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    My SP14 Build

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    ruffian

    Posts : 43
    Join date : 2010-02-26

    My SP14 Build

    Post by ruffian on Sat May 12, 2012 8:08 pm

    Finished this up earlier this week and have been enjoying it since! I made a few mechanical modifications to Roy's kit, but the board is stuffed with stock parts save for the Mundorf output caps. I figured I would go with the board as Roy sells it, and then upgrade parts later if I want. That way I can see if I am making a difference. But the switches and wiring are not going to ochange so I did it as I wanted now. The selector and attenuators are Goldpoint, along with the selector being rear mounted with an extension rod. I figured by doing so I could reduce the total amount of wire and shorten the tape loop, which I do use. The signal wire is Cardas litz, another rea$on for attempting to minimize the amount of wire in it. I also changed out the RCAs for Cardas ones. Can't say if they will make one bit of difference, but thats what I wanted so I bought them. I also routed signal wire around the board instead of under it as Roy's standard practice appears to be.

    How's it sound? Great! Definitely noticing it go through some phases as it breaks in, but nothing extreme. For a while I thought the low end sounded a bit bloated and tubey, but that seems to have gone away. Probabably coming up on about 20 hours now and it seems pretty stable. No listening fatigue at all. Highs are crisp and defined without being bright. Low end is now pretty solid. I need to reach around back and move the outputs to the Russian PIOs to see how they sound, but I don't want to turn things off while I'm listening.

    For anybody thinking of building one, it is not very hard to make. Roy just gives you a stuffing diagram and wiring layout. He does not give you step by step instructions. But he has plenty of pictures of his builds so it is pretty easy to figure out.

    I am blaming Roy for the lack of sleep I have had this week. Twisted Evil Been staying up an extra few hours listening when I should have been going to bed.





    I'm not totally happy with my wiring job across the front attenuators. It could have been neater.










    Tube Nube

    Posts : 603
    Join date : 2008-12-06
    Age : 53
    Location : Calgary, AB

    Re: My SP14 Build

    Post by Tube Nube on Wed May 16, 2012 12:27 pm

    Nice! Really nice. I'm just delighted with mine, too.

    plexus

    Posts : 94
    Join date : 2012-02-18
    Location : Toronto, Canada

    Re: My SP14 Build

    Post by plexus on Wed May 16, 2012 6:27 pm

    Really nice build! I like that you did twisted pairs and routed around the board. also the shorter wire path to the selector switch. all these little things will add up. not sure about the bundling of wires though: i typically don't bundle mine up and prefer to leave more air between them. sure there might not be any significant cross talk but i figure why bother bundling them up. that would also increase capacitance in the signal chain. but, that's a design decision i make and i am sure the result is not significant. otherwise great stuff!

    t8ter

    Posts : 10
    Join date : 2010-01-03
    Location : Calgary, Alberta

    Re: My SP14 Build

    Post by t8ter on Wed May 16, 2012 8:18 pm

    Very nice Ruffian! Everything looks nice, square and trim. Let us know how it sounds.

    Alan-14

    Posts : 46
    Join date : 2012-03-31
    Age : 56
    Location : Melbourne - Australia

    Re: My SP14 Build

    Post by Alan-14 on Thu May 17, 2012 10:55 am

    Great work with the build Ruffian, very neat work and well laid out.
    I like the extension on the selector shaft too.

    As we speak Roy is building my SP14 & SP15 ... so can't wait till they are finished ... and I've gone for the same knobs as you Smile

    Tube Nube

    Posts : 603
    Join date : 2008-12-06
    Age : 53
    Location : Calgary, AB

    Re: My SP14 Build

    Post by Tube Nube on Thu May 17, 2012 2:22 pm

    Alan, I hope you'll give us a review of your pre-amp when it arrives!

    T8ter -- Another forum member from Calgary! Homey! Nice to know I'm not the only tube-o-phiac in the city.

    Alan-14

    Posts : 46
    Join date : 2012-03-31
    Age : 56
    Location : Melbourne - Australia

    Re: My SP14 Build

    Post by Alan-14 on Fri May 18, 2012 11:54 am

    Tube Nube wrote:Alan, I hope you'll give us a review of your pre-amp when it arrives!
    Yes I sure will Brenton ... Actually I used your pre-amp as the base for mine ... so we have very similar mods Smile
    I got an update email from Roy today saying my pre-amps should be ready sometime next week ... then probably another 10 days to ship to AUS Laughing

    Tube Nube

    Posts : 603
    Join date : 2008-12-06
    Age : 53
    Location : Calgary, AB

    Re: My SP14 Build

    Post by Tube Nube on Fri May 18, 2012 12:24 pm

    I bet you weren't able to get the custom Pacific North-West Rain Forest-Inspired Green anodized face plate, though.

