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Blade guitar preamp

PostPosted: 31 Dec 2008, 15:01
by nickthemen
Very nice midboost, i am planning to build it in a stompbox.

Re: Blade guitar preamp

PostPosted: 31 Dec 2008, 19:08
by Rocket Roll
Some pictures of Blade Texas Custom 20 preamp:

Image

Image

Image

I believe this one uses MC33174N quad opamp.

Re: Blade guitar preamp

PostPosted: 01 Jan 2009, 15:12
by nickthemen
it seems to be the same guitar as i have , made in switserland, it has one dual opamp

Re: Blade guitar preamp

PostPosted: 02 Jan 2009, 18:46
by Nikifena
Dear nickthemen, thanks for the schematic. Blade are swiss guitars, and I have a chanse to open one of them a long time ago.
I make a picture of a pcb. Here it is:
Image

I'm not sure why on your schematics there is only 2 opamps and on the board is 4 opamp chip?

Re: Blade guitar preamp

PostPosted: 03 Jan 2009, 15:46
by jt
Hi nikifene,the schematic that nickthemen has posted is the second version of the vsc pream.The one in your photo is version 3. I have a blade texas standard withe vsc 2 and it definitely has a LF442 op amp.
By the way it would be great if someone could post a schem of vsc3 as blade says that it is more vintage sounding than vsc 2 and has less battery consumption.

Re: Blade guitar preamp

PostPosted: 16 Mar 2009, 02:40
by SirElwood
I have a blade texas standard pro strat, and I love that midboost (mine is with MC33174N chip). Unfortunetly guitar itself is not that good quality. I had (have) some bad problems with it. Truss rod was busted on first one, they replaced whole neck. Now I need to take it to my guitar tech to check if the new neck is ok. Lots of trouble.

Re: Blade guitar preamp

PostPosted: 30 Mar 2009, 02:25
by shadowen
I'd also appreciate a VSC-3 diagram.

I suspect some of the extended battery life is actually due to the 33174 being able to work with lower voltage levels, so it can keep working as the battery loses voltage, but there are probably other improvements.

Re: Blade guitar preamp

PostPosted: 11 May 2009, 13:42
by ryanuk
Hi

Just saw this post.

Am keen try out this preamp but need to confirm how it would be wired into the guitar.

From the description on Blade's website I assume that this circuit has 2 modes - Treb/Bass boost mode and Mid boost mode.

With reference to the diagram (above), I assume that the upper section is for Mid mode and lower section is for Treb/bass mode. I also assume that the input is the node to the left of the diagram, and the nodes to the right are descrete outputs for the 2 modes. Battery to + and ground.

Am I correct?

Blades site indicates that they utilise this circuit via a 3 way switch toggling between BASS/TREB, PASSIVE MODE and MID boost. Assume this is a on/on/on switch.

With regard to the differences between v2 and v3 circuits, the parts count is similar. I imagine that whilst a quad op amp is used in v3, the circuit may actually only utilise 2 of the 4 op amps in the MC33174N. Might be that the quad op amp is more efficient as suggested.

Re: Blade guitar preamp

PostPosted: 12 May 2009, 07:03
by jt
Hi ryanuk
You are right about the switch.It is a 3 way on-on-on and it's function is mid boost in one position ,passive in the midle,treble and bass boost in the other as you have assumed.

Re: Blade guitar preamp

PostPosted: 12 May 2009, 10:14
by ryanuk
jt

Thanks for your reply.

I sat down last night and tried to figure out how the ON/ON/ON switch is wired - I baked my noodle and got nowhere.

Any chance you take some pics of your blade preamp (front and back) and the switch so I can trace it??

Ry

Re: Blade guitar preamp

PostPosted: 12 May 2009, 21:08
by jt
Unfortunately my camera is pretty useless for close up photos but i can help you with the switch wiring.
If you number the switch terminals like this :
1 | 2
3 | 4
5 | 6
Terminal 1 is connected to junction of R3-R4,
2 is jumpered with 3,
4 is connected to output jack,
5 is connected to lug 2 of volume pot and also to junction of R1-C5,
and terminal 6 is connected to R2.
Hope that helps.

Re: Blade guitar preamp

PostPosted: 14 May 2009, 21:10
by ryanuk
That helps a lot jt, thanks!!

Can you confirm the circuit posted above?? Does it compare with yours??

Re: Blade guitar preamp

PostPosted: 18 May 2009, 08:20
by jt
Hi,I will try to verify the posted schematic in the next few days.

Re: Blade guitar preamp

PostPosted: 09 Jun 2009, 11:11
by shadowen
jt, do you know what the connector into the board is? I've got hold of a VSC but I need to connect it in and I can't work it out from the header... I don't recognize that type.

Re: Blade guitar preamp

PostPosted: 10 Jun 2009, 17:28
by jt
Shadowen the connector looks like it's custom made,at least i haven't seen something similar for sale.
I would desolder it from the board and then use the pcb holes to solder single wires.
To ryanuk the posted schematic as long as i can tell looks right.Problem is that it's a double sided board and at the components side some traces are covered by silk screening and by some components.So i can't be totally sure.

Re: Blade guitar preamp

PostPosted: 09 Apr 2011, 00:24
by vachyasu
I'm sorry it is broken English.

It was in Japan of the 90's that I obtained blade guitar rh-4.
The ash body, the ebony finger board, and PU are 3s, the falcon tremolos, and vsc. 、
Afterwards, rh-2 was obtained.

When having analyzed it in several years, those vsc circuits were the same things.

The schematic diagram that you showed is wonderful !!

The vsc circuit that I read is presented.

There are a few disadvantages though it is stomp box's. (Do not make it to the control by the hand. )

Two substrates were not able to do it by the piling in an original + power supply.
+ power supply was connected by the jump.
The power supply in a fresh battery or the DC is recommended for the reasons.


The substrate chart enters the case with the MXR type from the size by 19.5% printout.

Re: Blade guitar preamp

PostPosted: 09 Apr 2011, 00:37
by Greg
nickthemen wrote:it seems to be the same guitar as i have , made in switserland, it has one dual opamp


Irrelevant to the purpose of this thread really .. but I think you'll find that they're made in Asia.
People like to claim the early ones were made in Switzerland, but I think they've always been made in Asia.

I have an early one and it's good guitar, although the neck is a bit thin for my taste.
The electronics have been removed and are stored in my workshop.. but you seem to have them covered.

Re: Blade guitar preamp

PostPosted: 09 Apr 2011, 17:18
by mcaviel
had a chance to play some last year they are made in Japan (still Asia tough..)

Ooops ! I was wrong.

PostPosted: 11 Apr 2011, 20:30
by vachyasu
I'm Sorry.
I correct the unit of condenser.
I show a right layout.

Re: Blade guitar preamp

PostPosted: 26 Jun 2011, 13:07
by alexradium
Hello everybody
i recently acquired 2 Blade Texas strats ,one with VSC2 the other with version 3.
V2 has the LF442 chip (like Demeter boost,very clean sounding and low consumption)like in the first schematic,V3 has an LMC6464 and the circuit is the same as in previous picture posted.
This chip is the lowest current consuming op amp available,such the MC33174 according to alldatasheet files
It seems all connected so i guess there is at least one stage for each frequency band and maybe one on input or output,go figure.
also on the back of the board there seems a gooped component,maybe a resistor or a cap
if anyone is really interested i can post some pics of the actual circuit and perhaps try to trace it if i have the time and patience

ciao
Ale