Blade VSC Preamp

harmaes · Post by **harmaes** » 19 Aug 2012, 09:36

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:

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.

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

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.

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

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

harmaes · Post by **harmaes** » 19 Aug 2012, 14:13

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

sinner · Post by **sinner** » 19 Aug 2012, 14:54

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.

Hi Harry, 4n7 cap on your vero shorts

What you need is a trace cut under it

Thanks for schematic

sinner · Post by **sinner** » 19 Aug 2012, 14:59

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

I think it's all

harmaes · Post by **harmaes** » 19 Aug 2012, 15:19

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.

sinner · Post by **sinner** » 19 Aug 2012, 15:28

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

harmaes · Post by **harmaes** » 19 Aug 2012, 15:33

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

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

sinner · Post by **sinner** » 19 Aug 2012, 16:50

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

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

sinner · Post by **sinner** » 19 Aug 2012, 17:02

Is that your schematic?

harmaes · Post by **harmaes** » 19 Aug 2012, 17:21

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:

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.

sinner · Post by **sinner** » 19 Aug 2012, 17:32

ok, I know what's going on finally

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

harmaes · Post by **harmaes** » 19 Aug 2012, 17:51

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.

sinner · Post by **sinner** » 19 Aug 2012, 18:40

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

harmaes · Post by **harmaes** » 19 Aug 2012, 19:37

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

harmaes · Post by **harmaes** » 22 Aug 2012, 13:23

These vero layouts both work (verified by myself):

Mid-boost:

EQ (Bass/Treble):

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.

induction · Post by **induction** » 01 May 2013, 20:15

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:

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:

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.

roseblood11 · Post by **roseblood11** » 26 Jun 2022, 16:20

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...

karul · Post by **karul** » 26 Jun 2022, 17:36

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

roseblood11 · Post by **roseblood11** » 26 Jun 2022, 23:16

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

roseblood11 · Post by **roseblood11** » 03 Jul 2022, 20:38

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

Harry

Does anybody have this schematic?

Blade VSC Preamp [traced]