TC Electronics - Sustain Parametric EQ  [schematic]

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Re: TC Electronics Sustain Parametric EQ

Postby Gila_Crisis » 20 Mar 2013, 10:30

lolbou wrote:Just bought a vintage one for... 5 euros. :mrgreen: (Went today in a tiny music shop in a tiny town in Brittany. Asked to the owner : "any oldies in the arrière boutique"? Yes the guy said. A minute later, I had the unit in hand. Screws missing. Covered in dust. He had it for years after someone trade it for a Boss GE-7 :slap: ...)

Anyway, back home now, I'll check the unit tommorrow. Any requests? (@Gila_Crisis : did you sort out the DC jack wiring?)...

(ps: now smiling and/or laughing at this...)


you lucky boy! btw I don't need no more those pictures, I managed to fix it following the schematic!
btw Why not post the pictures! may be helpful for other users in future!
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Re: TC Electronics Sustain Parametric EQ

Postby Gila_Crisis » 20 Mar 2013, 10:34

lolbou wrote:I play three open Es, the first with Sustain at minimum, the second half way, and the third max. You can clearly hear the signal getting louder and louder. I know the thing adds sustain, but this is rteally odd, isn't it?

mp3.png

Any input appreciated. Cheers!


that's why I love this compressor: it's almost behaving like an ebow, you just get a really trasparent compression with INFINITE sustain!
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Re: TC Electronics Sustain Parametric EQ

Postby roseblood11 » 20 Mar 2013, 15:41

has anyone tried a better opamp? The specs of the XR4212 are close to the old 741, this circuit deserves something better...
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Re: TC Electronics Sustain Parametric EQ

Postby Gila_Crisis » 22 Mar 2013, 12:53

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Re: TC Electronics Sustain Parametric EQ

Postby benobo » 22 Mar 2013, 12:55

askwho69 wrote:Can i ask whats that DG1 AA/119? where can i get it? is it common?
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Re: TC Electronics Sustain Parametric EQ

Postby lolbou » 26 Sep 2013, 08:57

lolbou wrote:Just bought a vintage one for... 5 euros.
And just sold it for 130€, that's a nice enough turnover to me... :mrgreen: I really wonder how can shop owners be ignorant about how much such devices cost. I mean, you just have to google it to see!

OT: friend of mine did the same "any oldies?" trick in a freshly-opened bicycle store. "Yes" said the guy. And he showed him a few, but one was labelled "René Herse". And my friend knows its stuff. These are hand made bicycles (almost everything is lovingly hand crafted), made out of Reynolds 531 steel, and these are HIGHLY sought after bicycles. I didn't knew about René Herse before, but my friend did. "It's like finding a Tele made by Leo himself", he said.

He tried it : perfect fit (lucky for a custom made bicycle). And got it for 40€.

Estimated value : 6000-7000€. :blackeye

Another shop owner in the same category... :slap:
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
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Re: TC Electronics Sustain Parametric EQ

Postby aionios » 09 Mar 2014, 16:18

electrosonic wrote:
LED lights up when activating the pedal, but fades away after few seconds...any advices about this issue


Maybe someone with more knowledge can suggest how to mod so the LED stays on or off like a regular pedal.

If it is power by DC, does it work normally? (Never tried on mine because it uses a 1/8" mini jack for power)


(Skip to the end if you want to know how to mod it so the LED behaves like a normal pedal, but here's the long version.)

I just picked up one of these from eBay for super cheap ($70 USD) that was described as broken because it had this "issue". I knew better and got a crazy deal because of it :) Both of the 1/8" jacks were broken as well, which is pretty common with these, but otherwise it's working perfectly.

These are a pretty close replacement for the 1/8" jacks: http://www.smallbearelec.com/servlet/Detail?no=1152

They're PCB mount instead of solder lugs, so you have to bend the pins over to form a hook to solder the wires to, but otherwise they're identical. I would have replaced it with a standard DC jack, but the fit is incredibly tight and it would have required some hacking that I didn't want to do. Plus I have a couple of 1/8"-to-barrel-plug adapters from my 1-Spot, so it wasn't a problem to use the original jack.

Anyway: the way it's supposed to work is that when it's on battery power, the LED fades out after a second to preserve battery life, as someone said earlier. When the DC jack is plugged in, the LED stays on while the effect is on.

Here's a photo of the original DC jack wiring:

Image

The trick is that the DC jack is doubly switched, but in a nonstandard way. The shield switch is a "make" connection, so when DC power is plugged in, the green wire on the left is connected to ground. When it's unplugged, this connection is broken. The tip switch a "break" connection, like a standard DC jack, so the 9V battery is disconnected from the circuit if external power is used. When the green wire is connected to ground, the LED stays on when the effect is on. When the green wire is not connected to ground, the LED fades out after a second when the effect is turned on.

