Blade VSC Preamp  [traced]

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harmaes
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Post by harmaes »

I'm working on VERO layouts for the Blade VSC preamp and I'm also trying to create one for only the Mid-boost part of the preamp which I think is very nice!
Since I'm a beginner I'm learning as I'm going, working with bread board layouts and schematics and trying to create veroboard layouts from there.
It would be great if I could get some help with the layouts I'm creating!

The schematic for the Blade VSC preamp:

Image

I've created this vero layout for it. I've verified the mid-boost part for it so that's correct. The EQ (Bass/Treble) part is not confirmed yet.
If you could please check the above schema and the vero layout below to check if it's correct that would be great? Also, if there's a better way to layout the vero or some tips/tricks to share please lemme know.

Image

I have a ne5334 opamp lying around and I breadboarded it for only the mid-boost part. Sounds nice. Here's the diagram:

Image

I've attempted the following vero layout but it doesn't work (the opamp is working correctly, the mid-pot doesn't seem to do anything: no gain, no mid freq boost)? Any idea what's causing this? I've looked over it for a number of times and can't seem to find the issue.

Image

Here's another vero layout for you with the Storm DIY layout creator:

Image

As I've mentioned, I'm learning from building simple circuits. I'd like to bring in some of the work I'm doing for the vero layouts of the Blade VSC preamp. They're not finished yet and it would be great if you could give me some leads to finish them so we can share them with the FSB forum!

Thanks,

Harry

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harmaes
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Post by harmaes »

Correction on the schematic, lines of the bass VR were crossing:

Image

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Post by sinner »

harmaes wrote: I've attempted the following vero layout but it doesn't work (the opamp is working correctly, the mid-pot doesn't seem to do anything: no gain, no mid freq boost)? Any idea what's causing this? I've looked over it for a number of times and can't seem to find the issue.

Image
Hi Harry, 4n7 cap on your vero shorts

What you need is a trace cut under it

Thanks for schematic :thumbsup

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Post by sinner »

Also... Pin 4 of your op-amp should go to GND, and pin 8 to V+

I think it's all

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harmaes
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Post by harmaes »

So the 4n7 can't be on the same strip completely?

BTW, you're quoting my first image. In that image the 4 is already to ground and the 8 to V+.
The second schema uses a ne5334 (single opamp). The opamp is working normally but I have no working gain/mid pot. Did you check that one too?

Thanks.

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Post by sinner »

So the 4n7 can't be on the same strip completely?
it may, but it need a space between "hot" legs of the capacitor, otherwise this cap wouldn't serve any function
BTW, you're quoting my first image. In that image the 4 is already to ground and the 8 to V+.
The second schema uses a ne5334 (single opamp). The opamp is working normally but I have no working gain/mid pot. Did you check that one too?

Thanks.
Oh yeah, I'm sorry, for some reasons I didn't notice that jumper, my bad

I was looking on your layout using one aye only ;) let me look on it again, I'll post back in a while

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Post by harmaes »

Clear about the cap. That's probably why vero layouts have most components vertical. :wink:

Great, lemme know if you find any other possible issues. Thanks for your time!

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Post by sinner »

harmaes wrote:Clear about the cap. That's probably why vero layouts have most components vertical. :wink:

Great, lemme know if you find any other possible issues. Thanks for your time!
looks good otherwise. You've switched the opamps, but thats doesn't matter :)

Could be smaller IMO if you going to pack it into guitar cavity

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Post by sinner »

Is that your schematic?

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Post by harmaes »

sinner wrote: looks good otherwise. You've switched the opamps, but thats doesn't matter :)

Could be smaller IMO if you going to pack it into guitar cavity
I've soldered this layout but the mid/gain is not working:

Image

Any idea why it's not working? Seems correct... :(

The schematic is from a preamp that's in Blade Levinson guitars. I have one in my Blade strat and want to build it into a pedal for usage with my other guitars.

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Post by sinner »

ok, I know what's going on finally ;)

Send the DIYLC project file to turretboard [at] gmail.com I'll fix it for you

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Post by harmaes »

sinner wrote:ok, I know what's going on finally ;)

Send the DIYLC project file to turretboard [at] gmail.com I'll fix it for you
Cool, email is send. ;)

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Post by sinner »

Ok, the simplest way to fix it is to swap the resistor and the jumper around

As I said by email, I'll do my take on it, but I just understood I should focus on my actual work ;)

I'll back to it..

Anyway, swap it, and enjoy

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Post by harmaes »

No problem mate! Thanks for your help!
Looking forward to your take! No rush here! ;)

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Post by harmaes »

These vero layouts both work (verified by myself):

Mid-boost:

Image

EQ (Bass/Treble):

Image

They can probably be smaller. ;) I will place these in an enclosure with another boost circuit (Demeter Fat) so I don't need them to be small.

Have fun with it. :D

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Post by induction »

Since this circuit was designed to be placed inside a guitar and operated with a battery, the schematic doesn't include the power filtering you'd want to include if you use it with a power adapter. I intend to put the mid-boost circuit in a box with two other boosts (Demeter fat control and Catalinbread Naga Viper) and I don't like batteries, so I drew up a compact vero layout that includes these extras. I also added a volume control (so that the tone shaping and volume boost are independent), a pulldown resistor on the input, an led current limiting resistor, and a polarity protection diode.

Here's the modified schem:
Zorro_schem.PNG
Note that I changed the bias resistors from 1M to 10k, put a filter cap at Vref, and added a 470k resistor between Vref and the positive op-amp input. This should reduce the amount of AC hum that gets amplified, while maintaining the input impedance.

And here's the layout:
Zorro_vero.png
Like all my layouts, it's designed to fit the caps I have in my stash, so verify that yours will fit before you cut your board.

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Post by roseblood11 »

Does a full schematic of the VSC-3 circuit exist? I`d modify it for use with a symmetrical power supply ( +/- 9V from two batteries) and build it inside a guitar, with all controls at the top...

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karul
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Post by karul »

Well, something popped up on ebay. I can not comment on it's accuracy.
https://www.ebay.com.sg/itm/114697773041
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Post by roseblood11 »

Many thanks! There`s a guy in Poland who sells replica boards, this must be one of them.

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Post by roseblood11 »

harmaes wrote: 19 Aug 2012, 09:36
The schematic for the Blade VSC preamp:

Image

Harry
Does anybody have this schematic?

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