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Post by newey on Dec 22, 2019 15:46:01 GMT -5
I assume this one would be solid state. But . . .
If memory serves me, a number of years ago we had a guy who was asking about building a battery-powered tube amp, using some Soviet-era miniature tubes. Might be some ideas in there for you.
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Post by thetragichero on Dec 22, 2019 16:02:25 GMT -5
battery-powered will definitely be solid state. I looking to use the mosfets in some cd4007 cmos chips for the preamp (haven't sussed out what exactly, but I've downloaded a few schematics that use em to draw inspiration from) no weird obscure tubes for me. i try to only work with easy to find stuff (the tube amp can be quite happy using a 12au7 for the power amp but since i have the 12bh7 "super 12au7" i might as well use it. i may make one off projects using some weird/old semiconductor i pulled from an organ but i prefer to use common stuff like 2n5088/2n5087 so that the people can copy what i did and play along at home
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Post by newey on Dec 22, 2019 16:08:27 GMT -5
Not sure, memory may be failing me, but it may have been this thread I was thinking of, which concerns a building a mini-tube onboard preamp,not a power amp guitarnuts2.proboards.com/thread/4775
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Post by thetragichero on Dec 23, 2019 2:45:41 GMT -5
wired up the tube sockets, artificial center tap for the heaters, output jack. intended to wire up the mains switch and indicator led but the brake caliper paint i used on the bracket must've been painted on too thick because three days later it still wasn't dry. buzzed it all off and hit it again with etching primer. will get some gold rattle can paint and hit it with that. afterwards it's volume, tone, nfb switch, and input jack and i think she's done. gotta figure out a way to keep the lid from fully opening to keep everything where i placed it I'm happy where I've ended it today bedtime
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Post by thetragichero on Dec 31, 2019 19:58:27 GMT -5
dukane intercom gets a nice bright red coat of paint. got it from the auto parts store, it's meant for brake calipers so I'm hoping it'll be durable. I've got a nice red tolex so this'll get a matching 2x10 cabinet (I've got a couple 10" Alnico organ pull speakers) this will be a take on the trainwreck express. switchable tube or solid state rectifier. since I'll have a spare triode i may throw in an effects loop
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Post by thetragichero on Jan 1, 2020 14:21:01 GMT -5
should've known better at the store when a brush on oil based paint was suggested. to thick too dry or level out and i couldn't get it to come off with heat, scraping, chemicals so i had my first emotional breakdown of the decade and set it on fire happy new year!
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Post by sumgai on Jan 1, 2020 19:35:06 GMT -5
trag,
I think you just found some of those 2v resistors you've been looking for in your signature!
Seriously, sometimes the most opportune things come out of the least likely places/events/etc. I'm betting that you couldn't get the fire hot enough to actually melt the metal chassis and thus distort it, so tell us.... did the paint finally come off so you can start over?