Problem is, the Cliff jacks aren't available in this configuration anymore, so it's impossible to find an exact replacement. The Small Bear ones are switched, but they're both "break" connections, so this original functionality can't be preserved. Good thing the original functionality is confusing and unnecessary. So when wiring a replacement jack, or just modding an original one so the LED stays on, all you have to do is connect the green wire to the lug on the right instead of the lug on the left.
Aion Electronics - DIY PCB projects for classic and obscure circuits

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TC Electronic Sustain + Parametric EQ (compressor pedal)

Postby Marco Pancaldi » 30 May 2014, 03:21

Hello,

this is a great pedal. Only problem: it's so squashing that, even with sustain @min and gain/out level @max the volume is less than bypassed. There is a little loss with single coils, but very large with modern, powerful humbuckers. I think the unit was designed focusing on SC output, because the compression is really too much with HB.

So, I'd wish to try to "offset" the sustain control to have a little less compression, to reduce the squashing, and maybe put some gain on the output, to realize a good balance between ON and BYP volumes.

This is the modified original schematics, with values:
http://www.sabrotone.com/wp-content/upl ... tching.png
Another idea can be substitute the XR4212 opamp with a modern 2134, to reduce hiss.

Any help/suggestion welcome.

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Re: TC Electronics Sustain Parametric EQ

Postby pinkjimiphoton » 22 Jan 2015, 21:20

restored one of these last nite. nice unit.
came in dead, or close to it...

replace ALL the electros.. a couple of the small 10u ones up by the knobs had gooed all over the board, had to clean it up a bit.. but instantly worked when i fired it back up.

cool box! so if having weird issues, change the caps. should take care of it.

oh, and to get the knobs off, pry off the green plastic caps. ;) :mrgreen: there's screws underneath 'em
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Re: TC Electronics - Sustain Parametric EQ

Postby DTM » 11 Nov 2015, 16:16

I was looking to separate the sustain circuit from the EQ circuit.
A quick glance with my limited knowledge seemed to show that P2 (Gain) was a suitable separation point but then I noticed the feedback resistor R55 from pin 14 of IC1. Could someone please help explain the role of the IC1 opamp (pins 12, 13, 14) after P2 wrt to feedback to IC1 (pins 5, 6, 7) and the parametric EQ.
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Re: TC Electronics - Sustain Parametric EQ

Postby notnews32 » 12 Jan 2016, 20:48

I've been considering parametric EQs/Comps lately and have been looking at different designs.. this circuit intrigues me but I'd really like to have the ability to dis/engage the EQ and comp circuits independently. I'm still a bit of a burgeoning diy guy, so I could use your help... does this circuit allow for such a mod without overhauling the entire design? Rather than having a parametric EQ and a multi-band comp on my pedalboard, I'd love consolidating the EQ and comp functions into one pedal. where I can engage the comp without the EQ and the EQ without the comp, or both together if I'd like.. I can't tell from looking at the circuit if this design lends itself to a mod like this, or if this design makes a mod like that pragmatically impossible.

Thanks for all the help in advance.. anything is seriously appreciated!
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Re: TC Electronics - Sustain Parametric EQ

Postby Fender3D » 27 May 2017, 19:10

notnews32 wrote:... does this circuit allow for such a mod without overhauling the entire design?...


I know it's more than 1 year later, but:

SPE1sm.jpg


SPEgutssm.JPG


Made it for the company I work for...
I added a 4053 for switching effects, actually bypass sustain, changed some values 'cause found compressor's attack way too long, and ditched some parts for a linear frequency response.
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Re: TC Electronics - Sustain Parametric EQ

Postby Dirk_Hendrik » 28 May 2017, 07:24

That looks a lot better than the original. I serviced one a few weeks back. Nice pedal but a bitch to work on. And that includes the readability of the original factory schems.
Sorry. Plain out of planes.

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Re: TC Electronics - Sustain Parametric EQ

Postby Fender3D » 28 May 2017, 18:43

Thanks Dirk,

you're right, it's always an headache working inside those vintage TC Electronics pedals...
Thanks God, I'm paid for the time wasted (yet)... :D
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Re: TC Electronics - Sustain Parametric EQ

Postby zintolo » 27 Dec 2017, 01:34

If anyone is interested in the power and bypass jacks, you can find them here (Cliff USA clone from CHK Electronics; P/N JC-6250BB):
http://www.smallbear-electronics.mybigc ... -pc-mount/

And here the jacks Cliff USA p/n FC1066A:
http://www.smallbear-electronics.mybigc ... -straight/
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Re: TC Electronics Sustain Parametric EQ

Postby zmix » 13 Jun 2018, 05:48

electrosonic wrote:
LED lights up when activating the pedal, but fades away after few seconds...any advices about this issue


That's not a bug its a feature. My TC line driver / booster does the same thing. I guess it is supposed to extend battery life. I find it annoying, but haven't got around to modding it yet. Looking at the schematic of the sustainer, D15 is the 3mm LED (bottom right)

Maybe someone with more knowledge can suggest how to mod so the LED stays on or off like a regular pedal.

If it is power by DC, does it work normally? (Never tried on mine because it uses a 1/8" mini jack for power)

Andrew.


Looks like C32 is the only difference between the LED powered constantly when using an external power supply and temporarily when using a battery.
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Re: TC Electronics - Sustain Parametric EQ

Postby Alex Frias » 15 Jun 2018, 14:35

Finally I've found an unity working great!
It is a very strange device, but it does things any other one could do!
Really loving it!
Using it a lot in my AJJA Duo Project of improvisational live music.
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