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Messages - mark123

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31
VFE Projects / Re: Tractor Beam - all buttoned up.
« on: November 25, 2017, 03:12:00 PM »
The 1.43k ohm resistors are marked 1.4k on the silkscreen, correct?  I'm just going to replace them. 

32
VFE Projects / Re: Tractor Beam - all buttoned up.
« on: November 25, 2017, 02:18:32 PM »
First thing I would look at it making sure you have used 1.43k (or closest value to it) where it says and that your trimmer is actually 20k (not 2k, etc). The output section is really simple so either the resistors going in or the trimmer are to blame for too low a signal.
Hmmm.  Everything looks to be correct.  I'm going to try a 200k trimmer if I can get it back apart.  I tried the 200k trim pot and dimed it almost gets to unity. Hmmm.

33
VFE Projects / Re: Tractor Beam - all buttoned up.
« on: November 25, 2017, 01:46:14 PM »
Code: [Select]
OPA2134 DC      LM358 DC      TLE2074 DC     
1 *mV              1 varies           1 *mV             
2 *mV              2 varies           2 *mV             
3 *mV              3 varies           3 *mV             
4 -8.38v           4 -8.38v           4 9.05v
5 *mV              5 varies           5 *mV
6 *mV              6 varies           6 *mV
7 *mV              7 varies           7 *mV
8 9.05v            8 9.05v            8 *mV
                                       9 *mV
                                       10 *mV
                                       11 -8.38v
                                       12 *mV
                                       13 *mV
                                       14 *mV

34
VFE Projects / Tractor Beam - all buttoned up.
« on: November 25, 2017, 01:05:15 PM »
I finally got the Neutrik jacks I needed in the mail today and got the Tractor Beam all buttoned up.  I noticed that when the effect is engaged that I get a rather significant volume drop.  The phasing works as it should and it has TONS of adjustment and versatility.  I really like it.  The 20k LEVEL trim pot is dimed and it still has the volume drop.

Any tips?

35
VFE Projects / Re: VFE Switching Board - questions while building
« on: November 23, 2017, 11:47:19 AM »
Cool thanks.  :)

36
VFE Projects / Re: VFE Switching Board - questions while building
« on: November 23, 2017, 11:37:09 AM »
Thanks for the info. Is this common?

Peter suggests 1/2W for when and 18v power supply is used but so far all the VFE pedals I've seen are 9v only. A 1/4W is fine for all the VFE projects I've released so far and is actually what is recommended in the new switching board doc. There's no downside to using 1/2W (the upside being better current handling and slightly less noise prone), though. It's just less commonly used in pedals.
Thanks.

Is using the P in the P1K have any significance to anyone other than VFE?

37
VFE Projects / Re: VFE Switching Board - questions while building
« on: November 18, 2017, 06:30:09 PM »
Thanks for the info. Is this common?

38
VFE Projects / Re: Tractor Beam update
« on: November 18, 2017, 12:29:26 PM »
The Tractor Beam uses the TC7662B and the low ESR Electrolytics, correct?  It's not listed in the switching board "Used With" column but it is in the picture of the doc.

39
VFE Projects / VFE Switching Board - questions while building
« on: November 18, 2017, 11:55:21 AM »
I have a 1/2W 1k resistor near the Zener and the other 1k resistor in the schematic comes off the switch on the silkscreen it's marked P1k but I'm not familiar with the P.  What does it mean?

40
VFE Projects / Re: Tractor Beam update
« on: November 11, 2017, 10:34:14 AM »
... you can view NomNom docs
I saw that mentioned but didn't know what it meant. I Binged it and figured it. Thanks.

From the Nomnom doc:
Quote
You want to find the closest matching voltage readings on these transistors. At least within 5% of one another, although I generally shoot for 1% or less. So, if a device reads 0.75vDC, I would look for another one that measures 0.74 to 0.76v.
Exactly what I was looking for.  Since we're looking at Vgs I'm just thinking of picking up a semiconductor analyzer.

41
VFE Projects / Re: Tractor Beam update
« on: November 11, 2017, 07:22:26 AM »
When I'm matching the JFETs, what is the tolerance? How close do they have to be?

42
Any CAD program could be used. Inkscape or the like could be put into service.

dave
Ok, so any CAD program has a schematic view??  ???

43
Weird. I was just thinking about this same thing lol.
Well, DIYLC looks to be the answer if you can run Java. Maybe I'll install a virtual machine and give it a go.

I don't trust Java when considering security.

44
DIYLC requires Java.  I'll keep looking.

45
Give DIY Layout Creator a try. It has turret support also.

https://code.google.com/archive/p/diy-layout-creator/downloads
Thanks! I'll give it a try!

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