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Behringer TD3 DIY Mods
Old 19th January 2021 | Show parent
  #661
xox
Gear Nut
 
🎧 5 years
Quote:
Originally Posted by xox ➡️
I have done the declick (C51) and rubber (D22) mods and now the only difference I really notice with the OG is exactly what you described in a previous post about the filter of the TD3 being too "direct" and not "wappy" enough.
I realise I said "filter" where I meant accent!
Old 19th January 2021 | Show parent
  #662
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by xox ➡️
I realise I said "filter" where I meant accent!
Ah, I see - accent generally too short or hitting too much?

If the first is the case, then accent decay modification might be interesting (lift anode D15 and insert a trimmer/pot/resistor)

If the latter, accent affects filter and vca- for "softening the blow" on the vca, a bit of slew on c26 might help (say 100nf or so?)- pic attached with via of junction r26-c26. generally, you could also reduce the intensity of accent to vca by enlarging r26 (47k)9 to, say 56k or higher.

if accent impact on filter is a thing, then you might want to test a bit of slew on the cathode of d9 (not accessible from back of pcb)

a bit cruder, but maybe also interesting- slew on middle pin accent pot
Attached Thumbnails
Behringer TD3 DIY Mods-c26.jpg  
Old 19th January 2021 | Show parent
  #663
xox
Gear Nut
 
🎧 5 years
Quote:
Originally Posted by Deleted 9d681ab ➡️
Ah, I see - accent generally too short or hitting too much?
I would say hitting too much

Quote:
If the latter, accent affects filter and vca- for "softening the blow" on the vca, a bit of slew on c26 might help (say 100nf or so?)- pic attached with via of junction r26-c26.
Do you mean that I should try to place a 100nf capacitor between the highlited point on your pic and ground?

But to be honest the result at this point is very very close and it may vary depending on the settings.

As an example I have attached 2 files A & B. One is a 38 year old OG 303 and the other is a modded TD3 (only vca C51, rubber D22 & vr1 at 12). Nothing scientific here but just a pattern with settings I like. Difficult to tell which one is better!
Attached Files

A.wav (1.45 MB, 1960 views)

B.wav (1.45 MB, 2014 views)

Old 19th January 2021 | Show parent
  #664
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by xox ➡️
I would say hitting too much


Do you mean that I should try to place a 100nf capacitor between the highlited point on your pic and ground?

But to be honest the result at this point is very very close and it may vary depending on the settings.

As an example I have attached 2 files A & B. One is a 38 year old OG 303 and the other is a modded TD3 (only vca C51, rubber D22 & vr1 at 12). Nothing scientific here but just a pattern with settings I like. Difficult to tell which one is better!
Ha, those clips sound really close! you should turn it into a guessing game in the main td3 thread

B is td? (listening with old cans in the living room- think on lower cutoff accent on b is a tad harder)

at any rate not much bteween those two clips! & yep, 100nf (shot from the hip, as it were) between that point and ground *should* round off accent onset on vca a bit (my td's on the shelf atm, so i didn't test but checked slew on c26 a while back - second half of clip attached you can hear the onset rounded off a bit - can't remember the cap value used though...)
Attached Files

c26_mod.wav (1.25 MB, 1919 views)

Old 19th January 2021 | Show parent
  #665
xox
Gear Nut
 
🎧 5 years
Quote:
Originally Posted by Maffez ➡️
Ha, those clips sound really close! you should turn it into a guessing game in the main td3 thread

B is td? (listening with old cans in the living room- think on lower cutoff accent on b is a tad harder)
you win!

Quote:
at any rate not much bteween those two clips! & yep, 100nf (shot from the hip, as it were) between that point and ground *should* round off accent onset on vca a bit (my td's on the shelf atm, so i didn't test but checked slew on c26 a while back - second half of clip attached you can hear the onset rounded off a bit - can't remember the cap value used though...)
May try this but I don't have much components (actually just the ones to do the basic mods) Can I use a220nf greenie or does it have to be bipolar? (I guess the higher the value the more pronounced the effect will be?
Old 19th January 2021 | Show parent
  #666
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by xox ➡️
you win!



May try this but I don't have much components (actually just the ones to do the basic mods) Can I use a220nf greenie or does it have to be bipolar? (I guess the higher the value the more pronounced the effect will be?
ha, sweet! & nope, no polarized needed - dunno off the cuff what effect (if memeory serves i tried 100nf to 1uf back then with 1uf being too much)
Old 20th January 2021 | Show parent
  #667
xox
Gear Nut
 
🎧 5 years
I have attached 4 files that summarise the 3 mods.
1: no mod (other than C51+D22)
2: mid pin of env 1uf to ground
3: 3rd pin of res 1uf to ground
4: "C26 slew" 1uf to ground

2: this affects non accentuated notes: very similar to what I've heard from the R45 "rubberduck" mod. Nice but not permanently : deviates from OG303

3: My favorite. It smoothes the accent and bring elasticity. Maybe too much? Should be interesting to try lower values: there might be a sweet spot value to match the OG303

4: Nice as well but maybe not as nice as 3. More "waff" (which I like) but does not seem to affect resonnance like 3 so it seems less "natural" IMHO. Could be used as an effect mod. Or maybe a lower cap value would make the perfect accent "waf" mod.

