likes this.

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