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    Latest SP14 Build

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    gener8r

    Posts : 56
    Join date : 2012-04-28

    Latest SP14 Build

    Post by gener8r on Sun Mar 31, 2013 6:56 am

    Recently finished up a second SP14 build, this one done as a 12SN7 version. Simply a matter of changing R20 and R21's values on the board and going with a different filament tranny. Vintage 12SN7 tubes are abundant and I am finding them much less expensive then vintage 6SN7s.

    This one is the Best preamp ever although I still need to build the SP13 and compare it also.

    I have built over a dozen Transcendent Sound Ground Grid preamps. It is an excellent preamp in its own right, however I have concluded that no matter what you do to the GG it is bettered by the SP14.

    Any future preamp builds will be SP14s. The SP14 is the king. Better definition, seperation and much better response, especially in the lower frequencies.

    See it here:

    http://www.flickr.com/photos/59541088@N08/8606079038/in/photostream

    http://www.flickr.com/photos/59541088@N08/8606072618/in/photostream


    nerpissad

    Posts : 58
    Join date : 2012-09-16
    Age : 43
    Location : amsterdam

    Re: Latest SP14 Build

    Post by nerpissad on Sun Mar 31, 2013 7:37 am

    good job!
    that's a beautiful wooden enclosure you used there.

    Sprags

    Posts : 123
    Join date : 2013-02-27

    Re: Latest SP14 Build

    Post by Sprags on Sun May 12, 2013 11:30 pm

    I like it!

    hawaii.ken

    Posts : 157
    Join date : 2012-01-31

    Re: Latest SP14 Build

    Post by hawaii.ken on Mon May 13, 2013 1:57 am

    What's the 2 brown things? Caps?

    Zimmer64

    Posts : 112
    Join date : 2013-01-29
    Age : 52
    Location : Switzerland

    Re: Latest SP14 Build

    Post by Zimmer64 on Mon May 13, 2013 2:53 am

    Nice build! I am looking forward to finish mine Very Happy

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: Latest SP14 Build

    Post by tubes4hifi on Mon May 13, 2013 12:32 pm

    yeah, those look like some sort of brown PIO output coupling caps, tell us what they are!

    turbotoy

    Posts : 47
    Join date : 2012-04-15

    Re: Latest SP14 Build

    Post by turbotoy on Mon May 13, 2013 9:06 pm

    Exceptionally nice design and workmanship on all of your amps AND your listening room! And I thought my couple of tube amps added a lot of cooling load to the room!

    You appear to be uniquely qualified to really assess the different pre and power amp designs out there. Also, what are you using for your main speakers?

    ramon68

    Posts : 83
    Join date : 2009-04-12
    Age : 75
    Location : naples fl

    Re: Latest SP14 Build

    Post by ramon68 on Mon May 13, 2013 9:25 pm

    The output coupling caps look like Jupiter .47uF beeswax paper and aluminum foil to me. I'm waiting on some K40y PIO caps I ordered from Russia
    on ebay.

    gener8r

    Posts : 56
    Join date : 2012-04-28

    Re: Latest SP14 Build

    Post by gener8r on Thu May 16, 2013 6:17 pm

    Those are the output caps. Deuland Copper Cast PIOs. 0.47ufs as they were the same price as the 0.33s at the time, so I went with the larger cap. I didn't add a switchable second output cap. No need with the Deulands. Expensive, yes. But I spared no expense with this build. In a preamp as a coupling cap, both in the SP14 and other preamps, this is the second best capacitor I have yet heard.

    Worth it? That's always an individual's call. For my own personal gear, yes. The SP14, as a candidate, meets a certain criteria for me and is a worthy unit to install something that good in, otherwise I would not.

    There's really not much one can do to upgrade/mod/improve a SP14 as far as sound quality goes. The circuit is top notch. How good it can sound is then pretty much parts selection, and the output caps play a big role in that with the SP14.

    The V-Cap CuTF is better yet, to the point of amazing and stunning. IMHO worth every penny if you can afford them. For that "once in a lifetime" build. One of my next SP14s will have a pair of those. Just waiting for a sale.........

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: Latest SP14 Build

    Post by tubes4hifi on Thu May 16, 2013 7:08 pm

    nice! if you can afford it . . . worth it!! Let's see, the Duelands are around $190 each? The V-caps around $225 each?
    Makes the Mundorf Silver PIOs a super bargain at around $39 each, no wonder they are so popular!
    hey, if I could afford a Porsche, I'd buy one!! unfortunately, I'm still driving a Toyota, and my stereo system is at a relative price.
    Yes, the SP14 circuit can sound great, or sound incredible! just a matter of $$$. Thanks for the great comments! Very Happy

    Sprags

    Posts : 123
    Join date : 2013-02-27

    Re: Latest SP14 Build

    Post by Sprags on Thu May 16, 2013 8:10 pm

    How does the more expensive caps improve the sound quality?

    gener8r

    Posts : 56
    Join date : 2012-04-28

    Re: Latest SP14 Build

    Post by gener8r on Thu May 16, 2013 10:20 pm

    Turbotoy; Sorry, didn't see your post.

    In that listening room are KEF 104/2s as the main L&R. Highly modded crossovers in those. Driven by various OTLs amps.

    The Center & ".1" are combined into a highly modded Infinity SM152. Driven by an ST70.

    The rear speakers are some old Radio shack 2 way bookshelf cabinets (actually made out of mahogany) attached to the walls that I ripped the tweeter and 8 inch driver out of and replaced with some upgraded drivers and new crossovers. Drriven by a low powered PP tranny coupled amp. Chosen for their off axis clarity.

    Thats there at my "permanent" home which I only get to enjoy a few weeks out of the year when I'm home on vacation. Where I currently live and work I use point source full range drivers, almost exclusively from Common Sense Audio. My favorite is the Audio Nirvana 10" Alnico model in a 3 CuFt box, and that is on my vinyl set up with OTL amps. In the other set up I have here; digital, I use some sort of Dynaco amp and whatever was the latest speaker I built. Currently that is a vintage 12" Utah coaxial and a 12" passive in about a 6 CuFt. box.

    Don't know how qualified I am to assess anything, I'm still learning.

    Roy: FYI I use the Mundorff Silver in Oils in your ST70 VTA boards and will use them in MKIII boards too. As you said, excellent price to performance. I have a company car here and consider myself very fortunate. Otherwise I'd be driving a beater so I could afford and continue with my audio projects. Priorities!

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: Latest SP14 Build

    Post by tubes4hifi on Fri May 17, 2013 11:21 am

    yeah, the good life! I was a corporate jockey for 20 some years, went thru a couple of booms and busts, along with the normal promotions,
    job transfers, and eventually layoffs, repeat, repeat, repeat. Now I really love working for myself! Very Happy

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