Unfortunately I have no other caps than 220nf, 1uf and 2uf. Will have to order more.

Thanks again for bringing me to the right directions
Attached Files

no mod.wav (1.32 MB, 1819 views)

mid pin of env 1uf to ground.wav (1.14 MB, 1846 views)

3rd pin of res 1uf to ground.wav (1.12 MB, 1900 views)

c26 slew 1 uf to ground.wav (1.14 MB, 1874 views)

Old 20th January 2021 | Show parent
  #668
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by xox ➡️
I have attached 4 files that summarise the 3 mods.
1: no mod (other than C51+D22)
2: mid pin of env 1uf to ground
3: 3rd pin of res 1uf to ground
4: "C26 slew" 1uf to ground

2: this affects non accentuated notes: very similar to what I've heard from the R45 "rubberduck" mod. Nice but not permanently : deviates from OG303

3: My favorite. It smoothes the accent and bring elasticity. Maybe too much? Should be interesting to try lower values: there might be a sweet spot value to match the OG303

4: Nice as well but maybe not as nice as 3. More "waff" (which I like) but does not seem to affect resonnance like 3 so it seems less "natural" IMHO. Could be used as an effect mod. Or maybe a lower cap value would make the perfect accent "waf" mod.

Unfortunately I have no other caps than 220nf, 1uf and 2uf. Will have to order more.

Thanks again for bringing me to the right directions
thanks for sharing those recordings!

yep c26 only affects vca, not reso, so that's why both soudn a bit dissociated, but whaff is there too - i think you can hear really well how at 3 and 4 accent gains this kind of smear/whaff as if you dragged it a bit back - yep, testing lower values might get you there & get more groove into that thing
Old 21st January 2021 | Show parent
  #669
xox
Gear Nut
 
🎧 5 years
Quote:
Originally Posted by korupt303 ➡️
I know this was a tad overkill, but I removed the vr1 trimpot and made it external with a 500k pot.
Could you explain a bit more how you did it (with a picture maybe)? Why a 500K pot? Linear or Log?
Old 21st January 2021 | Show parent
  #670
xox
Gear Nut
 
🎧 5 years
Is it possible to use a potentiometer instead of a trimmer to make the pw square externally tweakable?
If yes, which one would you recommend ? A 50K linear as for the trimmer?
Old 25th January 2021 | Show parent
  #671
xox
Gear Nut
 
🎧 5 years
Can the pre filter overdrive mod (500K log pot in // of R24) be done at the back of PCB?
Old 25th January 2021 | Show parent
  #672
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by xox ➡️
Can the pre filter overdrive mod (500K log pot in // of R24) be done at the back of PCB?
edit: simplest version attached as pic - this setup will slightly increase your vco level (even when pot is fully down) since R23, R24 remain intact. (so, prim and proper way would be to replace them with resistor+pot in series.)

also, nb that if there is too much load on the saw wave, its pitch will slip up, so there's a minimum of around 20k you need to use as resistance in between


also, as for pw adjustment - some few people did this on a potentiometer but there's not much sense in doing so imo. trimmer is the way
Attached Thumbnails
Behringer TD3 DIY Mods-simplified_preod.jpg  
Old 25th January 2021 | Show parent
  #673
xox
Gear Nut
 
🎧 5 years
Thanks!
Old 26th January 2021 | Show parent
  #674
With recent discussion on the main TD-3 thread about wanting more filter wetness I thought... why not? So I did the higher resonance mod (in Maffez's guide) of replacing R97 with a 15k trimmer and almost killed my filter due to my amateur skills I share more details in case it can help somebody...

Removing surface mount components has gotten easier for me - just add more solder and the component practically jumps off the board - but the hard part is soldering to those tiny pads. So after removing R97 I soldered two wires to the pads to attach the trimmer. And well... one of the pads ripped off the board so I did my best to solder to what was left of the trace next to the pad.

After attaching the 15k trimmer to the wires leading to where R97 used to be, I powered up and crossed my fingers. Then, no resonance! Powered down, reheated the damaged pad to renew the solder, tried again, twice, then it worked! But then, the trimmer was wired backwards. Ok, no problem, switched the connections to the trimmer and resoldered it, and it works. I cranked the trimmer for max resonance and now it's all good. The filter is back and sounding more present than I remember, but I didn't do a before/after comparison.

