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/mr

Joined: Aug 05, 2007 Posts: 223 Location: Elektron City, Sweden
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Posted: Thu Apr 17, 2008 11:04 am Post subject:
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It says "Capacitors SMT, 35 x 100nF"
What are these? Surface mount??
I can't see them in the overlays/schematics/photo... or am I just blind again?  |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
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Posted: Thu Apr 17, 2008 11:43 am Post subject:
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| /mr wrote: |
It says "Capacitors SMT, 35 x 100nF"
What are these? Surface mount??
I can't see them in the overlays/schematics/photo... or am I just blind again?  |
100nF bypass caps on all the opamps. Not shown in schemos. Located on solder side of PCB. Yes- a bit of surface mount technology here.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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guitarfool

Joined: Feb 26, 2007 Posts: 162 Location: Maryland
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Posted: Sun Apr 20, 2008 10:42 am Post subject:
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I'm just starting the panel layout for this thing. Is there any advantage to having BOTH linear AND exponential manual tuning? At the same time?
I'd rather just have exponential coarse/fine tuning, or one set of coarse/fine controls with a 4PDT "lin/exp" switch.
I am doing Moog/dotcom format, and I can get it all on a 2 width panel if I only have the one set of tuning controls. Otherwise, I have to go to 4 width as there are no 3 width panels available . |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Sun Apr 20, 2008 12:18 pm Post subject:
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| guitarfool wrote: | I'm just starting the panel layout for this thing. Is there any advantage to having BOTH linear AND exponential manual tuning? At the same time?
I'd rather just have exponential coarse/fine tuning, or one set of coarse/fine controls with a 4PDT "lin/exp" switch.
I am doing Moog/dotcom format, and I can get it all on a 2 width panel if I only have the one set of tuning controls. Otherwise, I have to go to 4 width as there are no 3 width panels available . |
Personally I find the 4 potentiometers very comfortable.
You can set your maximum range (for a manual sweep) with the exponential pot, and then use the full rotation of the linear pot to perform this sweep, with zero shift at 12 o'clock position.
The linear fine tuning knob helps to set very precise sweeps near the zero point (for "infinite phasing"), even when a rather large range is set with the exponential pot.
The exponential fine tuning helps tuning the oscillator when you want your frequency shift amount to be in a precise musical relation to your input signal. ("Tracking Shift")
You certainly can omit some of this, and find a (smaller) configuration that fills your needs. What I recommend is the 4-pot solution - what I provide is linear and expo CV inputs at the same time, which allows you any other way to control it that you like.
You could replace each coarse/fine pot pair with a vernier dial and a single pot, of course. Or a set of concentric pots. Or substitude some of it with a rotary switch + resistor divider. Or connect a joystick.
It's up to you.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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/mr

Joined: Aug 05, 2007 Posts: 223 Location: Elektron City, Sweden
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Posted: Sun Apr 20, 2008 12:27 pm Post subject:
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Thanks for a good explanation of why having all four pots makes sense.
I was also thinking of the chances of omitting some of them, but now I'll keep them.  |
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neandrewthal

Joined: May 11, 2007 Posts: 672 Location: Canada
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Posted: Sun Apr 20, 2008 6:58 pm Post subject:
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Hmm. IMO a frequency shifter has to have one gigantic knob. Which one should it be? _________________ " I went through quite a few trannies til I found one I liked" - Wild Zebra |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Sun Apr 20, 2008 11:14 pm Post subject:
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| neandrewthal wrote: | | Hmm. IMO a frequency shifter has to have one gigantic knob. Which one should it be? |
The linear, coarse potentiometer (labelled "Manual").
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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/mr

Joined: Aug 05, 2007 Posts: 223 Location: Elektron City, Sweden
Audio files: 1
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Posted: Mon Apr 21, 2008 2:02 am Post subject:
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The desire of Le Bigge Knobbe and the sense of symmetry bring up new doubts about keeping all four tuning knobs... so now I'm thinking:
| jhaible wrote: | | You can set your maximum range (for a manual sweep) with the exponential coarse pot, and then use the full rotation of the linear coarse pot to perform this sweep, with zero shift at 12 o'clock position. |
If the exponential pot is mostly seen as a "range selection" for the linear pot, would it make sense to replace the exponential pot with a toggle switch giving three pre-set ranges?
If the exponential coarse pot is rarely used for finetuning or "manual play", it shouldn't be very important to have it continuously variable. In addition, it would allow the linear coarse pot to have a proper scale with real Hz values on the panel, since it's not determined by another pot. The toggle switch could then have three scale multiplier values like "1x/10x/100x".
Any opinions?  |
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/mr

