#26 pre amp - Page 249 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 7th February 2013, 08:50 AM   #2481
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by Wavebourn View Post
Try to add resistances and inductances of wires into your SIM, variable current drawn, and you will see why ground sign have to be drawn near C3 instead of near C1.
I always read all people said to connect the ground to 1st cap psu
  Reply With Quote
Old 7th February 2013, 08:51 AM   #2482
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by mogliaa View Post
Felipe, that's not my design. Either way 12mvpp ripple is not bad at all! Are you planning to use a shunt regulator?
Ale
I'm sorry Ale the post was for Andy. Yes, Salas hig voltage shunt regulator version 2
Felipe
  Reply With Quote
Old 7th February 2013, 09:02 AM   #2483
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by euro21 View Post
Felipe, can I do some comments?

Such a low transformer DCR not optimal for (mesh) AZ1. It would be better 100-200R DCR.
IMHO C1 low, thus output voltage also low. There are no high charging current (AZ1 unable to do so) therefore increase C1 up to 1-5uF. If output ripple bothering you, increase C3.

ps. PSUD a little cheating, output voltage about 220V, not 230.

Ps2. Attachment is my working #26 preamp (common raw PSU- each side: SSHV2- cascode CCS loaded 26 -TVC) raw HT supply.
Of course you are welcome, you are right because one time for other project I use AZ1 with other transformer with secondary DCR 83,2 ohms and was to add one resistor in series with the phase of 78 ohms or AZ1 not optimal.

Thanks for support and advices
  Reply With Quote
Old 7th February 2013, 09:04 AM   #2484
palmas is offline palmas  Portugal
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by merlin el mago View Post
Ale I have simulated your PSU, simulator saids have more ripple, or I'm misunderstanding something, see attached image.
In simulation you have 10H 10Ohm chokes for 30mA
More realistic would be 100 to 300Ohm choke. That can make some difference on the outcome
  Reply With Quote
Old 7th February 2013, 09:04 AM   #2485
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
In place to use two 125VAC in series what about to use as an isolation transformer to get 230VAC, due to the fact that I don't need so hign voltage can get a better psu?
  Reply With Quote
Old 7th February 2013, 09:05 AM   #2486
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by palmas View Post
In simulation you have 10H 10Ohm chokes for 30mA
More realistic would be 100 to 300Ohm choke. That can make some difference on the outcome
Thanks for advice, could I add in series resistor 290R? could you elaborate so I can learn? psud2 don't show any difference of ripple.

Last edited by merlin el mago; 7th February 2013 at 09:12 AM.
  Reply With Quote
Old 7th February 2013, 09:13 AM   #2487
palmas is offline palmas  Portugal
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by merlin el mago View Post
Thanks for advice, could you elaborate so I can learn.
10H chokes have thousands of spirasl in a iron (typically) core, so you cannot use big seccion wire, or it won't fit, or it will be enourmous and very expensive.
So you use thin wire (as requested by the 30mA), so wire resistance will be a lot higher than 10Ohm. Fro experience (I build them myself) for a 10H 200mA choke resistance will be about 100Ohm and for a 10H 100mA typically about 300Ohm. For 30mA could be more.
If you make that change on the simulator you will see that output voltage and ripple are a little different.

By the way, 0,1Ohm on caps is also too low if you're using electrolitic.

Cheers
  Reply With Quote
Old 7th February 2013, 09:29 AM   #2488
palmas is offline palmas  Portugal
diyAudio Member
 
Join Date: Jun 2007

did you measure inductance with 100mA?
  Reply With Quote
Old 7th February 2013, 09:31 AM   #2489
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by palmas View Post
10H chokes have thousands of spirasl in a iron (typically) core, so you cannot use big seccion wire, or it won't fit, or it will be enourmous and very expensive.
So you use thin wire (as requested by the 30mA), so wire resistance will be a lot higher than 10Ohm. Fro experience (I build them myself) for a 10H 200mA choke resistance will be about 100Ohm and for a 10H 100mA typically about 300Ohm. For 30mA could be more.
If you make that change on the simulator you will see that output voltage and ripple are a little different.

By the way, 0,1Ohm on caps is also too low if you're using electrolitic.

Cheers
Thanks for advices, I use Bartolucci chokes are rated 10H 100mA 10 ohms, attached pic.

I'm using mkp in oil ASC X386S, attached pic.

Cheers
Felipe

P.S. How can measure lytics impedance?
Attached Images
File Type: jpg DSC00229.jpg (625.6 KB, 241 views)
File Type: jpg DSC00230.jpg (449.3 KB, 232 views)
  Reply With Quote
Old 7th February 2013, 09:37 AM   #2490
palmas is offline palmas  Portugal
diyAudio Member
 
Join Date: Jun 2007
I need to buy these bartolucci chokes and reverse engineer them!

About the caps it is easier to rely on manufacturer specs and calculate connections resistance. But there is not a significant difference from 0.1 to 1Ohm on the cap
  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 11:35 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