| Author | Message | ||
| jseitang
Junior Username: jseitang Post Number: 17 Registered: 6-2002 |
so after some years, i've seriously decided to get my own alembic F-2B. 2 questions: anybody out there know where the best place to shop for one NEW?(best, lowest deal) i'm thinking gguitars in new haven, ct? any leads? also i'm bidding one on ebay but its an older one ehcih bring me to my next question, really is there a difference, if any from the early ones and the ones made now? | ||
| pace
New Username: pace Post Number: 2 Registered: 4-2004 |
I was talking to Brian at Gguitars about getting a Superfilter & according to him the filter and the F-2B are both built per order from factory (so it might take longer than you expected). If you're cool with the wait, I'm sure they'll hook you up with a great price | ||
| mica
Moderator Username: mica Post Number: 1619 Registered: 6-2000 |
We've been asked this question a few times, so I asked my dad to help me out and write this "F-2B Revision History," AKA "We Don't Like to Change Things Much Around Here." ------------------------------------------------ The F-2B has been in continuous production and largely unchanged since 1969. Aside from the superficial changes in the chassis and decoration, only two electronics changes have been made. 1. The first couple hundred units used a pilot light with a jewelled cover for a power indicator. After that, we've used an LED. 2. Knobs. The earliest units had black plastic knobs with two set-screws spaced about 120 degrees apart, tapped into a metal insert that was not visible when the knob was installed on the unit. They had a smooth red cap that was super-glued onto the main body of the knob. They were manufactured by Knobex in a factory in Burlingame, California. This company eventually stopped producing the parts, so for a few hundred units, the knobs were all-aluminum with two set-screws and could be found in both black and natural aluminum colors (both colors were anodized). The supplier was Alco. Since about 1990, the knobs are a collet style plastic knob with a skirt glued onto the bottom to conceal the nut mounting the pot bushing. The collet knobs have no set-screws visible, and you pry off the cap with your fingernail or a knife to reveal the collet screw, which is loostened with a 6mm nut driver or alternately with a large flat-blade screwdriver turning the slots milled into the collet nut. 3. Filter capacitors. The high voltage power supply of the F-2B uses a voltage doubler followed by two stages of decoupling. Originally, we used Sprague "Atom" capacitors of 20uf. Later units used the premium type "Compulytic" type (39D) in 35 or 40uf. When Sprague discontinued these, we changed to Cornell-Dubilier WBR series. The capacitors are axial-leaded aluminum electrolytic type and the negative leads are spliced longer so they can return to the printed circuit board for connection. The ends of the capacitors away from the circuit board are supported by foam tape attached underneath to the chassis, and above to the lid of the enclosure. If the F-2B is regularly used, the capacitors will have a very long life, more than 25 years, so virtually all units that are in use will remain in good functional condition. However, if the units are stored and left powered off for perhaps 5 or 10 years, the capacitor life will be shortened, and they may need replacing. The foam tape also will deteriorate after 20 years or so, and will need to be replaced so that the connections to the circuit board will not be stressed by vibration during transportation. At some point in 2004 or 2005 we plan to change the capacitors from the axial-leaded type to a so-called "snap-in" style where both leads exit the same face of the capacitor and solder directly into the printed circuit board. This will eliminate the need for the foam tape. Other than that, things are pretty much the same inside. We're still even using the original printed circuit board artwork. | ||
| bsee
Junior Username: bsee Post Number: 43 Registered: 3-2004 |
Mica, are you trying to avoid that tax work you mentioned yesterday? | ||
| flaxattack
Junior Username: flaxattack Post Number: 21 Registered: 4-2004 |
i bought mine yesterday at nj guitar- jsei- i can send you photos of his stock- i tried to email you but it was returned - send an email to jsf5653@optonline.net and i will send photos to you | ||
| mica
Moderator Username: mica Post Number: 1621 Registered: 6-2000 |
