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Distortion in an Kasino Club PA head [message #15669] Thu, 19 May 2011 09:31 Go to next message
jh45 is currently offline  jh45
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I made a trade the other day with some Home Audio stuff that was given to me which I would never use so I traded it off for a Rasa (Panasonic) 12 channel Mixer which works great and they guy threw in an old Kasino Club 100 watt (Kustom) 4 channel mixer from the 70's. I hooked it up last night to some speakers I have that I have pushed with my CS800 and the Rasa Mixer and my BI-AMP powered mixer and the speakers sounded fine. Hooked them up to the Kasino head and if you even turn them up even a little bit the speakers did not sound clear and slightly distorted expecially on the bass notes of the music I was playing. Would you suspect caps or Output transistors or both? Or something else. The Reverb is out of it but that I would suspect should not cause any speaker distortion.
Re: Distortion in an Kasino Club PA head [message #15673 is a reply to message #15669] Thu, 19 May 2011 12:28 Go to previous messageGo to next message
chicagobill
Messages: 1935
Registered: April 2003
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Welcome to the place.

If all channels distort, then the problem is probably in the power amp. The cause could be any number of things. Some simple, and some not so simple.

Are you planning on fixing this yourself?
Re: Distortion in an Kasino Club PA head [message #15675 is a reply to message #15673] Thu, 19 May 2011 14:23 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Yes I plan on working on it myself I cannot see spending the money on a tech doing it as it is just a project amp to me and will just be used as a spare amp. Before you give me the dangers of working in amps I know all about that. I have done a cap job in an old Traynor Mono Block Bass amp and did a Cap job on my Fender MusicMaster Bass amp. I replaced the Filter caps on several other amps and built two guitar amps from old tube chassis. But I have messed with tube amps more then Solid State amps so I need a bit of ideas on this one where to look. What I am trying to say is I am not a tech by any means but I do know a bit of electronics. I took a Electronics class back in the 70's but never used it as circumstances had other plans for me. Only test equipment on hand is a digital multi-meter.
Re: Distortion in an Kasino Club PA head [message #15676 is a reply to message #15675] Thu, 19 May 2011 15:02 Go to previous messageGo to next message
C4ster
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Location: Mukwonago, WI (Milwaukee...
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The amp you cited, the CS800 is a power amp only with an input range of 1 volt to 20 volts from a mixer. The first thing in that amp that your signal sees is a volume control to limit the input to deliver the maximum output. The Kustom amp however, has preamps that take much less input than the CS800, in the millivolt range. The first things in that preamp are transistors that you are probably overdriving. The volume controls are after these input transistors. So even if you turn the volume down, the amp is already distorting before the signal gets to the output stage. Try a high impedance mic in the Kustom and see if it distorts, or a guitar. That might tell you plenty.
Conrad
Re: Distortion in an Kasino Club PA head [message #15678 is a reply to message #15669] Thu, 19 May 2011 16:37 Go to previous messageGo to next message
chicagobill
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The pc boards in your amp are marked with numbers such as PC102 on the foil side. If you list them we can either send the correct schematics or send you to site to get them. That is if you don't already have them.

I would suggest starting by checking the power supplies for the power amp and the preamps and go from there.
Re: Distortion in an Kasino Club PA head [message #15680 is a reply to message #15676] Thu, 19 May 2011 17:07 Go to previous messageGo to next message
jh45 is currently offline  jh45
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C4ster wrote on Thu, 19 May 2011 14:02
The amp you cited, the CS800 is a power amp only with an input range of 1 volt to 20 volts from a mixer. The first thing in that amp that your signal sees is a volume control to limit the input to deliver the maximum output. The Kustom amp however, has preamps that take much less input than the CS800, in the millivolt range. The first things in that preamp are transistors that you are probably overdriving. The volume controls are after these input transistors. So even if you turn the volume down, the amp is already distorting before the signal gets to the output stage. Try a high impedance mic in the Kustom and see if it distorts, or a guitar. That might tell you plenty.
Conrad


