774LC=low cost from Jelco maybe. I have the original designed by John Bicht, the Versa Dynamics guy. http://www.zenn.com.sg/Mission.htm
You can use whatever 10-11mA matched between positions and channels. The 27R can be a 50R trimmer so to match your channels finer for output level around that original value, so to offset slight gain differences from less than perfect matching naturally.
Can this be done with "normal" 2sk170bl ?
I have some in that 10.5mA range
Can this version compete with the previous 56dB 37V version if used without the bypassing EL ?
besides the higher gain and working voltage, what are the main differences ?
Is there any kind of "special" dip switch ?
Of course. Mind you, isn't a matter of previous, but of different IDSS. This one will have 3dB less hiss though, since it is aimed for Low MC too. Double In-Line Package pcb switches plain vanilla as on your computer's motherboard will do. I would prefer pins and a nice solder joint non the less, if you would not bother not to be changing carts on the fly.
Well I suppose that instead an internal dip swicth can be done by a external toggle switch.
I mind is to suppres C10 so instead 63dBs ultra low gain MC will be 57dBs mid gain MC, that's possibility is very good for me due to the fact that I have several MS carts ultra low gain & mid gain
Don't be much afraid of C10. Its an SE phono full of capacitive coupling and ''creative'' passive parts selection cookery anyway.
I'm ready to start building my riaa circuit but I don't know if it's better to buy a new cartridge.
I've a new, old version, Ortofon MC10 that is 0,1mV 3ohm, that I bought for a low mass tonearm (high compliance). Now I change the tonearm and I'd like to buy a new Denon like DL103R or DL301 or may be use the MC10 that is very hard to sell.
May be that the new 63db version will fit all this cartridges?
I don't like step up transformers but I'd like to know if this version have more noise than a higher outup pich-up (like DL301) with a 56 db version.
Any suggestion?
Guglielmo
I've a new, old version, Ortofon MC10 that is 0,1mV 3ohm, that I bought for a low mass tonearm (high compliance). Now I change the tonearm and I'd like to buy a new Denon like DL103R or DL301 or may be use the MC10 that is very hard to sell.
May be that the new 63db version will fit all this cartridges?
I don't like step up transformers but I'd like to know if this version have more noise than a higher outup pich-up (like DL301) with a 56 db version.
Any suggestion?
Guglielmo
Hi Salas,
I don't know if you have ArcProtractor, because you don't tell wich model do you have I will post the 2 that I have:
228,48mm long
An externally hosted image should be here but it was not working when we last tested it.
228mm long
An externally hosted image should be here but it was not working when we last tested it.
Enjoy.
p.s. "WARNING" First of all, you must be absolutely sure to have the same mounting distance on your turntable than on the ArcProtractor.
MAXIMUM error on this dimension must be within +/-0.5mm. Otherwise, it is useless trying to align.
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Set-up & data-base with all Arc-Protractors, link in French & English:
ls3-5a-forum.com
- 1 - Print the file at real scale.
After downloading the file (clic on it or right clic then save link as).
There are differents solutions, with irfanview, xnview or any photo editing software.
Anyway, Word is very usefull for this kind of work. So, there is a template word file for download. Simply replace the protractor by your.
Check at least one dimension in each direction, 260mm must be 260mm (or 10,23inches), 170mm must be 170 mm.
- 2 - Drill the centering hole
The best solution than I found for the moment is "to cut out" using a tack by making small holes all along the center circle, slightly towards the interior "to tighten" the axis.
You can reinforce this place before cutting by sticking a small piece of Scotch tape on each face. Like that :
An externally hosted image should be here but it was not working when we last tested it.
4 - Put the Ultra-Protractor on a LP on the turntable.
The disc centering shaft should make jump easily the conféti we just cut.
Disable the antiskating device and lock the plater.
- 5 - Adjusting the length
Place the stylus on the arc right at the edge of the disc.
Raise the arm and move close to the center, lower the arm.
If the diamond is has the interior of the circle, it is that the effective length is too short, then move the cartridge forward and vice versa, repete until a correct position.
- 6 - Adjusting the offset angle
Choose one of the 2 grids and turn the cartridge so the cantilever is aligned with the front line and be centered between the 2 rear lines. Like this :
An externally hosted image should be here but it was not working when we last tested it.
Control on the other grid, normally must be good except if the length moved, go in - 7 -
- 7 - Verifying the length.
During the rotation of the cell, the length doubtless changed.
Remake the test as into - 5 - with an additional test between the two grids.
Correct and control alignment.
- 8 - Never give up
until all is good, 0.5mm is significant.
If it makes you crazy, go to bed and resume the following day.
- 9 - Check the vertical tracking force
Do not forget to re-enable the antiskating and listen to finally the difference.
Waiting will be usefull, enjoy.