Yes, Bob, sometimes you just need a break from those endless columns of numbers! At least I think next quarter our new accountant can do all of this without much help from me. Back to the tax proofreading, you gotta sign that stuff under penalty of perjury, so it better be correct. | ||
| jseitang
Junior Username: jseitang Post Number: 20 Registered: 6-2002 |
hey mica i just ordered a brand new alembic f-2bfrom g guitars.. can i request the "axial-leaded type to a so-called "snap-in" style" filter capcitators? is it available ? thanks | ||
| dfung60
Junior Username: dfung60 Post Number: 36 Registered: 5-2002 |
Mica - What a great historical capsule about the F2B! This (of course) raises a couple of questions: 1) Even though the F2B has a vintage vibe, did you guys ever try building them with more modern high-performance components (Vishay laser-trimmed resistors, silver litz wire, etc.)? I appreciate maintaining the fidelity to the original design which included a lot of "best-of" components from the day, but I'm curious whether the newer stuff is better, worse or no different. 2) What about the tubes? The 12AX7s are at the very heart of the design. What's the history of what you've used, and what do new F2Bs have? I haven't changed tubes much in my old F2B and it's had the same old and pretty vanilla RCA tubes for many years. I did buy an expensive Telefunken some years ago and used it in there for a while. I don't really have sufficient "tube vocabulary" to explain the differences other than to say that "harsh" wouldn't be too far afield (perhaps it was just a bad tube). I ended up switching back to the RCA. Thanks, DF | ||
| effclef
Intermediate Member Username: effclef Post Number: 146 Registered: 1-2004 |
David, the laser trimmed resistors are great for precise applications. I am not sure if the F-2B circuit would actually need 0.1% tolerance on its resistors - I would think that would matter more for balanced op-amp designs where you want both sections of a circuit to be precisely matched. (Well, the F-2B is stereo...so maybe it should.) As for Litz wire, my understanding is that Litz was made more for radio frequency applications where RF rides on the outside of conductors more than the center (the "skin effect"). I've got a roll of it around here which I have always wanted to use in making a crystal set radio with. Those oatmeal box crystal sets were always sensitive and hi-fi. Anyway, whether newer stuff is better: from Mica's capsule it sounds like Alembic pays attention to improvements in technology. The vintage amp guys would probably do better by not using carbon comp resistors and new-old-stock leaky caps ... I guess the engineer in me wants to see some sort of printout of the response of a circuit. Descriptions in Bass Player like "meaty, focused tone" and "shimmering dynamics with an organic feel" leave me unhappy and confused! EffClef | ||
| gblick
New Username: gblick Post Number: 3 Registered: 10-2003 |
>"2) What about the tubes? The 12AX7s are at the very heart of the design. What's the history of what you've used..?" I bought an F-2B brand new in 1982 and the tubes that it came with were labled "Amperex 12AX7A/7025 Made in W. Germany". We all know that real Amperex's were not made in W. Germany so I knew that these tubes must have be relabled. After years of wondering what tubes these really were I finally found out. I came across a closeup picture of a 12AX7 made by "RFT" and it is absolutely identical to my tubes. RFT's were actually made in E. Germany but I have no doubt that these tubes that came in my F-2B are in fact RFT tubes relabled as Amperex W. Germany. BTW, they are fantastic sounding tubes and still sound great after 22 years. >"I did buy an expensive Telefunken some years ago and used it in there for a while. I don't really have sufficient "tube vocabulary" to explain the differences other than to say that "harsh" wouldn't be too far afield (perhaps it was just a bad tube).." It must have been a bad Telefunken that you tried. I've tried several different tubes in my F-2B (not a whole lot though, and most weren't high dollar 'boutique' brands), but the only tubes I tried that I liked better than the stock RFT's were indeed Telefunkens. The best words I can use to describe the tone provided by these Telefunkens are smooth, sweet, & very musical. There's not a better tube out there IMO, but admittedly I haven't tried any of the other high dollar brands like Amperex (the 'real' ones) or Mullards. I don't need to, as I'm set now with these Telefunkens. -Gus |