OK so your telling me due to its design a mic or guitar maybe fine but playing music through it is over driving the pre amp transistors. I did try a mic and it did not sound all that bad. Since I have two PA mixers that work fine for playing music and other PA chores It is not that important that I use this for a PA. I wanted it to borrow to folks who ask me to borrow my expensive stuff that are in need of a PA. I will recheck it with a Mic again and report back.
Re: Distortion in an Kasino Club PA head [message #15681 is a reply to message #15669] Thu, 19 May 2011 17:33 Go to previous messageGo to next message
jh45 is currently offline  jh45
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OK I tried a mic with limited success because I tried it in my utility room where most of my stuff is stored and since it is little feedback is an issue but your right the music was over driving the input. If the amp had a Power amp IN I would keep it but since it only has line out and monitor out I think I will trade it off. Since I already have a powered mixer and other other mixer set up which both are more advanced than this older mixer. I do not need an other amp for guitar either so I think I will trade this one off if the music store will take it.
Re: Distortion in an Kasino Club PA head [message #15683 is a reply to message #15681] Fri, 20 May 2011 02:26 Go to previous messageGo to next message
C4ster
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Location: Mukwonago, WI (Milwaukee...
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I understand about loaning equipment out. A CS800 is big stuff and heavy too. The early PA heads usually don't have a line in so using that head with a mixer ahead of it can be tricky. Unless your music source is a very low level signal, controlling the output of the PA can be frustrating.
Conrad
Re: Distortion in an Kasino Club PA head [message #15684 is a reply to message #15683] Fri, 20 May 2011 08:56 Go to previous messageGo to next message
jh45 is currently offline  jh45
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I am surprised that Kustom did not make a amp in and amp out on their mixers as they were good equipment for their day. I had a Fender PA head that was Solid State that would have been the same time frame as the Kasino and it had not only a power amp in and out but a in and out for effects with a switch for each channel. It too was a 4 channel 100 watt mixer. I sold it and an other amp to get some quick cash to buy a guitar amp I got a great deal on.
Re: Distortion in an Kasino Club PA head [message #15687 is a reply to message #15684] Fri, 20 May 2011 16:40 Go to previous messageGo to next message
pleat is currently offline  pleat
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I'm not a tech but the Kasino Club PA uses the same power amp as the K100-5 PA power amp. The amp is 50 watt RMS into an 8 Ohm total load. Using a lower impedance will make the amp run hot and could shut down.
As far as a line in and line out jack. That's a simple install. There are three wires going to the power amp. Red Green and either a tan or blue. Red and green are the voltage wires. The third wire is the signal from the pre amps. Cut and install two switchcraft 12A switching jacks and your good to go.
pleat
Re: Distortion in an Kasino Club PA head [message #15688 is a reply to message #15669] Fri, 20 May 2011 16:47 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Called the music store they said they would take it even though they have an other one in stock. I need a power supply 9V AC 1.3 amp that cost twenty bucks I said I would trade the mixer for the power supply. A fair trade since I suspect they will only put 50 bucks on it.
Re: Distortion in an Kasino Club PA head [message #15707 is a reply to message #15688] Wed, 25 May 2011 22:01 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Well cannot take it to the music store until I try to fix it Reverb is not working I checked the tank and one wire was off so I re-soldered that but still not working so I will have to check it out again the rubber washers for the screws holding the tank pretty much rotted away. Any way Distortion on all 4 channels with a mic so I suspect something in the power amp section.I am wondering if the power transistors might be distorting/ I got some other Power Transistors I took out of an other older PA I will have to check to see if them are the same numbers and try replacing them unless some one has an other idea what is causing the distortion.
Re: Distortion in an Kasino Club PA head [message #15711 is a reply to message #15669] Thu, 26 May 2011 11:58 Go to previous messageGo to next message
chicagobill
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Distortion from the power amp is not usually caused by the output transistors. It is more likely a power supply problem or a bias problem.

