Building the Meat Sphere

Started by Taylor, July 27, 2011, 03:39:06 PM

Previous topic - Next topic

WhenBoredomPeaks

#220
I added the Moog-switch yesterday, it is a must have in my opinion.

I want to add a jack for external DC control signal input. Looking at the schematics, the easiest way to do this is to connect a wire to one of the legs of the intensity pot. (because one of the legs of that pot is connected directly (well, almost, there are two 100ohm resistors between them but they seem necessary) to the LDRs.) (i will use a DMM to find out which is the correct leg)

The question is, will those LDRs survive 8-9V control signals? (i suspect that there is no reason for using signals that strong because that LM1458 probably can't deliver more than 6-7V but i am asking this because i don't want to destroy those LDRs.)

After a second look it seems like that those 100ohm resistors connected to the LED side of the LDR are forming a voltage divider so they are halving the incoming control voltage which is cool because LEDs can take 4,5V i guess. (in worst case)

SteveFromBerlin

Any update on new PCBs? I can't wait to order this and the Analog Octave Down!

lwatford

 :icon_question:
Quote from: SteveFromBerlin on March 27, 2012, 07:08:29 PM
Any update on new PCBs? I can't wait to order this and the Analog Octave Down!

Beo

How important is it for the two opto's to match closely? I have a bunch of opto's that I'm testing, and even my two NSL32's seem to vary between each other a fair bit.

Taylor

I never measured mine and still got good results. I don't think it's critical. I suppose the effect of not having matched parts would be that the resonance will vary somewhat over the frequency sweep, but as this is an effect rather than a diagnostic tool, I don't think that would be noticeable or a bad thing. If you consider that often this type of filter is swept with a dual-gang pot, and that the wafers in a dual pot will vary sometimes 30% across their sweep, it doesn't seem like it's ever an issue for anybody in effects apps.

villll

#225
Quote from: SteveFromBerlin on March 27, 2012, 07:08:29 PM
Any update on new PCBs? I can't wait to order this and the Analog Octave Down!
News on this? My soldering iron is itching for this one!
Oh yeah should've checked the site first :facepalm:

SteveFromBerlin

Quote from: villll on April 25, 2012, 08:35:31 AM
Quote from: SteveFromBerlin on March 27, 2012, 07:08:29 PM
Any update on new PCBs? I can't wait to order this and the Analog Octave Down!
News on this? My soldering iron is itching for this one!

+1!

Taylor

Quote from: SteveFromBerlin on April 25, 2012, 08:37:03 AM
Quote from: villll on April 25, 2012, 08:35:31 AM
Quote from: SteveFromBerlin on March 27, 2012, 07:08:29 PM
Any update on new PCBs? I can't wait to order this and the Analog Octave Down!
News on this? My soldering iron is itching for this one!

+1!

Hey guys, the board is back in stock now.  :)

mroenq


sgmezei

Put this one in my "fail" box for the past couple months as it was not working. A bunch of questions but the most important is:

Will this work with the switches mounted "wrong" on the component side?



Uploaded with ImageShack.us

Taylor

Yes, since that type of switch has contacts that are symmetrical, it will work the same with the switches on the wrong side, except of course that the positions will all be backwards.

teej212

would it be devestating to use 1.5 meg resistors in place of the 1.8 meg resitors?

Taylor

The one connected to pin12 of the TL074 is not critical. The other one sets the gain of the amp in the envelope detector, and I'm not positive how finicky this is as I haven't experimented with it. My guess is that it won't make a noticeable difference.

teej212

well the other 1.8 M resistor is only 1M in the Mutron Filter, so I would assume that one is not that important either.

mroenq

Maybe a question that´s already answered but as the dumb Swede I am...

The "Range"-rotary, shall I set it to 3 or 4 amount of turns?

Taylor

It should be set for four positions. I did not mark this correctly in my schematic, I realize now.

albru80

I've just received my board and I have a stupid question.
I've never used rotary switches and I'm not sure what to do.
Mine have 4 lugs in the center (A,B,C and D).
Am I supposed to solder two together or leave one out?
Which one?

Thanks

LaceSensor

Sounds like you bought the wrong type.
You want 3p4t (three poles, 4 throws, ie 3 common central pins A B C, and 4 positions for each pin to connect to)
I beleive you probably purchased 4p3t with 4 common pins A B C D

Post a pic for avoidance of doubt

Govmnt_Lacky

#238
Quote from: sgmezei on May 19, 2012, 05:50:03 PM
Put this one in my "fail" box for the past couple months as it was not working. A bunch of questions but the most important is:


Does anyone else notice that the Attack pot is wired wrong? Second from the right in the picture.

EDIT: Nevermind... just noticed that it is used as a variable resistor  :icon_redface:
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

albru80

Thanks LaceSensor. Those I've bought are exactely like those in the picture here:

http://www.musikding.de/Switches/Rotary-Switches/Rotary-switch-3P4T-sealed-pcb::2852.html?XTCsid=5796d2def3358cfc22b4479931d047ed

It says 3P4T and it has 4 lugs in the middle.

Are those wrong?