Sonic Frontier Line 3 vs McIntosh C2500

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

Hehe.  If I wasn't still unpacking I would have told you that your pre-amplifer was absolutely garbage but for $50 I would help take it off your hands..... :D :D :D

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

Great! Chris is a great guy.  I buy parts from PCX all the time. 

Let me know what upgrade you get and how it sounds. :)  I'm unable to switch right now because of my 5.1 needs... but the SP3 has always been one of those romances I wish I had committed to. :) 

Best,

Erik

Prettty awesome.  What duelunds did you get?

It's kind of funny, but kind of true that a good tube preamp is:

"A bunch of the very best caps money can buy surrounded by tubes and other such nonsense"

By the way, only 1 or 2 caps per channel are coupling. The rest are power supply related, or feedback and the like and less critical.

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

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

Audio asylum or diyaudio should let you. ;)