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Erik dP
Silver Member
Sweden
150 Posts |
 Posted - 06/20/2005 : 14:51:39
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| Does anyone know where in a DD-2 a high cut mod can be done? |
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Goran
Double Platinum Member
Sweden
2203 Posts |
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boss freak
Gold Member
USA
663 Posts |
Posted - 06/21/2005 : 15:29:13
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| On either the effct level or feedback control pot. I can't recall which it is exactly. It is one of the easiest mods you can do for yourself. |
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Erik dP
Silver Member
Sweden
150 Posts |
Posted - 07/01/2005 : 18:36:07
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I read on another forum that someone from Argentina came up with this high-cut mod.
A 0.057 CAP across the legs of the "Level" pot. And a 0.047 CAP across the legs of the "Feedback" pot.
Modification on only one of the pots will only change one aspect of the sound as I understand it. (Get the first echo darker + Progressively darker sound.)
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Edited by - Erik dP on 07/01/2005 18:37:49 |
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boss freak
Gold Member
USA
663 Posts |
Posted - 07/02/2005 : 20:18:55
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| That sounds about right, but in the mod I did, I only put a capacitor on on pot, not on two. If anyone tries this method, please report back with your findings. I wish I had the time to try this mod myself. |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 07/02/2005 : 20:34:21
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57nF isn't a standard capcitor value. Sure it wasn't 47nF on both pots?
When you use a capacitor across the solder points of a pot, you will normally move the filter's cut-off frequency with the setting of the pot. If the pot's effect on the filter is negligible you're fine but if it is part of the filter you have an undesired effect as the level and feedback pots now control 2 settings each. |
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Erik dP
Silver Member
Sweden
150 Posts |
Posted - 07/04/2005 : 13:37:08
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As I understood it it was 57 micro F and 47 micro F?!? Not nano F if that is what "n" stands for. (I guess that micro should be "u").This is the post I read:
http://www.diystompboxes.com/sboxforum/viewtopic.php?t=32632&highlight=dd3
However another post suggest this:
It will work on DD3 for sure. Just plug the 1uF NP Cap on the outer lugs of the E.Level if you want the warmer sound to be constant on the whole wet signal reps, without adding. If you want cut more highs on every rep, you must use the Feedabck pot (good for real reverb simulation).
Bye!
Fuzz
maybe a combination of both of these things would be best? I want all of the repeats to be warmer then the stock setting, and I want them to get warmer with each repeat. So perhaps a .47 cap on the feedback pot and a .47 cap on the E. level? Or would you recommend other values?
http://www.diystompboxes.com/sboxforum/viewtopic.php?t=27454&highlight=high+cut+boss+dd
In this case the suggestion is much lower, but still 10 times higher than 47 nano F.
I guess the best thing would be a variable capacitor to be able to experiment? |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 07/04/2005 : 15:02:47
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Larger caps will give lower cut-off frequencies. Capacitors in the uF often filters every audible frequency away. In tone controls you normally see nF capacitors in the bass control and pF caps in the treble control. We're talking about a hi cut (low pass) filter here so he may have meant pF.
If I can find the schematic I might do the math and see how this filter will work.
The standard values are 10 - 22 - 33 - 47 - 68 so it should probably be 47 on both caps fo this mod. |
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boss freak
Gold Member
USA
663 Posts |
Posted - 07/04/2005 : 22:44:45
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I only used one cap and I believe it was a .047 uF or .1 uF
The larger the value, the more high-cut. I think I even tried two 1 uF caps in parallel just to see what it would sound like and although the ducking (high-cut) sounding good, I could only get a few audible repeats even with the repeat control maxed out. |
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Erik dP
Silver Member
Sweden
150 Posts |
Posted - 07/05/2005 : 15:37:23
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Hi Bossarea. Here is the DD-2 schematics:
http://www.8bitsindgenug.net/boss_dd2.png
As you can see when you enlarge it the two pots are 50 K ohm each. Apparently it is linear (according to another post).
http://www.diystompboxes.com/sboxforum/viewtopic.php?t=30651&highlight=boss
Update...
Someone suggested this:
"Yup, try putting a cap to ground in the feedback loop, at the junction of R33 (47k) and R31 (22k), that should kill highs with increasing repeats (repeats get darker). Or dink with the value of C25, that network forms a low pass filter - start with 0.047uf and work up/down from there.
Oh yeah if you want to figure out the low pass frequency (i.e. frequency at which highs start to get cut) use the formula:
1/2piRC, where pi=3.14, R = value of resistor (in M ohms), C = value of cap (in uf). Stock, highs get cut at around 1200Hz." |
Edited by - Erik dP on 07/05/2005 16:34:35 |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 07/05/2005 : 16:19:04
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Thanks for link.
It looks really complicated but I'll drop the numbers into pspice and simulate it with and without the caps. Hope I can get it to work  |
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Erik dP
Silver Member
Sweden
150 Posts |
Posted - 07/05/2005 : 16:34:13
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Hi again.
Did you see my update of my last post? |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 07/05/2005 : 17:30:48
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| Yes this is what I did when I wrote that 47uF probably wasn't the right value. I didn't know what the resistor values was but the cut-off frequency would then easily drop below the audible area and absolutely everything would be filtered away. |
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fancy pants
Copper Member
USA
30 Posts |
Posted - 12/18/2007 : 23:19:49
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| I'll have to try this. |
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pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 12/19/2007 : 05:24:18
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Hey welcome to the forum fancy pants |
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fancy pants
Copper Member
USA
30 Posts |
Posted - 12/19/2007 : 06:46:07
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thanks 
Is the mod you guys are talking about just an internal one without the 3 way switch? |
Edited by - fancy pants on 12/19/2007 06:47:50 |
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Topic |
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High cut mod on DD-2/3?
