+ Reply to Thread
Page 26 of 28 FirstFirst ... 162425262728 LastLast
Results 251 to 260 of 271

Thread: Solid state preamp grain compared to valves

  1. #251
    Join Date: Aug 2008

    Location: Suffolk, UK

    Posts: 1,473
    I'm Paul.

    Default

    A passive attenuator be it a volume pot or otherwise will attenuate the noise floor of everything before it, as well as the music signal. So if the volume is too loud and needs to be reduced anyway it’s a bit of a win-win situation, especially if the impedances have been thought out in order to not have any objectional HF roll off.

    A preamp (with gain) generally will amplify the signal and the noise, and add more noise. However, exactly how this is done depends on the circuit design. Valve pre’s tend to have a passive volume pot as the very first thing and being a passive attenuator reduce the noise floor and signal before amplifying whats left, not always a good thing in every case, but can work well. So what you have is a passive attenuator followed by gain. SS pre’s often have the volume pot buffered. I think it can become a bit of a head-scratcher as the wanted signal and the noise may not have the same output impedance. If you buffer the signal you do not have any gain as such but you also lower the output impedance of the noise, making it potentially harder to deal with.
    Last edited by Primalsea; 28-07-2018 at 13:12.
    ~Paul~

  2. #252
    Join Date: Feb 2008

    Location: South Wales

    Posts: 9,151
    I'm NotTakingLifeTooSeriouslyTheseDays.

    Default

    Something that has occured to me, while discussing this thread with Barry, is; before we can generalise on the effect of a passive attenuator network, we really need to know the type of input circuit configuration it will be used with, ie; some amplifier inputs have series resistors, or capacitors, which tend to isolate [to a point] the effect the attenuator might otherwise have in comparison to an amplifier without.
    This is where I fear some of the confusion has risen from!
    A...
    Last edited by anthonyTD; 28-07-2018 at 10:46.
    "Today scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality"
    Nikola Tesla



    Its now a conspiracy theory to believe that the Immune system is capable of doing the job it was designed to do.
    A fish is only as healthy as the water its swimming in ! [Dr Robert Young]


    www.tubedistinctions.co.uk

    Matthew 5:10

  3. #253
    Join Date: Jan 2008

    Location: Wrexham, North Wales, UK

    Posts: 110,012
    I'm AudioAl'sArbiterForPISHANTO.

    Default

    Quote Originally Posted by Primalsea View Post
    A passive attenuator be it a volume pot or otherwise will attenuate the noise floor of everything before it, as well as the music signal. So if the volume is too loud and needs to be reduced anyway it’s a bit of a win-win situation, especially if the impedances have been thought out in order to not have any objectional HF roll off.

    A preamp (with gain) generally will amplify the signal and the noise, and add more noise. However, exactly how this is done depends on the circuit design. Valve pre’s tend to have a passive volume pot as the very first thing and being a passive attenuator reduce the noise floor and signal before amplifying whats left, not always a good thing in every case, but can work well. So what you have is a passive attenuator followed by gain. SS pre’s often have the volume pot buffered. I think it cam become a bit of a head-stracther as the wanted signal and the noise may not have the same output impedance. If you buffer the signal you do not have any gain as such but you also lower the output impedance of the noise, making it potentially harder to deal with.
    Hi Paul,

    Could you correct the typos above, so that it doesn't spoil an otherwise good post, and thus becomes clear what is was you meant? Ta!

    Marco.
    Main System

    Turntable: Heavily-modified Technics SL-1210MK5G [Mike New bearing/ETP platter/Paul Hynes SR7 PSU & reg mods]. Funk Firm APM Achromat/Nagaoka GL-601 Crystal Record Weight/Isonoe feet & boots/Ortofon RS-212D/Denon DL-103GL in Denon PCL-300 headshell with Funk Firm Houdini/Kondo SL-115 pure-silver cartridge leads.

    Paul Hynes MC head amp/SR5 PSU. Also modded Lentek head amp/Denon AU-310 SUT.

    Other Cartridges: Nippon Columbia (NOS 1987) Denon DL-103. USA-made Shure SC35C with NOS stylus. Goldring G820 with NOS stylus. Shure M55E with NOS stylus.

    CD Player: Audiocom-modified Sony X-777ES/DAS-R1 DAC.

    Tape Deck: Tandberg TCD 310, fully restored and recalibrated as new, by RDE, plus upgraded with heads from the TCD-420a. Also with matching TM4 Norway microphones.

    Preamps: Heavily-modified Croft Charisma-X. LDR Stereo Coffee. Power Amps: Tube Distinctions Copper Amp fitted with Tungsol KT-150s. Quad 306.

