Geoff Farina is determined. He won't settle for a crummy guitar sound and this has led him on an amazing quest of knowledge and sound. He is currently a member of Karate (who have an album out on Southern Records) and the Secret Stars (a duo who have a fine album out on Shrimper Records.) He's also helping a friend set up and run a cool studio in the Boston area, which he talks about briefly. But most fascinating is what he's learned about tube guitar amps and the ways one can achieve optimum performance and great sounds. Remember though, unplug your amp before trying any of these modifications, and don't blame us if you break it.
How did you get into the modifications of tube equipment and building some of the oddball things?
I think mainly because when I was in bands before and in doing Karate everything always sounded bad. I always used old amps and everybody's amps sounded bad and the one thing I noticed was that there was a huge amount of myth about tube amps and stuff among people like me and my friends. Not being high end blues players the information just isn't there. I just wanted stuff to sound good. When we went into this studio about a year ago to make the Karate record, I wanted to see if I could make things sound better. I read a lot of old tube manuals I would find at thrift stores or libraries. Like school libraries with engineering departments and stuff. I started to get a basic knowledge of how a tube works and why it is used. I'm totally a hacker. I know so little math, I'm unable to do a lot of the math work you need to do to be a real engineer. I really have this fragmented knowledge of everything. That's how I got into it. I had this one amp that was a '68 Fender Twin; Fender was sold to CBS in '65 and in '68 they changed to "silver-face" amplifiers which supposedly don't sound as good. What I learned was that the circuitry didn't necessarily change, the things that changed were relatively small for the first couple of years, in '68 and '69. If you know what you're ding, you can go in and rip out some of the parts and go to Radio Shack and get a couple of certain value resistors for a quarter and just make a few little changes and have a really amazing sounding amp. I just happened to have one of these [Fender] amps and since then I've gotten another one from the exact same year that's three serial numbers away from the one that I already owned. I kinda knew what I was doing when we did that record. I wanted a real clean guitar sound and it came out pretty good. So that's basically how I got interested in it...just having everything sounding terrible and everyone having amps that sound mediocre or don't sound good at all.
And they don't really know why.
Yeah, the myth is that you need to get new tubes but you can buy new tubes and if your amp isn't biased correctly it'll still sound terrible. A lot of Fenders don't even have a bias control. They have what's called a balance control; two of the tubes will be working really hard and two won't be doing anything. You'll spend $50 on new tubes and you're ruining them, basically, and your amp doesn't sound any better. Here in Boston, which is a huge music city, there's a whole lot of mediocre or bad repair people around and a few really good ones. I've taken my stuff out and had it worked on and it doesn't sound any better. There's one guy in particular who's notorious for being just not good at all.
Had you had any experience with doing electronics before?
Not really. I've always been into trying to fix things myself but I've never had any real electronics experience. The guitar player in Karate, my friend Eamomn, is actually this total computer geek and electronics guy, or was at one point in his life. He gave me my first little lesson on it. I was on tour for three months and all I did this summer was read electronics manuals and two or three really good books about tube amps. I just really tried to get a concept of how things worked. The thing that I started to realize about it is that there's no real physical metaphor for how electricity works. Like current is a metaphorical term. That works up until a point but when you start to think about the difference between voltage and current...current flows in one direction but what's called holes, this sort of negative space which creates voltage, moves in the other direction simultaneously and it's just kind of weird. The metaphors just kind of break down. You have a certain degree of that and then you have this practical knowledge and you know that if you change these two resistors that it's gonna sound good or it's gonna sound different. It's not something that I've been able to figure out. If anybody has that total grasp on it then that's great for them! It's really difficult!
What are some of the books on tube amps that you mentioned?
