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 
 Forum index » DIY Hardware and Software » Thomas Henry designs
Vco-1 pulsewidth pitch problem
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 2 [26 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Goto page: 1, 2 Next
Author Message
oculus



Joined: Oct 30, 2011
Posts: 34
Location: Iceland, Reykjavik

PostPosted: Fri Jul 12, 2013 7:51 am    Post subject: Vco-1 pulsewidth pitch problem Reply with quote  Mark this post and the followings unread

hi i just breadboarded a VCO-1, im using thomas henry 15volt powersupply i just finished to power it up.
the vco seems to work fine, but the only thing is that, when i increase the pulsewith the pitch also seems to go a little bit up
along with the pulsewith

the pitch drops almost a semitone from almost full left to almost fully right
on the pw knob.

Anyone have an idea what might be the problem?



btw i don´t have a tempco in the VCO-1 yet im waiting for it to arrive
but don´t think this should affect this problem,(in fact it track quite well without the tempco)
thanks kind regards
Oculus
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Tue Aug 22, 2017 9:25 am    Post subject: Reply with quote  Mark this post and the followings unread

hello there,

are you still on breadboard?
it may well be a poor grounding issue. I had the same problem with my Thomas Henry 555 VCO.
when sweeping the PWM the VCO pitch horribly fluctuated.
I sorted it by adding a few more ground points from the VCO breadboard GND straight to the power supply GND and it worked
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Thu Aug 24, 2017 1:56 am    Post subject: Reply with quote  Mark this post and the followings unread

after a quick look over the schematic i would try to remove / lower R45 and raiseR12 to 10k and R7 to 5k
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Thu Aug 24, 2017 3:56 am    Post subject: Reply with quote  Mark this post and the followings unread

hey
what schematics are you referring to?
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Thu Aug 24, 2017 6:47 am    Post subject: Reply with quote  Mark this post and the followings unread

sry your rigth
http://www.birthofasynth.com/Thomas_Henry/pdf/VCO-1/vco1_schem2.pdf
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Thu Aug 24, 2017 9:08 am    Post subject: Reply with quote  Mark this post and the followings unread

no worries g.gabba !

i built the 555 VCO by Thomas Henry only. And not the VCO 1 yet Smile
so i can't tell.
May i ask you to explain what the resistor value modifications would add to, or improve the PWM section?
cheers
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Fri Aug 25, 2017 1:39 am    Post subject: Reply with quote  Mark this post and the followings unread

nice one ! head banging monitor
i understood that oculus had breadboarded the th-vco1

regarding the resistors: oculus has described a strange behavior of the PWM section, so i tought:
2.2M is getting close to the "internal" impendances of an opamp so it is getting harder for the opamp to understand and regulate the feedback current.

3k and 1.8k on the out put gives a power consumption of only 3.125 mA from the (20-25mA the opamp can deliver), but, even that can result in strange behaviors under unfortunate circumctances like breadboard, opamp from bangladesh, no stabilizing caps..
and what i forgot in the previous post: ground the metal-capsule of the pot - no joke

gl
hf
gabbagabi
geek flower dwarf
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Fri Aug 25, 2017 3:10 am    Post subject: Reply with quote  Mark this post and the followings unread

thanks g.gabba
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Fri Aug 25, 2017 9:12 am    Post subject: Reply with quote  Mark this post and the followings unread

in my strange mix of portuguese and italian:
non sei para o que ma,
niente Smile
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Fri Aug 25, 2017 9:26 am    Post subject: Reply with quote  Mark this post and the followings unread

where are you from ? Cool portugal?
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Fri Aug 25, 2017 1:37 pm    Post subject: Reply with quote  Mark this post and the followings unread

ich bin ein berliner! - io so berlinese!

but my wife lived 8 years in fregene so she is even able to speak romanatio and now we are thogether in mosambique where they speak portuguese.
so i picked up a funny mix of those latin linguas.

ciao
buona notte
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sat Aug 26, 2017 12:01 am    Post subject: Reply with quote  Mark this post and the followings unread

Smile
it must be fun to live in Berlin
Back to top
View user's profile Send private message
wackelpeter



Joined: May 05, 2013
Posts: 385
Location: germany
Audio files: 10

PostPosted: Sat Aug 26, 2017 6:04 am    Post subject: Reply with quote  Mark this post and the followings unread

Nope...

In recent times Berlin is overrun by hordes of hipsters...

Hipster apocalypse - the night of the living beard

Very Happy

Best thing to emigrate into a hipster free - safe zone like Mosambique

_________________
https://soundcloud.com/bastian-j
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sat Aug 26, 2017 6:45 am    Post subject: Reply with quote  Mark this post and the followings unread

cheesy

bastian are you from Berlin?
its electronic music scene has always appealed me. Techno and minimal.
And after watching Depeche Mode interviews,where they sing the praise of 1983-1986 Berlin night vibe i got really curious to sample it Wink

but the city turned into something completely different to the mid 80's,apparently.
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Sat Aug 26, 2017 7:56 am    Post subject: Reply with quote  Mark this post and the followings unread

may enjoy a documentary about the tresor?
https://www.youtube.com/watch?v=SGGA3a_8Crs&t=790s

and if u not afraid about streaming a docu about berlin-west in the 80's
http://vidzi.tv/xg6o9y79djup.html

there is a third one about Skaters and Music in the 80's in East- Germany,
but i could not find a link for that, more info here
https://www.amazon.com/This-Aint-California-Ronald-Vietz/dp/B01GWC68Z0

all very well done, its always hard to find sleep for me when i watched them, cos those where my golden times

and very sorry oculus! for missusing ur thread but nowadays is so less communication here on em

mosambike could be a nice place if i only could find well-working Potentiometers here:-)

cheers
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sat Aug 26, 2017 8:19 am    Post subject: Reply with quote  Mark this post and the followings unread

don't worry g.gabba about going off topic Very Happy
since the creator of this thread can't seem to be active anymore here, we can take advantage of this space and swap some infos and opinions.

