pendergast said:
...
Question 1: how does that upgrade (of 4 years ago) compares with the actual iron upgrade available through Magnequest?
Question 2: doing the iron upgrade today, I need to purchase from Magnequest. But 4 years ago, the upgrade kit came with capacitors, I believe. So the question is, how do I get those caps today?...
Here's the link to the instructions:
http://www.bottlehead.com/et/adobespc/S.E.X./ironsupplementkit.htm
That is really hard to find - hopefully Doc B will crawl out from under the 2765 other things demanding his attention and make that more clear sometime soon!
Meanwhile:
Question 1: The original SEX upgrade iron is now sold direct from Magnequest, as the BH-1 nickel pinstripe output transformer with the BH-2 plate chokes. The instructions above used slightly different model designations because this was the first of the custom Bottlehead versions that Magnequest made. Personally, I prefer 100% nickel - a little more costly, but more transparent. The regular (M3 or perhaps M4 - ask Mike when you order) is less expensive, and I would say a bit more gutsy - it has "grip" for want of a more precise term, and will handle the really deep bass a bit better - we're talking organs and symphonic bass drums; rock and roll bass is loud but not extremely deep. The pinstripe is in between. (I have nickel in my own SEX amps.) The bass improvement is almost entirely a result of the iron upgrade.
Question 2: When first introduced, we had some custom capacitors made by ICW (Clarity Caps). They are quite good, but too many people had their own favorite capacitor and wanted the upgrade without our custom caps, so we stopped doing that - we're a kit house, not a capacitor house! I recommend Auricaps (Clarity Caps are comparable I believe) if you don't have a favorite type; you can get them from Parts Connexion in Canada (they've been reliable and fast, in our experience) and other sources. If you ask for advice on the Forum, you'll find very many different favorites. It can be fun to experiment, if your muse leads you in that direction. I have Auricaps in my Paramounts, IIRC I have the original ICWs in my SEX amp.
The third component of the original upgrade is the C4S plate loads for the driver. Bottlehead still sells those along with the necessary hardware etc. even though it does not appear on the current web site. Best bet is to email Eileen and ask. I think this part is quite significant audibly and not very expensive.