electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links
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 » Ken Stone designs - CGS
Bridechamber's Matched Transformer and Diode Set
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
camelneck



Joined: Sep 27, 2008
Posts: 68
Location: KY (USA)

PostPosted: Thu Mar 19, 2009 2:41 am    Post subject: Bridechamber's Matched Transformer and Diode Set Reply with quote  Mark this post and the followings unread

When I bought my Wave Multiplier PCB set from Bridechamber, I also purchased the Matched Transformers and German Diode set for the real Ring Modulator in this particular project.

When I was installing the diodes, I noticed that the diodes were "gold-doped diodes" instead of "germanium diodes". I also measured the forward voltage drop for each of these diodes and although all 4 diodes were equally matched, the forward voltage drop was 0.66 volts, which is consistent with gold-doped diodes, and not the 0.25 to 0.3 volts that one would find when measuring the forward voltage drop of a germanium diode.

There is a note on the PCB that says to use germanium diodes for the ring of the Real Ring Modulator. So I'm sure that this will effect the overall sound of the real ring modulator and its associated distortion.

Did anyone else who purchased this Transformer+Diode set from Bridechamber also get gold-doped diodes? How did this effect the overall sound?

David
Back to top
View user's profile Send private message
v-un-v
Janitor
Janitor


Joined: May 16, 2005
Posts: 8933
Location: Birmingham, England, UK
Audio files: 11
G2 patch files: 1

PostPosted: Thu Mar 19, 2009 4:21 am    Post subject: Reply with quote  Mark this post and the followings unread

Hi David.

I really don't think you will notice much difference. I built a RM circuit using modern diodes, and comparing to a friend who built one using germanium diodes, there really wasn't any difference in sound.

You can really get hung up on this kind of stuff- like using coaxial cable for interconnects etc, but it makes little difference. Smile

Tom

_________________
ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!
DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.
ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.
Back to top
View user's profile Send private message Send e-mail
camelneck



Joined: Sep 27, 2008
Posts: 68
Location: KY (USA)

PostPosted: Thu Mar 19, 2009 11:33 pm    Post subject: Reply with quote  Mark this post and the followings unread

>>I really don't think you will notice much difference. I built a RM circuit using modern diodes, and comparing to a friend who built one using germanium diodes, there really wasn't any difference in sound. <<Tom>>You can really get hung up on this kind of stuff- like using coaxial cable for interconnects etc, but it makes little difference. <<

You're absolutely right. That's a very good point.

The same applies to VCO waveforms. Often, the waveform don't have to look like a perfect triangle wave on an oscilloscope to sound like a perfect triangle wave. It doesn't matter that much to our ears. However, there may be other applications, including non-music applications where you might need a signal generator to produce a near perfect triangle wave in order for the equipment to function properly.

However, you have to remember that engineers like myself, are trained to scrutinize even the most minute details until we are sure that they have no impact on the circuit. In other words, we are trained and paid to be "anal". Smile

Consider the case of the CGS Wave Multiplier vs the YuSynth/JH Wave Multiplier. Although the circuits are quite different, both depend upon diode rectifiers to do the "wave folding". However, the BOM for the YuSynth WM calls for matched diodes while the CGS WM calls for regular diodes. Although the waveforms produced by the YuSynth Wavefolder may look more symmetrical due to the matched diodes, apparently both WM's do a fairly good job of mangling the original waveform and the sound.

So, I'll trust your ears and go with the diodes I bought, at least for now. Smile
Thanks again for your post.

David
Back to top
View user's profile Send private message
Rykhaard



Joined: Sep 02, 2007
Posts: 1290
Location: Canada

PostPosted: Fri Mar 20, 2009 7:59 am    Post subject: Reply with quote  Mark this post and the followings unread

Hey - I wish I'd thought to post this question earlier. Shocked

As per transformers for the 'real ring modulator', the other day when I was scrapping some old equipment I'd rescued from the trash at work, I took out from a control board's PCB a pair of miniature transformers. The only way that I could 'match' them, were by the # atop of each of the transformers. (There was a total of 4. 2 each having the same #'s.)

Now, I haven't an LCR meter to measure each of the coil's Inductances on the transformers. Measuring each of them for resistance, both sides of each come out to your standard 0.02 ohms (test lead resistance).

Each of transformers (1/2" x 1/2" x 1/2") have 2 leads to one coil and the other is center-tapped.

Outside of that - I've NO other clue about them. Sad What the PCB / enclosure was from or what it is. (Possibly came from early surface mount machinery; parts placement VCD machine or something.)

What parameters do I need to know / worry about, for the 'real ring modulator', as far as the transformers go? Do the coils have to be somewhat matched on each side of the transformer, or a certain ratio to each other?

Or should I just hook them up with my 1N34A germaniums and see what happens?

Thanks for any thoughts. Smile (I'm not an Eng. I'm self-taught in everything.)
Back to top
View user's profile Send private message Yahoo Messenger MSN Messenger
v-un-v
Janitor
Janitor


Joined: May 16, 2005
Posts: 8933
Location: Birmingham, England, UK
Audio files: 11
G2 patch files: 1

PostPosted: Fri Mar 20, 2009 10:27 am    Post subject: Reply with quote  Mark this post and the followings unread

Go for it Rych! Smile
_________________
ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!
DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.
ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.
Back to top
View user's profile Send private message Send e-mail
BananaPlug



Joined: Jul 04, 2007
Posts: 307
Location: Philly
Audio files: 5

PostPosted: Fri Mar 20, 2009 5:47 pm    Post subject: Reply with quote  Mark this post and the followings unread

You might get a chuckle out of this. The National Library of Australia lists a book in their catalog titled:
"Miniwatt" transistors geranium diodes & silicon diodes"

http://nla.gov.au/nla.cat-vn2942371
Back to top
View user's profile Send private message Visit poster's website
blue hell
Site Admin


Joined: Apr 03, 2004
Posts: 24081
Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320

PostPosted: Fri Mar 20, 2009 6:03 pm    Post subject: Reply with quote  Mark this post and the followings unread

BananaPlug wrote:
geranium diodes


o i love that Laughing use it myself at times.

Geranium diodes with silicon flowers.

_________________
Jan
also .. could someone please turn down the thermostat a bit.
Posted Image, might have been reduced in size. Click Image to view fullscreen.
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


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