    Cables & Sundries: Mark Grant HDX1 interconnects and digital coaxial cable, plus Mark Grant 6mm UP-LCOFC Van Damme speaker cable. MCRU 'Ultimate' mains leads. Lehmann clone headphone amp with vintage Koss PRO-4AAA headphones.

    Tube Distinctions digital noise filter. VPI HW16.5 record cleaning machine.

    Speakers: Tannoy 15MGs in Lockwood cabinets with modified crossovers. 1967 Celestion Ditton 15.


    Protect your HUMAN RIGHTS and REFUSE ANY *MANDATORY* VACCINE FOR COVID-19!

    Also **SAY NO** to unjust 'vaccine passports' or certificates, which are totally incompatible with a FREE society!!!


  4. #254
    Join Date: Jan 2008

    Location: Wrexham, North Wales, UK

    Posts: 110,012
    I'm AudioAl'sArbiterForPISHANTO.

    Default

    Quote Originally Posted by anthonyTD View Post
    Something that has occured to me, while discussing this thread with Barry, is; before we can generalise on the effect of a passive attenuator network, we really need to know the type of input circuit configuration it will be used with, ie; some amplifier inputs have no series resistors, or capacitors, which tend to isolate [to a point] the effect the attenuator might otherwise have in comparison to an amplifier without.
    Did you mean with, rather than without? Without doesn't really make sense. Otherwise, that's a VERY good point, and probably explains why passive preamps, although a technically more elegant solution than their active counterparts, aren't guaranteed to perform optimally in all set ups.

    Marco.
    Main System

    Turntable: Heavily-modified Technics SL-1210MK5G [Mike New bearing/ETP platter/Paul Hynes SR7 PSU & reg mods]. Funk Firm APM Achromat/Nagaoka GL-601 Crystal Record Weight/Isonoe feet & boots/Ortofon RS-212D/Denon DL-103GL in Denon PCL-300 headshell with Funk Firm Houdini/Kondo SL-115 pure-silver cartridge leads.

    Paul Hynes MC head amp/SR5 PSU. Also modded Lentek head amp/Denon AU-310 SUT.

    Other Cartridges: Nippon Columbia (NOS 1987) Denon DL-103. USA-made Shure SC35C with NOS stylus. Goldring G820 with NOS stylus. Shure M55E with NOS stylus.

    CD Player: Audiocom-modified Sony X-777ES/DAS-R1 DAC.

    Tape Deck: Tandberg TCD 310, fully restored and recalibrated as new, by RDE, plus upgraded with heads from the TCD-420a. Also with matching TM4 Norway microphones.

    Preamps: Heavily-modified Croft Charisma-X. LDR Stereo Coffee. Power Amps: Tube Distinctions Copper Amp fitted with Tungsol KT-150s. Quad 306.

    Cables & Sundries: Mark Grant HDX1 interconnects and digital coaxial cable, plus Mark Grant 6mm UP-LCOFC Van Damme speaker cable. MCRU 'Ultimate' mains leads. Lehmann clone headphone amp with vintage Koss PRO-4AAA headphones.

    Tube Distinctions digital noise filter. VPI HW16.5 record cleaning machine.

    Speakers: Tannoy 15MGs in Lockwood cabinets with modified crossovers. 1967 Celestion Ditton 15.


    Protect your HUMAN RIGHTS and REFUSE ANY *MANDATORY* VACCINE FOR COVID-19!

    Also **SAY NO** to unjust 'vaccine passports' or certificates, which are totally incompatible with a FREE society!!!


  5. #255
    Join Date: Feb 2008

    Location: South Wales

    Posts: 9,151
    I'm NotTakingLifeTooSeriouslyTheseDays.

    Default

    Sorted!
    A...
    "Today scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality"
    Nikola Tesla



    Its now a conspiracy theory to believe that the Immune system is capable of doing the job it was designed to do.
    A fish is only as healthy as the water its swimming in ! [Dr Robert Young]


    www.tubedistinctions.co.uk

    Matthew 5:10

  6. #256
    Join Date: Jan 2008

    Location: Wrexham, North Wales, UK

    Posts: 110,012
    I'm AudioAl'sArbiterForPISHANTO.

    Default

    That's more like it

    Marco.
    Main System

    Turntable: Heavily-modified Technics SL-1210MK5G [Mike New bearing/ETP platter/Paul Hynes SR7 PSU & reg mods]. Funk Firm APM Achromat/Nagaoka GL-601 Crystal Record Weight/Isonoe feet & boots/Ortofon RS-212D/Denon DL-103GL in Denon PCL-300 headshell with Funk Firm Houdini/Kondo SL-115 pure-silver cartridge leads.

