RE: Help needed: OTL3 Front End Bias not reaching 85V - Banat - OTL Asylum

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RE: Help needed: OTL3 Front End Bias not reaching 85V

In Reply to: RE: Help needed: OTL3 Front End Bias not reaching 85V posted by unlisted on February 6, 2015 at 09:37:00:

-Check for bad solder joints on all tubes sockets pins on underside of PCB board ,with special attention for Magnoval tube sockets pins dedicated for output power tubes and voltage regulator tubes , ( hope that original tube sockets are ceramic high quality types ) .
-Also check few small electrolytic capacitors for correct values which are placed on the top of PCB , they want to dry up when work in hot surrounding as is by any OTL amp.
-Check all resistors which are with mega-ohm values , and all others resistors with values above 220K , after long period of use those resistors sometime want to change(raise)the value .
-And yes , before doing anything from above make sure that NO electricity is present inside of that OTL unit , with special attention on PSU electrolytic capacitors , since they want to keep the potentially shock hazard electrical charge for several days .

Best Regards

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Follow Ups Full Thread

Topic - Help needed: OTL3 Front End Bias not reaching 85V - unlisted 14:38:42 01/29/15 (9)

RE: Help needed: OTL3 Front End Bias not reaching 85V - rhinohifi714 19:48:53 01/30/15 (3)

RE: Help needed: OTL3 Front End Bias not reaching 85V - unlisted 09:16:43 01/31/15 (2)

RE: Help needed: OTL3 Front End Bias not reaching 85V - unlisted 09:37:00 02/06/15 (1)

RE: Help needed: OTL3 Front End Bias not reaching 85V - Banat 17:57:56 02/06/15 (0)

RE: Help needed: OTL3 Front End Bias not reaching 85V - Lew 19:43:25 01/29/15 (0)

When was the last time filter caps were changed in the bias supply? nt - Ralph 14:46:25 01/29/15 (3)

RE: When was the last time filter caps were changed in the bias supply? nt - unlisted 15:02:37 01/29/15 (2)

Yes- resistors that have gotten hot. nt - Ralph 08:12:44 01/30/15 (1)

RE: Yes- resistors that have gotten hot. nt - unlisted 09:42:53 01/30/15 (0)

Follow Ups

RE: Help needed: OTL3 Front End Bias not reaching 85V - Banat 17:57:56 02/06/15 (0)

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