RankStranger Posted March 8 Posted March 8 16 minutes ago, aussievintage said: I always do my own setup. I learnt what I like while making my own guitars, so I have a feel for what can be done and how it will turn out, while trying a guitar in a shop. As this is a DIY thread, I will mention that I think anyone into playing should learn the basic setup and acquire the few tools needed. Most end up being able to do the basics, like bridge/nut height, intonation and truss rod adjustment. It's good to also be able to level/dress/polish frets, Make a new nut, or adjust the slots in an existing one, etc. Unless you can speak to the luthier, it's the only way to get it just the way you like it. Besides, if you change string gauge, for example, it needs to be setup again. You can get tool kits from Amazon. I used to do all mine, not out of any devotion to the craft but because I could only afford cheap gear and a couple hours work could make a $250 guitar sound convincingly like a $400 guitar, at least until the humidity changed and it forgot it wasn’t still a tree at one point I was considering getting into making guitars as a job then I met a guy who worked at the maton factory that put me off (something like you’re sold the idea that you’re part of this rich history but you’re just an underpaid factory worker). I made some cursed Frankenstein mods to some cheap gear and incorporated stuff into my work for my sculpture degree then kind of lost interest, mostly I made a few of my own effects pedals, too, just working from cheap kits and old electronics books my dad found me. I never knew what I was doing so I could only ever use them for what we affectionately termed the "f*** s*** up" sections of our "songs" 1
RankStranger Posted March 9 Posted March 9 Just by coincidence, I’ve got this on the bench right now I picked it up for free off gumtree on Boxing Day a couple years back. Some kid had got it for Xmas and killed it dead on the same day, poor bugger my kid is talking about guitar lessons so I dug it out to see what I could make of it. Pretty clean break with some long grain for the glue to take so I’m optimistic about its chances. I’m In it for less than $50 for parts including new strings so if it doesn’t work out it’s not the end of the world 2
aussievintage Posted March 9 Posted March 9 7 minutes ago, RankStranger said: Just by coincidence, I’ve got this on the bench right now I picked it up for free off gumtree on Boxing Day a couple years back. Some kid had got it for Xmas and killed it dead on the same day, poor bugger my kid is talking about guitar lessons so I dug it out to see what I could make of it. Pretty clean break with some long grain for the glue to take so I’m optimistic about its chances. I’m In it for less than $50 for parts including new strings so if it doesn’t work out it’s not the end of the world If it seems a bit weak you can route a couple of slots in from the back, across the break, and glue insome thin pieces of wood. I have seen that done on a broken Ovation neck, and it has held for 40 years . 1
RankStranger Posted March 9 Posted March 9 7 minutes ago, aussievintage said: If it seems a bit weak you can route a couple of slots in from the back, across the break, and glue insome thin pieces of wood. I have seen that done on a broken Ovation neck, and it has held for 40 years . Yep, splines are plan b quite a bit of surface area in the break so hoping it won’t be necessary. And my 13yo won’t be doing any international touring for a while so it shouldn’t have too hard a life 1
playdough Posted March 10 Posted March 10 Gday Speaker build became a little easier as a Dayton DATs V3 has been added to the test gear. For fun and harvest of speaker driver electric and mechanical small parameters. Actual measurement numbers can be added to Win ISD speaker box simulator., which is the next part of the project. Compression drivers are a little tricky to measure and seem to need an acoustic load to measure properly, someone else might know about this. The graph shows the sub, bass, mid and tweeter drivers for a project speaker set (4 way) that is moving along into woodwork, with these measurements. 2
playdough Posted March 10 Posted March 10 (edited) To add, photo of the graph depicts 6 drivers over laying for comparison. Impedance and phase, log scale. Comparison verifies the pairs of drivers are very close to being perfect matches. Was a little concerned the cheaper drivers may have been, well meh,,, but no they are all good/reasonable. Easier to test than try decipher some of the Manufacturer Specs. Moving to simulation, at this point, measured 12 drivers in total as well as the venerable B&C 464 coaxial compression drivers.. Very handy also for working out what frequency range each driver is best capable of and what the target crossovers may well be, also little resonances that show in bumps/wiggles that will effect actual response. Edited March 10 by playdough 2
MarcAL Posted March 11 Posted March 11 9 hours ago, playdough said: Gday Speaker build became a little easier as a Dayton DATs V3 has been added to the test gear. For fun and harvest of speaker driver electric and mechanical small parameters. Actual measurement numbers can be added to Win ISD speaker box simulator., which is the next part of the project. Compression drivers are a little tricky to measure and seem to need an acoustic load to measure properly, someone else might know about this. The graph shows the sub, bass, mid and tweeter drivers for a project speaker set (4 way) that is moving along into woodwork, with these measurements. Yes, you are correct about adding an acoustic load to a compression driver. Definitely use a high pass filter such as a small decent quality capacitor (the value is based on the drivers impedance and expected frequency response) or use a band limited amplifier to avoid any over-excursion of the drivers diaphragm. 1