    Paul Hynes MC head amp/SR5 PSU. Also modded Lentek head amp/Denon AU-310 SUT.

    Other Cartridges: Nippon Columbia (NOS 1987) Denon DL-103. USA-made Shure SC35C with NOS stylus. Goldring G820 with NOS stylus. Shure M55E with NOS stylus.

    CD Player: Audiocom-modified Sony X-777ES/DAS-R1 DAC.

    Tape Deck: Tandberg TCD 310, fully restored and recalibrated as new, by RDE, plus upgraded with heads from the TCD-420a. Also with matching TM4 Norway microphones.

    Preamps: Heavily-modified Croft Charisma-X. LDR Stereo Coffee. Power Amps: Tube Distinctions Copper Amp fitted with Tungsol KT-150s. Quad 306.

    Cables & Sundries: Mark Grant HDX1 interconnects and digital coaxial cable, plus Mark Grant 6mm UP-LCOFC Van Damme speaker cable. MCRU 'Ultimate' mains leads. Lehmann clone headphone amp with vintage Koss PRO-4AAA headphones.

    Tube Distinctions digital noise filter. VPI HW16.5 record cleaning machine.

    Speakers: Tannoy 15MGs in Lockwood cabinets with modified crossovers. 1967 Celestion Ditton 15.


    Protect your HUMAN RIGHTS and REFUSE ANY *MANDATORY* VACCINE FOR COVID-19!

    Also **SAY NO** to unjust 'vaccine passports' or certificates, which are totally incompatible with a FREE society!!!


  7. #257
    Join Date: Apr 2008

    Location: Warrington

    Posts: 3,451
    I'm Neil.

    Default

    Quote Originally Posted by Macca View Post
    I thought the opposite was true and that we are not very good at picking up on phase errors?

    Also that any phase error would only exist over a very narrow frequency band and therefore be unlikely to be audible?
    We are very good at picking up phase errors. Speakers have by far more of an influence on this though e.g. port / crossover phase shift, group delay etc.

    I would rather have excellent phase and time domain performance than a flat frequency response, any day.
    Mana Acoustics Racks / Bright Star IsoNodes Decoupling >> Allo DigiOne Player >> Pedja Rogic's Audial Model S DAC + Pioneer PL-71 turntable / Vista Audio phono-1 mk II / Denon PCL-5 headshell / Reson Reca >> LFD DLS >> LFD PA2M (SE) >> Royd RR3s.

  8. #258
    Join Date: Feb 2008

    Location: South Wales

    Posts: 9,151
    I'm NotTakingLifeTooSeriouslyTheseDays.

    Default

    I think the only reliable way of knowing what affect [if any] a passive attenuator may have on influencing the following circuitry is; to test the system as a whole, otherwise we end up generalising, or trivialising what some perceive as a real, and obvious trait of using such Attenuators in a known system.
    Quote Originally Posted by RothwellAudio View Post
    The phase shift of an RC filter and its frequency response are intimately linked and are at the ends of its passband.

    As I commented way back in the thread, the roll-off - and therefore phase shift - of a passive preamp can be at frequencies well beyond audio frequencies.
    "Today scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality"
    Nikola Tesla



    Its now a conspiracy theory to believe that the Immune system is capable of doing the job it was designed to do.
    A fish is only as healthy as the water its swimming in ! [Dr Robert Young]


    www.tubedistinctions.co.uk

    Matthew 5:10

  9. #259
    Join Date: Mar 2008

    Location: Galashiels

    Posts: 13,669
    I'm inthescottishmafia.

    Default

    Should have my new pre shortly, uses an AVC. Look in products-signal- inductive volume control-

    http://www.tribute-audio.nl
    “Music has always been a matter of energy to me, a question of fuel. Sentimental people call it inspiration, but what they really mean is fuel. I have always needed fuel. I am a serious consumer. On some nights I still believe that a car with the gas needle on empty can run about fifty more miles if you have the right music very loud on the radio”

    Hunter S Thompson

  10. #260
    Join Date: Feb 2008

    Location: South Wales

    Posts: 9,151
    I'm NotTakingLifeTooSeriouslyTheseDays.

    Default

    I shall wait with interest for your evaluation Ali.
    Quote Originally Posted by Ali Tait View Post
    Should have my new pre shortly, uses an AVC. Look in products-signal- inductive volume control-

    http://www.tribute-audio.nl
    "Today scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality"
    Nikola Tesla



    Its now a conspiracy theory to believe that the Immune system is capable of doing the job it was designed to do.
    A fish is only as healthy as the water its swimming in ! [Dr Robert Young]


    www.tubedistinctions.co.uk

    Matthew 5:10

+ Reply to Thread
Page 26 of 28 FirstFirst ... 162425262728 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •