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Thread: DIY phonostage.

  1. #341
    Join Date: Oct 2016

    Location: Bolton, England

    Posts: 627
    I'm Andrew.

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    Quote Originally Posted by YNWaN View Post
    You are rather missing the point.
    Maybe I am. What is the point?

  2. #342
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,394
    I'm Jez.

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    Quote Originally Posted by RothwellAudio View Post
    It all sounds a bit mad. BC327s are common transistors that cost 4 pence each when you buy 100 of them. These guys will select ones with Hfe of 400 and charge you 9.52 each for them. However, the usual design approach is to use negative feedback to eliminate component variations so the particular Hfe of any one transistor doesn't really matter.
    It has no negative feedback and is DC coupled...
    Arkless Electronics-Engineered to be better. Tel. 01670 530674 (after 1pm)

    Modded Thorens TD150, Audio Technica AT-1005 MkII, Technics EPC-300MC, Arkless Hybrid MC phono stage, Arkless passive pre, Arkless 50WPC Class A SS power amp, (or) Arkless modded Leak Stereo 20, Modded Kef Reference 105/3's
    ReVox PR99, Studer B62, Ferrograph Series 7, Tandberg TCD440, Hitachi FT-5500MkI, also FT-5500MkII
    Digital: Yamaha CDR-HD1500 (Digital Swiss army knife-CD recorder, player, hard drive, DAC and ADC in one), PC files via 24/96 sound card and SPDIF, modded Philips CD850, modded Philips CD104, modded DPA Little Bit DAC. Sennheiser HD580 cans with Arkless Headphone amp.
    Cables- free interconnects that come with CD players, mains leads from B&Q, dead kettles etc, extension leads from Tesco

  3. #343
    Join Date: Oct 2016

    Location: Bolton, England

    Posts: 627
    I'm Andrew.

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    Quote Originally Posted by Arkless Electronics View Post
    It has no negative feedback and is DC coupled...
    I'm not sure I could even get anything useful out of a BC327 without negative feedback
    I certainly don't want to pay 952 for the 4(?) I want plus 96 I don't want.

  4. #344
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,394
    I'm Jez.

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    Quote Originally Posted by RothwellAudio View Post
    I'm not sure I could even get anything useful out of a BC327 without negative feedback
    I certainly don't want to pay 952 for the 4(?) I want plus 96 I don't want.
    They are a perfectly normal BJT and fairly quiet at the bias used. A lot are used in this design. To match properly you need to do it at the conditions seen in the circuit. Matching them with the Hfe setting on a multimeter will not do! Potentially, several matching jigs or one adjustable one will be needed. I can't be arsed to count them but there's probably something like 30 transistors per channel in this design and most need matching. You wouldn't need to match for example all the BC327 to each other, more a case of pnp and npn opposites to each other. To get enough matched pairs with close enough matching you may well need to buy say 500 to build one unit and it will take hours of work to do.... Even though I would agree that the price of the pre-matched ones above is well steep!
    Arkless Electronics-Engineered to be better. Tel. 01670 530674 (after 1pm)

    Modded Thorens TD150, Audio Technica AT-1005 MkII, Technics EPC-300MC, Arkless Hybrid MC phono stage, Arkless passive pre, Arkless 50WPC Class A SS power amp, (or) Arkless modded Leak Stereo 20, Modded Kef Reference 105/3's
    ReVox PR99, Studer B62, Ferrograph Series 7, Tandberg TCD440, Hitachi FT-5500MkI, also FT-5500MkII
    Digital: Yamaha CDR-HD1500 (Digital Swiss army knife-CD recorder, player, hard drive, DAC and ADC in one), PC files via 24/96 sound card and SPDIF, modded Philips CD850, modded Philips CD104, modded DPA Little Bit DAC. Sennheiser HD580 cans with Arkless Headphone amp.
    Cables- free interconnects that come with CD players, mains leads from B&Q, dead kettles etc, extension leads from Tesco

  5. #345
    Join Date: Oct 2016

    Location: Bolton, England

    Posts: 627
    I'm Andrew.

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    I haven't seen a circuit diagram from this design but when I'm designing something I prefer not to rely on transistors having any specific performance. I thought that's what good design was all about.

  6. #346
    Join Date: Mar 2017

    Location: Liverpool

    Posts: 59
    I'm Sandro.

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    Well one thing is they will charge 550 even if they can not match them
    On semi sez that they can screen the PNP but not the NPN but advertise them as complementary Case for advertising standard ombudsman ?
    Other quoted that to get screened transistor the minimum Purchase Quantity would be 250000 units Maybe around 16000 (possibly much less )
    Group buy any one?

    I had the R2 built and believe me it is one of the best around
    Simon did ear it for about an hour or so and ended up building 23 of those

    One thing that I found was that Salas Simplistic had much more accurate staging and I am sure that this is not a Paradise related problem but due to my build whit poor transistor matching

    I have the DCA pro (best money ever spent) now and I am sure I can do much better than before but trust me when I tell you testing 5000 transistor will give you sore back

  7. #347
    Join Date: Mar 2017

    Location: Liverpool

    Posts: 59
    I'm Sandro.

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    Quote Originally Posted by RothwellAudio View Post
    I haven't seen a circuit diagram from this design but when I'm designing something I prefer not to rely on transistors having any specific performance. I thought that's what good design was all about.
    Quite agree whit you I wish I could design circuits I am much better at hammering and welding
    That you have not seen the circuit is lets say not good just a few resistor values to change and use Toshibas complementary pairs may be the answer but this is way above what I can do

  8. #348
    Join Date: Oct 2012

    Location: NE England

    Posts: 4,394
    I'm Jez.

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    Quote Originally Posted by RothwellAudio View Post
    I haven't seen a circuit diagram from this design but when I'm designing something I prefer not to rely on transistors having any specific performance. I thought that's what good design was all about.
    Yes it makes things vastly cheaper, easier and more reproducible to do things that way... but not always better
    Arkless Electronics-Engineered to be better. Tel. 01670 530674 (after 1pm)

    Modded Thorens TD150, Audio Technica AT-1005 MkII, Technics EPC-300MC, Arkless Hybrid MC phono stage, Arkless passive pre, Arkless 50WPC Class A SS power amp, (or) Arkless modded Leak Stereo 20, Modded Kef Reference 105/3's
    ReVox PR99, Studer B62, Ferrograph Series 7, Tandberg TCD440, Hitachi FT-5500MkI, also FT-5500MkII
    Digital: Yamaha CDR-HD1500 (Digital Swiss army knife-CD recorder, player, hard drive, DAC and ADC in one), PC files via 24/96 sound card and SPDIF, modded Philips CD850, modded Philips CD104, modded DPA Little Bit DAC. Sennheiser HD580 cans with Arkless Headphone amp.
    Cables- free interconnects that come with CD players, mains leads from B&Q, dead kettles etc, extension leads from Tesco

  9. #349
    Join Date: Mar 2014

    Location: KY - Scotland

    Posts: 2,070
    I'm Mike.

    Default DIY phonostage.

    I'd like to try one of these stages but it would need to be built for me or are there any demo ones available? I'm assuming not but I live in hope.
    Last edited by mikeyb; 12-08-2017 at 22:07.

  10. #350
    Join Date: Nov 2010

    Location: Yorkshire

    Posts: 6,624
    I'm AnDreW.

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    Quote Originally Posted by mikeyb View Post
    I'd like to try one of these stages but it would need to be built for me or are there any demo ones available? I'm assuming not but I in hope.
    You need to buy one.
    SS CD Teac VRDS25X(Mega Modded) DAC Caiman SEG+Anker PSU DECK 1210 Mat Analouge Studio Crystal Mods MN Base/Bearing/Platter+Ebony arm Board Feet Isonoe PSU Paul Hynes SR7EHD-27XL/DCSXL Ag DC lead/Jaeger(low-impedance) connector/3 StageRegs/Recapped PCB+No Pitch/Strobe/Light ARM SME V(Kondo Ag Rewire&Tags) MCOrtofon Cadenza Black CABLES Arm Yannis SPD-4 IC Yannis 222 Litz+Ag bullets Power WAR PRE ATC SCA2 SPEAKERS ATC 50ASL STANDS Atacama PHONO Sugden Masterclass PA4 SUT Ortofon ST80SE POWER PSAudio P10

    Valve PRECroft Epoch(Mega Modded) AMP Sondex S100 SPEAKERS Tannoy 15"MG+RFC Warwick cabs+ Reference XO DECK Garrard301 MatTeunto GunMetal Bearing401 PlinthMoldovan Arm SME 3012(Ikeda Ag wired) PSUPheonix PSU+Tachomter MCAg Meister SPU/DECCA Maroon CABLESArm Yannis 420.5 Litz+ Speaker3mm2Ag IC Oyaide FTVS-510 AgWBT 0110Ag Phonostage4Box Paradise


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