Diezel VH4 Pedal  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.

Re: Diezel VH4 Pedal

Postby psychepool » 20 Apr 2018, 09:12

I read all the contents and try to make my own layout. I have some questions that I need to confirm.

1. I want to run it through the 9v power supply for convenience.
I am going to get 9v and drive it by making bipolar doubler through 7660 or 1054.
What is worrisome is whether to supply 18v bioplar power or 12v bipolar power through a 12v regulator.
Is the 18v bipolar power source too much choice? Is it better to supply 12v through the regulator?

2. Are R28 and R34 100R or 1K?

3. There is a controversy about the tone stack in connection with the middle pot connection.
Is it correct to connect according to the current circuit diagram? Or is it just like connecting a vintage amp with a tone stack?

Thank you for always helping me to do happy DIY. please answer about my question.
psychepool
 
Posts: 37
Joined: 04 Jan 2012, 06:51
Has thanked: 1 time
Have thanks: 18 times

Re: Diezel VH4 Pedal

Postby mnemonic » 21 May 2018, 22:27

I finally got around to building this pedal on Bugg's PCB. Great pcb as always, sounds great and works perfect.

I used the requisite TC1044SCPA and its silent, no switching noise.

pictures attached.
You do not have the required permissions to view the files attached to this post.

For this message the author mnemonic has received thanks:
sixthfloor (23 May 2018, 15:24)
mnemonic
 
Posts: 7
Joined: 28 Sep 2017, 17:22
Has thanked: 2 times
Have thanks: 4 times

Re: Diezel VH4 Pedal

Postby the_ungod » 24 May 2018, 11:10

Does any one knows whats the point of the send? I understand that it may be a buffer if we dont make the pedal true bypass. But using a 3PDT does it make sense to include C3 and R4?!

Thanks
the_ungod
 
Posts: 31
Joined: 03 Jan 2008, 17:12
Has thanked: 1 time
Have thanks: 7 times

Re: Diezel VH4 Pedal

Postby Optical » 25 May 2018, 02:19

It's useful as a key input for noise gates or recording a dry signal.
Other than that you can leave it out
Optical
Breadboard Brother
 
Posts: 55
Joined: 28 Jul 2016, 23:44
Location: Auckland
Has thanked: 7 times
Have thanks: 13 times

Re: Diezel VH4 Pedal

Postby icziko » 29 May 2018, 21:58

Guys, thanks for this fantastic schematic and this thread - it is very useful and informative.
I built using Tagboard layout and pedal sounds fantastic.
I had problem with oscillation when gain is above 60%. I tried option with 560pF instead of 47p in C10 but additional cap decreased gain a lot and entire pedal became muddy. I prefered to have better sound but oscillation above 60%.
After, I used JHS Little Black Buffer in front of pedal (clone also as per Tagboard layout) and I can crank gain to 100% without any oscillation except when my MIDS are really hi (like 70-80%) and gain at 100% than oscillation came back. Anyway I did not plan to use total gain but I will try idea to shorten connection wires between pots and board. But just to let You know, buffer pedal helps a lot but not fixed situation completely.
I also had some squeal floor noise/background - I could play but it was annoying - I figured out I used 7660A instead of 7660S. Change to 7660S solved noise issue.

I have a question - maybe somebody had similar issues so it could help me out.
My Gain Pot from 0-40% of rotation is giving me clean sound. Then between 40-50% there is big jump and it gives me hi gain stuff. It does not look like original pedal shown on Youtube. Generally on promo videos I saw that this pedal can also deliver some blues crunchy stuff, however in my situation it gives me clean to 40% and then hi gain stuff.
I already replaced pot because I thought it might be good solution but I was wrong thus gain pot is still as it is.
Does anybody have similar issue?

Thanks
icziko
 
Posts: 4
Joined: 27 Jan 2016, 21:22
Has thanked: 3 times
Have thanks: 0 time

Re: Diezel VH4 Pedal

Postby eddyc666 » 28 Jun 2018, 19:05

Hey guys,

Normally i tend to stick to reading and building, but there is something i dont understand about this build that isnt mentioned already..

The 10R resistors! (R38/R39) By the looks of the original pedal and the diy builds in this thread everybody uses 1/2watt resistors.. Arent they way to small considering the voltage that passes true them? Whats up with that! .. Is it because normal resistor wattage calculations are based on worst case scenario's? Or am i missing something?

Like i said i cant wrap my head arround it and its driving me crazy! :whappen: Thanks.. Also for this great forum and thread i love it!
eddyc666
 
Posts: 2
Joined: 02 Jun 2018, 23:53
Has thanked: 1 time
Have thanks: 0 time

Re: Diezel VH4 Pedal

Postby bmxguitarsbmx » 29 Jun 2018, 08:53

Ohms law says Power equals Current squared multiplied by resistance.

