Q for transient designer user (proto on the bench)

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zamproject

Well-known member
Joined
May 11, 2010
Messages
1,502
Hi all

I have in mind since time now to build a TD, because studying the complex side chain is so interesting, with this clever dual envelope comparator. Also because I find the original unit absolutely ugly and I want to design my own frontpanel...

It's done and I suppose it work as it should (I have no original unit to compare)
I use the schemo available around, with some check from pcb pictures also laying around.
Basically just redraw the whole sidechain (for 2 ch) in a single eurocard, with minor modification to use Studer VCA card for I/O buffer and gain element.
I'll build a 4ch unit, 2U for large knob and clear reading label.

So the question is I probably want to make it steped, with +/- 5 pos (basic lorlin) and maybe a x2 and/or x3 selector for the gain value.
Original state +/- 15dB for attack and +/- 25dB for sustain.
What is the usual range some of you having the TD set up with different audio content?
eg. for attack, did a fine 1dB step (1 to 5) make sense ? or coarse 3 dB step is enouth (3 to 15) ? or both ?

Tks for advise !
Zam
 
Ok I finally take time to play various material, not as accurate than crash testing on real mix but give me a clue
The sweet spot seem between first quarter and third at each side of the pot (relative to center 0v CV) so a fine/coarse divide as I wish don't make sense as it will most of the time be in between... I'll stay with full range pot and if I really want step later I'll invest in multi-detent pot or 20+ pos rotary switches.

So far it's a great tool, just have to figure out some intermittent and erratic rail shut down that for now seem tricky to identify the cause...
 
500 version seem to have same range, so you use it more or less in the +/-10dB range
Tks for the feed back

About feedback, I'll try the side chain in a feed back topology (currently this envelope comparator is FW topology), should probably make things strange with counter reaction on counter reacting/comparative side chain :rolleyes:
I also add insert in the sidechain, filter should be interesting too

Cheers
Zam
 
500 version seem to have same range, so you use it more or less in the +/-10dB range
Tks for the feed back

About feedback, I'll try the side chain in a feed back topology (currently this envelope comparator is FW topology), should probably make things strange with counter reaction on counter reacting/comparative side chain :rolleyes:
I also add insert in the sidechain, filter should be interesting too

Cheers
Zam
Yes mainly +/- 10 - only very occasionally try it full. Also find the mix function handy so recommend adding that if you can
 
Cool project! I hope you'll share your finished build with us. (If you happen to offer it in some form as a project for others to build, even better! This seems like a fun one.)
 
Yes I see that TDx have mix and make-up added

It's probably too late as mix/blend is probably activ, side-chain pcb already done and I recycle VCA sub card with integrated line I/O, not sure I can easily implement a blend with the actual topology. I have mixer panpot laying around (log+antilog), can try something at the VCA card...

I can also try with paralel processing on the desk to see, and if I feel the need I can build another one only dual/stereo with added functions (have a dual side-chain pcb left)

So far I'm happy with the prototype, I'll test in mix condition soon, then finish aesthetic with nice frontpanel/rack
 
Cool project! I hope you'll share your finished build with us. (If you happen to offer it in some form as a project for others to build, even better! This seems like a fun one.)
Yes, funny project so far.
Not sure I can share this (of course I'll show the final build) but this is a 100% design rip off with minor change, and using schematic laying around
I only redo the sidechain circuit, in one eurocard for two sidechain, VCA section and I/O is very basic and already have part that can do the job.

Cheers
Zam
 
Not sure which version(s), we have three units total.

And I’m not the only one who uses them (commercial facility with five partners) so stock is probably the way
 
To me there is 3 versions from SPL, dual, quad and the mono 500 then there is the Elysia version (same designer) with augmented eq dynamic section.

For sure if there is various user, mod may not be the taste for everyone.

here is how the actual prototype look like:
on the left the two SC pcbs with SMD opamp
on the right the 4 VCA subcard from Studer

TDPROTO.jpeg
 
All three of our units are the quad units from SPL. If there are different revisions, etc. I’m not sure which we have.

I typically only use them in corrective fashion—“I wish I had just a little more attack from this kick” or “this snare is just a touch too pointy.” And as such I tend to do the least I can get away with
 
Yes, funny project so far.
Not sure I can share this (of course I'll show the final build) but this is a 100% design rip off with minor change, and using schematic laying around
I only redo the sidechain circuit, in one eurocard for two sidechain, VCA section and I/O is very basic and already have part that can do the job.

Cheers
Zam
HI Zam is it possible to show any simple block diagram?
As you said it has an interesting sidechain arrangement
I m learning detectors so I m very curious about yours
Best
Richi
 
Last edited:
No it can't.
CV output is differentially applied to the pot, with 0V at centre. You'll probably need a bell curve pot then.
Also not sure at all of the desirable effect of a dB scale applied to a V/dB VCA.
 
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