Getting a phono that sounds just right requires many hours of trial and error. Is high resolution a bad thing? Just by the specs one might want to directly couple that OPA134 for MM an MC but then again what will it pickup, The pickup itself is a lossy filter so that only the strong signal comes through
When you run a thd+noise curve, the noise dominates at the low signal levels of an MC cartridge.
The OPA134 is quiet but more than ten times the noise of the Pearl 3 input stage. Adding about a two dollars worth of transistors helps get more out of a $500+ cartridge.
The OPA134 is quiet but more than ten times the noise of the Pearl 3 input stage. Adding about a two dollars worth of transistors helps get more out of a $500+ cartridge.
Does a BAF video exist where Wayne explains the details in P3 (e.g. similar to 2018 Linestage, headphone amp etc.)?
Would it be possible to lower noise even further by using 2SK2145 dual fets in stead of 2SK170? (like in the XONO 2019). R4-R7 20R in that case? Or would this cause problems for Q5?
You're not getting/having a SWB Ferrari GTO? That is sad. Listed for less than 20 grand brand new....
Russellc
2sk2145 is dual of 2sk209 with the source pins connected together. Its transconductance is lower than, for example, LSK170.
Chassis Update - the 1st 2 box (PSU + RIAA) solution will leave Gianluca's shop today. Let's see how fast FedEx gets here. The renderings looked really nice, so I can't wait to see the metal.
I will transplant the boards from my temporary box to the nice ModuShop boxes and share some pix.
I will transplant the boards from my temporary box to the nice ModuShop boxes and share some pix.
If you used 4x 2SK2145GR, at least in simulation, the gain of the JFET stage would be a bit higher than that of 4 of the LSK170A.
Mind you, this is just from simulation, the input noise of 4x2SK2145 would be ~1nV/RtHz @1kHz, but the 4xLSK170A would be less than 0.7nV/RtHz. At these levels it shouldn't make much of a difference at all.
Mind you, this is just from simulation, the input noise of 4x2SK2145 would be ~1nV/RtHz @1kHz, but the 4xLSK170A would be less than 0.7nV/RtHz. At these levels it shouldn't make much of a difference at all.
Thanks, I'll cherish the matched quads of 2SK170's from previous Pearl 2 incarnations then for a possible future Pearl 3 build.
Yes, video was taken but the edits are coming out slowly, so it’s not released yet. Just hang tight.
🙂
I swapped out the Talema toroid PSU for a ST split bobbin transformer. Both are CRCRC with 4700uF and 4R7 in the filters.
This raw power supply outputs 19.xV rails to feed the 15V regs. Perfect. Sound is fantastic, just like the other one.
No measurements beyond playing tunes. 1st LP for this setup is a 2023 release by Norwegian heavy rock band “Flight”.
This raw power supply outputs 19.xV rails to feed the 15V regs. Perfect. Sound is fantastic, just like the other one.
No measurements beyond playing tunes. 1st LP for this setup is a 2023 release by Norwegian heavy rock band “Flight”.
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Ooohhh!! Lucky!!
My package, which has the 2nd chassis design in addition to the one you bought, has just shipped today. The race may be on, but you’re ahead by a long mile!
My package, which has the 2nd chassis design in addition to the one you bought, has just shipped today. The race may be on, but you’re ahead by a long mile!
Wayne's presentation at BAF'23 is now up on the video page: https://burningampfestival.com/videos/
-Tom-
-Tom-