sumgai
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Post by thetragichero on Jan 1, 2020 22:34:33 GMT -5
yup! paint mostly turned to soot so 95% of it came off first pass with the wire brush attached to my drill press. hit with etching primer and duracolor spray paint. need to figure out control locations to label them with waterslide decals and then hit with clear poly. THEN i can finally start wiring 'er up! purchased 1x10 common pine(sides), 1/2 bcx ply (for baffles. not worried about void free ply since the back will be covered with tolex and the front will mostly be speakers and bracing), 1x2 poplar (for bracing), 1/4 oak dowel (for attaching bracing, etc) for the cabinet. 2x10 sealed back (Fisher brand Alnico organ pull speakers) 14x24x10 (well, whatever dimension the 1x10 is... 9 1/2 or something). plan is for a vertical "piggyback" configuration. I'm gonna try mitered butt joints with dowels and bracing for stability. i didn't like how my router table cut the end grain with the regular butt joint 2x12 (which is still sitting undone... used too small of a router bit on the edges for the corners i have so i have to do them again) also bought white paint for the as of yet in the works Hammond ao-43 chassis. will be using blue tolex so i figure the white chassis will look dope
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Post by sumgai on Jan 2, 2020 0:43:56 GMT -5
trag, I'm gonna let you build the cabinet the way you want/described. But please take lots of pictures, and post them when you're done. Joinery is a fine art unto itself and should not be shortcutted, particularly when an assembly is intended to be both portable and subjected to less-than-friendly forces. Do recall that a box joint is all Leo ever used on every amp/cab ever made with his name on it. YouTube videos aboond that show how to use a table saw for making box joints. Fast, simple, easy, and repeatable - what's not to like? Here's an example, a short one. But there are plenty of others on YT that get really carried away, if that's your cup o' tea. BTW, this young lady has more than one video on building guitars, might wanna check out that bit, too. HTH sumgai
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Post by thetragichero on Jan 2, 2020 11:04:20 GMT -5
much better. gotta figure out what i need to fill up a full sheet if waterslide decals. I'm no good at this planning ahead thing. 's why i have a fully cult amp chassis i didn't clearcoat (so there's some rust spots that need handling) and labeling (will use some of the waterslide for that)
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Post by sumgai on Jan 2, 2020 11:42:49 GMT -5
..... gotta figure out what i need to fill up a full sheet if waterslide decals. Did I mention that the same YL as in the Box Joint video also has a vid on waterslide decals? She did the job for her own guitar, and she makes it look easy. Try her channel. HTH sumgai
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Post by reTrEaD on Jan 2, 2020 13:02:16 GMT -5
..... gotta figure out what i need to fill up a full sheet if waterslide decals. Did I mention that the same YL as in the Box Joint video also has a vid on waterslide decals? She did the job for her own guitar, and she makes it look easy. Try her channel. HTH sumgai I looked at her channel yesterday after you posted the finger joint video. She made two guitars, one for herself ... a Tele with a hexagon overlay on the body for herself and another for her son. Kit stuff, but with lots of her own personal touches. I admire the way she thinks. Creating jigs and using 'non-ruler' measurement processes. Much like Tom Silva of This Old House.
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Post by newey on Jan 2, 2020 17:04:34 GMT -5
As for using a whole sheet of waterslide decal paper, I just make duplicates for future projects. I have whole sheets of "Newey Guitars" headstock decals. But I doubt these things will last forever, some of my sheets must be a dozen years old by now, they may well be too old to still slide off in one piece.
But, at the rate you're cranking out amp projects, a whole sheet of "Volume", "Bass", "Treble" etc/ labels may not last very long.
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Post by sumgai on Jan 2, 2020 21:01:03 GMT -5
I looked at her channel yesterday after you posted the finger joint video. She made two guitars, one for herself ... a Tele with a hexagon overlay on the body for herself and another for her son. Kit stuff, but with lots of her own personal touches. I admire the way she thinks. Creating jigs and using 'non-ruler' measurement processes. Much like Tom Silva of This Old House. Ah, I knew she was channeling someone I'd seen a long time ago. I like her manner of presentation, but sometimes she assumes a lot about the viewer's level of competence/experience. Nonetheless, she keeps it short and sweet, and that's almost never a bad thing. ;D
sumgai
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Post by blademaster2 on Jan 2, 2020 22:03:13 GMT -5