playdough Posted March 11 Posted March 11 2 hours ago, MarcAL said: Yes, you are correct about adding an acoustic load to a compression driver. Definitely use a high pass filter such as a small decent quality capacitor (the value is based on the drivers impedance and expected frequency response) or use a band limited amplifier to avoid any over-excursion of the drivers diaphragm. Hi MarcAL Thanks thought that was the case with the highly resonant peaks, wild changes in impedance across the graph with both the mid range and high range coils I run another sweep with my hand cupped over the driver aperture, which looked better, not saved. Measurement is of the B&C 464, both diaphragms. Guess it’s about time I put it on a horn, set up the amps as you suggest, filter in place and test with a mic in REW. Simulations of the other drivers going well. 1
MarcAL Posted March 12 Posted March 12 22 hours ago, playdough said: Hi MarcAL Thanks thought that was the case with the highly resonant peaks, wild changes in impedance across the graph with both the mid range and high range coils I run another sweep with my hand cupped over the driver aperture, which looked better, not saved. Measurement is of the B&C 464, both diaphragms. Guess it’s about time I put it on a horn, set up the amps as you suggest, filter in place and test with a mic in REW. Simulations of the other drivers going well. Yes that is definitely the way to go. Taking a frequency response measurement using the same horn with a calibrated microphone placed 1m away and if possible in the same listening room for all drivers under test will allow you to get a very accurate response in a real world situation. You will know reasonably quick how it will sound before you even start making cabinets. This works for horns but bass drivers is not the same deal. Tuned bass driver cabinets are everything but good software these days make the design job a lot easier. If you have a reasonable sized cabinet already that allows you to tune it as well that will make the job somewhat easier and eliminate guess work. Most of all enjoy learning this art as it does pay off in the end. 1
playdough Posted March 12 Posted March 12 13 hours ago, MarcAL said: Yes that is definitely the way to go. Taking a frequency response measurement using the same horn with a calibrated microphone placed 1m away and if possible in the same listening room for all drivers under test will allow you to get a very accurate response in a real world situation. You will know reasonably quick how it will sound before you even start making cabinets. This works for horns but bass drivers is not the same deal. Tuned bass driver cabinets are everything but good software these days make the design job a lot easier. If you have a reasonable sized cabinet already that allows you to tune it as well that will make the job somewhat easier and eliminate guess work. Most of all enjoy learning this art as it does pay off in the end. Thanks for comments, I have the Azura horn set to start testing and gone through bass enclosure design, although that HF set (B&C coax) for an entirely different bass set up, 2 pairs of 18” drivers in fact. Nothing wrong with testing the horn, it could be a failure at this point as the horn has a lower tuning frequency, we well see. Measurement will tell all. That project is after this smaller system, currently modeling. The 5.25” aluminum ceramic mid range suits a smaller 5 liter box. 5.25” carbon bass driver works well in a 9 liter and finally the 6.5” aluminum bass with 8” passive radiator tuned to resonant frequency of 56Hz before any other tuning in a 10 liter. Baffle step compensation and identification will likely be of most concern after the enclosures are made up. I could go onto enclosures Qtc and tuning frequency’s I guess if there is interest, with the rational behind it. Learning yes ver much so and having the Dayton V3 driver tester has certainly helped enhance the fun factor and less guessing. Photo is of the remote test site where all this is going on,,,,,fresh build lovely quiet place and now with a cement floor ! 1
aussievintage Posted March 12 Posted March 12 8 minutes ago, playdough said: hoto is of the remote test site where all this is going on,,,,,fresh build lovely quiet place and now with a cement floor ! Nice ! 2
playdough Posted March 12 Posted March 12 (edited) 11 minutes ago, aussievintage said: Nice ! It’s on the side of a 45degree angle cliff So set up for testing will be dangerous but fun, have to watch your steps, as the next one might involve, gravity. Being on site, should inbox the Azura horn and have a day with that job. Edited March 12 by playdough 2
aussievintage Posted March 14 Posted March 14 (edited) Just musing over possible future projects. What do people think of these? They are sold all over the usual places, and info suggests they use a basic class A push-pull circuit. https://www.aliexpress.com/item/1005005060091439.html Edited March 14 by aussievintage 2
mwhouston Posted March 15 Posted March 15 7 minutes ago, aussievintage said: Just musing over possible future projects. What do people think of these? They are sold all over the usual places, and info suggests they use a basic class A push-pull circuit. https://www.aliexpress.com/item/1005005060091439.html Looks good. Go for it. The real expense is in the tranni and enclosure but this is a good and cheap start.
