Mike,
Boldly going where angels fear to tread, again?
But! I don’t see any duct tape, ABS, PVC, or especially, blue painters tape. You can’t have your pudding if you don’t use blue painters tape.
Doug
Boldly going where angels fear to tread, again?
But! I don’t see any duct tape, ABS, PVC, or especially, blue painters tape. You can’t have your pudding if you don’t use blue painters tape.
Doug
Springs - we're probably getting old, dear friends
This is also an already discussed topic
#5314 ... i made an attempt on LC1 (on Walter advice),
Look at #2441 -Walter advice - and #2448-2452 drawings+test mockup - my attempt on the B version of Lil Casey at #2470. (+ comments)
c
Quote all you say friend Doug, not only becoming old, but maybe stoned
Blue tape? interesting hint...
This is also an already discussed topic
#5314 ... i made an attempt on LC1 (on Walter advice),
Look at #2441 -Walter advice - and #2448-2452 drawings+test mockup - my attempt on the B version of Lil Casey at #2470. (+ comments)
c
Quote all you say friend Doug, not only becoming old, but maybe stoned
Blue tape? interesting hint...
Blue painters tape, I couldn't live without it. It gets used for all sorts of markups and scratch prevention when machining. it also comes in various widths.
@warrjon
Just a heads up. The side 2 pink noise tracks on the Ultimate Analog Test LP are unreliable. There is a 5 dB dip in the region below 1 kHz. This will not be of concern with the demonstration of the effect of capacitance on the HF peak, but makes the tracks useless for checking overall FR flatness.
https://www.diyaudio.com/community/...est-lp-aapt-1-vs-hfn-001.303100/#post-6089468
I need a technical answer please, is there a difference between the blue painters tape and the green type i use?
If there is, and it warrants it, i will seek out the blue variety, otherwise you will soon see some green painters tape in my constructions, its sure to enhance the sound.
By the way, the variety i have here is Frog tape which i believe will resonate with some builders.
Electrical tape came to hand when wishing to make these modifications temporarily.
And that's become rather useful as so far it doesn't work properly! - maybe i used the wrong width tape.
Components are on order to try to get back on track........
M
Sorry Mike, for some reason I’m not getting this thread pushed to my email anymore. Your new iteration looks excellent I like your design a lot. I glad you posted images of the parallelogram CW mock up as I was intrigued by this from your video a while back. Also, all the information recently about wiring will be invaluable soon as I’m close to getting something which resembles a LTA! Regarding the capacitors mentioned in the RCA leads/DIP box, forgive my ignorance but do these have to be ‘audio’ grade as in the case when I build crossovers?
I also attach progress to the sapphire wheels
S.
Attachments
Hi again Sether, good to see your progress as well.
I have been advised to look for good quality caps with various recommendations including polypropylene which are on order.
The amp designer says;
G0G/ NP0 ceramic are one of the best you'll get. Some people like silvered mica or polystyrene, but you won't hear a difference.
I will update if i make progress!
M
I have been advised to look for good quality caps with various recommendations including polypropylene which are on order.
The amp designer says;
G0G/ NP0 ceramic are one of the best you'll get. Some people like silvered mica or polystyrene, but you won't hear a difference.
I will update if i make progress!
M
Just use MKP or any film capacitor. Capacitors have distortion profiles and film caps have the lowest THD+N.
Mike the difference between blue and green tape is the length of time you can leave it on the surface.
Mike the difference between blue and green tape is the length of time you can leave it on the surface.
I spent some time over the past few days experimenting with loading. Here are the results. I guess the point of this post is to demonstrate you need to verify results as most of these test LP's have some error and quantifying this error as best we can is key to verifiable results. The uncertainty is still quite large because we have no verifiable reference.
Test LP's used
HFN Pink Noise L then R channels modulated
AP Vertical Pink Noise
Vinyl Check Frequency Response sweep 20Hz to 20kHz used to verify cartridge FR, results not shown as I only wrote them on a bit of paper.
None of the Pink Noise tracks were perfectly flat when compared to the VC Frequency sweep. The VC showed FR between 600Hz and 4kHz varied less than 2dB. Which correlates well with the HFN Pink Noise above 1kHz but the AP is off. Note that there was a difference in FR between channels above 4kHz using the HFN which is the tracks on the LP as there was less than 0.5dB difference in levels using the sweep, and there was no difference using the AP vertical Pink Noise.
These are identical loading showing the Left Channel, the only difference is the LP. The tracks are vertically modulated so I would expect the plots to roll off at about 300Hz. But here we're looking at cartridge loading so we're only interested in the plot above 1kHz.
AP test LP
HFN Test LP
Test LP's used
HFN Pink Noise L then R channels modulated
AP Vertical Pink Noise
Vinyl Check Frequency Response sweep 20Hz to 20kHz used to verify cartridge FR, results not shown as I only wrote them on a bit of paper.
None of the Pink Noise tracks were perfectly flat when compared to the VC Frequency sweep. The VC showed FR between 600Hz and 4kHz varied less than 2dB. Which correlates well with the HFN Pink Noise above 1kHz but the AP is off. Note that there was a difference in FR between channels above 4kHz using the HFN which is the tracks on the LP as there was less than 0.5dB difference in levels using the sweep, and there was no difference using the AP vertical Pink Noise.
These are identical loading showing the Left Channel, the only difference is the LP. The tracks are vertically modulated so I would expect the plots to roll off at about 300Hz. But here we're looking at cartridge loading so we're only interested in the plot above 1kHz.
AP test LP
HFN Test LP
"The tracks are vertically modulated so I would expect the plots to roll off at about 300Hz. But here we're looking at cartridge loading so we're only interested in the plot above 1kHz."
I assume this is below 300Hz Warren, as one can see in the plots, for interest why does vertical modulation do that please?
M
Plots are intriguing, do you also hear the differences in those results clearly?
I assume this is below 300Hz Warren, as one can see in the plots, for interest why does vertical modulation do that please?
M
Plots are intriguing, do you also hear the differences in those results clearly?
The reason for the rolloff in the vertical modulation is because under 300Hz in an LP the modulation is mono (horizontal) too much energy for vertical.
I didn't listen to the pink noise only recorded the plots. But I would suggest it would be audible due to the level variation.
I didn't listen to the pink noise only recorded the plots. But I would suggest it would be audible due to the level variation.
Hi Warren, no that first picture is just me roughing out the wheel and checking for flat spots. Total mass 1.395g before shaping and polishing. I’ve got the wheels as circular as possible with my equipment and surface polished to 0.1 microns, the same process as with the TC rails. They’re not on the axle/hubs yet as need to make a centring jig as per niffy’s instructions.
S.
S.