In my ongoing research I decided to perform the best comparison I could between solid body guitar woods. I will refrain from calling this a 'tonewood' comparison, although that is essentially what this is. To do it with the fewest other factors that I could manage I did the following experiment: Similarities:- I installed Seymour Duncan SSL-1 pickups, each mounted into a neck-position humbucker mounting ring, into two solidbody guitars - Both guitars had pickup heights set to the same distance from the strings and very close in position along the string length - Both have Fender-style bridges, hard-tail mounted - Both have set necks - Both have rosewood fingerboards of the same density and of the same scale length - The electronics of the two guitars is of the same design. - Both had the same string gauges installed, and are (reasonably) new. - Both guitars are between 35-40 years old, so their relative aging/drying are pretty similar Differences:- One guitar is made from walnut and the other from birdseye maple. (Edit: the body shapes are different, of course, but the body thicknesses are approximately the same in the vicinity of the strings and pickups) Missing investigation:I never took the volume up such that the sound from the amplifier made a noticeable impact on the guitar response (I would love to, but neighbours may object). One slight headache was the need to deepen the pickup route for one of the guitars. I do not think I could perform a more controlled experiment (although I did not electrically measure and compare the two SSL-1 pickups as I assume that their manufacturing processes will bring them pretty close to each other in that regard). Results:- I would never expect to 'see' a difference if an oscilloscope or spectrometer was used (heck, I could not tell if a 'scope trace showed a guitar or a piano), so I never even tried that although I do own an oscilloscope. I rely on hearing and feel, over many minutes of playing. - I played both guitars through the same amplifier, same cable, same volume and tone settings, alternating between them. There *are* differences in tone, mostly on the attack, but they are subtle. I would say that they had very different 'personalities'in their tone, and I would be inspired differently when playing them. - The SSL-1 provided roughly the same glassy brilliant high frequencies for both guitars, but the slightly lower frequencies from those highs were stronger on the maple body than on the walnut body. - The maple body gave more crisp edge on the attack, whereas I heard a warmer smoother tone from the walnut guitar. If someone else was playing or if this was played through different amplifiers and different settings I might not hear these differences, but I am convinced that they were there in my comparison. Conclusions:This strengthens my belief that the body wood makes a difference even in solid body guitars, but this result also tells me that some opinions of 'cork-sniffing' enthusiasts may not be warranted. This difference is subtle, but I find it important in how I play and respond to the guitar. Nonetheless I would never try to tell people what they hear. This is my own finding, and others might have heard it differently (I would like to get other players to compare these same two instruments).
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Post by thetragichero on Jan 3, 2020 13:21:25 GMT -5
i used to do it for 12/13 hours per day but hell for me is sitting in front of a computer filling up a decal sheet. should get several amps, cabs, stomp boxes out of this but man would i love to be testing out the peavey power amp i repaired (besides the burning guy had 12ax7 in the 12at7 driver spots so the 12at7s i ordered came in. all I'm waiting for for that is the weirdo peavey "spider" pot to replace the one with the broken shaft)
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Post by newey on Jan 3, 2020 13:34:58 GMT -5
blademaster2- They are also different shapes, as per your photos. Nice-looking guitars, BTW . I don't know if the difference invalidates your findings, but the argument could certainly be made that a different shape would resonate differently.
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Post by blademaster2 on Jan 3, 2020 14:19:39 GMT -5
Thanks!
Well, for an after-the-fact experiment I did not have the same body shape at my disposal but you make a valid point (especially at elevated volumes). Other than that, this was the most controlled experiment I can perform.
My sense is that beyond a limited 'penetration depth' the resonance due to the shape of the body outline will have decreasing effect and it will be mostly influenced by density and other material properties closer to the string and pickup anchor locations. However at elevated volumes I can easily imagine resonances of the various wings/protrusions bringing in something to add to the string vibrations. Then the pickups will sense any relative motion between their mounting point and the strings and this will be present there as well, which is why wood properties can have an effect (small in this case, but present nonetheless to my ears).
To be honest, I was a little surprised that I did not hear more difference than I did between the two, and I think this might be partly due to the brilliance of the SSL-1 pickups dominating the tone I heard. I also used my AMPEG V4 amplifier for this comparison, since it is the least "colouring" amp that I have and itself has a very clean high frequency response.
When I play either of these guitars I can feel the body surfaces vibrating in my hands, so by reciprocity these same surfaces must also couple the sound back into the bridge/pickups and strings. I *so* wish I could have cranked it up as part of the experiment (maybe I will someday).