mwhouston Posted March 15 Posted March 15 By pushing the idle current to max you will get more Class A so get a big enough tranni and lots of filtering caps.
VanArn Posted March 15 Posted March 15 6 minutes ago, mwhouston said: By pushing the idle current to max you will get more Class A so get a big enough tranni and lots of filtering caps. Add extensive heat sinking to the requirement list. 2
aussievintage Posted March 15 Posted March 15 22 minutes ago, mwhouston said: Looks good. Go for it. The real expense is in the tranni and enclosure but this is a good and cheap start. I have a big old transformer and power supply I can rework. Thanks 20 minutes ago, mwhouston said: By pushing the idle current to max you will get more Class A so get a big enough tranni and lots of filtering caps. Always 13 minutes ago, VanArn said: Add extensive heat sinking to the requirement list. To be calculated but I may even have a heatsink that will work. Thanks. 1
mwhouston Posted March 15 Posted March 15 9 minutes ago, aussievintage said: I have a big old transformer and power supply I can rework. Thanks Always To be calculated but I may even have a heatsink that will work. Thanks. If it is genuine Class A it will run very hot and particularly if idle C is high. 1
aussievintage Posted March 15 Posted March 15 (edited) Meanwhile, just arrived, this tiny amplifier board. For anyone who has to squeeze an amp into a small space... Not bad for $1.98 Edited March 15 by aussievintage 2
mwhouston Posted March 15 Posted March 15 1 hour ago, aussievintage said: Meanwhile, just arrived, this tiny amplifier board. For anyone who hgas to squeeze an amp into a small space... Not bad for $1.98 Supposedly how many watts into how many ohms. Got a link?
aussievintage Posted March 15 Posted March 15 15 minutes ago, mwhouston said: Supposedly how many watts into how many ohms. Got a link? Says 60 watts on the packet. Check the chips datasheet - TPA3118 https://www.aliexpress.com/item/1005006721527233.html 2
mwhouston Posted March 15 Posted March 15 5 minutes ago, aussievintage said: Says 60 watts on the packet. Check the chips datasheet - TPA3118 https://www.aliexpress.com/item/1005006721527233.html 60W into 4ohms at 10% distortion at a guess. Im always dubious I’d say 15W into 8ohm clean. Doesn’t mean it will not sound OK but what do you want for a few bucks.
mwhouston Posted March 15 Posted March 15 6 minutes ago, mwhouston said: 60W into 4ohms at 10% distortion at a guess. Im always dubious I’d say 15W into 8ohm clean. Doesn’t mean it will not sound OK but what do you want for a few bucks. They do say 60 into 8. Still think a clean 15.
aussievintage Posted March 15 Posted March 15 15 minutes ago, mwhouston said: 60W into 4ohms at 10% distortion at a guess. Im always dubious I’d say 15W into 8ohm clean. Doesn’t mean it will not sound OK but what do you want for a few bucks. Quite. I always derate these things a long way as well, but a 15 watt amp that size is very useful. I bought it as filler for one of those deals where you have to buy three things to get the discount. 2
mwhouston Posted March 15 Posted March 15 3 minutes ago, aussievintage said: Quite. I always derate these things a long way as well, but a 15 watt amp that size is very useful. I bought it as filler for one of those deals where you have to buy three things to get the discount. Well worth it. 1
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