There's three books that are really good. The first one I read was by a guy named Gerald Weber and it's called A Desktop Reference of Hip Vintage Guitar Amps and it's kinda cheesy but it's good. He was a weekend-warrior blues guitar player and he was in the meat packing industry and he got rich packing meat. He wanted to buy the best tube amp and there wasn't a good tube amp, in the 80's, to buy. So he learned about them and built one and now he has this company called Kendrick Amplifiers which, if you ever get the chance to hear one, it's a treat. I don't know any punk rockers who would spend $2500 on an amp but we played in Florida over the summer and the club next door was a blues club and I went over there and there was this really amazing guitar player playing one and it's just a treat how good they sound. You don't realize what a guitar can sound like til you hear one. But, anyway, his book is basically a whole bunch of excerpts from his writing for Vintage Guitar magazine and it's also got all the Fender schematics and the great thing about the Fender schematics, that no other amp company ever did, is that Fender printed layouts of amps. A schematic isn't a physical layout. It has a schematic on the top of the page and the layout on the bottom.
Where the parts are on the circuit board.
Which is really valuable when you're not that versed in reading schematics. The thing about this book is that it's really poorly written, actually all three of the books are really poorly written. There's a lot of really great stuff that you have to dig for. Little tricks you can do. For example, you can buy a resistor at Radio Shack and solder it to a couple of RCA plugs and plug it into the reverb in and out and use the reverb foot pedal and you have an extra gain stage. It actually sounds really good. That's what I used in Karate for a couple of years. There's another book by this guy Aspen Pittman, who runs Groove Tubes, and it's called The Tube Amp Book and it's volume 4.1 by now. That one's cool 'cause its got a lot of pictures of all these old amps and stuff and it's really and has reproductions of all these old Fender ads and everything. But it's also a huge ad for Groove Tubes which is kinda annoying. My personal opinion is that they're more of a marketing company. I can't tell the difference between them [Groove Tubes] and Sovteks, which cost half as much. The great thing about that book is that it has this little part of it in the back that has this step-by-step way to troubleshoot an amp. Where to start looking for problems. It's a way to service tube radios; this system you can use to troubleshoot amplifiers, and I've never seen that printed anywhere else. It's really valuable just for that. The other one is a book called Dave Funk's Tube Amp Workbook. This guy Dave Funk is really a total goofball. He's a genius, a real electrical engineer, and he's worked designing lab equipment and everything that you can imagine. But he's a terrible writer. The book's terribly written. I have a Masters in English and I edited journals and everything like that but I don't think I could have read these books without having that knowledge. There's a lot of stuff in there that's really valuable. To really get a sense of what I was doing, just being completely ignorant, I had to read all three of them a lot. The Kendrick book in particular is really great, down-to-earth and the most accessible of all of them.
What other kind of modifications have you done to amps?
This is all stuff that other people have done that I found out about. For example, a lot of Fender amps have two 68K ohm resistors that come off the two inputs. You can simply remove them. The reason that they're there is so you can use both of the inputs at once, which people used to do so you could put a guitar and a microphone in and you could sing and play guitar, which of course nobody does. So you can remove those and it sounds better without them 'cause they bleed off certain frequencies. There's other things you can do. On a two channel Fender amp, pull out the first preamp tube which runs the first channel. What that does is it makes the second preamp tube run a little hotter. The first channel doesn't work anymore but nobody uses the first channel. If you don't use the vibrato on a Fender Twin you can disconnect it. The way that a vibrato works on most of the later Fenders is that, even if you have it off, it always bleeds off some of the signal to the ground so you lose fidelity. There's a brown wire that's connected to the vibrato jack for the footswitch, and you can disconnect it and it disconnects the whole vibrato section of the amp. There's something called a negative feedback loop on a lot of amplifiers and that is where the signal goes through the amplifier and then it goes through the output transformer and then to the speaker jack. There's a wire that goes from the speaker jack back to another part of the amplifier, like one of the preamp stages. It sends part of the signal back to the preamp stage and the effect that it has, and I don't really understand exactly why, but it cancels out a lot of the odd order harmonics and enhances the even order harmonics and I think it might have something to do with the phase that it's in but I don't quite understand it. But the effect of simply disconnecting that wire is that you get a real sorta browner, crunchier sound out of the amplifier. Actually, a presence control on an amplifier isn't a tone control. Tone controls are passive circuits. There are different capacitors and resistors that bleed off certain signals depending on how much signal you put through them. But a presence control is actually a potentiometer (a variable resistor) on the negative feedback loop. So it's active and that's why that control makes noise. It actually has voltage on it from the negative feedback loop and controls how much of that goes back into the amplifier so you get that sizzling sound when it's really high.