Joined: Aug 05, 2007 Posts: 223 Location: Elektron City, Sweden
Audio files: 1
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Posted: Mon Apr 21, 2008 4:01 am Post subject:
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| guitarfool wrote: | I am doing Moog/dotcom format, and I can get it all on a 2 width panel if I only have the one set of tuning controls. Otherwise, I have to go to 4 width as there are no 3 width panels available . |
Have you removed the Left/Right Level pots yet? They are quite unnecessary, I guess.
After all, I find the needed panel space surprisingly small - not much bigger than the PCBs themselves (10*15cm). I first expected the opposite, since JH's drawing makes it look so huge.  |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Mon Apr 21, 2008 2:40 pm Post subject:
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| /mr wrote: |
If the exponential coarse pot is rarely used for finetuning or "manual play", it shouldn't be very important to have it continuously variable. In addition, it would allow the linear coarse pot to have a proper scale with real Hz values on the panel, since it's not determined by another pot. The toggle switch could then have three scale multiplier values like "1x/10x/100x".
Any opinions?  |
If 3 ranges are enough for you, then a toggle switch will do.
I'd go for a better resolution, though: You could use a rotary switch with positions that are an octave apart, for instance.
But this should not give you the wrong impression that you really have precise octaves: On a good day, the oscillator will track 3 octaves or so, not more. (Speaking of the 1V/Oct input, but this would also apply to scaled switches.)
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Fri Apr 25, 2008 3:09 am Post subject:
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http://www.jhaible.heim.at/fs1a/fs1a.html
updated - adjustment procedure description completed.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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guitarfool

Joined: Feb 26, 2007 Posts: 162 Location: Maryland
Audio files: 8
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Posted: Fri Apr 25, 2008 3:58 pm Post subject:
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Got my 2 sets of boards today
Haven't finished my panel layout yet, so I guess I'll go ahead and build one on a temporary scrap panel. Then I can test out what I think I want before finalizing the panel silkscreen.
I have an Encore FS (MOTM format) that will probably go up for auction on ebay soon I think I'll do an A-B comparison first, just for fun. |
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/mr

Joined: Aug 05, 2007 Posts: 223 Location: Elektron City, Sweden
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Posted: Fri Apr 25, 2008 4:16 pm Post subject:
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| jhaible wrote: | | /mr wrote: |
If the exponential coarse pot is rarely used for finetuning or "manual play", it shouldn't be very important to have it continuously variable. In addition, it would allow the linear coarse pot to have a proper scale with real Hz values on the panel, since it's not determined by another pot. The toggle switch could then have three scale multiplier values like "1x/10x/100x".
Any opinions?  |
If 3 ranges are enough for you, then a toggle switch will do.
I'd go for a better resolution, though: You could use a rotary switch with positions that are an octave apart, for instance. |
Interesting... But is the shifting effect really "pitched" in a way that makes this kind of octave switching natural?
| guitarfool wrote: | Got my 2 sets of boards today
I have an Encore FS (MOTM format) that will probably go up for auction on ebay soon I think I'll do an A-B comparison first, just for fun. |
Somebody should collect & publish "similar" sound examples from different frequency shifters for comparison - I expect them to be quite diverse!
I got my PCBs as well, I've been cudding with them all day  |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Sat Apr 26, 2008 2:05 am Post subject:
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| /mr wrote: |
Interesting... But is the shifting effect really "pitched" in a way that makes this kind of octave switching natural? |
Normally FS are most known for destroying harmonic relations.
But if you set the FS's internal oscillator to a "musical" ratio of your input signal, and transpose the two of them with the same CV, you can actully play little melodies ...
But I don't want to raise any high expectations. The tracking of the FS-1A's oscillator is very bad (more like two than three octaves) - the feature is that it does some kind of V/Oct tracking at all.
Don't expect digital precision here. (I think the Encore FS has a digital QVCO, which isn't a bad choice, IMO.) It's all analogue madness, with all its pros and cons.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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mph

Joined: Aug 25, 2007 Posts: 88 Location: France
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Posted: Sat Apr 26, 2008 3:56 am Post subject:
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Thanks Jürgen, I got my set of boards today
Btw, did someone do the comparison with a Dacs Freque2, it has the same frequency shift function (if I am right?)? Just curious... |
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oscilloclast
Joined: Sep 29, 2005 Posts: 49 Location: VA
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Posted: Sat Apr 26, 2008 5:38 pm Post subject:
Frequency shifter |
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| Got my boards today! Thanks. |
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TheAncientOne

Joined: Dec 26, 2006 Posts: 144 Location: United Kingdom
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Posted: Sun Apr 27, 2008 9:42 pm Post subject:
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I got my boards this weekend, thanks again Jurgen.
If anyone in Europe needs four of the 22pF surface mount caps, drop me a PM and I'll post them to you. I have got 100 of them, (minimum order quantity from Rapid). _________________ Mike |
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v-un-v
Janitor


Joined: May 16, 2005 Posts: 8932 Location: Birmingham, England, UK
Audio files: 11
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Posted: Mon Apr 28, 2008 1:08 am Post subject:
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JH, can you be so kind as to remind me how much a set of FS boards is again?
thanks!
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. |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Mon Apr 28, 2008 1:04 pm Post subject:
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| v-un-v wrote: | JH, can you be so kind as to remind me how much a set of FS boards is again?
thanks!
Tom |
Hi Tom,
it's in message 195 of this thread, or to make things easier, just follow this link:
http://electro-music.com/forum/topic-18587-195.html
JH.
Now playing: Tangerine Dream, Tangram (testing my new Goldring 1042) _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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v-un-v
Janitor


