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Post by thetragichero on Aug 4, 2021 2:52:58 GMT -5
started as a commissioned build for the fella i made the mini plexi for but her never made the deposit and i already ordered the few parts i didn't have along with pink tolex so i figured i might as well build it transformers are from a bogen chb35 pa amp. new steel chassis (should be fun to tool eh?) here's the rectifier, filter cap (besides a couple can caps and one on the main board), and bias board eyelet board with caps hot glued in place. will add resistors (and the couple ceramics) and tack solder until ready to install
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Post by thetragichero on Aug 4, 2021 21:28:51 GMT -5
got the board together and tack soldered where needed. you can see my mdf template above it first stage filter cap is on the board because i ran out of room on the filter cap board (pragmatism rather than an over design choice). almost all metal oxide resistors (after watching film resistors in a sick amp glow and then give up smoke i prefer the durability of 1w 2w 3w metal oxide) besides the phase inverter plate resistors (likely the best place for carbon composition mojo if it exists) and bright channel cathode resistor (you can tell I've been more fender-focused because i have a TON of 1k5 resistors but very few 2k7... the carbon comp here shouldn't add appreciable noise). always metal film for input stage grid and grid super resistors, but those go directly on input jack/tube sockets respectively now that the fun part (in my opinion) is over, it'll be awhile until this progresses more (need to whip up front and back plate graphics and send em off to the local trophy shop to be made and also start cutting and drilling the chassis. rip my drill bits
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Post by thetragichero on Aug 17, 2021 22:17:15 GMT -5
worked up front and back panels. the white will be bare metal. pink tolex with purple knobs besides red master volume knob and a pink led. this is going to be obnoxious in the most wonderful way still need to work up a name badge for the headshell
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Post by unreg on Aug 19, 2021 12:05:44 GMT -5
worked up front and back panels. the white will be bare metal. pink tolex with purple knobs besides red master volume knob and a pink led. You have a pretty design idea; great job on the graphics thetragichero! 😀
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Post by gckelloch on Aug 20, 2021 2:18:18 GMT -5
got the board together and tack soldered where needed. you can see my mdf template above it first stage filter cap is on the board because i ran out of room on the filter cap board (pragmatism rather than an over design choice). almost all metal oxide resistors (after watching film resistors in a sick amp glow and then give up smoke i prefer the durability of 1w 2w 3w metal oxide) besides the phase inverter plate resistors (likely the best place for carbon composition mojo if it exists) and bright channel cathode resistor (you can tell I've been more fender-focused because i have a TON of 1k5 resistors but very few 2k7... the carbon comp here shouldn't add appreciable noise). always metal film for input stage grid and grid super resistors, but those go directly on input jack/tube sockets respectively now that the fun part (in my opinion) is over, it'll be awhile until this progresses more (need to whip up front and back plate graphics and send em off to the local trophy shop to be made and also start cutting and drilling the chassis. rip my drill bits Can't find it now, but I did see the results of a study that showed Carbon resistors generate more noise, but they also reduce odd harmonic generation in the signal path of gain stages.
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col
format tables
Posts: 464
Likes: 24
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Post by col on Aug 20, 2021 6:52:00 GMT -5
Can't find it now, but I did see the results of a study that showed Carbon resistors generate more noise, but they also reduce odd harmonic generation in the signal path of gain stages. It all sounds a bit 'tone wood' to me, but I easily could be wrong about that. I did perform a quick search and came up with this Q&A article which seems relevant: www.aikenamps.com/index.php/technical-q-a
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Post by thetragichero on Aug 20, 2021 12:06:31 GMT -5
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Post by gckelloch on Aug 21, 2021 23:23:39 GMT -5
Can't find it now, but I did see the results of a study that showed Carbon resistors generate more noise, but they also reduce odd harmonic generation in the signal path of gain stages. It all sounds a bit 'tone wood' to me, but I easily could be wrong about that. I did perform a quick search and came up with this Q&A article which seems relevant: www.aikenamps.com/index.php/technical-q-aI thought it was BS myself until I found that comparison analysis I can't seem to find again. Other studies show that Carbon comp resistors exhibit more thermal nonlinearity than Metal, etc. A resistor that distorts more gradually will start to generate the 2nd harmonic more readily than the higher-order harmonics, and would then push the even harmonics in subsequent stages. That might explain why odd harmonics are less prevalent. Incidentally, the "tone wood" debates stem from a fundamental misunderstanding of what is transduced through a guitar pickup. The guitar is essentially a complex damping system. Whatever is lost through damping or resonance in the guitar is drained from the string. Different wood types have general characteristics that influence string energy loss, mostly through the neck end rather than through a thick metal bridge. A lightweight Swamp Ash body will damp differently than something heavy and tight-grained like Rock Maple. Ken Parker describes how some woods "fight themselves" more than others. He actually used rock Maple as an example that fights itself more than Mahogany. I guess it's a simple way of explaining the effect of lower-elasticity/higher-damping. Of course, every piece of wood is different.
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Post by thetragichero on Aug 22, 2021 2:51:26 GMT -5
i'm pretty agnostic when it comes to components. i like metal oxide because they're fairly cheap and quiet and available in 2w ratings with nice thick leads. i usually save the carbon comps for my 'mojo' pedal builds because many guitarists 'hear' with their eyes and dig that kinda thang. i've been building up my supply of a few values of 1w carbon films, mainly because it cost less to purchase 100 of em than it would for 20 lol. but yeah mostly pragmatism is what drive my choices (well that and i like the way the silver mod electro caps look and they're not much more expensive than the standard axial electro caps)
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Post by gckelloch on Aug 23, 2021 17:59:27 GMT -5
i'm pretty agnostic when it comes to components. i like metal oxide because they're fairly cheap and quiet and available in 2w ratings with nice thick leads. i usually save the carbon comps for my 'mojo' pedal builds because many guitarists 'hear' with their eyes and dig that kinda thang. i've been building up my supply of a few values of 1w carbon films, mainly because it cost less to purchase 100 of em than it would for 20 lol. but yeah mostly pragmatism is what drive my choices (well that and i like the way the silver mod electro caps look and they're not much more expensive than the standard axial electro caps) That makes sense because why would anyone want resistor distortion when there are tubes or other components that break up more smoothly and have some "weight"?
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Post by solderburn on Aug 28, 2021 23:19:44 GMT -5
I'm really looking forward to seeing the end result of this one! Sounds like a cool design, both practicals and cosmetics.
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