Jump to content

Pars

High Rollers
  • Content count

    6,373
  • Joined

  • Last visited

  • Days Won

    1

Pars last won the day on February 27 2013

Pars had the most liked content!

Community Reputation

532 Excellent

About Pars

  • Rank
    High Roller
  • Birthday 05/16/1954

Profile Information

  • Gender
    Not Telling

Converted

  • Location
    Chicago
  • Occupation
    engineer (telecom mktg)
  • Hobbies
    golf, music, cycling
  • Headphones
    AKG K601, Shure SRH840, Modded Fostex T50RP
  • Headphone Amps
    Gilmore dynamic (headamp v2 PCB), Dynahi (still proto stage)
  • Sources
    � Rotel RCD-855 modified (clocking, discrete output stage) � Rotel RCD-991 THS4031 I/V, AD8599 buffers
  • Other Audio Gear
    ? maybe Classe preamp, Odyssey Stratos poweramp, Von Schweikert VR4 Gen.II speakers

Recent Profile Visitors

4,234 profile views
  1. Balanced to unbalanced board

    Those look pretty sweet Marc! Sent from my iPhone using Tapatalk
  2. Balanced to unbalanced board

    I try to match complementary pairs, but going from N to P (both BJT and JFETs) usually doesn't match very well. It depends on the devices.
  3. And now what did you do TODAY?

    Really good news Jacob!! Sent from my iPhone using Tapatalk
  4. Part Sourcing Assistance/Advice Thread

    Matching never hurts... not sure that they need to be though. Sent from my iPhone using Tapatalk
  5. Happy Birthday skullguise!

    Happy Birthday! Sent from my iPhone using Tapatalk
  6. Happy Birthday bosebuttons!

    Happy Birthday! Sent from my iPhone using Tapatalk
  7. and now for something completely different part 3

    I tried this myself yesterday, though I bent the leg on the trimpot and soldered a jumper wire to it, so nothing in pin 5 of the dip socket. Seems to work fine, offset drifts some but nothing bad at all, probably in the +/- 3-4mV range while I was watching it. Listened to a cd with protection circuit in place and no issues. BTW, Kevin, this is a very very nice amp! Congrats! Sent from my iPhone using Tapatalk
  8. I would guess this is because he lays out the sense lines on the board going right to the rails on the phono section. I would think if you ran not only V+ and gnd, but also both sense lines separately, having the reg onboard wouldn't make a difference (shunt PSU only). The GRLV is extremely low noise (see thread for screen room measurements), so I am hoping that just using GRLV (or dual mono) will be as low noise, maybe lower, than the shunts are. I did lay out his shunt on a separate board which would fit just like his single board, but have very short jumpers to the phono board, in case I think I am wrong.
  9. KGSSHV Carbon Build Thread

    Would it be a better idea to use the LSK489 (and LSJ689 for those needing 2SJ109)? And BTW, does anyone actually have the LSJ689 in stock?
  10. and now for something completely different part 3

    Here is an updated spice file per Kevin's latest schematic (pls check). Still shows -51mV without the opamp. I guess the current mirrors purpose is just to take the servo out of the audio signal path, and not about offset without the servo? CFP2 1.10.zip
  11. The Multi Amp aka Dynalo Mk2

    Those were dual BJTs, not JFETs, that Justin bought. They are the dual version of the 2SA970/2SC2240. Sent from my iPhone using Tapatalk
  12. The Multi Amp aka Dynalo Mk2

    1. I have BOMs for both and the GRLV as well at home and can post or send tonight 2. Covered. My BOM has a “calculator” for this built in 3. Yes, you can use J74/K170 or equivalents. C-> D, B -> G, E -> S. Will plug right into the dip14 socket if you wish. 4. Maybe regarding the full vs. the mini. The mini uses the same devices, but the PSU is done using Meanwell AC/DC bricks 5. I am thinking about selling the mini boards and pots that I have (2). As for versions, the last GB earlier this year run by sbeylo would give you a handle on board versions. The MPSW06/56 thru hole devices are discontinued and not generally available so SMT with the PZTA devices would be the way to go. Both are setup to use the THAT340 for input. Sent from my iPhone using Tapatalk
  13. and now for something completely different part 3

    Looks like you have the servo input going into the noninverting pin of the opamp? Is that right? Sent from my iPhone using Tapatalk
  14. goldenreference low voltage power supply

    A 2x30Vac SumR is what I am using on mine. The Antek transformers seem to work well also, and much cheaper. Sent from my iPhone using Tapatalk You can do anything you want Whether it is a good idea or not is another matter. I know I asked Kevin a number of pages ago about using ceramics here and he said he couldn’t guarantee that it would meet the noise specs that he had measured. I would suspect electrolytic would have pretty abysmal performance here. Much higher ESR and leakage I would think. Sent from my iPhone using Tapatalk
  15. and now for something completely different part 3

    Here's a revised ltspice model with the revisions made (I think, someone check this as it was done vs. the gerber file). The current mirrors get the offset down to ~10mV without the servo opamp connected. CFP2 v1.10.zip
×