Yesterday i placed my mouser order for components. Seems like double and triple checking with the BOM ist not enough in my case. I realised that I forgot to order two 270R resistors for PS section R4. As i have some 220 Ohms resistors at hand i want to ask if i can substitute one of the 270R positions on the BIB boards with 220R without any loss of performance?
No problem, it will just run a bit more current in the PSU LEDs through J1. 270R is an about value to bring an average PF5102 J1 down to around 2mA. Depends on sample IDSS how much near to 2mA, but its in the ballpark for J1's proper dissipation since it sees much voltage across D to S.
The main circuit LEDs run at a higher and more precise 5mA since Q7 PF5102 has less VDS due to R18 and its hand picked and runs full on. For channels matching voltage bias of Q3's base. That is why builders may notice less glow in the PSU LEDs vs the phono LEDs. 2mA vs 5mA makes that glow difference.
The main circuit LEDs run at a higher and more precise 5mA since Q7 PF5102 has less VDS due to R18 and its hand picked and runs full on. For channels matching voltage bias of Q3's base. That is why builders may notice less glow in the PSU LEDs vs the phono LEDs. 2mA vs 5mA makes that glow difference.
Looking excellent. But I am afraid you have used incorrect 1uF C3 value instead of 0.1uF in both channels?
I finished my preamp, ULTRA FSP, Waynes 2018 linestage and power supplies all in same enclosure. I must say, my LP's have NEVER sounded better. The Ultra FSP is the BOMB!
I have a little hum coming from the speakers, my own fault being hard headed and putting the PS in the same enclosure. I've got parts ordered to fix that issue.
I also increase the gain on the linestage to 10, I'm going to decrease it to 6. Don't need as much gain as I thought.
I have a little hum coming from the speakers, my own fault being hard headed and putting the PS in the same enclosure. I've got parts ordered to fix that issue.
I also increase the gain on the linestage to 10, I'm going to decrease it to 6. Don't need as much gain as I thought.
I don't how that one behaves in practice. IFN147 is TO-18 and will stay out of stock in Mouser for some months. Its also priced at a cool $21.06 each. Is there its TO-92 PN147 version stocked in a better price elsewhere?
The other day to match a K369BL quad I went through about twenty unsuitable pieces. It might end up a costly thing anyway I mean.
The other day to match a K369BL quad I went through about twenty unsuitable pieces. It might end up a costly thing anyway I mean.
First attempt
This configuration is surprisingly quite. I dialed 10X gain into the Waynes boards which is too much, I move the volume about 3-4 clicks and it's at normal listening level. When volume is turned all the way up you get some hum. No way I could ever listen to it that high. I'm going to move the A/C out of the enclosure and switch the external power supply on with DC to the switch in the preamp. I'm also going to dial the gain in the Waynes boards down to 6X gain.
The combo of Ultra USP and Waynes Linestage is AWESOME. Extremely quiet and very dynamic.
This configuration is surprisingly quite. I dialed 10X gain into the Waynes boards which is too much, I move the volume about 3-4 clicks and it's at normal listening level. When volume is turned all the way up you get some hum. No way I could ever listen to it that high. I'm going to move the A/C out of the enclosure and switch the external power supply on with DC to the switch in the preamp. I'm also going to dial the gain in the Waynes boards down to 6X gain.
The combo of Ultra USP and Waynes Linestage is AWESOME. Extremely quiet and very dynamic.
Looks well arranged and versatile as a full preamp. Nice that you like the combo's sound. Congratulations.
About gain, dial a line amount that reaches loud enough sound pressure level for your system and listening space/position at three o' clock volume pot setting from vinyl source. Re-evaluate background hum at full volume after that. Before you modify further. AC mains wiring and transformers in same box with phono signals is bound to couple some hum. Even when acceptably low in general it can also be highlighted by excessive line gain.
Even before that, move the phono channels green ground wires to the chassis bolt for TT GND instead of being directly tied to the protective earth.
I just received the power supply enclosure today and have made an umbilical cord to connect the two. I will incorporate both of your suggestions and move the A/C out of the preamp enclosure. Your raw PS and shunt regulators are made to have an umbilical cord with the large caps on the regulators.
I'm using a VRDN for the supply for the Wayne's linestage, I'll add a couple nice size caps in the preamp enclosure to make sure it has reserve. If I'm not wrong, it will also form a CRC filter with the wires in the umbilical cord having a little resistance. I'm using 20 gauge wires just for that purpose.
I'm using a VRDN for the supply for the Wayne's linestage, I'll add a couple nice size caps in the preamp enclosure to make sure it has reserve. If I'm not wrong, it will also form a CRC filter with the wires in the umbilical cord having a little resistance. I'm using 20 gauge wires just for that purpose.