Mpp - Page 500 - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 30th January 2012, 11:25 AM   #4991
sampler is offline sampler  Lithuania
diyAudio Member
 
Join Date: Jan 2010
Quote:
Originally Posted by Joachim Gerhard View Post
Here is the official schematic.
Do i miss something here ? I can not see the 200 Ohm resistor.
No, i do not think that anybody has measured a working Paradise. The only one that is playing is the one that Hesener has and he is on a busyness trip. MiiB promised plus-minus 0.3dB and i already discussed with Ricardo that we will trim the circuit after we have measured the actual build. It can actually be that your calculation is more accurate. But please simulate first the official circuit too that is attached.
How is the balanced Starless going ? Have you put more work into it ?
Ok, I missed Neumann pole that is optional, but that doesn't change things much. That 0.8dB bass bump is biggest concern, and it comes from too much output impedance (65k to ground), hence proposed 56k, but only measurements will show exact value, as this depends primarily on current through mirrors and so on. I think Hesener mentioned Paradise having more bass then his FPS build, so it's a good guess for now.
My build has been on halt, as I had problems with my components order from mouser. I really started to hate customs by now Hope to have some progress going on this week. Yesterday while meditating with bjt sorting I had some ideas that I think is worth sharing here, so I have to prepare some sim's and will post it, hopefully this evening.
  Reply With Quote
Old 30th January 2012, 11:26 AM   #4992
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
Here are the instructions of the new Lyra Atlas. Here is some more detail about cartridge loading that takes also the capacitance of the cable into account.
  Reply With Quote
Old 30th January 2012, 11:31 AM   #4993
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
Here we go ...
Attached Images
File Type: jpg Atlas Loading.jpg (174.8 KB, 226 views)
File Type: png Lyra Atlas Picture.png (121.5 KB, 218 views)
  Reply With Quote
Old 30th January 2012, 12:32 PM   #4994
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
This Lyra cart loading is quite enlightening

Hi Sampler

As per my calculations, the "bass resistor" 65k should be 53600 but we must take in consideration that this 65k is parallel to the output impedance of the previous stage and may be also interacting with the input imp of the output buffer. That is why I did not propose any alteration there.

Anyway, using a 15k // 16k2 instead of 15k // 15k is enough to make a fairly good aproximation for optimal R18 (7793r), using the stock 40.8 and 13.6 caps.
__________________
RC
  Reply With Quote
Old 30th January 2012, 01:18 PM   #4995
sampler is offline sampler  Lithuania
diyAudio Member
 
Join Date: Jan 2010
Hi RCruz,
It falls to 0.2dB accuracy with 7.79k and 13.6nF, one could just add couple hundreds pF if it sounds on the bright side. Anyhow, final value for R9 should be selected using real build and measurements so lets wait and see how it goes.
Attached Images
File Type: png riaa_revised.png (18.6 KB, 199 views)
  Reply With Quote
Old 30th January 2012, 01:25 PM   #4996
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Yes... maybe it would need some picos in the 13.6nF (my target is 13.99) but that can be tweaked latter by hear if there is "subjectively" too much trebble. I found some resistance in oher threads regarding these adjustments because some claim 0.2dB difference is inaudible

As for R9, decreasing its value (with some megas in parallel) can also be done latter if needed. I prefer to call that resistor the "presence resistor" instead of "bass resistor" because it slides the curve up and down from 0 Hz to the upper midband.
__________________
RC

Last edited by RCruz; 30th January 2012 at 01:28 PM.
  Reply With Quote
Old 30th January 2012, 02:28 PM   #4997
diyAudio Member
 
Bksabath's Avatar
 
Join Date: Dec 2007
Hi Frans
Welcome back
Did you recieve files ok?
any comment on board as in post 4956?
  Reply With Quote
Old 30th January 2012, 02:33 PM   #4998
hesener is offline hesener  Germany
diyAudio Member
 
Join Date: Mar 2005
Location: Munich, Germany
Quote:
Originally Posted by Joachim Gerhard View Post
Here is the official schematic.
Do i miss something here ? I can not see the 200 Ohm resistor.
Hi, yes thats the schematic the PCB is based on, with one exception / there is a 220Ohm resistor in series with C1a/C1b, for those of you who want to implement Neumann. Otherwise just put a wire instead, or a 0 Ohm resistor if you like.
  Reply With Quote
Old 30th January 2012, 02:40 PM   #4999
hesener is offline hesener  Germany
diyAudio Member
 
Join Date: Mar 2005
Location: Munich, Germany
Quote:
Originally Posted by FdW View Post
The minimum transformer voltage is thus 25V ....

Maybe Hessener can comment on that (the temperature of the heatsink).
In my build I am using a 2x24V transformer with no problem, no-load voltage was 38V DC and loaded it was around 31V if my memory serves me well. I will measure the heatsink when I return, and some more...
  Reply With Quote
Old 30th January 2012, 02:47 PM   #5000
hesener is offline hesener  Germany
diyAudio Member
 
Join Date: Mar 2005
Location: Munich, Germany
Quote:
Originally Posted by RCruz View Post
Hi Joachim... the official schematic differs from the one I have and also from the boards inscriptions... R47 = 10 instead of 22 and R51 = 15 instead of 22... what values should I use.... My boards are almost finished
oops, sounds like the boards have the wrong values printed.... thanks for highlighting. I think I remember that there was some conversation around these resistors and that 10/22 was the final "verdict", so I must have changed them in the schematic but not on the PCB. Anyhow, maybe MiiB or Joachim can confirm so I can fix this bug, would be great!
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 09:21 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2