stephen? Messages: 11 Registered: November 2006 Location: Vancouver
Junior Member
hey there, i am in need of a k200-5 schematic, i know someone who is very good with electronics and knows more than me about amps so he will take a look at it.please!
I have a K200-A5 with a dead reverb driver. A schematic would be very helpful to me as well...if you have one.
Any possibility you'd have one in electronic form, and could e-mail it to me?
For that matter, if you have any suggestions where to look for problems, I'd be grateful for that as well. The reverb return pre-amp works fine...I can tap the tank and get plenty of thunder-crashing.
I'd also like to improve some of the components in this amp to get rid of the hiss. I've heard it can be done.
BTW, your posts here have been very helpful to me!!!
Thanks,
Dave O.
Dave 0 Wall-O-Bass
Webpage - <a href="http://webpages.charter.net/daveobieone/" target="_blank">http://webpages.charter.net/daveobieone/</a >
stevem Messages: 4739 Registered: June 2004 Location: NY
Senior Member
Hi, I do not mean to say that it can not happen, but I have never seen a kustom with a bad reverb driver transistor.since you say you need a schematic, how have you determinded that its a bad driver?Here are 2 ways to find out. (1) get a cord or adapter that has a RCA male on one end and a male 1/4" guitar plug on the other and plug it into the reverb send RCA in the amp and into another guitar amp and some guitar with the reverb up full and see if you get signal, or get a RCA to RCA cord and plug it into your stereo to check for signal.(2) With a voltmeter set for a low a/c voltage scale, clip the meter across the end of the rca plug feeding the reverb pan and again play while looking for signal.My guess is that the transformer on the input side of that pan is open.Have you ohm checked the input side of the pan? it should read about 180 ohms.
You can get schematics from this site.
Replacing the first and second gain stage transistors in both preamps with modern lower noise items helps the hiss problem.
Yes, I'm getting no drive to the tank.
I have 4 or 5 reverb tanks, and I'm quite sure they all work just fine. Measured the drive voltage to the tank, and there's practically nothing showing up there...even with no tank connected.
Does the remote foot-switch have anything to do with the drive to the reverb? I don't have a foot-switch. My problem could be there...but without a schematic, I'm not really sure what's going on.
Where do I find a schematic for the K200-A5?...or one that's quite similar? I haven't seen one for that head yet. Perhaps I'm just not looking in the right place.
Thanks for the tips on the transistors...I'll try that for hiss reduction.
Sorry I've been so long responding.
Dave O.
Dave 0 Wall-O-Bass
Webpage - <a href="http://webpages.charter.net/daveobieone/" target="_blank">http://webpages.charter.net/daveobieone/</a >
stevem Messages: 4739 Registered: June 2004 Location: NY
Senior Member
Hi Dave,I can fax you a copy of the early k200 head as it may be the same reverb and vibrato board(PC 301) as in the latter A serise head but I am not sure.
The PC301 board has one transistor(Q301) driving the pan thru a 10 MFD electrolitic cap.
The original 2n3565 transistor crosses to a nte123, or a 2n3904 that you can get at any radio shack location .I would just replace that transistor and That C301 10 MFD cap, as that cap itself could be bad and doing in the drive.
Their is also C309 cap, another 10 MFD that could be bad too, that is located off the center tap of the reverb control.
stephen? Messages: 11 Registered: November 2006 Location: Vancouver
Junior Member
THANK YOU SO VERY MUCH!!!!!!! as you can notice i havent posted since, which means ive been playing me new working amp.....and boy is it a beauty. why just today i had the cops come by on account of the volume!some people eh? and another thing!! that company backline ive told you about that tried pulling a fast one on me for the repair of the amp, well it ends up they stole the reverb pan out of the amp..or "misplaced" as the repair manager put it. but he said hed find me a new one or give me money for it, how much would it cost for one?(keeping in mind the guys a total dick who tries ripping off people who know little about amps)