TC 3rd Dimension chorus - add a stereo output?

Started by roseblood11, November 06, 2018, 04:00:29 PM

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roseblood11

I just got a TC Electronic 3rd Diemnsion chorus, which seems to be a clone of the Boss DC-2 Dimension C. But it just has a mono output. (Despite the older Behringer version...)

Is it possible to add a second output and make the pedal stereo? It's not bad in mono, but it's somehow missing the point...
If I understand the Boss schematic correctly, the signals of both delay lines are mixed together to output A if there is no jack in output B. So, if the §rd Dimension is an exact clone (and it sounds like that), the circuit should be complete, including both delay lines?
Unfortunately, there are just some gut shots at the moment, maybe I'll find time to draw the schematic, but not before winter holidays...
http://www.modezero.com/tc-3rd-dim.htm

zombiwoof

Quote from: roseblood11 on November 06, 2018, 04:00:29 PM
I just got a TC Electronic 3rd Diemnsion chorus, which seems to be a clone of the Boss DC-2 Dimension C. But it just has a mono output. (Despite the older Behringer version...)

Is it possible to add a second output and make the pedal stereo? It's not bad in mono, but it's somehow missing the point...
If I understand the Boss schematic correctly, the signals of both delay lines are mixed together to output A if there is no jack in output B. So, if the §rd Dimension is an exact clone (and it sounds like that), the circuit should be complete, including both delay lines?
Unfortunately, there are just some gut shots at the moment, maybe I'll find time to draw the schematic, but not before winter holidays...
http://www.modezero.com/tc-3rd-dim.htm
Can't help with the question, but I am wondering if the 4 modes of that pedal sound like the modes on the original Boss version?.  Have you compared them?.  I have a couple of those inexpensive TC pedals and the ones I have are great, especially the Mojo Mojo OD.
Al

Fender3D

pictures show just one BBD... it's half a clone!

IIRC Francisco (Tonepad) drew a daughter card for one of his choruses.. it might be easy enough to add
"NOT FLAMMABLE" is not a challenge


Mark Hammer

I haven't been able to find any gutshots, but are you sure there is only one BBD in there, and not a second one hiding under or behind something?  It would make no sense to market a standard single-BBD chorus with buttons, and the compander is really only compelled by the use of two different clocks, so why include it if there is no real need?  The mono-vs-stereo aspect I can understand since stereo adds to production costs and not very many players use the stereo option.  But I would need stronger evidence to accept that the 3D only has one BBD, when Behringer is responsible for cranking out those chips through Coolaudio.

ElectricDruid

Gutshots are on the link the OP posted:

http://www.modezero.com/tc-3rd-dim.htm

Agreed it's not very clear (not big version available) but that looks like a DIP8 V3102 and V3207 to me. The V571M SOIC compander is also visible.

I don't agree about the only reason to have the compander is two clocks. Yeah, that's one reason. But "noise" is the other reason, and there's always plenty of that in anything with BBDs. There are some flangers that use them, for example, and they only use the single BBD.

Mark Hammer

Possible that Larry (modezero) is only showing one of two boards, and there's a daughter-board underneath?
Listening to this DC-2/3rd D comparison, I am hard-pressed to hear a difference.

ElectricDruid

That is possible.

I wondered if there was surface-mount stuff on the other side of the PCB we saw, but the fact that they seem to have used through-hole parts for the BBD (Do CoolAudio do the V3207 in a SMD package? I haven't checked..) dissuaded me from the idea.

If you're going to clone it, cloning only half of it does seem weird. And not even cloning what you'd hear if you only used one input, but rather cloning what you're hear if you used both inputs, but then ignored one of them. Put like that, it makes no sense, and there must be another BBD in there somewhere, right?!

Scruffie

Surely there'd be some kind of header pins visible if it had two boards and no there's no SMD version of BBD's available from them.

Maybe it's a Dual LFO reworking?

Mark Hammer

I tried in vain to find what might look like the vestiges of a header, connecting a 2nd board and, like yourself, couldn't see one.  And it would make little sense to have an SMD version on one side and a thru-hole on the other.  So folks are entirely reasonable to draw the conclusion that there is but one BBD in that pedal....except that it sounds like a dual-BBD unit, and we know that Behringer made a DC-2 clone for several years and then appeared to have trimmed their own pedal catalog and farmed a lot of it over to TC.  And why on earth would anyone make a push-button chorus that would have the cosmetic features of a budget DC-2 but NOT the circuit or sound.

Larry, the guy who hosts the modezero site and takes the pictures, usually does a fairly thorough job of showing everything, so it is hard for me to imagine that there is a second board, or other side with components that he simply couldn't be bothered to show.  But is it just me or do the two choruses in that Youtube sound as close as two units with normal component-tolerance variations can sound?  Admittedly, I'm not listening through quality speakers, so I may be misled, but even in mono, that 3rd D doesn't sound like any single-phase chorus I've ever heard.

Something's odd here.  I have exchanged e-mail with Tore before, and he's quite generous with information.  Perhaps I'll write him and ask.

roseblood11

I can confirm that there's only one delay line. I took some more pictures, but they don't show more than those at modezero.
I don't have a DC-2 for a side by side comparison, but it really sounds like that. Much different from any other analog chorus I know.

Mark Hammer

That is truly weird.

Of course, if it IS possible to get DC-2 sounds with only one BBD, you can expect great interest in knowing just how the heck it's done, because - on paper - it ought not to be possible.

roseblood11

The guy in the video states that he made a wet/dry recording, with the 3rd Dimension on one side and the clean output B of the DC-2 in bypass mode on the other side. That's clearly not, what is really happening, as there's chorus sound on both sides of the stereo signal.

Mark Hammer

Just had to pull my Behringer CC300 apart today, and can verify that it does indeed have two BBDs and compander chips.

tiarlei crist

To whom it may interest...
The pedal schematic is available on this braziliam forum:

https://www.handmakersbrasil.com.br/topic/113-3rd-dimension-chorus-schematic/

ElectricDruid

Thanks Tiarlei.

Do we have to set up a login to see links on that forum? I got an error that "This attachment is not available. It may have been removed or the person who shared it may not have permission to share it to this location."

Could you post the link here? (No need to post the file, if you've got that hosted somewhere else).

tiarlei crist

#16

duck_arse

following the link to the handmakers site gives this error:

QuoteAlgo deu errado!

This attachment is not available. It may have been removed or the person who shared it may not have permission to share it to this location.
You hold the small basket while I strain the gnat.

tiarlei crist

The original link is a PDF and need to login.
But i added a preview to my post.

Mark Hammer