Across the 4 leds I 've 7,7V at 20V psu ( and the leds are bright like the other 3).
When the psu voltage goes up ,also the voltage across the 4 leds goes up ( and the 4 leds are brighter than the other 3)
I selected the quartet for 7,7V.
R13= 1k2
across R15 17V
K369 11.8 mA and Rs=R2= 4R7
When the psu voltage goes up ,also the voltage across the 4 leds goes up ( and the 4 leds are brighter than the other 3)
I selected the quartet for 7,7V.
R13= 1k2
across R15 17V
K369 11.8 mA and Rs=R2= 4R7
So I am ordering resistors for the FSP and having so many choices it's hard to decide.
I am trying to choose between welwyn rc55 0.1 25ppm, vishay cmf50/rn55 (mix of 0.1 and 1%) or generic 1% 50ppm resistors either from vishay, welwyn, irc.
The generic are the cheapest at a few cents each and the welwyn are about 1.70€ each.
I could go with prp or takman rey, which would be almost the same price as the welwyn but have 100ppm, and the welwyn at 0.1% and 25ppm might be a better choice.
Does anyone have tried generic 1% resistors? Caps will be obbligato or jentzen superior.
I'm not on a budget to build the fsp, but am trying to choose consiously. 5€ vs 40€ is quite a big difference to spend on resistors.
I am trying to choose between welwyn rc55 0.1 25ppm, vishay cmf50/rn55 (mix of 0.1 and 1%) or generic 1% 50ppm resistors either from vishay, welwyn, irc.
The generic are the cheapest at a few cents each and the welwyn are about 1.70€ each.
I could go with prp or takman rey, which would be almost the same price as the welwyn but have 100ppm, and the welwyn at 0.1% and 25ppm might be a better choice.
Does anyone have tried generic 1% resistors? Caps will be obbligato or jentzen superior.
I'm not on a budget to build the fsp, but am trying to choose consiously. 5€ vs 40€ is quite a big difference to spend on resistors.
Do you see Dale/Vishay PTF65 or PTF56 available?
They are some values available at Mouser, and for the tolerance and PPM and performance, I find the price fair and competitive. I use them where I can in FSP, except the 47K and customer PRP resistor I had made for 6.79x
Vishay ptf56 Metal Film Resistors - Through Hole | Mouser
Vishay ptf65 Metal Film Resistors - Through Hole | Mouser
I'm ordering from Farnell here in europe as I have free shipping and don't have to deal with customs. They have some ptf but very few values.
Those are about the same price as the welwyn ones I mentioned, which salas said somewhere in this thread that he liked quite a bit.
I'm just trying tho understand the advantages of these high precision ones against a quality brand 1% generic resistors.
What are you using for the 47K?
Those are about the same price as the welwyn ones I mentioned, which salas said somewhere in this thread that he liked quite a bit.
I'm just trying tho understand the advantages of these high precision ones against a quality brand 1% generic resistors.
What are you using for the 47K?
Debugged finally! All works perfectly now.
Linn Axis + Akito + Sumiko Blue Point is the analog front end of my friend.
B1 preamp, Murano class D amps and diy speakers .
The later are 3 ways with Beyma pro speakers - TPL150 AMT tweeter.
The old phono preamp was a McCormack.
The FSP is clearly better in all the aspects; highlights are definition, trasparency, dinamic and S/N ratio.
My friend is very happy!
So you are putting 600VA of toroid in with your RIAA??? That sounds like a strange decision, but if you say you have no hum, that is reassuring for me...
The worst culprit for hum for me has been wifi devices such as the baby monitor and wifi hub. I was rearranging grounding wires for hours and hours on my pre-amp before I realised it was the wifi hub at 30cm away! Keep them at more than 2 metres away, preferably 4 metres.
Why such huge toroids? How can that help the sound with such a tiny current requirement? It looks beautifully made by the way. Real craftsmanship!
The worst culprit for hum for me has been wifi devices such as the baby monitor and wifi hub. I was rearranging grounding wires for hours and hours on my pre-amp before I realised it was the wifi hub at 30cm away! Keep them at more than 2 metres away, preferably 4 metres.
Why such huge toroids? How can that help the sound with such a tiny current requirement? It looks beautifully made by the way. Real craftsmanship!
I use a wooden box (oak and mdf). tested the prints on a prototype mdf board before final boxing and had some problems with hum, i pointed the finger at the supposed sinner : my huge 2 X 300VA Torroids .
Experimented with location of the pcb relative to the toroids, no change......
There where more hum when holding my hand over the pcb than when moving the pcb directly over the toroid.
I then found out that the sinner was the metal (aluminum) cabinet under the prototype mdf board.
Lifting the board up 10cm above the metal removed all hum.
Good luck
P
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Congrats for good troubleshooting, and regards to your friend. His diy speakers seem interesting. We will be expecting to see your FSP finished too, and get to know how you liked it in four channels balanced config.
Hi Nick,
I need your advice….
I just received my Wilson Benesch Ply cartridge from re-tipping service (BTW for guys in US, the guy is in Seattle OR, Phono Cartridge Repair).
I got new boron stylus and they also replaced my coil. Now my Output is lower than the original one was. How low?, I do not know, but just for reminder, we assumed that I had about 1mV and I approached to the relevant set of parts: R13 was set to 2.2K, Q1 was 13.52/13.51 and R2 was set per table to 8.2R. Now, it’s the tricky point… You also advised me then to change value of some resistor and I actually don’t remember which one.
Do you recall that? Please let me know.
Now, I assume I need to go for 62-63dB version, so…
I have one matched pair of Q2 with 13.45/13.45. Assume that R3 should be the same as R2 = 8.2R.
R13 need to change to 1.2K 2W.
Did I missed anything?
Please let me know.
I need your advice….
I just received my Wilson Benesch Ply cartridge from re-tipping service (BTW for guys in US, the guy is in Seattle OR, Phono Cartridge Repair).
I got new boron stylus and they also replaced my coil. Now my Output is lower than the original one was. How low?, I do not know, but just for reminder, we assumed that I had about 1mV and I approached to the relevant set of parts: R13 was set to 2.2K, Q1 was 13.52/13.51 and R2 was set per table to 8.2R. Now, it’s the tricky point… You also advised me then to change value of some resistor and I actually don’t remember which one.
Do you recall that? Please let me know.
Now, I assume I need to go for 62-63dB version, so…
I have one matched pair of Q2 with 13.45/13.45. Assume that R3 should be the same as R2 = 8.2R.
R13 need to change to 1.2K 2W.
Did I missed anything?
Please let me know.
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