Which VD Lab OD is Correct

[markm]

I was just doing some house-keeping in the layouts gallery and received this message;

"From: juan  (Sun 11 Feb 20:23:33 2007)
It has herrores lacking a R 47K. After cap.3 and Check better Gilles Caron schematic in the same page of aronn The R11 is not of 250 is of 150 ohms I congratulate them on the page thank you

I made my layout from Justin Philpott's Schem, not knowing Gilles had one too  and this kind Gent tells me that Justin's has errors??
Can anyone verify which Schematic is correct?? 

[MartyMart]

I only have Justins, which I made a vero layout for in my gallery.
I can confirm that it works fine, his "mystery" resistor is labelled as red green black black red so 250 Ohms !
and the 47k across C3 100uf seems to be there too !
I can't see that making the 250 Ohm a 150 Ohm off the output pin would make a huge change.
MM.

[markm]

It has herrores lacking a R 47K. After cap.3

He's saying it should have a 47K going to the Gain pot.....Justin's doesn't have it Gilles' does.
Which is correct??

[Gilles C]

It's a long time ago, but I think there was a discussion about that 47K and the 150 ohms being a 250 ohms maybe on this forum.

I can't remember the details but I seem to remember that someone who had the original mentioned the correct values to use...

Gilles

[George Giblet]

I thought Giles' circuit was correct and he drew that up around the time the corrections were known. (shrug)

[Gilles C]

It's a long time ago, but I think there was a discussion about that 47K and the 150 ohms being a 250 ohms maybe on this forum.

I can't remember the details but I seem to remember that someone who had the original mentioned the correct values to use...

Gilles

I meant "the 250 ohms was corrected to 150 ohms"

Gilles

[markm]

I have a corrected version I will be posting this evening that is from the Gilles schemo (thank you Gilles C!! )
I think I'll leave both versions up as the one by Justin sounds pretty darn good too.....and not much different!

[JHS]

I never thaught about what schem is wrong or right. The 150E will give the unit a softer, rounder tone compared to the 250E. The 49k before the gain is quite large, the OD is not a Ge-diode MXR dist+.

When I built my clone I put a 100E and a 150E in series, so I can jumper the 100E if needed and I used a 22k timpot in series with a 4,7k before the gain pot (the trimpot is only fore finetuning the max. gain).

However, the IC is way more crucial, it's a TL 072P, but no infos about the manufacturer, so it needs some time to find the "right" 072 for this circuit (JRC072BD, TI072P are fine and a NS-LF353N is a good choice too).

JHS

[Gilles C]

I remember your suggestions JHS...

http://www.diystompboxes.com/smfforum/index.php?topic=49649.0

BTW Mark, did you see my new guitar?... Check my Avatar. (homemade Muddy Waters Tele)

Gilles

[MartyMart]

Just went back to my VooDoo OD and found my R11 to be a 250 ohm,
It was just starting to "whistle" with gain at max ( a 500KC reverse audio )
so i put a 2k2 resistor between lugs 1/2 & ground to stop that, sounds great, so
I'm pleased enough to box it up now
IC is a TL072IP

MM.

[markm]

I remember your suggestions JHS...

http://www.diystompboxes.com/smfforum/index.php?topic=49649.0

BTW Mark, did you see my new guitar?... Check my Avatar. (homemade Muddy Waters Tele)

Gilles

That look VERY cool Gilles!!
Does it even have the B/F fender amp knobs??
Nice work.   

Just went back to my VooDoo OD and found my R11 to be a 250 ohm,
It was just starting to "whistle" with gain at max ( a 500KC reverse audio )
so i put a 2k2 resistor between lugs 1/2 & ground to stop that, sounds great, so
I'm pleased enough to box it up now
IC is a TL072IP

MM.

Interesting.
Thanks for checking on that Marty.
I added an updated Layout from the Schem that Gilles did + I left Justin's up there too....what the Hell right?! 

[Gilles C]

I am still waiting for the knobs I ordered...

I still have a few adjustments to make before I start to try it with the last effects I built.

About the VD OD, I think the best is to have locations for all the parts, and use whatever sounds best. Like a 4.7K instead of 47K, and a 250 or 150 ohms.

Gilles

[markm]

About the VD OD, I think the best is to have locations for all the parts, and use whatever sounds best. Like a 4.7K instead of 47K, and a 250 or 150 ohms.

Gilles

Agreed.
My original layout did not have a provision for the "extra" resistor.
The new one does though!