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Post by reTrEaD on Jan 3, 2020 14:35:05 GMT -5
Well, for an after-the-fact experiment I did not have the same body shape at my disposal but you make a valid point (especially at elevated volumes). Other than that, this was the most controlled experiment I can perform. In my estimation, the shape of the body would have some effect but other factors would have more impact. Thickness could be a significant factor. Total area could be a significant factor. I would expect the area, depth and location of routings such as control cavities could be a significant factor. It seems like your experiment wasn't perfect but the use of identical necks, pickups, etc, was a good plan. The area of the bodies look slightly different. The maple body looks somewhat larger. But I wouldn't expect that to be a huge factor. I don't know about the thickness. If they were reasonably similar, I'd say close enough. Likewise the routings are probably close enough.
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Post by blademaster2 on Jan 3, 2020 15:12:32 GMT -5
True, and thickness is hard to assess because - although it is blocked because I never use it - there is a route on the back of the maple guitar for a fender-style whammy, which reduces the thickness there beneath the pickups. The body of the maple guitar is actually thicker but locally this brings it down to be probably the same or thinner in that region.
Without building the guitars in advance with this experiment in mind and with the exact same body design I had no other option there. Still, I do feel that the penetration depth for many higher frequencies would be limited and have diminishing effect as you get farther away from the bridge and pickups (and yet, since I can feel the resonance, there is a significant amount of vibration propagating to the outside surfaces across a good amount of the range).
Dunno - I will remain a student of this stuff and I will never claim to be a master.
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Post by thetragichero on Jan 3, 2020 19:11:52 GMT -5
let these dry and hit with acrylic clear, then a ton of poly. red one is based off the trainwreck express pdf earlier in the thread. 10 dpdt switches on the front so all sorts of mod options. tube/solidstate rectifier switch will be somewhere inside the top of the chassis near the tubes. thought about putting it as one of the options but i feel a lot more comfortable using a big horkin mains switch for that much voltage
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Post by thetragichero on Jan 7, 2020 13:42:50 GMT -5
after sounding Sunday overnight volunteering assy a cold night shelter with nothing to do besides research and get stuff down on paper, i finally got started last night on my jcm800-inspired 18watt build! bright channel is standard jcm800 first input stage, normal channel is jmp bass amp input stage. independent volumes meet at cold clipper stage. using a paralleled 12au7 cathode follower before the tone stack which is close to a standard James tone stack with another capacitor and a pot setup as a rheostat in parallel with the 330pf cap on the treble side as a mid boost control (so while technically it's a tmb tone stack its much more useful in my opinion). 12at7 ltpi into cathode-biased el84 with a big horkin cathode bypass cap (1000uf.... only because i didn't have a 220ish cap on hand) to give a bit more of a fixed bias sound. since this is higher gain than my last build i am being extra strict with my star ground points and i referenced the heater center tap to the power tube cathodes instead of ground like everything i build this will happen slowly. i find it super relaxing this is the third pair of pyle driver speakers I've pulled from lowery organs and they all have completely rotted out surrounds. this is the first poly cone pair I've gotten and i ended up finding a good deal on hemp (vs foam) surrounds from pmr/hempopotamus speakers so that's what these got dead voice coil on one of the stock eminence alnicos that came in this acoustic 105 cabinet i picked up in South Amboy, nj that the previous owner stenciled "mule" on caused me to temporarily replace it with a celestion speaker (was the only 16ohm speaker on hand, had to pull it from a 1x12 cabinet) so now this is getting fitted with pyles (i replaced the dust caps on the paper cone + foam surrounds with something smaller hoping to coax a bit more highs from them), but first some insulation had the speakers in, did a quick check with my multimeter and it showed a dead short. dumb dumb wired them wrong. but this is why i ALWAYS CHECK WITH A MULTIMETER. an extra ten minutes is a lot better then finding out it's wired wrong because my output transformer or in this case output transistors let out magic smoke from being essentially shorted to ground sounds great! i have enough treble available if i want it and a ton of midrange, which is what I'm after with my bass tones. this is technically a guitar cabinet and i intend it to serve double duty now to swap around speakers in some combos
