Australian/New Zealand Luthiers Forum

The guitar has been settling in for a few days - and the top is visibly less arched. I guess this means my bracing was not stiff enough... Sounds really good though! I intend to stiffen the back when I get back to the shop next week - and to work on my Chladni testing gear. I don't intend to take th...

I'm getting frustrated now. In the quiet comfort of my studio I set up VA to do another tap test.... and got 90, 165, 210 Falcate studio tap 230g.jpg Which hints that I didn't need to add 230g side mass. I may be getting clean tap spectra, but the inconsistency is annoying. I was playing around with...

It has become apparent that I need to set up a Chladni testing environment.... I found Trevor's detailed description of his DIY Sig gen/amp unit but wondered if I could make a unit based on the Luthier Lab android app I mentioned above. To this end I've just ordered a Bluetooth Amplifier board rated...

So.... Set up is pretty much there. Intonation is a little sharp, which is disappointing - I'll get on to that later. Here is the tap test on VA - 90, 173, 209 Falcate spectrum 11May.jpg I decided to add 230g side mass to shift T(1,1)2 and got this result - 90, 169, 208 Falcate spectrum 11 may 230g ...

I did struggle with setting up Visual Analyser at first but once I'd got the sample size and buffers right it works pretty well. So it must be my gear... I use an AKG D5 vocal mike on a boom mic stand (playing in a band helps!). This is connected to the laptop PC via a Yamaha AG06 mini mixer, so I'm...

Thanks John Intonation is very close to perfect - but I'm letting her settle down for a few more days before I refine the saddle and action. I'll update you then! If anything the sound was best with the side masses attached, but she was a hefty handful to say the least. And the wide fingerboard and ...

Thanks for your comments John & Dave I've read and re-read my grubby first edition so many times and have made 5 different (4 X-brace) guitars using the techniques. Somehow I missed the bit about reading the resonances under tension. It's certainly not in section 22.3. And I don't recall seeing anyw...

I haven't posted for some time but follow developments with keen interest. I've finally got round to making a TG falcate guitar (I was put off by epoxy and CF!) and followed the books and drawings faithfully, apart from a 25½" scale length. The specs are: Spruce English Walnut Wenge fingerboard Burr...

Trevor suggested I post some pictures of my latest build here. I have been inspired by 'the book' and it has made a huge difference to the quality and, most importantly, the tone of my builds. This parlour size guitar was designed with my customer involved at every step, which was inspiring. I don't...

Hi Trevor & All Time passes..... and the parlour guitar is finally there! I dimensioned the cocobolo back to 2mm as you suggested and did not scallop the brace. The body size is 485 X 355mm. The spectrogram is quite nice with T(1,1)1 at 112Hz and T(1,1)2 at 195Hz (I plan to work it down to 190Hz). H...

I was holding the plate at about 35% and tapping in the centre widthways.... ECross= 0.73GPa at 115.4Hz (.54GPa at 100Hz) I'm actually after a fairly conventional tonality so I'll leave f at 75. The back and sides are to be cocobolo, which is amazingly heavy! And unfortunately the set I have cannot ...

Thanks as always Trevor for the thorough reply! After posting I actually revisited tap testing my top and am still getting an ambiguous reading for the cross grain vibration. I've attached a spectrum which shows the challenge - 3 peaks! Punching the 3 values into the calculator gives me 2.72 (46Hz),...

Hi Everyone Just getting round to making a parlour guitar (finally) using Trevor's equations. I'm a little nervous about the dimension I got from the equations - 2.45mm seems awfully thin to me. I've attached a jpg of the input data to the spreadsheet with the output. The calculator has been fully t...

Thanks for the responses! I was very happy with the T(1,1)1 and T(1,1)2 at 95Hz and 169Hz prior to stiffening the back. 195 for T(1,1)3 was the challenge - I actually braced the back with 3/8" spruce so she came out more flexible than planned. As I mentioned, I did bolt on 70g of lead mass to get to...

I've recently completed my 7 string (Roger McGuinn style) dreadnought guitar - she's X braced with a live back and has been constructed using many of the principles in Trevor's book. http://www.martinsguitars.co.uk/MGR/Images/Mark/View.jpg The plates were thicknessed according to the formulae in the...

I promised an update on string up. The intonation formulae seem to have worked perfectly! I am working on a few resonance 'challenges' (I'll post on that in a few minutes as I'd appreciate advice...) but the guitar appears to be in tune on every fret on every string - she sounds lovely! http://www.m...

I''l be tackling the resonances when I enter the real world! I'll update you all when I string the baby up. By the way, the bundled solver in Excel will optimise this problem. I tried out the 'Premium' solver as I thought it might be where I was having trouble.... needless to say it was my design th...

It's been a journey, Trevor! I suppose we all expect the string to be longer than scale to compensate for the increase in tension from fretting and because all the commercially available intonation products (Buzz Feiten & Earvana) are made for the retro fit market. But for new builds we can shift th...

Trevor Intrigued by your comments about finding a geometry that works and then building it, I found the following... Scale: 647.7 (25.5") Body Join: 14 Frets: 20 Measured relief (at 7th): 0.1mm Finger pressure: 85% Alpha: 0.7 6th String action at 12th: 2.2mm Nut to tuner length: 0 String data: Mu = ...

On the de-bugging - lots of subtle things; not really errors (although there were a few bloopers). A few observations: It's important to keep in mind that the tension of the string is dynamic - that is when the model recalculates the string length including compensation then you need to recompute th...

Well after many hours of de-bugging I seem to be getting rational answers from my intonation model - which is great. But I've just checked the pricing of the premium solver I mentioned - US$895 :shock: Back to the drawing board.... I may need to redesign the spreadsheet so that the bundled solver wi...

Thanks Trevor I tackled the spreadsheet before building the test rig so I had already used the D'Addario tension chart and Young's Modulus.... so that means I have a coding error! My model keeps giving me very small nut compensation (if I let it!). It seems to me the most significant deflection is t...

Hi What an inspirational book! I've constructed a spreadsheet in Excel to calculate the compensation for nut & saddle and am using the premium solver ( http://www.solver.com/exceluse.htm ) to minimise the intonation error. However, I'm getting results that are not in the same ball park as the exampl...