In any case, this isn't the first pad I destroyed but they are salvageable. Just reheat and say a prayer and maybe it can still work.
Old 26th January 2021 | Show parent
  #675
xox
Gear Nut
 
🎧 5 years
I might be wrong but in my quest to find mod pictures I came to this one. It might be a way to do this mod from the back of the pcb?
Attached Thumbnails
Behringer TD3 DIY Mods-res.jpg  
Old 27th January 2021 | Show parent
  #676
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by xox ➡️
I might be wrong but in my quest to find mod pictures I came to this one. It might be a way to do this mod from the back of the pcb?
sure, that reso and pw - for pw you need to take out r189 first though as you want to increase resistance

edit- btw: worked on a td last weekend and got to toying with softerner for accent - arrived at a 560nf cap between middle pin of accent pot and ground and like the effect - softens lower accent values and (like with the filter slew thing) on higher values accent start hitting through
Old 27th January 2021 | Show parent
  #677
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by BAK ➡️
With recent discussion on the main TD-3 thread about wanting more filter wetness I thought... why not? So I did the higher resonance mod (in Maffez's guide) of replacing R97 with a 15k trimmer and almost killed my filter due to my amateur skills I share more details in case it can help somebody...

Removing surface mount components has gotten easier for me - just add more solder and the component practically jumps off the board - but the hard part is soldering to those tiny pads. So after removing R97 I soldered two wires to the pads to attach the trimmer. And well... one of the pads ripped off the board so I did my best to solder to what was left of the trace next to the pad.

After attaching the 15k trimmer to the wires leading to where R97 used to be, I powered up and crossed my fingers. Then, no resonance! Powered down, reheated the damaged pad to renew the solder, tried again, twice, then it worked! But then, the trimmer was wired backwards. Ok, no problem, switched the connections to the trimmer and resoldered it, and it works. I cranked the trimmer for max resonance and now it's all good. The filter is back and sounding more present than I remember, but I didn't do a before/after comparison.

In any case, this isn't the first pad I destroyed but they are salvageable. Just reheat and say a prayer and maybe it can still work.
yes, those traces come off easily- and best way is really add flux/solder and keep the terminals as hot and flexible as possible when taking components off. and yep, practice, practice, practice

for just increasing resonance, here's a through via, but having a trimmer is the way to gof if you want to find your sweet spot

btw check @ xox 's A/B with a 303 and a rubberised td3 earlier in this thread - not far off!
Old 27th January 2021 | Show parent
  #678
xox
Gear Nut
 
🎧 5 years
Quote:
Originally Posted by Maffez ➡️
sure, that reso and pw - for pw you need to take out r189 first though as you want to increase resistance

edit- btw: worked on a td last weekend and got to toying with softerner for accent - arrived at a 560nf cap between middle pin of accent pot and ground and like the effect - softens lower accent values and (like with the filter slew thing) on higher values accent start hitting through
Will test that this WE (order from das musikding on its way) + different values for the previous "slew" options and let you know my thoughts.
Old 27th January 2021 | Show parent
  #679
Quote:
Originally Posted by xox ➡️
I might be wrong but in my quest to find mod pictures I came to this one. It might be a way to do this mod from the back of the pcb?
Yes, that's what I followed (from the guide) for PW mod. Removed the resistor on the front of the PCB and then soldered in a 50k pot for external tweaking. Highly recommended if interested in getting non-303 timbres. I like having both the smooth square and a more aggressive pulse.
Old 27th January 2021 | Show parent
  #680
Quote:
Originally Posted by Maffez ➡️
yes, those traces come off easily- and best way is really add flux/solder and keep the terminals as hot and flexible as possible when taking components off. and yep, practice, practice, practice

for just increasing resonance, here's a through via, but having a trimmer is the way to gof if you want to find your sweet spot

btw check @ xox 's A/B with a 303 and a rubberised td3 earlier in this thread - not far off!
Thanks, yes, it's the removing that is no problem, but I've had issues with the wires I solder to the pads pulling away. I need to secure them better. Also, maybe the gauge of wire I'm using is too thick! Maybe I need a thinner, more flexible, gauge wire.