A lot of that is fidelity, making the amp sound clearer and not muddy but there's also things like changing power filters which are just these capacitors that are in every amplifier. When electricity comes into an amplifier it's AC and the rectifier changes it to DC but it's a pulsating DC and the capacitors even it out. But after ten years they get all brittle and they don't work anymore and that's when you get that 60 cycle hum in the amp and stuff like that. You can change them and build a variac, which is for charging them. I don't know if you have to, and some people don't, but I always do 'cause somebody told me that you did. But you can build a variac out of a lightbulb, a three prong adapter and a couple other things. The Kendrick book shows you how to do it. So you can charge them yourself and it saves you a hundred dollars. That makes such a dramatic difference. You're talking about getting a ton more volume and a ton more clarity out of the amplifier. Biasing tubes is real important. The way that I bias tubes is there's a certain point on the amp that has to be in this voltage range and you just fuck around with it and you listen to it and see what sounds best within that range. Those are all things that make a ton of difference. A lot of it's about knowing what you want.
I heard you had built these weird reverb units.
I know theoretically how a reverb works. Jodi, the other person in Secret Stars, has this old Danelectro reverb box and we saw one on the back of a Ventures [record] cover so we were kind of excited about it. But it sounds horrible, it's really bad and it says patent pending on it and I have the feeling that it's some kind of prototype or something, I don't know. The theory of how reverb works is that it takes part of the signal and it puts it through a transducer, which is simply like a guitar pickup, it changes mechanical energy to electrical energy or vice versa. It changes the voltage of the signal into mechanical energy that vibrates the spring and on the other end of the spring you have another transducer that takes that mechanical energy and changes it back into a "new" signal and runs it back into the signal path. The spring, of course, vibrates with all these different harmonics and that's how you get the reverb. I tried using guitar pickups as transducers and I built this thing that was in a project box from Radio Shack and inside it had two guitar pickups on either end connected to 1/4" jacks and it had the springs that the guitar pickups were supposed to pick up. It kind of worked but it's more of a feedback machine. It's kind of fun and it's also suspended in this old mail holder from the 50's. I can't even describe it. It's just this weird hollow big metal thing that has all these holes in it and I suspended the whole apparatus in this thing. Most reverb boxes, they have the springs, but then the unit is mounted on springs.
For shock resistance.
I think it also facilitates the vibration of the unit. What I learned by doing all this is that in the Fender reverbs, that are in the Twins and stuff, the wires that are the springs have to be magnetized. The transducers in those amps break so easily. If you take it apart you can't fix them 'cause they're so teeny. I don't think that you can build an actual spring reverb, I mean I haven't been able to do it. I'm sure people with "real" knowledge can do it. Fender and all the amp companies don't build them, they buy them from a company that makes them in Canada. The studio that I'm kinda working at wants to build a plate reverb, so I'm interested in getting involved in that.
Those sound really neat.
John Loder, who runs Southern Studios, built a plate reverb and it needs its own separate room.
What kind of studio are you working at?
It's a friend of mine who has a German 16 track, 2 inch machine and a couple of ADAT's. He wants to have an analog 16 track studio, but with a pre-production studio where people can go in and do stuff onto these ADAT's and figure out what they want before they put anything down on 2 inch. That's his philosophy. He wants me to help on guitar sounds and to bring in bands. I think he wants somebody who knows a little bit of what guitar players want, sort of how to mediate between the engineer and the band. Good engineers might know enough to leave the guitar sound alone, but they might not know the potential of how it could sound. A lot of people who play guitar don't know what their options are.
