electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
Live streaming at radio.electro-music.com

  host / artist show at your time
  EdisonRex Edison's Electronic Review
Please visit the chat
 Forum index » DIY Hardware and Software » Ken Stone designs - CGS
Synthacon, how to increase ouput level?
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [7 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
Lorenzo



Joined: Nov 09, 2008
Posts: 354
Location: Trieste - Italyjstan

PostPosted: Sun Mar 07, 2010 6:03 pm    Post subject: Synthacon, how to increase ouput level? Reply with quote  Mark this post and the followings unread

Hi

How can I increase my Synthacon ouput audio level?
I mean, now it sound very low/flat... in the PCB, where is write "level" I put a jumper, and 10k resistor just close...

thank you

_________________
Yes!
Oh Yeah!
Wow!
Back to top
View user's profile Send private message Visit poster's website
andrewF



Joined: Dec 29, 2006
Posts: 1174
Location: australia
Audio files: 4

PostPosted: Mon Mar 08, 2010 9:31 am    Post subject: Reply with quote  Mark this post and the followings unread

hi
just replace that link with a resistor.
maybe 100K would be a good startpoint.

or you could replace the link with a pot:

Ken's page describes what to do -
The final stage is a simple gain stage, as I found the original was too quiet for my needs. In the first version of the PCB, this stage was inverting, while on the Rev 1 PCBS, this stage is non-inverting. The LEVEL pads are to allow for a level pot to be installed. Use a pot with a value of 50k or 100k (going even higher if needed, e.g. 250k), depending on the overall gain required. Alternatively, a fixed resistor could be put here, or even a link, if the 47k in series with it is increased to compensate.
Back to top
View user's profile Send private message Visit poster's website
Lorenzo



Joined: Nov 09, 2008
Posts: 354
Location: Trieste - Italyjstan

PostPosted: Mon Mar 08, 2010 11:42 am    Post subject: Reply with quote  Mark this post and the followings unread

... ehmm
_________________
Yes!
Oh Yeah!
Wow!

Last edited by Lorenzo on Tue Mar 23, 2010 2:14 pm; edited 1 time in total
Back to top
View user's profile Send private message Visit poster's website
Lorenzo



Joined: Nov 09, 2008
Posts: 354
Location: Trieste - Italyjstan

PostPosted: Tue Mar 23, 2010 2:11 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hi,
just now I notice that Ken Stone has update the shematic of this filter!!!
v1.2

He corrects a "crack-click" problem of the resonance... (using a 10uf cap)!! Idea
and in reference to the topic
... adds a 47pf; an 330 ohm take the place of a 1K and a 47k resistor (in series with the volume pot) is now connect directly to OUT, instead of at previous 1k resistor!!! Exclamation

so I have to change my connections!
No problem with the resonance mod, I have already done it some time ago ... it was necessary
47pf is not a problem too ...
but I don't know what is the best way to put the level pot in series with 47k resistor directly to the out.

any ideas?

thank you very much in advance for your kindly reply!

_________________
Yes!
Oh Yeah!
Wow!
Back to top
View user's profile Send private message Visit poster's website
andrewF



Joined: Dec 29, 2006
Posts: 1174
Location: australia
Audio files: 4

PostPosted: Wed Mar 24, 2010 2:29 am    Post subject: Reply with quote  Mark this post and the followings unread

you do not have to do this mod.
Many Steiners work perfectly well with the feedback loop connected directly to the op amp output.

If you really want to do it:
put the 330R in the 1K position
the 47pF cap where the 47k resistor should go
install the link, with a nice little loop sitting up so you can solder a wire to it.
From the 'out' pad connect a 47k resistor, the other end gets connected to a wire that goes to your level pot.
Another wire goes from the level pot to the link, attach it to the top of the little loop you made when you installed the link.
The level pot will only have two wires connected to it.
one wire to the centre pin and an outer pin, the other to the remaining outer pin.
Back to top
View user's profile Send private message Visit poster's website
Lorenzo



Joined: Nov 09, 2008
Posts: 354
Location: Trieste - Italyjstan

PostPosted: Wed Mar 24, 2010 3:05 am    Post subject: Reply with quote  Mark this post and the followings unread

andrewF wrote:
you do not have to do this mod.
Many Steiners work perfectly well with the feedback loop connected directly to the op amp output.



ah hmmm ok... thanks Smile

so what is this mod? I thought it is for increase level ouput...
I'm just a little perplexed about how my Synthacon "works"!

_________________
Yes!
Oh Yeah!
Wow!
Back to top
View user's profile Send private message Visit poster's website
andrewF



Joined: Dec 29, 2006
Posts: 1174
Location: australia
Audio files: 4

PostPosted: Wed Mar 24, 2010 4:22 pm    Post subject: Reply with quote  Mark this post and the followings unread

The resistor and level pot are for gain, but the capacitor is for stability to prevent unwanted oscillation. I think that is also the idea of the feedback loop starting after the output resistor. Ken did write about this once but I can't remember where or exactly what he wrote

This is original article on the steiner, by N. Steiner at Yusynth:
here
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [7 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » Ken Stone designs - CGS
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use