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A Tube Works 4001 Direct Box (DI) made 2002 in Taiwan by Genz Benz

Discussion in 'Recording Gear and Equipment [BG]' started by Snaxster, Sep 20, 2012.


  1. Snaxster

    Snaxster

    Nov 29, 2008
    Since I don't see much info online about the Tube Works 4001 and 4002 model DIs (mono and stereo, respectively), I made some documentation of a 4001 I just acquired:

    2002 Tube Works Real Tube DI

    [​IMG]

    That's a Flickr gallery, in which each photo page contains my commentary.
    FAQ

    Q: What do you think of the 4001 Direct Box so far?
    A: I like it very much. It sounds great, is very useful, and is easy to use.

    Q: How does this made in Taiwan version sound compared to the earlier made in America ones?
    A: I don't know, since I can't recall ever using any other 4001 Direct Box.

    Q: How does this DI sound compared to an Aguilar DB 900 (which is also out of production and features post-tube audio in the hi-z output)?
    A: I don't know, since I never used the Aguilar model. But for my purposes, at 3 to 4 times the price now, the Aguilar DI would have to sound much, much better than the Tube Works DI to justify its greater price.

    Q: Would you use a Demeter, Aguilar, A Designs or other high-end tube DI instead if you could afford to?
    A: Probably. The Demeter or other for recording and the Aguilar for live: I want that post-tube audio for the bass amp. I would like to someday directly compare the sound of the 4001 DI to the high-end models. Until then, I think the 4001 DI gives amazing value for money.
    I hope this helps others with their research of tube DIs. If you ever owned or played through both U.S. made and Taiwan made versions of the 4001 DI, please post here with any impressions you recall of the two, especially comparing them. Thanks.

    Best,

    Snaxster
     
  2. svtb15

    svtb15

    Mar 22, 2004
    Austin,TX- New York,NY
    Disclosures:
    Endorsing Artist: Alleva-Coppolo| MESA |REDDI|Westone |EMG
    They dont make that anymore.. sadly...
    I think Genz Benz own that stuff now.. not sure.
    Im Thinking the 4001 as pictured above would sound very nice from what i have heard others say. No direct experience with it.
    I would get the REDDI over the Aguilar if you want big and fat .. Aggy is very nice. Used it a few times. But the A-Design REDDI is deeper and fuller sounding than the aggy with smooth top end clarity. The REDDI is just Huge sounding..
    The TW 4001 was said to be a favorite of Lee Sklar for many years. Would love to see a re issue one day.
     
  3. smcbass

    smcbass

    Nov 17, 2010
    37774
  4. Snaxster

    Snaxster

    Nov 29, 2008
    Hello. Thanks for adding that link to the thread.

    I will PM you about tubes, to keep the thread focused.

    Best,

    Snaxster
     
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  6. Snaxster

    Snaxster

    Nov 29, 2008
    Recently I've been learning about using different op-amps in audio devices. Swapping in alternative op-amps is like "tube rolling" with vacuum tubes.

    With the TI TL072CP op-amp that was stock in it, my Tube Works 4001 DI sounds very good. I have read some players describe the sound of this model as "huge".

    photo of the stock TI TL027CP op-amp in the 4001 DI

    [​IMG]

    Tonight I swapped a Burr Brown OPA2134PA op-amp into my 4001 DI, replacing its stock TI TL072CP op-amp.

    Burr Brown op-amps are widely considered to be at the high end, whereas TL072 op-amps are usually considered to be serviceable. But in the right hands, and to the right ears, any sound can be good.

    With the OPA2134PA in it, my 4001 DI sounded very different: it made much less low frequency output than the TL072CP, and it sounded less harsh and aggressive overall. My impression was that low frequencies, especially, now sounded more focused, relaxed and natural.

    So I believe that players' description of the 4001 DI as sounding "huge" was in part due to its stock op-amp boosting low frequencies.

    As in other instrument audio applications, I like the Burr Brown OPA2134PA op-amp in the 4001 DI for its relaxed, open and honest-feeling sound.

    photo of the Burr Brown OPA2134AP op-amp in the 4001 DI

    [​IMG]

    Soon I will upgrade all the capacitors in my 4001 DI. If nothing else, the original caps are now ten years old; but I think better quality caps will improve the audio in any case. Upgrading the resistors to metal film ones is also an option, but its a lot of work, and I haven't yet noticed my 4001 DI being too noisy.

    Best,

    Snaxster
     
  7. smcbass

    smcbass

    Nov 17, 2010
    37774
    I bought a 4001 Real Tube Direct on ebay a while ago. I read some posts on TB recently about "glory tube" DIs. Given the input power of this DI (30VAC/600ma), I wonder if it is a "glory tube" DI. Your comments welcome.
     
  8. Ender_rpm

    Ender_rpm

    Apr 18, 2004
    St. Louis MO
    Thread necropolis bump:)

    I just grabbed one of these NoS for $150! I think I did pretty good :) any more input on how people like it? Or how it compares t o newer designs? Goin to use this and a Barber Linden as my DI chain in the studio next month.
     
  9. Ender_rpm

    Ender_rpm

    Apr 18, 2004
    St. Louis MO
    Am I reading the manual correctly that there is a speaker sim/ high end roll off built in? Oh baby...
     
  10. Snaxster

    Snaxster

    Nov 29, 2008
    Hello. Very belatedly: No, I think this DI does not employ a glory tube, but instead gives its tube real voltage.
     
  11. Snaxster

    Snaxster

    Nov 29, 2008
    Hello. Two years later: I see what you mean. Here is a quote from the manual:

    "SPEAKER/ NORMAL — Used to select normal (instrument input) mode or create a line or mic-level send from the speaker output of an instrument am- plifier. To use in speaker mode: Plug output from amplifier to INPUT jack. Set switch to "SPEAKER". Plug speaker into SPEAKER/LOOP OUT jack. Signal available at the OUTPUT jack and the BALANCED will be an isolated signal with a smooth high frequency roll-off to compensate for the typical boost that is built into amplifier and is necessary for instrument speakers. This set up allows you to get the entire sound of your instrument plus your amplifier into the output of the RTD."​

    It sure seems that way. But I never tried that feature, so I didn't experience the sound. Now that you mention it, I will plan to try it. Thanks.
     
  12. Ender_rpm

    Ender_rpm

    Apr 18, 2004
    St. Louis MO
    I tried it once in the mean time, it was VERY noisy, was just easier to mic the speaker. But I did use it to record my old bands demo, and combined with a wound up miced amp, got a great sound. We recorded at Inner Ear in DC W/ Don Z. (Dischord records) ad he was actually very impressed with the TW unit.
     
  13. Snaxster

    Snaxster

    Nov 29, 2008
    Interesting. Thank you for that update. The noisy application aside, that's good news about using the 4001 in the demo and all.

    If you still have the 4001, and you have not yet tried swapping in an uprated op-amp and a nice vintage tube, I highly recommend it.
     
  14. Ender_rpm

    Ender_rpm

    Apr 18, 2004
    St. Louis MO
    Got any recommendations for the op-amp? I am not very well versed in such things :)
     
  15. Snaxster

    Snaxster

    Nov 29, 2008
    That's the one that worked for me. There are similar ones that may sound a bit different, but they all should be an improvement over the stock chip.

    For this application, just make sure you're getting dual channel op-amps. At about four bucks, the OPA2134PA is well worth a try. For example, from Mouser currently (TI brand, Burr-Brown design as I understand it):


    You should hear a difference between each of those. Go for it!