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 19th January 2013, 09:32 AM   #9031
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
A single warm enough SSLV1.1 is enough to get you 90% there for the folded, for now. If it will be to your liking or not it will show even in a less than all out double mono initial test config. See to have no hum and a tuned Riaa for starters. In about 48 hours it will mellow out a wee bit also after the lytics will almost shape up.
  Reply With Quote
Old 19th January 2013, 09:40 AM   #9032
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
hi buzz

Be aware that R6 is 1M and not 3M3....
__________________
RC
  Reply With Quote
Old 19th January 2013, 09:42 AM   #9033
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Replaced Vref with 470uF SilmicII, since its a RIAA. It has been run in for a while, so no worried there. The KG in the PSU are new. Caddock is current setting resistor. This is what i liked in the DCB1. Seemed bigger difference in DCB1 was higher current vs fancier parts, bu tit is hard to resist in DIY.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 19th January 2013, 09:44 AM   #9034
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Quote:
Originally Posted by RCruz View Post
hi buzz

Be aware that R6 is 1M and not 3M3....
Yup. Thanks for looking out. VGeorge caught Vref cap mistake. We shall see later today.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 19th January 2013, 02:20 PM   #9035
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
I have something just for fun hopping to get good comments:

After building a rig to measure 2SK170BL fet Idss and Vp, I found that Vp and Idss are linearly related so I constructed a table ranging from 6mA to 10.5mA using a linear regression method.

Then I analysed all my builds and designed a calculator enabling to determine Rd, Rs and Gain depending on Idss, Vdd and Vdsq.

If you know and want to use a specific Rd, there is an option too.

Severall methods for calculating Gain are presented.... feel free to pick the one you like most

This calculator is speciic for the Simplistic gain stages and may not be good for other purposes because it is based on factors used here.

You can even use it for the classic cascoded first stage because Rd is much lower than this stage output impedance so this cascode does not give more gain but much more bandwith and miller reduction.
Attached Files
File Type: zip Simplistic calculator.zip (84.1 KB, 27 views)
__________________
RC
  Reply With Quote
Old 19th January 2013, 02:29 PM   #9036
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia new Europe state
Wow, thanks for the great work Ricardo.
  Reply With Quote
Old 19th January 2013, 02:33 PM   #9037
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
The second stage in the folded measures about 37.5dB gain.
  Reply With Quote
Old 19th January 2013, 02:37 PM   #9038
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Back to work than.... what about the other functionalities ?
__________________
RC
  Reply With Quote
Old 19th January 2013, 02:42 PM   #9039
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
It looks like a very nice comprehension tool. Congratulations for putting it together. Maybe you got nothing wrong regarding functions and just a little tolerance in the measurements or in actual gm gives it 10% prediction error margin.
  Reply With Quote
Old 19th January 2013, 04:31 PM   #9040
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Thank you

It was really mented as a tool for experimentation and comprehension... as is it is no substitute for a simulator and I really believe we should always breadboard before building anything.

Anyway, The scale factor of 2 in gain Equations is nominal. According to the National Semiconductor FET Handbook (1977), that factor can range from about 1.1 to 2.5 but is typically near 2, so I can easily adjust it based on your input.

Can you give me some gain figures ?
48dB build 28V output stage Rd 4k7 Vd = 11v and Rs 47r
48dB 28V input stage Rd 3k3 Vd = 14v and Rs 33r
57dB 37V output stage Rd 6k3 Vd = 10v and Rs 27r

I believe these will beenough to find a good compromise for the gain equation.
__________________
RC
  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 05:53 PM.


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