Passive pre amps

Discussion in 'DIY Discussion' started by zanash, Dec 21, 2006.

  1. zanash

    zanash

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    I saw a passive preamp kit on fleabay [item number 290059483590].
    As the pound is high against the dollar I decided to take a punt on spec. The kit arrived in just over a week. The main part of course is the stepped attenuator fitted with dale vishay rn55[?] close tolerance resistors this was pre assembled and very neatly done. The case is adequate and pre drilled for the selector switch volume pot and ofcourse the four input and one output pairs.

    The kit was assembled and wired up in an hour......I used 0.3mm solid core silver in 3mmid pvc tube, just what I had to hand.

    Initially sitting the unit between cdp and existing pre showed there were no problems ...so taking the plunge wire it up between cdp to power amps.

    Sound .....it was obvious from the first moment that the imaging was pin sharp with an almost in your head feeling. The dynamics are better than the pre it replaced. Bass is fast clean and deep the top end resolution has revealed that my cable box distorts at low volume settings my other pre doesn't show this at all. On the down side the overall sound window seems a little smaller and has hint of coldness thats not great, though this may change as the unit burns in. Its churlish to be too critical of this unit at £60 as it's a tenth the cost of what my quad 77 pre was new back in '95.

    This unit will take over while I rebuild the quad as I feel it needs recapping as it sounds definately soggy compared with a current 99 pre.
     
    zanash, Dec 21, 2006
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  2. zanash

    Dik Dolan

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    My brother has the hificollective passive which uses the same stepped attenuator. They are damn fine for the money, he says it lacks a little "umph" compared to his michell argo pre (fitted with a dact attenuator) but has equal or better transparancy. They do take a while to burn in...and each volume step you use needs time.
    I see that hificollective are doing a tvc version now too..... *must resist.... i'm trying to save up for a new phono stage*
     
    Dik Dolan, Dec 21, 2006
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  3. zanash

    bottleneck talks a load of rubbish

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    I use the same stepped attenuator in my active pre-amp.

    It's definately a lot better than the alps-blue it came with.

    Despite being the same rating as the alps blue, there was a massive increase in volume. I used a resistor to bring it down (or the guy I use did!)
     
    bottleneck, Dec 21, 2006
    #3
  4. zanash

    bottleneck talks a load of rubbish

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    Dik - have you heard the hificollective transformer based passive?

    From memory, it's just as good as the music first, and is only a few hundred.

    For fans of passive pre-amps, I can strongly reccomend it.

    They also have a new EL84 amp which Im hoping to mess about with over xmas.

    Cheers
    Chris
     
    bottleneck, Dec 21, 2006
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  5. zanash

    Dik Dolan

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    Nope Chris, I've never heard a tvc but all the talk about them has got me wanting one..... and I dont even need one=) I currently use my ear 834p phono straight into my glasshouse, the 834 has a dact pot and I dont use any other sources so I dont need a preamp.... but I'm giving some serious thought to getting a new phonostage, probably the k&k kit, which can also be fitted with a voulume control (or I could fit Nicks new tvc into that, maybe ) ....I'll be taking a good look at the new WAD phono when that's announced too, but then i'll probably need their matching preamp too.. or the hifi collective tvc... decisions decisions.=)
     
    Dik Dolan, Dec 21, 2006
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  6. zanash

    bottleneck talks a load of rubbish

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    hmm options options!!

    how about....

    1) putting the stepped attenuator (above) into the glasshouse power amp to replace the alps pot in there?
    ...cheap and effective solution that one!!

    2).. I prefer a valve pre-amp, have you tried a few?

    3) If you like passives, the HFC tvc is the one to get on price, and it would match your power amp.
     
    bottleneck, Dec 21, 2006
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  7. zanash

    Dik Dolan

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    Too many choices=)
    My glasshouse is the poweramp version, no volume pot in that.
    My setup is LP only, so I'm loath to spend money on a preamp that I dont really need. The only valve pre I have heard was my brothers musical fidelity pre the cheapo x-can one, but not tried it in my current system. I'm hoping that my next phonostage will be ok with a built in volume control so I can stay direct.... I don't really fancy drilling a hole in the facia of my glasshouse to fit a pot=)
    If I go for the WD phono I'd probably need to get their matching pre, just for the drive........don't know how well it would work into a passive, hence my interest in the k&k, which has had rave reviews and has good drive.

    Edit it's WD not WAD anymore=)
     
    Dik Dolan, Dec 21, 2006
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  8. zanash

    bottleneck talks a load of rubbish

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    wow, no cd?! hardcore!!! :D
     
    bottleneck, Dec 21, 2006
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  9. zanash

    Dik Dolan

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    We've just ordered the upgrade tvc kit for my brothers hfc passive..should give me plenty of soldering practice again=)

    Edit: Apologies Zanash, hijacked your thread.
     
    Dik Dolan, Dec 26, 2006
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  10. zanash

    Dik Dolan

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    The kit arrived today, great service from hificollective! Had one small problem deciphering the instructions, sent Nick an email at 6pm, got a reply within the hour=) Hopefully should have it done tomorrow.
     
    Dik Dolan, Dec 28, 2006
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  11. zanash

    rollo

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    The transformers look very familiar.Just dressed up for the party.Where are they sourced from Malaysia maybe?
    rollo
     
    rollo, Jan 22, 2007
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  12. zanash

    larkrise Sheepdogs prefer red wine

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    any links to hi fi collective?
     
    larkrise, Jan 22, 2007
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  13. zanash

    T-bone Sanchez

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    T-bone Sanchez, Jan 22, 2007
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  14. zanash

    smegger68

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    I have an old Harman/Kardon PA2100 Power Amp lurking around somewhere - I have no instructions for it so no idea what its input requirements are. I'm guessing that most line input power amps would require a 10K pot on a passive pre, is that right? I'm not even sure in what circumstances i'd need a higher value. Can someone clarify this for me?

    Cheers guys :D
     
    smegger68, Jan 22, 2007
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  15. zanash

    zanash

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    more like a 50k .....but most will respond to the various values you can get.

    The Hk should be tolerant of input impedance ..but you may find that you have to turn the vol control a long way to make a volume change [I always get this the wrong way round] big resistance small movement and visa versa.
     
    zanash, Jan 25, 2007
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