Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 4th December 2010, 02:08 PM   #1
diyAudio Member
 
Mosquito's Avatar
 
Join Date: Sep 2009
Location: Santa Fe, Argentina
Default A different (?) line level circuit

Hi everyone!
I was trying this circuit from G.Velez (Gabevee) just to see the behaviour on LTSpice. I'm a newbie on electronics as well as in the use of Spice, so, independently if you like this circuit or not, can someone point out if there is some mistake in the original drawing or in my translation to LTSpice?
"Solid State Tube" Preamplifier
It seems to me that the freq response is somewhat restricted, and not 5 to 600Khz as claimed...
Thanks in advance
J
Attached Images
File Type: gif Nueva imagen (1).gif (41.4 KB, 214 views)
__________________
If I only had a dollar for every song I've sung...

Last edited by Mosquito; 4th December 2010 at 02:12 PM. Reason: mistake
  Reply With Quote
Old 4th December 2010, 03:13 PM   #2
godfrey is offline godfrey  South Africa
diyAudio Member
 
Join Date: Nov 2009
Location: Cape Town
Quote:
Originally Posted by Mosquito View Post
... can someone point out if there is some mistake in the original drawing or in my translation to LTSpice?
Dunno. Can you show us what it looks like in LTSpice?
Quote:
Originally Posted by Mosquito View Post
It seems to me that the freq response is somewhat restricted, and not 5 to 600Khz as claimed...
What do you get?
  Reply With Quote
Old 4th December 2010, 03:37 PM   #3
diyAudio Member
 
Mosquito's Avatar
 
Join Date: Sep 2009
Location: Santa Fe, Argentina
Your desire is an order
Attached Images
File Type: gif Nueva imagen.gif (145.6 KB, 188 views)
Attached Files
File Type: zip Sand-O-Kan.zip (1.6 KB, 8 views)
__________________
If I only had a dollar for every song I've sung...

Last edited by Mosquito; 4th December 2010 at 03:52 PM.
  Reply With Quote
Old 4th December 2010, 03:54 PM   #4
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
I don't use Lt spice but a couple of quick thoughts.

At the top end R6 looks a problem, try 2k2

At the bottom end increase C6 to 220uf
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 4th December 2010, 03:57 PM   #5
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
In fact increase all the caps C3 C4 and C7 as well by a factor of ten. Also what load is on the end of C4 ?

As I say I don't use LT but whats the output impedance of the generator... if that's high that will add to HF roll off.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 4th December 2010, 03:58 PM   #6
diyAudio Member
 
Mosquito's Avatar
 
Join Date: Sep 2009
Location: Santa Fe, Argentina
Thanks Mooly, I'll try these mods/fixes
cheers
J
__________________
If I only had a dollar for every song I've sung...
  Reply With Quote
Old 4th December 2010, 04:12 PM   #7
godfrey is offline godfrey  South Africa
diyAudio Member
 
Join Date: Nov 2009
Location: Cape Town
The main problem is probably that you're using power mosfets instead of small-signal mosfets.

I see you changed a few other component values as well, but that shouldn't make much difference except for R13, which he says should not be changed, but you've changed from 330R to 2.2K. There's a capacitor missing too. That shouldn't affect high frequency response but might be important for something else?

btw I've no idea how I missed the schematic in your first post. I could swear it wasn't there when I first looked.
  Reply With Quote
Old 4th December 2010, 04:24 PM   #8
godfrey is offline godfrey  South Africa
diyAudio Member
 
Join Date: Nov 2009
Location: Cape Town
As long as Mooly's changing everything anyway...
I'll agree with increasing C6, and vote for increasing C1 as well.
  Reply With Quote
Old 4th December 2010, 04:57 PM   #9
diyAudio Member
 
Mosquito's Avatar
 
Join Date: Sep 2009
Location: Santa Fe, Argentina
Thanks godfrey, you're right I missed to attach the picture by first, and then correct..
Ok can you suggest suitable signal mosfet from those in the default LTSpice library? (I've changed some componens figures in order to have the voltage figures pointed out in the original drawing, not any other reason than that)
Thanks again
J
__________________
If I only had a dollar for every song I've sung...
  Reply With Quote
Old 4th December 2010, 05:13 PM   #10
godfrey is offline godfrey  South Africa
diyAudio Member
 
Join Date: Nov 2009
Location: Cape Town
Quote:
Originally Posted by Mosquito View Post
Ok can you suggest suitable signal mosfet from those in the default LTSpice library?
Nope, I'm pretty clueless regarding both LTSpice and mosfets. It looks like you can get the Spice model for BS170 from Fairchild over here though.
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
balanced line level baffle step circuit Harolda Analog Line Level 2 5th September 2010 06:13 PM
Line to instrument level converter :Re-Amp circuit? 0vid Instruments and Amps 7 2nd May 2010 09:02 AM
Speaker to line level adapter circuit question. Flatlander Parts 5 10th May 2006 12:33 AM
Line level signal delay circuit wigginjs Solid State 3 26th September 2004 02:51 PM
Line level signal delay circuit wigginjs Parts 2 24th September 2004 11:36 AM


New To Site? Need Help?

All times are GMT. The time now is 07:16 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