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Alembic F-1X preamp

Discussion in 'Amps and Cabs [BG]' started by BassistGod, May 5, 2003.


  1. This question is for alembic f-1x owners and others familiar with this pre. What do you set the preamp's volume at?

    I wanted to know if I should adjust the volume knob on the Alembic or level on the power amp. Since there's no gain knob or light on the alembic, I don't know at what point the preamp is getiing an optimium gain level from my bass. I've messed with it alot and I can't really hear an audible difference until I max the volume out. At that point, there is a bit of overdrive. Anyone have some info on this?
     
  2. i don't know the technical aspects of this but I am fairly sure that it is always best to max the power amps volume and adjust the sensitivity from the preamp. This gives you a better dampening factor for the speaker cones and a tighter sound.
     
  3. I've been using one on and off for the past 6 years. I think it sounds best when I set the volume at about 12:00 and adjust the volume with the power amp gain knob. You have to crank it almost wide open before it will distort. They have a ton of headroom.
     
  4. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    It does? How?

    Alex
     
  5. JohnL

    JohnL

    Sep 20, 2000
    Grayson, GA
    I don't know the tech reasons, but I had always heard to max the amp and adjust from the pre. That's how I do it with my Alembic/Crest combination, and it sounds great to me. BTW, to answer your original question, I rarely turn up past "4".
     
  6. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    I'd think that you'd want to run the preamp as hot as possible to minimize noise.

    Also, if you run your poweramps faders full up and something happens to the preamp-poweramp cable, your speakers might not like it too much...
     
  7. I don't know anything much about the dampening factor but I usually do keep my poweramp level high and keep my alembic at about 11 o'clock. But I'm wondering if I should turn the volume way up right before a hint of distortion or break up and then go with the poweramp from there.

    BTW does anyone use the Alembic for an overdriven tone?
     
  8. i don't think that you could? With such high plate voltage, the headroom is enourmous. What do you do, just max the volume knob? Isn't that post EQ, not pre-EQ? I prefer to dial up a stellar clean tone and use an outboard more more control; my dredgetone bass Angler for example.
     
  9. rockindoc

    rockindoc Daily Lama

    Jan 26, 2002
    Bonham, Tx
    I keep mine at 6 to 6 1/2 (about 1 o'clock CST). I hear less hiss there. With my PLX 1602 at 24 (also about 1 o'clock) I'm plenty loud. FWIW I keep the bass and treble at 5 (Noon) and the mid maxed at full clockwise.
     
  10. lowfreqguy

    lowfreqguy

    Oct 18, 2000
    I keep my bass's volume maxed out, the power amp gain control maxed and run my F1-X preamp between 2 and 4, depending on volume needs. I also have an SF-2 running through effects loop of the F1-X and use the two filter volumes to add different tone sculpting as needed. When I zero the filter gains, I can't tell that the SF-2 is in the loop.
     
  11. Cool. I have the same exact setup. I'll have to try those settings on the eq.

    Lately, I keep the bass maxed, the mid at 12 o'clock (don't think it adds mids in this configuration until after 12 but I like it there.) And I tweak the treble from about 2 to 4 o'clock. Usually between 2 and 3. Deep switch off and the high switch off too. This should provide some serious thump in your sound. Especially through an svt-410HLF and 112aguilar.

    I'm going to try keeping the Alembic volume as high as possible without any breakup. Will the tube be pushed harder that way?
     
  12. i really don't think so guys? this just doesn't make sense for me? The volume knob is not a preamp gain to my knowledge.
     
  13. Yea, the higher the gain the more you work the tube. I max mine and turn down the power-amp from time to time to get a really cool overdrive tone. Keeping your pre-amp volume higher does 2 things. 1) It is quieter (less hiss) and 2) due to the fact that your power-amp is turned down you are less likely to accidentally blow a speaker. jmho
     
  14. I did not know this. You have expanded my horizons. Thanks, Madsubwoofer!
     
  15. geshel

    geshel

    Oct 2, 2001
    Seattle
    Well - I don't think it's true. ;)

    First, it's "damping" not "dampening".

    Anyway, the gain knob on an amp doesn't affect the damping factor at all. It's just another voltage gain knob in *front* of the power section.

    There have been a number of threads about the pre/power gain question. No strict answer in all cases, but in general: increase gain early, rather than later, to keep noise at a minimum.

    Also, the volume knob on the Alembic does affect gain - it wouldn't work if it didn't* - and since the tube is providing 100% of the gain, then it will definitely have an affect on any overdrive that occurs. Whether or not it overdrives will depend on how hot the input signal is, but it will do it on mine with the 10dB boost from the SF-2 in effect.

    *it could be a passive voltage cut, after the tube, with the tube gain always at maximum, but I'd think this would be a bad design from a noise and efficiency standpoint. I could be wrong though.
     
  16. Well I don't take everything on TB as gospel and I definitely agree and have read that you want to maximize preamp output to improve s/n.

    That's the whole idea of the preamp (hence the name): to pre-amplify the signal and increase it's level and s/n at the input of the power amp.
     
  17. ichinumba9

    ichinumba9

    Feb 15, 2002
    CA
    You know there is an Alembic website. There is a discussion forum there so go to www.Alembic.com and Mica usually will answer your questions. She is very good about getting info from her father for the electronics questions. By the way I have not turned my volume up over 5 and have been pretty happy with the tone.
     
  18. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    The only time I've gotten OD from my F2B is cascading the two channels. But, I've never tried to crank the volume past 2 o-clock simply because there's so much boost. I'll have to see what happens when I turn it to 11. :eek:
     
  19. rojo412

    rojo412 MARK IT ZERO! Supporting Member

    Feb 26, 2000
    Cleveland, OH.
    I just spotted one of these used and was wondering what they should go for in price. It's a newer one(?), has the green logo stripe near the input.

    Is this pre something that's just an all around tone tweaker or is it specifically vintage, modern, classic rock, or something else?
    Are they prone to problems?
    How do they react to super-high powered input (Status Empathy 18V)?
    Is it wise/not wise to run this into a GK 1001RB or does it matter (I have various ways of going about it in my head)?
     
  20. rockindoc

    rockindoc Daily Lama

    Jan 26, 2002
    Bonham, Tx
    rojo412, I got mine for $350 used. I was happy with the deal because I've seen them go up to $400 on Ebay.