And indeed, @ xox , it's sounding really good. Looking forward to hearing your next mods. I'm getting tempted to go more rubbery with the rubber duck.
Old 28th January 2021 | Show parent
  #681
Quote:
Originally Posted by xox ➡️
I have attached 4 files that summarise the 3 mods.
1: no mod (other than C51+D22)
2: mid pin of env 1uf to ground
3: 3rd pin of res 1uf to ground
4: "C26 slew" 1uf to ground

2: this affects non accentuated notes: very similar to what I've heard from the R45 "rubberduck" mod. Nice but not permanently : deviates from OG303

3: My favorite. It smoothes the accent and bring elasticity. Maybe too much? Should be interesting to try lower values: there might be a sweet spot value to match the OG303

4: Nice as well but maybe not as nice as 3. More "waff" (which I like) but does not seem to affect resonnance like 3 so it seems less "natural" IMHO. Could be used as an effect mod. Or maybe a lower cap value would make the perfect accent "waf" mod.
These are great and easy to implement. Cheers for these!

Since I've been wanting to do the rubber duck mod to R45, instead I did # 2 and 3 above to achieve what I was hoping for: more "rubber". Sounds great! And I put them both on switches.

Every time I close up my TD-3 after doing another mod I think "Woah, that was close, good thing I didn't destroy it this time. I should stop while I'm lucky." And then I do it again But maybe I'm finally, really, done this time.
Old 29th January 2021 | Show parent
  #682
xox
Gear Nut
 
🎧 5 years
Quote:
Originally Posted by Maffez ➡️
edit- btw: worked on a td last weekend and got to toying with softerner for accent - arrived at a 560nf cap between middle pin of accent pot and ground and like the effect - softens lower accent values and (like with the filter slew thing) on higher values accent start hitting through
I have tried it but I don't hear much difference, even with 1 or 2 uf. Maybe I did something wrong?

I have implemented the "accent decay" mod with a 500K log pot. It can be quite subtile up to 25%.

I have also implemented the "3rd pin of res to ground" with a 0.56uf cap. It is more subtle than with 1uf.It add some elasticity at some settings (makes the accent "slobbery" a bit like miaowing).
Edit: this one could even be permanent, part of the "rubbering kit" along with C51 and D22 to get even closer from the OG 303 (maybe with a even lower cap value to make it even more subtle)

I will probably implement the "mid pin of env to ground" with 1uf as the "env slew" mod and the C26 slew" aka the wapp mod with a 2uf cap. But I am running out of switches now.
Old 30th January 2021 | Show parent
  #683
xox
Gear Nut
 
🎧 5 years
For those who are interested I have attached 2 files of my latest mods.
  • TD3 ARS: Accent Resonance Sweep Slew (2 bars off, 2 bars on)
  • TD3 AD: Accent Decay (from 0 to max) with ARS on

NB: TD3 goes to caline orange burst with OD set to minimum for a nice crunch.
Attached Files

TD3 ARS.wav (4.04 MB, 1436 views)

TD3 AD.wav (7.57 MB, 1456 views)

Old 30th January 2021 | Show parent
  #684
xox
Gear Nut
 
🎧 5 years
Did the Pre Filter Overdrive. Just put a 500K linear pot in between the 2 points indicated by Maffez on the back of the pcb.
It's fine. You just don't have to push to the extreme (last 5-10%) if you don't want the saw wave to pitch up (fine with square wave however).

It adds a subtle nice crunch around 50%. I guess it is better than vca drive /R106 mod as it is pre filter.

This could be an easier alternative to vca drive to insert a fix resistance (around 250K I guess) as a permanent mod.
Old 1st February 2021 | Show parent
  #685
xox
Gear Nut
 
🎧 5 years
Where can I find a description of how to do the VCA/Gate on forever mod?
Old 1st February 2021 | Show parent
  #686
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by xox ➡️
Where can I find a description of how to do the VCA/Gate on forever mod?
if memory serves right,

+9V via diode to bottom d22 - gate on
-- top d21 for vca on
Old 2nd February 2021 | Show parent
  #687
xox
Gear Nut
 
🎧 5 years
Thanks. Would someone know which type/reference of diode to use?
Old 3rd February 2021 | Show parent
  #688
Gear Maniac
 
captaink's Avatar
 
🎧 10 years
Just checking is the value of the VCF offset trimmer 500K? Thinking I read earlier that it is was.

Thanks
Old 3rd February 2021 | Show parent
  #689
Deleted 9d681ab ðŸŽ™ï¸
Guest
Quote:
Originally Posted by captaink ➡️
Just checking is the value of the VCF offset trimmer 500K? Thinking I read earlier that it is was.

Thanks
yep 500k
Old 3rd February 2021 | Show parent
  #690
Gear Maniac
 
captaink's Avatar
 
🎧 10 years
Quote:
Originally Posted by Deleted 9d681ab ➡️
yep 500k
Thanks. I am looking to wire a pot externally so I can change as need be as I like different settings. Could I just set the internal trimmer fully down and then just solder a pot on to trimmer with out removing it? Saves a desolder if I can Thanks
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