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lohworm
Copper Member
France
27 Posts |
 Posted - 01/06/2010 : 18:35:50
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Hello !
Does anybody know the use of the internal trim-pot in the PH-1 ?
(Maybe someone has the service notes ?)
Thanks
Laurent |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 01/06/2010 : 18:43:38
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| The trim pot sets the operating point for the FETs. |
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lohworm
Copper Member
France
27 Posts |
Posted - 01/06/2010 : 19:25:42
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How can I check it's properly set ?
What would be the consequences of a badly tuned trim-pot ?
Is it a "sound / no sound" impact, or could it be gradual ?
Does the fine tuning require an oscilloscope (I do have one) ?
(so many questions... ) |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 01/06/2010 : 19:35:00
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For a phaser, it either works or it doesn't. If you have phasing, the trimpot is set to approximately the right place. There is a highly technical setting procedure requiring a scope, but, the best way is to do it by ear. Tweak the pot until the phasing "sounds best". I know it sounds like the easy way out, but I've found that it is the easiest way to get a good sound if you don't have the service notes or a scope.
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lohworm
Copper Member
France
27 Posts |
Posted - 01/06/2010 : 19:47:57
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OK, thanks for all !
I asked these questions, because the PH-1 is fully working but I found the phasing effect lighter than with other pedals, even when the depth is full clockwise...
Maybe it's the normal sound of the PH-1 ? Or a consequence of some aged components ?
I should try to find sound samples on the net... |
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archimedes
Silver Member
United Kingdom
191 Posts |
Posted - 01/07/2010 : 13:51:17
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quote:
Originally posted by lohworm
!
I asked these questions, because the PH-1 is fully working but I found the phasing effect lighter than with other pedals, even when the depth is full clockwise...
Maybe it's the normal sound of the PH-1 ? Or a consequence of some aged components ?
I should try to find sound samples on the net...
The PH-1 doesn't really do deep phasing, it is quite a subtle beast, shallower than say an MXR Phase 90, yours is probably working just fine.
David
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lohworm
Copper Member
France
27 Posts |
Posted - 01/07/2010 : 18:55:49
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OK, thanks !
My PH-1 #7900 is definitely working good !  |
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ssanyee
Silver Member
Hungary
288 Posts |
Posted - 01/09/2010 : 19:48:17
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Hi lohworm,
Yes, I agree with Laurie but I would recommend you an adjustment based on the Service Manual too!
I have a digital copy of PH-1 Service Manual -> PM me if you want it!
cheers |
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Topic |
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trimpot inside PH-1 : what for ?
