Geo

One sexy little nymph on that fingerboard!

Looks good... it's awesome that you can work on that with your wife. If I could find a girl who likes to build guitars... Where I live, summer makes the attic hot and humid all the time, while in winter it's freezing cold. Maybe your house has better insulation etc.... but you might want to be careful storing wood up there. I definitely wouldn't store guitar wood in my attic. Keep up the good work!

Lookin' sweet... keep it away from that tabasco sauce!

Are you sure you killed your tone pot? Unless you smashed it or something, I kind of doubt that.

Do you have the right values on hand as "guitar pots"? They should work fine, but if you're buying them, I would buy pots from an amp parts seller. Then you know you'll be in the right wattage rating. I don't know what amp pots and guitar pots are rated wattage-wise. Yeah, use audio taper, although I think the mid pot in a Fender tone stack should be linear. When in doubt, check a schematic of a classic amp. Volume controls are definitely audio taper.

If you do your homework and understand how pickups "work", you'll know what you need to make a given circuit.

Hey, glad to help. It will sound sweet I'm sure.

Ha ha, yeah, the little guys crept into the picture again. Right now my closest thing to a bass amp is a homebuilt thing. It's a Plexi preamp into a single EL84, about 3 audio watts. I can get some good recorded bass tones with it if I tweak the low-mid EQ a little, using the amp's dark channel. I have a friend's Squier P-bass on loan. I've played around with it, I'm fairly familiar with its "tone". I'll soon be building a new amp, a Plexi preamp into a Deluxe Reverb-style poweramp. The dark channel on that amp will have a switch to bring in a more bass-friendly voicing. (it will basically be a guitar amp that consents to doing bass.) So... I don't have a whole lot to measure this pickup against in terms of tone. The DC resistance is 12k, so it will be high output, probably somewhat lacking in treble. But I like a warm bass tone, so it should be good. Thanks for the compliments... it means a lot!

I believe the 250pf, .02uf, .02uf of the tonestack will do that. The tone stack in a typical blackface Fender has no cap between the plate and the tonestack input, for example here. http://el34world.com/charts/Schematics/fen...VERB_AA1164.pdf

Hey, thanks for checking in. The poplar is from the local Lowe's glitzy appliance and garden plant--er--hardware store. I don't think it was more than $20 total. The body is laminated from 6 pieces. Basically I glued the halves first so that I had three "layers" that were the full width and length of the body. Then I did the routing for each layer. For the back, this meant routing away about half of its thickness. For the middle section, I routed around the area that would be hollow and then cut that out with a jigsaw. I glued the back and middle together and then cut out the body outline. For the top section, I cut out the body outline (leaving 1/4"-1/8" extra). Then I carved it and routed away some on the underside. Then I glued the top and body together and cut the top down to match the curves of the body with a chisel. Yeah, that was stupid. But I don't have a bandsaw, so my options are limited. I just cut the first octave of fret slots.

Thanks for the compliments. I just routed off 1/16" from the fingerboard blank, bringing it down to 1/4".

Doh, sorry about the small text. I didn't realize the resolution went down so bad on photobucket. If you want I can email the file to you. Just send me a personal message with your address. As to that 1meg resistor, I'll just explain what I wrote in the schematic. I don't think the 1meg at the grid of V3a is necessary. The grid needs a high impedance path to ground, but it should get that through the pots in the tone stack since the bottom of the mid pot is grounded. Try it both ways; there may not even be a difference in the sound. Your 3rd Draft looks good. With the voltage divider before the "drive" control: the 10k will determine the amount of gain that gets through to the volume control. So, if you have too much gain, make it smaller. I imagine anything down to 1k should be fine, though 1k would probably cut too much signal and not make as much distortion. The ratio between the two resistors in the voltage divider determines how much signal is dumped to ground. So, with 10k/470k, only 1/47 of your first stage output gets through to the next stage. And once you turn the "drive" control down from there, it's even less. 1/2 of a 12AX7 has a voltage gain of roughly 50. So if you have say 20mv signal from the guitar, the first stage will put out about 1 volt of signal. (This is all very rough.) If you play twice as hard, you have 2v from the first stage. That will drive the next stage to full output, because the next stage will probably have 1-2v on its cathode at idle. Taking a larger view... a voltage divider of 10k/470k (ratio of 50) basically elminates the voltage gain of the first stage (about 50). So, your ears may want something higher than 10k. For example, a divider of 470k/470k would only dump half of the signal before the volume pot. OR, you may prefer the sound with no voltage divider before the volume pot. That part is up to you. This thing will probably sound killer. The preamp is pretty hot--it should be an overdrive machine! Glad to help you out. When I was first figuring out tube amps (about a year and a half ago), folks on the Hoffman tube amp forum helped me out a lot. They're very welcoming of newbies. http://www.el34world.com/Forum/yabb2/YaBB.pl

