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Kustom 2001A-1 Grounding [message #12032] Mon, 28 September 2009 22:01   LZBass Messages: 16 Registered: September 2009 Junior Member This is my first amp repair. I have a 1968 Kustom K200A-1 amp that I am trying to get into service. First I want to replace the power cord with a 3-wire version. I've also read about replacing the large filter caps. They seem to be original. Should these be replaced as routine? Then it's on to repairing the amp! Thanks in advance for the help, -- Phil -- Report message to a moderator

Re: Kustom 2001A-1 Grounding [message #12037 is a reply to message #12032] Tue, 29 September 2009 05:59   stevem Messages: 4733 Registered: June 2004 Location: NY Senior Member Installing a grounded cord is easy. The new white and black wires go where the old ones from the power cord went to, the new green ground wire gets bolted down to the chassie, and lastly the .022 at 600volt cap that goes to ground off of the on/off switch gets cut out. In rguards to the filters, they may be good or they may be on there way out, as in amps that are used a fair amount they will tend to hold up better than amps that have just been sitting around. On the Mallory brand caps you will see on top a small out lined circle, if this is not flat and pushed up some than the filter is drying up and should be replaced. on other brand filters they may have no circle and you will than have to look for just a pushed up bump to tell you its time to change them out. If you play the amp loud and or play bass you can get a tad more clean head room by stepping up to 8000 to 10,000 MFD filters from the stock 4500 MFD filters, just use the at least the same 50 volt rating. AS a side note, a 100 volt or better filter will last twice as long as the stock 50 volt. So whats wrong with the amp that needs to be fixed? Report message to a moderator

Re: Kustom 2001A-1 Grounding [message #12048 is a reply to message #12037] Tue, 29 September 2009 15:45   LZBass Messages: 16 Registered: September 2009 Junior Member Thanks for the quick respone! I've have an order for the new power cord and will install it as soon as it arrives. I just picked the unit up a couple of weeks agao. At that time it didn't power up but did managed to give a "tingle" to the seller when he touched the power "ON" toggle switch. When I opened the unit up I found the input power fuse blown. Someone had installed a 7A fast-blo fuse. I wan't to change the power cable before I power it up again. I checked the two filter caps and they seem OK... no bulging of the RED dot or anywhere else. I intend to play bass through it so I'll probably go with different caps as you suggested. I bought the proper schematics on ebay for the unit. I'll know more once I apply power back to it. Thanks for the help and I'll keep you posted on my progress. -- Phil -- Report message to a moderator

Re: Kustom 2001A-1 Grounding [message #12073 is a reply to message #12048] Thu, 01 October 2009 19:10   LZBass Messages: 16 Registered: September 2009 Junior Member I was wondering if there are any other circuit modifications required when I install a new 3-wire power cord in addition to removing the .022uF cap from the input circuit as the chassis will be common ground. Just asking as it looks like the circuit boards run off of +34V and -34V. Thanks in advance, -- Phil -- Report message to a moderator

Re: Kustom 2001A-1 Grounding [message #12077 is a reply to message #12032] Fri, 02 October 2009 07:16   stevem Messages: 4733 Registered: June 2004 Location: NY Senior Member Nothing else needs to be done it install the grounded cord, but there are 3 electrolitic cpas that I would replace in the amp. On PC602 replace C601. a 25 mfd at 35 volts cap(radio shack carrys 22 at 35v which is fine) On PC502, replace C501 which is that same value cap. On PC702 the driver/power amp board, replace C703. a 100 mfd cap at whatever voltage is marked on it. You can always go higher in voltage rating on these caps and it will help them to live longer, but NOTE they must be installed with the plus(+) marking going back in the board the way they came out. Report message to a moderator

Re: Kustom 2001A-1 Grounding [message #12078 is a reply to message #12077] Fri, 02 October 2009 10:31   LZBass Messages: 16 Registered: September 2009 Junior Member Thanks for the response. Are these being changed because they may be old (value change/leaky, etc) or for some other reason? Also, as this is a K200A-1, it uses the following boards: Regulator: PC502 Power Amp: PC702 Pre-Amp: PC102 Should I assume that the same caps you identified be changed on these boards too? Thanks, -- Phil -- Report message to a moderator

Re: Kustom 2001A-1 Grounding [message #12079 is a reply to message #12032] Fri, 02 October 2009 12:21   stevem Messages: 4733 Registered: June 2004 Location: NY Senior Member Do not forget what I responded to in one of your other posting, use a 1.5 amp fuse due to the fact that if someone before had to replace a fuse it was most likly do to a short in the output stage. This means that you probibly have one or more shorted output transistors and a driver transistor also. I would pull all 4 outputs and check them for shorts before powering up the amp even with a 1.5 amp fuse in it. Report message to a moderator

Re: Kustom 2001A-1 Grounding [message #12286 is a reply to message #12079] Fri, 23 October 2009 22:45   mevalade Messages: 5 Registered: September 2009 Location: Montreal Junior Member Hello Steve! You wrote a lot of interesting stuff here. I was thinking of grounding my Head too. Why remove the 0.022uF 600V cap? Report message to a moderator

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