Passive Volume Control for DACs/Sources

Discussion in 'Digital: DACs, USB converters, decrapifiers' started by Madaboutaudio, Dec 20, 2015.

  1. randytsuch

    randytsuch Friend

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    A long time ago, I picked up a pair of the SB tx102's, they were the pair used for the Bent Audio prototypes. Bent used tx102 before changing to Slagles.
    Used it for many years, but traded it a while ago for a tube amp, a trade which I regret lol.

    I've been thinking about picking up the Slagle AVC for a long time.
    I'd skip the lower cost version myself, I'm not sure it has enough steps, and might be hard to get the volume setting you want with headphones. IMO, speakers are a little more forgiving for too much/little volume. I also don't like the idea of dual switches, I want to turn one knob to set the volume. I'm also not going to pay $750 for this, so I'd buy the bare AVC and a switch and wire it myself. I bought the bare tx102's and had to hand wire it, it was kind of a pain but not the worse thing I've built.

    Another thought would be to connect to a bunch of relays, and then you could implement a remote control pretty easily. Might be able to adapt something like a amb delta for this, not sure but seems possible. But that would be a bigger project, and I'm sure I'm too far into diy land already for this thread.

    One parting thought is that Tribute also makes autoformers. He seems to be in semi retirement mode, but I guess he still makes transformers that don't require any design work. Someone here bought some AVC's from Tribute recently. I don't know their cost, but from an ad I found they seem to be more expensive than Slagle.

    In the amp I just built, I used a Dact stepped. I pickup up a few of these a long time ago for a good price, so I had it available. I don't think I would buy them now at the current asking price.
     
  2. OJneg

    OJneg The Most Insufferable

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    Can I contact Dave to order silver AVCs? Anyone else thinking group buy?

    Edit: looks like hes selling them on the site but only the complete units. Might be worth it regardless
     
  3. OJneg

    OJneg The Most Insufferable

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    Yea I saw that. I was hoping for a 23 position (which I found sufficient for headphones or speakers) autoformer that I could wire up myself. The standard Cu ones go for $200 a pair... maybe the Ag ones would be $400-600?
     
  4. randytsuch

    randytsuch Friend

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    From what I can tell, $200 gets you a 14 position AVC. IMHO, not enough steps.
    $400 will get you a pair of 28 tap AVCs, in copper. And silver seems to more than double the costs.

    But page also shows a 23 tap AVC, mounted with switch for $425
    Seems like a good deal you if can live with two switches to control volume.

    Randy
     
  5. bazelio

    bazelio Friend

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    47 steps is overkill IME. I've probably never adjusted volume by a single 1.25dB step. That said, I think it's difficult to escape the non-trivial price increment. 50 or so feet of silver wire per side probably gets costly. I've also heard that, for some reason, the silver wire is more difficult to work with. One of the other passive pre companies recently said f**k it and stopped offering a silver version of their TVC. Either MFA or Bespoke, I forget which. But whatever the challenge is, that might also be factored in to the asking price.
     
  6. colhd

    colhd Acquaintance

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    I think it was me that you were referring to regarding the Tribute AVC, in my case last year. Cost at that time for a 23-step stereo unit was 435 Euro incluing VAT (sales tax) at 21%. A 4-gang unit for balanced designs was also available at a little less than twice the price. I have not heard from Pieter at Tribute recently so I do not know if these are still available.

    [​IMG]
     
  7. Armaegis

    Armaegis Friend

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    I've got a fancy TVC that's been collecting dust since I'm a schlub who uses digital volume control from his dac. Do I think the TVC sounds better in some voodoo way? Yep. Am I willing to give up my desk real estate for that? Nope. Sigh, I should probably sell it.

    This is mine: https://6moons.com/audioreviews/stereoknight/1.html
    (I know I know, 6moons, bleh, but I can't be bothered to take pictures)
     
  8. ogodei

    ogodei MOT: Austin AudioWorks

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    That is absolutely gorgeous. If you actually want to sell that you will have crowd of buyers, calling dibs now.
     
  9. Thenewerguy009

    Thenewerguy009 Friend

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    "the copper version of the balanced Silverstone retails at $1.450 and the silver version at $2.000. Remote control (what we call the Silverstone B&R) adds $400 over the manual version."

    Pricing isn't bad. Seems fair compared to the $3,000+ some are charging that don't look half as nice.
     
  10. Kernel Kurtz

    Kernel Kurtz Friend

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    If you are not using it and would not mind loaning it out I would really appreciate a brief listen......
     
  11. David Ketley

    David Ketley New

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    Try the Stereo Coffee preamp not expensive a solves many of the problems of volume controls.
     