I see some things that I think you should still change. http://i134.photobucket.com/albums/q119/Ge.../Modified2a.png You have the signal grounded after C8. I.e., no sound. I noted a few other things in the schematic. I'm not sure about the "047" cap feeding the tone stack. The values of caps in series act like the values of resistors in parallel, so the "047" and 250pf in series might be creating a strange value. I don't know. I would just take the "047" out and feed the tone stack directly from the plate of the driver. You may find that you can't get clean sounds with 1/2 12AX7 feeding 2/2 12AX7, even with the "drive" control. If this is a problem, you can add a voltage divider before the volume control. This is basically a fixed volume control, and you can tweak the value of the top resistor until you get a usable sweep to the "drive" control. Your amp has a cool phase inverter. I believe it's called a "split load". The first half of 6AN8 is a gain stage, while the second half probably has unity gain or less but makes out-of-phase signals off its cathode and plate. (Note that the cathode and plate have equal load resistors, so a signal appears at each place.) I've read that a split-load PI contributes to a more distorted sound, which is probably a good thing. Aha... by "practice amp", I thought you meant practicing alone, i.e. bedroom volume levels. This amp will probably be great for playing with an unmiked drummer. It will probably be a lot louder than your SS amp too. Checking voltages is a good first step. Be sure you know how to do this safely (i.e. one hand in your back pocket, always aware of where the high voltage is, etc.) That should determine if the amp is healthy. After having turned it on and then off, you'll need to drain the power supply before going to work in it. The power supply caps can hold a lot of voltage. Make sure you read up on that if you aren't familiar with it. And DON'T leave it plugged in. (done that three times, twice in one day.) Have fun and don't kill yourself.

Hey, good pickup. That circuit has a lot of potential. The expensive parts of an amp are the transformers, so you've got those and some tubes and a chassis if nothing else. Here's something you could do with the amp. I find the " .005uf-500k-5M-500k pot" part confusing. I would simplify it the first time it appears and dump it the second time. But, I might be wrong... It looks like some kind of tone filter. http://i134.photobucket.com/albums/q119/Ge.../Modified1a.png The only doubtful thing, I think, is the tone stack placement. I know the Fender-style tone stack (basically what youv'e got but with Marshall values) is high-loss. But you have a lot of gain before the tonestack, so it might still be enough drive into the PI. Or you could totally change it... 6AU6 as input gain stage > volume > 1/2 12AX7> 1/2 12AX7 as cathode follower > tone stack (driving the tone stack that way reduces loss) > 1/2 6AN8 and resuming the original schematic. You could throw in a master volume if you like that sort of thing. By the way, this amp will be probly be too loud to distort at practice volumes. I have a 12watt amp. I wear earplugs when I play it loud. Still, this is a great starting point for an amp.

It could be anything. But yes, you always change tubes first when a tube amp is sick. For 100 euros (which I think would be approx. 120 USD???), I would buy it. If you have to tweak it, you still got an amp for very little money.

I finished the parts of the pickup. I only need to pot the coil and then the pickup will be complete. Making the cover: http://i134.photobucket.com/albums/q119/Ge...t/pickup001.jpg Cover finish-sanded: http://i134.photobucket.com/albums/q119/Ge...t/pickup002.jpg Next to a Strat pickup to give you an idea of the size (it's HUGE): http://i134.photobucket.com/albums/q119/Ge...t/pickup003.jpg Parts laid together for looks: http://i134.photobucket.com/albums/q119/Ge...t/pickup004.jpg Assembled pickup: http://i134.photobucket.com/albums/q119/Ge...t/pickup005.jpg The color of the bloodwood (difficult to capture): http://i134.photobucket.com/albums/q119/Ge...t/pickup006.jpg I finally figured out what bloodwood smells like. I make a black raspberry pie every summer... it smells like that baking!

I have two of them in a guitar I built. I love them--but that's totally subjective. I've used them to record a lot of songs. Here's a link... http://www.acidplanet.com/artist.asp?songs=590945&T=2430 I always record with the guitar straight into the amp, so there's no pedals here to mask the "true tone" of the pickups. "Venus Descends" has clean and distorted parts through a Marshall-style amp. I think I recorded the clean part at the beginning with the bridge pickup in single-coil mode. "Pleasure Can Be Had" is through a distorted Marshall-style amp with the bridge pickup in humbucker mode. "The Pendragon" (past the intro) gives you the bridge humbucker through a distorted Fender Princeton Reverb, and later the neck humbucker through the same amp. "guitar test" has several pickup config's through the Princeton Reverb. Keep in mind that the Fender-style amp has a "mid-scooped" preamp, so it sounds "chimier" and colors the natural tone of the pickups more than the Marshall-style amp does (I think). All the parts were recorded with a Weber 12" Signature Alnico and an SM57. Hope that's helpful.

Awesome... Can you elaborate on the boiled linseed oil? I've used it, but not alone. Someone on another forum shared a finish recipe with me. You mix 1 part linseed oil, 1 part clear gloss miniwax, and 1 part turpentine. As far as I can tell, this worked well (I only used it on the neck). Just curious how you did it.

I'm guessing you didn't find the right thing at Lowes. But I know very little about spray-finishes, so there you go... FYI (if you're still considering it), the finish I shared can't be sprayed as far as I know. But the wood really glows under it. It turned my pinkish-brown mahogany to a rich red-brown. Your guitar looks fabulous. The shape is original, and you definitely picked the right pickups (aesthetically) for it. Don't forget to fret the fingerboard.

Just to throw another option out there... Someone shared this recipe with me. (scroll down to reply #15) http://www.el34world.com/Forum/yabb2/nph-Y...?num=1168216998 Advantages: 1) cheap 2) no special equipment needed 3) neck is nice and fast Disadvantage--doesn't seem very durable compared to a factory spray-on lacquer finish.

Hey, gotta watch that margin. Hm, I've never heard of S.B. Guitars.

I just screwed mine in.

That's pretty much a universal saying that's been used throughout the galaxy since the 1960s. Hm. I was only a twinkle in the ol' captain's eye back then. Sorry... I thought he was making a mean comment. I used to watch Next Generation when I was like 4... that would be 1990...

I don't get it.

Wow, sweet spalt. What kind of wood is that?