However it looks like that electromusic is getting more and more quite.
I've only been here for a year but there seems to be definitely less action.
what do you reckon?
Back to top
View user's profile Send private message
wackelpeter



Joined: May 05, 2013
Posts: 385
Location: germany
Audio files: 10

PostPosted: Sat Aug 26, 2017 10:30 am    Post subject: Reply with quote  Mark this post and the followings unread

No, i'm not from Berlin but many Hipsters from my hometown moved to Berlin (sadly not all of them). Very Happy

Regarding the movies mentioned before that Documentation/Film by Mark Reeder is really recommended. This can be found on YouTube to i believe.
The link provided here has some suspect looking adds...

Btw. any Progress with your 555VCO? Did you already looked at it with an scope?

_________________
https://soundcloud.com/bastian-j
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sat Aug 26, 2017 1:45 pm    Post subject: Reply with quote  Mark this post and the followings unread

hey Bastian,
i will take a look at those movies soon !
As far as the 555 VCO...well, no, i haven't checked it yet. Wink it got a bit negleted in favour of some other little modules that were in my to-do-list, but definitely tonight i'll check the signals amplitude.

hipsters are ubiquitous.
even is southern Italy, where i am from, they mushroomed help
not my cup of tea. Both their look and their attitude piss me off to no end
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sat Aug 26, 2017 1:49 pm    Post subject: Reply with quote  Mark this post and the followings unread

if you ever come to Sardinia island on holiday, drop me a line!

during the summer many Germans seem to enjoy our beaches and...beers too beer
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sat Aug 26, 2017 4:40 pm    Post subject: Reply with quote  Mark this post and the followings unread

so,

i scoped up the 555 VCO output signals , and the amplitude of all waveforms stays consistent through the whole frequency sweep.

However, it still puzzles me that the voltage read on DMM changes upon frequency value.

The saw tends to be even , about 2 V
the square varies from about 1.8 to 4 V
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Sun Aug 27, 2017 3:42 am    Post subject: Reply with quote  Mark this post and the followings unread

good morning guys,

i wish i had a peroni Smile , next time i will bring some from South Africa.

The hipsters, they really like the long wished product of that secrect circle that is stearing the world. They are the pre-version of the brainless-working-eating-consuming-and-feel-good-about-drones that they wish to have to Smile
They are really the enemys of us natural born DIYselfis.

Regarding the DMM measurement, i would say its because cos a DMM does filter the incomming signal.

Regarding this thread i finally realised that it is from 2013 Idea

About the quantity of communication here on EM, my guess is we should do what we are doing right now, going a bit more personal.
I really love this place, did not seen any other worth it. guys are also on Muffwiggler but for some reason i cant leave this place.

What else? The film. They somehow deleted the Berlin Docu on youtube.

cheers
gl
hf
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sun Aug 27, 2017 4:16 am    Post subject: Reply with quote  Mark this post and the followings unread

hey g.gabba,

Yes, i think it's a nice thing to become friends here, and make some more "private" lines of communications, for a lack of a better term Smile
And besides the electronic DIY side it's nice to get each other a bit, talk about life, it won't harm !

Now someone brought in the Hipsters topic, which would have me talking about that forever. Smile This trend,along with many others,it's something i love to analyze. It tells a lot about our society.
They claim to be strong anti-capitalists, to have anti-consumerist attitudes (but that doesn't apply to Apple or Ray-Ban they buy)
and in short ,those scumbags are consumers of culture, not producers of original content whatsoever. Better forgotten.

Peroni is an ok beer ,yet it's considered quite average over here. Laughing Laughing
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sun Aug 27, 2017 4:31 am    Post subject: Reply with quote  Mark this post and the followings unread

back to the 555 VCO, it sounds awesomely good, it has that unmistakable "80's" flavor to my ears.
Can't wait to couple it with a Roland filter to get the best out of both modules Smile
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 175
Location: berlin
Audio files: 18

PostPosted: Sun Aug 27, 2017 4:50 am    Post subject: Reply with quote  Mark this post and the followings unread

alan,
lets open a thread in the chat room area and leave this here.
cu there
Back to top
View user's profile Send private message
alanwilder81



Joined: Sep 03, 2016
Posts: 325
Location: italy

PostPosted: Sun Aug 27, 2017 5:52 am    Post subject: Reply with quote  Mark this post and the followings unread

hey g.gabba

i don't know how the chat area works ! Rolling Eyes
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 2 [26 Posts]
View unread posts
View new posts in the last week
Goto page: 1, 2 Next
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » Thomas Henry designs
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