Audio asylum or diyaudio should let you. ;)
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And I convinced you to do this without explaining the major part of the upgrade! :) Please be careful opening up tube gear. Voltages inside are LETHAL at 300V or higher. This is different than solid state, that is rarely over 15V for a preamp, 60V-ish for an amp. Turn it off, unplug and let sit for about 10 minutes to ensure caps are fully discharged before poking around inside. :) Best, Erik |
Caps do a lot of thing, but unfortunately in tube preamps they are a necessary evil we wish we could avoid. The biggest issue with caps in a tube preamp are the caps used in the signal path, and are almost never neutral or transparent enough, so good ones command the big bucks, and some makers will provide "special editions" of a model which are identical except for the caps. Conrad Johnson and PrimaLuna are examples, but may add other part upgrades. The coupling caps must is block the DC voltage that's always present at the output of a tube while letting the music through untouched. The DC is around 300V. Obviously, you don't want your amp, designed for 1-2 Volt signals getting the high voltage bias, so you have to use at least 1 coupling cap at the output. These are small farads (2-4uF) but high in voltage. They must be high enough to block DC even if the full voltage of the power supply should be applied, which is possibly around 4-500 Volts. The physical size is proportional to the farads x voltage (more or less). So, a 4uF cap at 600 V may appear enormous. Then, for fancy caps, the higher the price, usually the larger and more complicated they are physically. Some use serial construction, a hugely wasteful (of uF) design where you put one cap after another in the same tube. Trouble is, each cap must be double the final size. That is, for a 2uF cap, you build 2 x 4uF. That is, you create a cap with 8uF of which you'll get 2 out. I have no idea if this is actually better, but it's the basis for the highest end Mundorf among others. Best, Erik |
Hi DZ... Do you also own a Line 3? I'm not very savvy with electronics, so I don't even know what the caps do! My set of tubes seem to be the same that you have though... This was a major rehaul though because I got a bagful of all the old stuff that got removed. I could take a picture of the guts so can see what was done... I have before and after.... |
I still haven't changed the fuse but may try that next. My coupling caps are Audio Note Silver, I often wonder how V-Caps would sound, they are great in my cross overs. My last re-tube consisted of NOS Telefunken diamond base E88CC (LV1, V2), NOS Sylvania 6U8A (V1, LV2), and Russian 6H23p-eb for the rest as recommended by Chris at the time. |
True. Some of the caps they are using now are a huge improvement over what was available 20 years or so ago. Worthwhile. I honestly don’t know of a preamp that is inherently better than the SF 3. I know of a lot using more modern or more expensive parts, but not better sounding or better designed. I would not let a SF 3 go out of my hands. However, I might loan it to Chris to modernize the caps. :) In preamps caps have a very large contribution to the sound, and paying for an upgrade is relatively cheap compared to buying a new preamp with the same caps. You can really go up a few notches with the right cap upgrade. I would however encourage you to listen to other british speakers like Monitor Audio and see if you feel the B&W's are still the best match. Best, Erik |
fijunc I would say it's probably a better allocation to go the upgrade route, the preamp you have is well made with a robust power supply. And upgrade and refresh of older parts after 15 years may be a bit of a revelation soundwise, and I don't know that the McIntosh would be that much of an improvement. Either way good luck and happy listening and to answer your earlier question you would connect the Chinook to a line level input and not a phono input. |
Have you thought of some upgrades for your SF L3? Ask at PartsConnexion. The owner was a founder of SF. :) I'd ask around though, I loved the SF preamps I heard, but have not kept up with tubes at all. I'm just mentioning it as a way to go, without necessarily championing it. :) Be well, Erik |
Beautiful system! I really think that you would love the McIntosh....But I would give another one a look... the Manley Labs Jumbo Shrimp is great for injecting a lot of rich organic earthy quality with a real palpable sense and a huge soundstage with plenty of rise and decay, I say this because you currently have a Chinook and the combo is amazing! Its what I use over a Mac pre amp. My brother has the C2500 with the exact same system as mine, and it sounds very accurate warm and detailed as hell. I have a Project Xtension 10 and I spin a lot of vinyl, and I wanted something special sounding. You would not be making a bad choice either way. IMO. Matt M P.S. never heard the SF pre amps |