P=I^2 xR

I would be "supply current" on the op-amp datasheet added up for each op-amp.

For this message the author bmxguitarsbmx has received thanks:
eddyc666 (29 Jun 2018, 17:14)
bmxguitarsbmx
Breadboard Brother
 
Posts: 138
Joined: 25 Mar 2010, 22:15
Has thanked: 246 times
Have thanks: 72 times

Re: Diezel VH4 Pedal

Postby eddyc666 » 29 Jun 2018, 17:27

bmxguitarsbmx wrote:Ohms law says Power equals Current squared multiplied by resistance.

P=I^2 xR

I would be "supply current" on the op-amp datasheet added up for each op-amp.


I know a little bit about ohms law but i always based my calculations on the Voltage of the circuit. And in this case that would tell me i needed one giant resistor.. If i make my calculation based on amps like you suggest the opamps combined would need a max of 10mA so the wattage minimum of the 10R resistors are only 0.001watt which makes much more sense... Thank you very much for answering my noob question.. :block:
eddyc666
 
Posts: 2
Joined: 02 Jun 2018, 23:53
Has thanked: 1 time
Have thanks: 0 time

Re: Diezel VH4 Pedal

Postby bmxguitarsbmx » 30 Jun 2018, 19:22

No problem man. You would need giant 10 ohm resistors if they were going directly to ground. But these 10 ohm resistors are feeding the rest of the analog circuitry. They are there to RC filter out noise that might be left over from the lt1054 voltage converter, which does some chopping up of the voltage to derive the negative supply.

You can use ohms law to find the voltage drop across this one of these 10 ohm resistors.

E= I*R. We'll use your value of 0.01A*10ohms = 0.1V drop.
bmxguitarsbmx
Breadboard Brother
 
Posts: 138
Joined: 25 Mar 2010, 22:15
Has thanked: 246 times
Have thanks: 72 times

Re: Diezel VH4 Pedal

Postby dsvilanova » 13 Sep 2018, 14:38

edy_wheazel wrote:I also build mine a while ago with the PCB I posted.
Depending on the tone settings I also have a whistle when I turn the Gain up, but I don't use it at the max anyway.
Overall it's a kick-ass pedal! Try to use "C" pot's for "Presence" and "Deep", I used liniar ones and, as Bajaman said, the entire spectrum is available on around 15% of the pot's range. Also, I have the impression that the "Gain" and "Vol" pot's range is not liniar, but maybe it's just my impression and it' not a problem anyway.

Thanks for the schematic, it's a fun build!



Hi, I also have that whistle, any suggestions to solve it? This 'high feedback" is pretty bad :| I'm using pots B type for presence & deep, the circuit is on a veroboard, from tagboard effects.
Thanks anyway!
dsvilanova
 
Posts: 3
Joined: 03 Jul 2012, 15:22
Has thanked: 1 time
Have thanks: 0 time

Re: Diezel VH4 Pedal

Postby caspercody » 13 Sep 2018, 14:55

I put a buffered pedal right before the VH4, and I get not whistle. If I remove the buffer before the VH4, it whistles.

For this message the author caspercody has received thanks:
dsvilanova (13 Sep 2018, 15:08)
caspercody
Resistor Ronker
 
Posts: 251
Joined: 15 Jul 2009, 15:34
Has thanked: 30 times
Have thanks: 38 times

Re: Diezel VH4 Pedal

Postby dsvilanova » 13 Sep 2018, 15:11

caspercody wrote:I put a buffered pedal right before the VH4, and I get not whistle. If I remove the buffer before the VH4, it whistles.


Interesting! I did everything, but not this :D
I will test some buffer before, thanks man.
dsvilanova
 
Posts: 3
Joined: 03 Jul 2012, 15:22
Has thanked: 1 time
Have thanks: 0 time

Re: Diezel VH4 Pedal

Postby dsvilanova » 14 Sep 2018, 12:58

Nope, connecting a buffer before VH4 didn't solve the whistle. The question is: does the original do it? The last try will be use the pots C type.
dsvilanova
 
Posts: 3
Joined: 03 Jul 2012, 15:22
Has thanked: 1 time
Have thanks: 0 time

Re: Diezel VH4 Pedal

Postby edy_wheazel » Today, 00:29

dsvilanova wrote:Hi, I also have that whistle, any suggestions to solve it? This 'high feedback" is pretty bad :| I'm using pots B type for presence & deep, the circuit is on a veroboard, from tagboard effects.
Thanks anyway!


I left it that way. Have more then enough gain before the whistle starts :))
edy_wheazel
 
Posts: 19
Joined: 07 Dec 2013, 17:40
Has thanked: 9 times
Have thanks: 25 times

Previous

Return to Modern Stompbox Effects (1975 - ...)

Who is online

Users browsing this forum: alsirazi, Lani and 3 guests