Joined: May 16, 2005 Posts: 8932 Location: Birmingham, England, UK
Audio files: 11
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Posted: Mon Apr 28, 2008 1:52 pm Post subject:
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| jhaible wrote: |
Now playing: Tangerine Dream, Tangram (testing my new Goldring 1042) |
Thanks JH! Number 195?
Tangram. I haven't played that in ages. I remember it to be one of the better ones of the latter part of TD's career, along with "Thief". Stein really dislikes Exit, but "Remote Viewing" on Exit is probably TD at their very finest during the 80's period imo.
Have you heard "As Falls Wichita, So Falls Wichita Falls" by Pat Metheny/ Lyle Mays? This reminded me of Tangram in a way. Wichita Falls is a real Prophet 5 lovers LP . Tangram was the 2nd TD LP I heard too -the first being the Wages of Fear soundtrack, which I first heard in Canada- really fitting for the British Columbian countryside too imo  _________________ 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. |
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numbernone
Joined: Aug 16, 2006 Posts: 477 Location: new york city
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Posted: Mon Apr 28, 2008 2:18 pm Post subject:
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FREQUENCY SHIFTER BOARDS SPOTTED ON AMERICAN EAST COAST!!!!
Maybe in a few years I will have my stuff together enough to actually build it!!
One of these boards is so dense that it boggles the mind. |
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/mr

Joined: Aug 05, 2007 Posts: 223 Location: Elektron City, Sweden
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Posted: Mon Apr 28, 2008 2:25 pm Post subject:
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| numbernone wrote: | | One of these boards is so dense that it boggles the mind. |
Depends on how you see it... I'd rather say that the other board is overly sparse!
I'd love to have some experiment board area there in the big oceans of nothingness...  |
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/mr

Joined: Aug 05, 2007 Posts: 223 Location: Elektron City, Sweden
Audio files: 1
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Posted: Tue Apr 29, 2008 11:59 am Post subject:
OP-amp choices |
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Most of the OP-amps in the BOM are TL072/TL074. These are good common standard OP-amps with moderate noise, moderate offset voltage, good slewrate - but remarkably good offset current / bias current / input resistance.
Are they chosen with this input resistance feature in mind, or would some of them actually benefit from being exchanged for some other OP featuring lower noise and lower offset voltage instead?
I was thinking of the earlier explanation about how some "small" errors would cause enormous artifacts during the shift process, rendering a certain frequency shifter design practically unusable... and I was wondering if for instance a lower-noise OP-amp in some of the early stages would make an ever bigger advantage than just lowering the noise.
If you see what I try to mean.
(Then I'm also wondering about the "301" printed on all the TL07x OP-amps... is it the LM301 coming up as an invalid alternative?)  |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Tue Apr 29, 2008 12:40 pm Post subject:
Re: OP-amp choices |
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| /mr wrote: | Most of the OP-amps in the BOM are TL072/TL074. These are good common standard OP-amps with moderate noise, moderate offset voltage, good slewrate - but remarkably good offset current / bias current / input resistance.
Are they chosen with this input resistance feature in mind, or would some of them actually benefit from being exchanged for some other OP featuring lower noise and lower offset voltage instead?
I was thinking of the earlier explanation about how some "small" errors would cause enormous artifacts during the shift process, rendering a certain frequency shifter design practically unusable... and I was wondering if for instance a lower-noise OP-amp in some of the early stages would make an ever bigger advantage than just lowering the noise.
If you see what I try to mean.
(Then I'm also wondering about the "301" printed on all the TL07x OP-amps... is it the LM301 coming up as an invalid alternative?)  |
All opamp types have been chosen very carefully.
I guess you can find good alternatives for each opamp in the circuit (one of the reasons why I chose what I chose was to use the least expensive part that does the required job).
Just two caveats:
(1) You must know exactly what you're doing. An upgrade for a OP-07 will be a very different part than an upgrade for a TL071, for instance.
(2) I don't expect any advantage from upgrading opamps.
The main problem of any FS is not noise, but bleedthru. If anything, a higher noise level will be better to mask the bleeding sine wave.
The way you build the whole thing, and your patience adjusting it, is a lot more important than component selection.
For instance, in my first prototype I used a rather long cable for the +/-15V from board 2 to board 1. And I got increased bleedthru from coupling the oscillator GND to the audio GND that way. Especially with the dual colour "Rate" LED flashing at audio rate.
You can run into problems like this even with a perfect cancellation of the oscillator signal in the modulators themselves.
Bringing the two boards closer together and using a short +/-15V connection did fix this.
Just an example to show where the real challenges are.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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fredw
Joined: Jul 08, 2007 Posts: 10 Location: Berkeley, CA
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Posted: Fri May 02, 2008 6:28 pm Post subject:
Frequency Shifter |
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Yes Yes Please! Freq Shifter PCBs would be great!
Thanks. |
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