TC Electronic Integrated Preamplifier - Veroboard Layout

[fallingfurther]

Hey guys, the TC Integrated Preamplifier is a sought after preamp that was extensively used as a booster by the metal band Meshuggah through most of their career.  It can be powered up to 30V I believe and has active treble and bass controls (+/- 15 db).  They fetch more than $200 on ebay these days, so of course I would like to make it myself!  The people that use it say it is the best clean boost available, so I think it would be a great addition to the community.

There are no pcb, vero layouts or anything for this pedal.  I have found the schematic and was wondering if anyone wants to help me make a veroboard layout for it?  I am really bad at designing layouts like this.  I was going to try to use the Stripboard Magic program to help me make it, but that program won't run on my computer with Windows 7.

Thanks!

[electrosonic]

Here's the user's manual for this pedal

https://files.me.com/electrosonic/45vgev

The schematic looks a bit odd to me. I see a fixed gain op amp, followed by a baxandall tone stack (or is that james?) and a passive volume control.

Not quite sure how the signal switching works, and there seems to be a lot of extra parts for a simple gain stage.


Andrew.

[electrosonic]

Looking at the user's manual it says that if you power it with a 32 volt supply, if can put out up to 25 volts peak to peak. I can't imagine what my poor old Fender would sound like if it was slammed with a signal that big.
Andrew.

[slacker]

Here's another clearer schematic http://www.eskimo.plus.com/fxstuff/tc-pre.gif. I'll have a go at a vero layout.

[dano12]

What is all that goo around the power supply, Q1 and the two diodes? This would be worth a quick breadboard if it would work with everything before the .047 before Q2 lopped off...

Also not sure why vBias is 100k/1M. Isn't vBias usually half of the supply voltage?

It really is amazing how little I've learned over the last 5 years

[Gus]

Q1 and the two diodes are a constant current circuit, this is true if there is power connection to the transistor via the collector.   The two diode voltage drop - the Vbe drop / 22K the emitter resistor = the CC.  A good CC has a very high impedance.   Is there a DC path from what is before the input  or is it bleed down for any charge from what it is before the circuit?

[fallingfurther]

Here's another clearer schematic http://www.eskimo.plus.com/fxstuff/tc-pre.gif. I'll have a go at a vero layout.

That would be awesome and much appreciated!  My layout attempt would be very embarassing I'm sure.

[fallingfurther]

Looking at the user's manual it says that if you power it with a 32 volt supply, if can put out up to 25 volts peak to peak. I can't imagine what my poor old Fender would sound like if it was slammed with a signal that big.
Andrew.

Yeah, this preamp can give you a MAJOR boost!  From what I understand, Meshuggah turned the bass all the way down and the volume all the way up, boosted into a Mesa Dual Rectifier.  I think they used a high voltage too.  Pretty amazing results, it barely sounds like a Dual Rac anymore- very tight and defined gain:
http://www.youtube.com/watch?v=QCtBcbTqr1o
I know that's not everyone's cup of tea, but it's one example of how it can be used.

[spaceace76]

i've seen this pedal once or twice before on a few forums but not much has come of it, never seen any working builds or verified layouts from anyone. i found a messhugga (sp?) forum where one member got a DIY'er to build him a clone. his worked but had clipping in the low end, although some mentioned this pedal can do that on 9v with modern high output pickups, plus the guy is using a 7 string. the builder also subbed a 909k for R8, which should be an 820k, not sure how this circuit works so perhaps it's just misbiased. the user got an 18v adapter and seemed to like what he heard. he also seemed to confirm the schematic from the first post of this thread is legit. here's his clone version, edited from the "original" schematic, with links to the forum i found it on. he has a picture of his build on the second page, complete with traces so you can easily see what was and wasn't used from the original schematic.

http://www.sevenstring.org/forum/gear-equipment/68781-tc-electronic-integrated-preamplifier.html

[slacker]

As promised here's a vero layout http://www.aronnelson.com/gallery/main.php/v/slackers-stuff/tcpreboardfinal.jpg.html.

It follows the first schematic, with the exception of D4, which I left out because there's no way to connect it using a standard DC socket, looks like the original might use a 1/8" jack socket. It looks like it only adds some extra reverse polarity protection, on top of that given by D1.
If you don't think you need Q1 then it can be removed, along with D2,D3,R1,R5,R7 and the wire to the ring of the input socket..
If you want to keep Q1 and build it into a stompbox with normal truebypass switching then you can leave off the wire going to the ring of the input socket, remove R1 and move the bottom connection of R5 down a row, so it's connected to ground. That will make Q1 behave as though the jack is inserted all the time. That way you can do the standard battery wiring without having to use a stereo output socket.

[slacker]

Bugger just noticed R8 should be 820k, I'll change that.

[slacker]

Fixed

[fallingfurther]

You're the man slacker, thanks!  I will try building this soon and verify it.  I ended up caving in and buying an original one too, so I will let you know how it compares to the original.  I just got the original about a half an hour ago in the mail, so I haven't had much time with it.  But I can already tell you it's something special, adds a certain tightness and smoothness to the tone I haven't gotten from any of the boosts I have used.

[patd]

Awesome thread....and just at the perfect time. I have had one of these TC Integrated for about 6 years. When i first got it it could only opperate via batteries(was almost 20 years old when i bought it), so I had a tech wire up a higher voltage power supply to it. Anyway, a few months ago I started to get incredible noise and hum when using this thing. It sounds like the grounding has gone bad or something. Anyone here have any suggestions if I took a pic of the inside for you to see?

[fallingfurther]

Just finished building the veroboard layout and it works perfect!!!  And it sounds exactly like the original I have from the 70's or 80's.

Heads up if anyone is going to make one of these...do not bother running it on anything under 12 volts.  This circuit does not work with 9 volts, it sounds horrible and clips ferociously from even average output pickups.  This happens with the veroboard build and the original I have.  Hook up 12 volts and it sounds amazing.  Super tight and smooth boost with very effective tone controls.

I bought a 30 volt adapter for it, and now it sounds INCREDIBLE!  It is super clear and hi-fi sounding, noticable difference from 12 volts.  If you are running a Pedal Power supply, try 18 or 24 volts and you should get the same effect.  Also, I have heard some people pass this off as just simply a clean boost.  It is more than that.  Besides the very useful tone controls, the pedal adds a subtle compression and tonality that is just beautiful.  Doesn't squash the tone or dynamics or anything...it just makes the notes POP out effortlessly.  Palm muted notes can be made ridiculously tight which makes it really good for metal guitarists (or anyone else) looking to tighten up a flabby sounding bottom end.

Huge thanks to Slacker for making this happen!

[electrosonic]

So is this being used at the end of your signal chain (before your amp)? Otherwise I think you could damage other pedals.

Andrew.

[roseblood11]

Can anybody compare this pedal to the Boss FA-1? I wonder if it's worth building it, as I use a FA-1 clone regularly.

[bool]

TC's got quite a different amount of mojo.

Breadbord it first to see if it suits you.

You'll have to run the TC at 18V.