    It was a pretty funny story, I'd opted for bronze, and after the anodizer kept Roy waiting for weeks, they sent him back the green one that was so far off from what he ordered that, well, let's say that Roy commented to me in an email or two that he was somewhat disappointed.

    But when he showed me the picture of it, compared to what it should be, I liked it WAY better and insisted he let me have it.

    I'm sure you're gonna love this pre-amp. It's just achingly good!

    Alan-14

    Posts : 46
    Join date : 2012-03-31
    Age : 56
    Location : Melbourne - Australia

    Re: My SP14 Build

    Post by Alan-14 on Fri May 18, 2012 6:44 pm

    Hehe ... Roy told me all about your custom Pacific North-West Rain Forest-Inspired Green ... I kinda liked the color too.
    But I've gone for what you might call a more retro look ... brushed aluminium Smile

    I'm sure I'm going to love the pre-amp too ... should go very nicely with the ST-120 I've nearly finished building.

    ruffian

    Posts : 43
    Join date : 2010-02-26

    Re: My SP14 Build

    Post by ruffian on Fri May 18, 2012 10:16 pm

    Alan-14 wrote:
    Tube Nube wrote:Alan, I hope you'll give us a review of your pre-amp when it arrives!
    Yes I sure will Brenton ... Actually I used your pre-amp as the base for mine ... so we have very similar mods Smile
    I got an update email from Roy today saying my pre-amps should be ready sometime next week ... then probably another 10 days to ship to AUS Laughing

    Going with the relay? I gave some thought to a relay vs. the rear mounted selector and opted for the rear mount. My basic thougth was to keep it mechanical. Either was I think the same the result is the same.

    I have 60 hours +- on my SP14 now. The music keeps sounding better an better. Last night's selection was some Pretenders, Mazzy Star and The Cowboy Junkies. I am amazed at how good it sounds. Highs are clear and crisp with solid bass. Extension, staging, presentation. It is all there. You are going to be very happy when you get to turn yours on.

    Did you get the octal board for your ST-120? I have a VTA ST-70 that I was thinking of putting the octal board on. Right now I have the high output board, was the only thing that was offered when I bought it. Got the itch to get my solder iron hot again. Of course I could make a PH15...

    Alan-14

    Posts : 46
    Join date : 2012-03-31
    Age : 56
    Location : Melbourne - Australia

    Re: My SP14 Build

    Post by Alan-14 on Sat May 19, 2012 11:58 am

    Yes ... when I saw the switching relays I thought that was a great idea keeping the signal paths short and just had to go with it.
    Didn't even think a rear mounted selector could be an option ... definately like how you have done yours.

    Apparantly the Russian PIO caps need 100 hours or so before they give there best ... and maybe similar for the mundorf's ...
    So with 60 hrs on yours the best is still to come Smile

    I went for the high output 12AT7 board on my ST-120 to keep the overall look of the amp more in keeping with the original Dynaco ST-70.
    I also have an original ST-70 that I bought second hand back in the early 70's ... it had been modified with silicon rectifiers, removal of the cap can and upgraded components on the original driver board when I got it.
    After I've got my ST-120 up and going I'm thinking of stripping down the ST-70 and rebuilding it back to original condition, keeping the 7199 driver tubes going back to tube rectification and replacing the cap can.

    I see you've got 2 phono inputs on your SP-14 ... one of them would just have to be for an SP-15 ... get that soldering iron out again Very Happy

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: My SP14 Build

    Post by tubes4hifi on Sat May 26, 2012 1:25 am

    Alan (and Ruffian who started this), hope you don't mind, I'm gonna show off your coming preamps . . . . they are a matched pair . . .
    let's start a vote on black VS silver . . . that's the biggest difference here . . .
    to make it interesting, I'll start by saying I like TubeNube's the best so far! That color is NOT available!!
    And I also like his "knurled" knobs better . . . . . TubeNube SP14





    Alan-14

    Posts : 46
    Join date : 2012-03-31
    Age : 56
    Location : Melbourne - Australia

    Re: My SP14 Build

    Post by Alan-14 on Sat May 26, 2012 11:25 am

    Hey look ... there's my preamp Laughing

    ruffian

    Posts : 43
    Join date : 2010-02-26

    Re: My SP14 Build

    Post by ruffian on Sat May 26, 2012 4:20 pm

    How about a picture of black with unpainted letters (just the routed aluminum)? I have a feeling that will look better that my white lettering, especially with the aluminum knobs.

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