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Disco Stu
Silver Member
USA
303 Posts |
 Posted - 11/16/2008 : 04:00:52
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So I found a reference somewhere to a quick and dirty SD-1 mod: clip the leads to C6. Has anybody done this? Would it be worthwhile to do this with a spare SD-1?
Supposedly it effectively "takes the blanket off the amp" or something like that. I'd be interested to hear what the mod wizards here think about that, as it is within my extremely limited technical skills and I have my fourth SD-1 on the way...
Thanks
-- Disco Stu |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 11/16/2008 : 06:38:33
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Hi Disco Stu
Some did this in a recent post, within the past few days.
Regards Dr. Bob |
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Dr. Bob
Moderator
Australia
6593 Posts |
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Disco Stu
Silver Member
USA
303 Posts |
Posted - 11/16/2008 : 08:23:04
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Thanks Dr. Bob --
I looked earlier but could not locate that post. It somehow astounds me that clipping the leads on a cap would not simply result in a dead pedal.
Now if I can find some tiny little snippers...
-- Disco Stu |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 11/16/2008 : 09:05:04
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Hi Disco Stu
You know you only have to cut one lead (one side)
Leave enough to resolder if you don't like it.
If you look at where the cap is in the circuit, you would see why you don't end up with a dead pedal.
Regards & Good luck Dr. Bob |
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Dirk
Platinum Member
Netherlands
1309 Posts |
Posted - 11/16/2008 : 10:25:42
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Yeah, that works.
It's also part of some aftermarket mod kits. |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 11/16/2008 : 12:43:28
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Tried it on its own, and its a nice simple mod,
its a low pass filter, you won't find them on TS pedals tho |
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Disco Stu
Silver Member
USA
303 Posts |
Posted - 11/17/2008 : 01:23:18
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Thanks all,
For your 'input' ! So I guess if C6 is a low pass filter, then clipping it puts a little more bass into the eq curve? Other than that how might I expect the sound to change versus a stock Taiwan SD-1? Does it basixally just affect the tone knob while leaving the overdrive parameters intact?
As of now, my SD-1's are a stock MIJ, a stock MIT, and an analogman MIT with the push-pull knob for symmetrical/asymmetrical clipping and the 'Silver' mod. With one more on the way, I figure it's time for an easy home mod attempt. Not like I have to worry about any emergency shortages.
--Disco Stu
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 11/17/2008 : 03:08:15
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quote:
Originally posted by Disco Stu
So I guess if C6 is a low pass filter, then clipping it puts a little more bass into the eq curve?
It's the opposite, it lets more highs back in.
A low pass is the same as a high cut or a treble cut, like a high pass is the same as a low cut or a bass cut |
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zentropa
Gold Member
USA
837 Posts |
Posted - 11/17/2008 : 16:33:45
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i'm not a big fan of removing C6.
i did, however, find some decent success with changing C6.
removing it made things a bit too harsh, but i can't remember what value i ended up leaving in there... as i swapped out like 14 diff cap values. |
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Disco Stu
Silver Member
USA
303 Posts |
Posted - 11/18/2008 : 01:04:15
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Well, my latest SD-1 arrived in the mail today AND it was in a pretty robin's-egg blue HR-2 box!! S/N is illegible from past velcro, but it's a Taiwanese silver label.
So I'll try clipping a leg on C6 after I test it out and compare it with my other generic MIT... I can always solder it back in the future.
Zentropa, I'm certainly curious what value you finally settled on if you ever take a peek in there.
-- Disco Stu |
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zentropa
Gold Member
USA
837 Posts |
Posted - 11/18/2008 : 06:14:39
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just for the record, when i was swapping these out it was with a fulldrive 2 conversion SD-1.
i believe it was like 220pf that i liked best. i also got some interesting results from some higher values such as 0.22uf and 0.47uf... these seemed to add a touch of compression feel to it, sort of like older DS-1's. i ended up swapping in so many caps that i managed to burn the pads off and i converted it to a TS808 :P
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copper
Bronze Member
USA
73 Posts |
Posted - 11/27/2008 : 16:44:00
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| I also did the Fulltone mod, but I was digging the sound best with the C6 removed. Made it a little more transparent to me. |
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Disco Stu
Silver Member
USA
303 Posts |
Posted - 12/06/2008 : 05:12:57
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OK -- Finally getting around to sharing the results here. Had two MIT SD-1's to compare. They both were serialless, but had the same numbers on the (Citizen) PCB board and quite-similar appearing components and wires. Same JRC 4558DD chip in both. There was a slight variation in the appearance of PCB boards... the latest acquisition had shinier-looking field (Not the traces).
In sound comparisons, the latest and oldest were quite similar, but the latest seemed more shrill, rough, harsh and less musical somehow, while the earlier (in my collection that is) sounded smoother, sweeter and less harsh. These subjective opinions were formed comparing the two with various matching knob settings. They were more similar than different, and the distinctions were quite subtle.
After desoldering C6 on the "new" SD-1, I compared them again and the big difference is a brighter, more trebly curve without that Capacitor. Otherwise, it did not change the overall function of the pedal that much. The difference between the C6-less Taiwan pedal and the stock Taiwan is really just a matter of treble and upper-midrange quantity to my ears.
After removing C6, the pedal seems to shriek and squeal noticeably with the "tone" control turned up.
So that was my first attempt at altering a pedal, using a very wide soldering tip that I use for stained glass work. Sort of like hunting squirrels with a 10-gauge shotgun. I think that I would like to try some further mods on this thing in the future... Laurie's Lovepedal Eternity mod might be a nice winter project. But I need to study further before messing around any more.
Hope this data is useful for someone!
-- Disco Stu
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 12/06/2008 : 15:36:48
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Thanks for the update DS!
If the modding bug bites you... try your local electronics parts wholesaler - they usually have nice soldering stations on sale. My local guys have had a Hakko one for $99.95 for a couple of months.
The role of C6 is to control the shrieky treble... Technically what it does is provide "high pass negative feedback" to the opamp, and the negative feedback cancels out the high frequencies it passes back, hence removing them. Your practical experience aligns really well with the theory :-) |
Edited by - Laurie on 12/06/2008 18:40:34 |
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Disco Stu
Silver Member
USA
303 Posts |
Posted - 12/07/2008 : 00:57:43
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I've got a Weller WLC200 with variable heat control, It's been a reliable enough iron for several years. I just need to get a tiny tip for it.
Before I begin destroying modding pedals, though, I need to learn about the proper types of solder and flux, the good kind of desoldering braid, and some basic electronics theory.
Understanding the difference between different types of resistors and capacitors would be a bonus too. |
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Topic |
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SD-1 C6 Mod: Anyone tried this?
