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swingerfunky
Copper Member
USA
2 Posts |
 Posted - 02/13/2010 : 23:59:25
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Hi everyone, This is my first post on this excellent site and I have decided to get some help after searching the forums first. Here we go.
I recently purchased the DS-1 Roxx mod from Monteallums, and without infringing on his copyright, it includes a dual op-amp chip adapter that that runs 2 TI NE5532P chips. My problem is that after the mod, with both chips installed I get a thinner sounding distortion that breaks up into a slight scratchy sound before the note naturally fades. But with only 1 op-amp in the pedal works great. I consulted with him via email and we were not able to pinpoint a problem. Has anyone used a similar set up and had the same result? I am using a 9v adapter. Thanks for any help up front!! |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/14/2010 : 01:09:19
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G'day swingerfunky and welcome!
This is a pair of chips "stacked"? |
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cctsim
Silver Member
United Kingdom
418 Posts |
Posted - 02/14/2010 : 01:19:52
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| I would put sockets on the adapter and try to see if any of the opamps is damaged by swapping with a good one. |
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zerksies
Double Platinum Member
USA
3406 Posts |
Posted - 02/14/2010 : 01:48:29
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| Welcome to the forum |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 02/14/2010 : 01:58:27
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Hi swingerfunky
Welcome to the forum from Australia.
Regards Dr. Bob  |
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Boss_8
Copper Member
USA
44 Posts |
Posted - 02/14/2010 : 14:21:52
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quote:
Originally posted by swingerfunky
Hi everyone, This is my first post on this excellent site and I have decided to get some help after searching the forums first. Here we go.
I recently purchased the DS-1 Roxx mod from Monteallums, and without infringing on his copyright, it includes a dual op-amp chip adapter that that runs 2 TI NE5532P chips. My problem is that after the mod, with both chips installed I get a thinner sounding distortion that breaks up into a slight scratchy sound before the note naturally fades. But with only 1 op-amp in the pedal works great. I consulted with him via email and we were not able to pinpoint a problem. Has anyone used a similar set up and had the same result? I am using a 9v adapter. Thanks for any help up front!!
I just did a CS-3 Monte Allums mod and it had a stacked chip adapter to replace the original SIP chip. With both chips in it would clip or cut out so I just pulled one chip out and it works fine now. When you stack chips there is an increase in gain, I think it was too much gain for the circuit in the case of the CS-3, I'm not sure about the DS-1 though? Maybe those more in the know about electronics can chime in.... |
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swingerfunky
Copper Member
USA
2 Posts |
Posted - 02/14/2010 : 18:10:50
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Hi everyone and thanks for the warm welcome!!
quote:
Laurie Posted - 02/14/2010 : 01:09:19 G'day swingerfunky and welcome!
This is a pair of chips "stacked"?
Laurie, by stacked to you mean running in parallel? If so then yes they are stacked.
quote:
cctsim Posted - 02/14/2010 : 01:19:52 I would put sockets on the adapter and try to see if any of the opamps is damaged by swapping with a good one.
Cctsim, I have tried each individual op-amp along with trying 2 Bur Brown OPA2134PAs I had laying around and the pedal does the same thing if with a slightly different tone due to the op-amps.
quote:
Boss_8 Posted - 02/14/2010 : 14:21:52
quote:Originally posted by swingerfunky
Hi everyone, This is my first post on this excellent site and I have decided to get some help after searching the forums first. Here we go.
I recently purchased the DS-1 Roxx mod from Monteallums, and without infringing on his copyright, it includes a dual op-amp chip adapter that that runs 2 TI NE5532P chips. My problem is that after the mod, with both chips installed I get a thinner sounding distortion that breaks up into a slight scratchy sound before the note naturally fades. But with only 1 op-amp in the pedal works great. I consulted with him via email and we were not able to pinpoint a problem. Has anyone used a similar set up and had the same result? I am using a 9v adapter. Thanks for any help up front!!
I just did a CS-3 Monte Allums mod and it had a stacked chip adapter to replace the original SIP chip. With both chips in it would clip or cut out so I just pulled one chip out and it works fine now. When you stack chips there is an increase in gain, I think it was too much gain for the circuit in the case of the CS-3, I'm not sure about the DS-1 though? Maybe those more in the know about electronics can chime in....
Boss, I too just did a CS-3 Mod and I was experiencing the same thing. What I did was remove the Diode (D10) and Resistor (R32) and ran a jumper between them and I am now able to use both op-amps while running a 9v adapter. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/14/2010 : 18:19:34
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Stacked chips work best when the chips are off the same silicone "die"... ie. they are manufactured side-by-side so have nearly identical specs. When the specs are slightly different, one chip tries to drive the other where they are mismatched which has unpredictable results for the sound (generally not good).
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MervsMods
Bronze Member
USA
133 Posts |
Posted - 02/16/2010 : 06:24:30
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| This works for me - just about every time... Take some electrical tape and wrap it around the dual IC adapter 2-3 times. It you're getting the same result, chances are you either have a solder bridge under the IC sockets on the adapter assembly, OR you have a bad op-amp. The electrical tape insulates the adapter from shorting out against other components when you close up the pedal. Try that and see if it works... I've done at least a half dozen of the Roxx mods (Even threw it in a couple of DF-2 with amazing results....) |
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MervsMods
Bronze Member
USA
133 Posts |
Posted - 02/16/2010 : 06:27:08
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| Oh and another thing... Make sure that the adapter stays in the socket "extenders" supplied with the kit. That's another issue that I've come across with with the dual opamp adapters. When I know for sure that the adapter is separating from the circuit, I "tack solder" the end pins to the sockets. (that just popped into my head) |
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Topic |
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Troubleshooting a DS-1 post allums mod