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Post by thetragichero on Jan 9, 2020 12:33:19 GMT -5
last night started heater wiring, figured out power supply node dropping resistors, started wiring first two preamp tube sockets. unsure whether i want to use the stock Marshall 10k cathode resistor or go for the soldano 39k. maybe a fixed resistor in series with a trim pot. i should be able to keep most of the components on the tube sockets so I'll use a minimal amount of terminal strips for a very minimalist layout. all new capacitors but the majority of the resistors (besides the 2W+) are salvaged but tested good if i were using all new i could probably do some neat sano-style tidy component placement but i kinda like the chaos I'm really liking the trimpot idea for the cold clipper. will have to do some calculating tonight also finishing up the clear coats over my labeling on the dukane intercom. still have to cut a metal plate for the back (jacks and power connectors) along with one for the logo to replace the front speaker
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Post by thetragichero on Jan 10, 2020 1:53:52 GMT -5
input jacks including a center jack that sends to both channels. star ground point for input and first preamp tube and tied to second tube ground point. got my trim pot for marshall-to-soldano cold clipper stage, just mounted it on the back panel. not ideal spot because it's between v3 and v4 instead of v2 but it's a convenient and secure spot so I'll have to live with it also used some big hole perf to make the first filter stage for the trainwreck build. that'll show up later when I'm working on it
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Post by thetragichero on Jan 14, 2020 0:53:55 GMT -5
last night i tore apart my old Marshall dual super lead. when it was working it just wasn't my thing and between it stopping working (no sound from preamp, which happened every once in awhile since i got it until it was permanent) and poorly done mods on my part (first amp i attempted to work on. all the pcbs and ribbon cables and whatnot were quite a foil for my i'ma-do-it attitude and heavy hand with a weller 100w gun), along with known bias issues.... anyway, i recently dismantled an old hp test oscillator and decided the big horkin power transformer would suit my bass amp build smashingly. had to slightly cut the chassis tho make it fit. figured out where the choke will fit. obviously drilling will commence tomorrow received partial payment for the peavey repair in pedals. already sold one to purchase the jj kt77 power tubes for this build
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Post by thetragichero on Jan 14, 2020 13:23:45 GMT -5
after fighting with duncan's wonderful PSU designer all morning, i'm going to use the choke that came out of the test oscillator as it has twice the DCR of the jcm800 replacement choke i had on hand. at almost 600v unloaded b+ that extra ~10v voltage drop might just save the screens of the jj kt77 i've ordered. max screen voltage per the data sheet is listed at 600v but the further under it i go the better in my book glad to have these wonderful tools as figuring out the maths on paper or (much more my style) trial and error would prove friggin frustrating
about to ride my bike to the hardware store for more chassis screws/lock nuts. way cheaper than from one of the electronics suppliers
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Post by thetragichero on Jan 16, 2020 1:00:36 GMT -5
first three preamp stages (save for volume and tone controls... ordered pots earlier today). also did a bunch of work on the Marshall chassis, cleaning it up before paint, and making adjustments for a can cap and choke
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Post by thetragichero on Jan 16, 2020 11:58:50 GMT -5
cut chassis for choke, filter cap, sanded corrosion, hit with rattle can paint put back together. time tho affix waterslide decals
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Post by thetragichero on Jan 16, 2020 12:49:56 GMT -5
waterslide decals applied. big mouser shipment coming tomorrow. finally will have pots to build these amps!
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Post by thetragichero on Jan 20, 2020 0:51:14 GMT -5
my order with pots, metal oxide resistors, and safety capacitors came Friday but we have been busy since then. with a 7am call time Sundays are a long day so count my surprise when i ended up with all of the pots wired. preamp is done just need to dob phase inverter, power amp, mains wiring oh and build a head cabinet and figure out if i pair this with 1x15 or 2x12. and then build that lol but progress!
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