  12. bilboda

    bilboda Florida boomer

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    I'd consider an ldr if I understood what kind of load it presents to the source and the amplifier and if was actually measured by somebody for linearity. Just went thru a lengthy thread flame/fest on diy forum and it was generally, try it, see for yourself, etc. I have other measured solutions that I can try instead. I will know how they will react with loads. Maybe with nothing better to do for a long time, I will try an ldr cause there is no compelling information available to make me want to try it now.
     
  13. allegro

    allegro Friend

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    Before you buy an LDR preamp browse Tortuga Audio LDR3 measurements. See quote below:
    I tried one out, returned for a refund and replaced with a Saga. Saga measures and sounds better at one fifth the price of the Tortuga.
     
    Last edited: Jun 17, 2019
  14. WHO23

    WHO23 New

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    Schiit Saga+ Passive or Active Remote Tube Hybrid Preamp (Passive Relay Attenuator +Remote +Active Stage)
    [​IMG]
    [​IMG]


    Tisbury Audio Mini II Passive Preamplifier (Stepped Attenuator)
    [​IMG]
    [​IMG]
    [​IMG]


    Promitheus Audio TVC Balance Volume Control Preamp (Transformer)
    [​IMG]
    [​IMG]


    ericyam Balance SMD Dual Mono Passive Preamp (Stepped Attenuator)
    [​IMG]
    [​IMG]


    ericyam Dale Resistor Passive Preamp (Stepped Attenuator)
    [​IMG]
    [​IMG]


    Yisheng Hi-Fi Balance Passive Preamplifier / Passive (Relay Attenuator)
    [​IMG]
    [​IMG]


    PGA 2310 Preamplifier Bluetooth (Relay Attenuator +Remote)
    [​IMG]
    [​IMG]


    Sanchun Balance Passive Volume Control (Relay Attenuator +Remote)
    E173F827-3A09-4A5A-82E5-F45B7BAE46C6.jpeg
    2B7E26A5-DE26-44F1-B4C4-548806C23445.jpeg


    Bonus: Allo Volt+ (Stepped Attenuator)
    [​IMG]
    [​IMG]
    [​IMG]
     
    Last edited: Jun 29, 2020
  15. Kernel Kurtz

    Kernel Kurtz Friend

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  16. WHO23

    WHO23 New

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    The Promitheus sounds great. The volume knob feels amazing and the attenuation works well. There is no noticable noise when using it for speakers but I can't be sure if there was distortion. Similarly using my headphones (DT1990) it works really well even when turning the knob on the Promitheus TVC all the way down.

    When switching between inputs, it's not as smooth and sometimes some noise can get induced into the line. Wiggling the knob fixes this. The unit is very heavy so something might have gone loose. Also while I was switched to an unwired RCA channel, I could still hear some faint music from the other RCA channel which was playing at line level.

    I have not used the XLR channel, but I will try it out in the future. Also I found an interesting new preamp: Nord One Pre-TVC. https://www.nordacoustics.co.uk/pretvc
     
    Last edited: Jul 8, 2019
  17. wormcycle

    wormcycle Friend

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    My SA1X, that as I reported here, got mysteriously fried after I connected it between two Bryston units, came back from Goldpoint Controls. Arn checked it carefully, he did not want to repair it under warranty (he was right about that), but said that it appeared to be working with maybe some static sound when changing volume.
    Well I connected it and it is working, no cracks or static of any kind, all volume level work, no channel imbalance I could hear.
    I was very surprised and spent like two hours listening with two DACs, one good and one not so good, and nothing I could hear that would be different.
    And that device was in fumes. Amazing quality.
     
  18. androxylo

    androxylo Acquaintance

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  19. Forza AudioWorks

    Forza AudioWorks MOT: Forza AudioWorks

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  20. lehmanhill

    lehmanhill Almost "Made"

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    Don't forget the Glasshouse TVC Passive Pre from hificollective.co.uk. As a kit, its 450 pounds or $550 in today's weak pound to dollar. I haven't heard it personally, but a friend has one and it is very well received in reviews. Only good for single ended, no balanced.

    I have been using a relay switched stepped attenuator since 2010. Mine is a Reliaxed2 which is a pcb and BOM to build it yourself. I like the stepped attenuators a lot and have no reason to replaced mine.

    Going back to the LDR discussion, I once borrowed a LightSpeed LDR Attenuator (Uriah Dailey DIY) from a friend and compare the LightSpeed to a nice quality Alps potentiometer and the Reliaxed 2. I preferred the Reliaxed 2 over both the LightSpeed and the Alps.
     

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