I used to provide more options for C2Y, but there was very few people deviating from the lower range, so I reduced the amount of caps to roll.
Tea in the BOM link lists 150pF,220pF,330pF 2.5% tolerance 2 pieces each. They should have some printed indication on them.
DMMs are usually not that great for measuring nF or pF range caps mainly because of significant residual capacitance in their long test leads. Some meters also have a delta/zero button. You press that for the display to show about zero residual capacitance before attempting nF or pF range caps. Skipping auto range by selecting the likely smallest capacitance range manually with the range button before zeroing, and not disturbing much how the leads are laying after that, helps the situation further. Dedicated LCR meters have short Kelvin sense leads with four shielded connections to be accurate.
OK, that makes sense. I didnt think my multimeter was giving the correct reading on such a small cap.
Looking at the tiny caps under magnification, I can see150/100, 220/100 and 330/100. Now those values are clear, 150, 220 and 330.
Thanks for clearing that up for me,
Russellc
Looking at the tiny caps under magnification, I can see150/100, 220/100 and 330/100. Now those values are clear, 150, 220 and 330.
Thanks for clearing that up for me,
Russellc
Am I correct that most settle on one and go with it, or is this a good place for a plug to allow rolling rather than just solder them in?
I'm using a "HO" (2.5 mV I think) SAE 1000 MC cartridge but am considering a new one, maybe Hanna, so it may need changed? Not there yet but just wondering. I think its time to track down a SP-10 and begin that fun?
Russellc
Oh stop it! I'm in enough trouble! Oh well if not that it would be something else. Too many unfinished projects...but wanted to spruce up vinyl system, yes likely to include SP-10...then on to some speaker project or the other. 😀
Russellc
Russellc
Drop all the current projects and pursue the SP-10 if you are a vinyl guy. You will not believe what you’ve been missing your whole life. (Yes, really)
Seconding 6L6—firm yes on SP-10—no apologies. I socketed C2Y—pretty sure Tea included some sockets for that purpose—I play around with the treble trim. Might be obvious—but—easiest method to install sockets I've found is to attach them to the caps...then into the board and solder.
Just find a nice used SP-10 MKII and you will just wonder why you did not that already. Wish I knew that years ago.
Fit a nice heavy plinth and you are done for life.
Yes, I saw the sockets and that's what prompted the question. Thanks for the reply, I was next going to go over your photos under magnification to locate them!
I have another question regarding schematic, VR-1 says 1K 7.35%. Wondering what 7.35% refers to, and should these pots be left at mid position, power supply pot as well? I figured power supply wouldnt be as crucial, but perhaps pot in line stage should be set somewhere?
Thanks again,
Russellc
Not too practical of a percentage, it's just how I manipulated the drawing program to get 4V T.P. on the virtual DMM. You install the trimmer as it comes from the factory and when the time comes you adjust for real 4V on the real test point pads with a real Volt meter.
After you first configured the sensitivity of your choice with the mini switches when the power was still off. If you change that configuration in the future for another type of cartridge you should readjust the test point too.
After you first configured the sensitivity of your choice with the mini switches when the power was still off. If you change that configuration in the future for another type of cartridge you should readjust the test point too.
I notice R5, and R6 are reversed positions? Red resistor = R5? Should be next to switch, not small black caps? I'm just getting ready to put that one in and noticed the difference between your photo and one on post #18511?
Maybe it is just the angle?
russellc
I tried to make this clear in the BOM
R5 and R6 should only be populated in one spot. R5 makes the most sense, and leave R6 empty. That resistor is meant to make a best as possible value. better than a 6.8k and 1M together in parallel.
So, please don't populate R6 with a 1M if using my PRP resistors.
It looks like elwood625 may have his mounted wrong.
Using a 1M in parallel to it may not change the overall value too much, so may not affect sound too much.
Here is the board pic for reference.
Imgur: The magic of the Internet
quarantaine project
Hi,
Had to stay inside for 10 days so figured i could do this little circuit. Build the mm circuit from page 182. Sort of. Works nice and sounds quite ok but a bit lean in the bass/lower mids. No hiss or hum above that of the power amp. Highs are quick and clear. The Aleph (cl)Ono i have for comparison is quite a bit firmer in the bass.
I'm looking to tune that a bit, but have little experience building riaa stages. so where to start?
R3 = 46.7k
R4 = 6.8k
C2 = 49n according to the dmm but that might be off, all 47n I had consistently measured high.
C3 = 16.3
Current in the input stage is about 3.3 mA. Second stage is far to high at 5mA but it works with a lower load on the drain and higher source resistor, only had v grades left. psu voltage is 25.5 The output buffer is replaced with a B1 line stage.
Any pointers? input is a grado black. piccie below.
Joris
Hi,
Had to stay inside for 10 days so figured i could do this little circuit. Build the mm circuit from page 182. Sort of. Works nice and sounds quite ok but a bit lean in the bass/lower mids. No hiss or hum above that of the power amp. Highs are quick and clear. The Aleph (cl)Ono i have for comparison is quite a bit firmer in the bass.
I'm looking to tune that a bit, but have little experience building riaa stages. so where to start?
R3 = 46.7k
R4 = 6.8k
C2 = 49n according to the dmm but that might be off, all 47n I had consistently measured high.
C3 = 16.3
Current in the input stage is about 3.3 mA. Second stage is far to high at 5mA but it works with a lower load on the drain and higher source resistor, only had v grades left. psu voltage is 25.5 The output buffer is replaced with a B1 line stage.
Any pointers? input is a grado black. piccie below.
Joris