Do you have access to a volt meter?
Re: Distortion in an Kasino Club PA head [message #15712 is a reply to message #15711] Thu, 26 May 2011 12:55 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Yes I have two of them. They are cheap digital ones but they work
Re: Distortion in an Kasino Club PA head [message #15713 is a reply to message #15711] Thu, 26 May 2011 12:56 Go to previous messageGo to next message
jh45 is currently offline  jh45
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So your saying the filter caps?
Re: Distortion in an Kasino Club PA head [message #15714 is a reply to message #15669] Thu, 26 May 2011 13:32 Go to previous messageGo to next message
chicagobill
Messages: 1935
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Probably not, you should always start by checking the power supply. If the voltages are off they can cause the amp to die, distort, etc.

Take you voltmeter and read the voltage across the two big filter caps. Each one should have about 40-45 volts dc on them. The preamps run on + and - 8 volts dc.

Remember that when working on an amp that is plugged in and turned on can be dangerous. Be very careful what you touch and where you stick the meter probes, so as to not hurt yourself or the amp.
Re: Distortion in an Kasino Club PA head [message #15716 is a reply to message #15714] Thu, 26 May 2011 14:17 Go to previous messageGo to next message
jh45 is currently offline  jh45
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I have repaired and recapped tube amps so I know about the dangers of working on electronics. But a friendly reminder never hurts. I will probably check it out this weekend as it is supposed to rain all weekend.
Re: Distortion in an Kasino Club PA head [message #15834 is a reply to message #15669] Sun, 12 June 2011 10:28 Go to previous messageGo to next message
stevem is currently offline  stevem
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now it seems we have someone by name of Alice posting mindless comments to the board!
Re: Distortion in an Kasino Club PA head [message #15835 is a reply to message #15834] Sun, 12 June 2011 10:32 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Yea I seen that yesterday spam I guess. Not sure what I want to do with this amp yet as I would not get much out of it from the music store and it is something I really would not use I might just scrap it out.
Re: Distortion in an Kasino Club PA head [message #15913 is a reply to message #15687] Mon, 27 June 2011 22:53 Go to previous messageGo to next message
cassent5150 is currently offline  cassent5150
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I took on this Kasino Club PA for a project. Its a cute little Basic PA. Not at all like the usual square head like the K100-5. Its like the early 70's tolex K-III PA. I just got the Kasino Club in the mail today and opened it up. Its got the PC-5033 driver. Everything is clean as a whistle. Took all of 5 min. to track the problem to the driver board. Good clean signal from the line out. Saw those old square black caps still in it so I replaced the 2 27uf caps and while I was at it popped in new transistors next to the 2 caps I replaced. Didn't change a thing as far as distortion is concerned. I may just go right through it and be done with it. It probably would be a whole lot faster than trying to pull parts check and reinstall them. I love these cute little boards. They dont take up much room and they can really put out some sound for the 75 watts they're rated at.

Steve C
Re: Distortion in an Kasino Club PA head [message #15915 is a reply to message #15913] Mon, 27 June 2011 23:57 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Glad your happy with it Steve. Let me know when you get it finished up what you found with it.
Re: Distortion in an Kasino Club PA head [message #15916 is a reply to message #15915] Tue, 28 June 2011 04:35 Go to previous messageGo to next message
cassent5150 is currently offline  cassent5150
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Sure Thing THANKS! !

Steve C
Re: Distortion in an Kasino Club PA head [message #15922 is a reply to message #15915] Tue, 28 June 2011 19:13 Go to previous messageGo to next message
cassent5150 is currently offline  cassent5150
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OK, I got back into it today when I got home from work. I recapped the board and replaced the driver transistors and BINGO!! A Driver transistor had a bad leg connection to the board, so bad in fact it burned the leg in two from all the arcing. Its purring like a kitten and quiet as a mouse. Kind of a cute little thing and fairly loud for a 75 watt PA.

Steve C
Re: Distortion in an Kasino Club PA head [message #15924 is a reply to message #15922] Tue, 28 June 2011 23:39 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Congrats was that one of the transistors on top of the PA or on the board its self?
Re: Distortion in an Kasino Club PA head [message #15925 is a reply to message #15924] Wed, 29 June 2011 04:29 Go to previous messageGo to next message
cassent5150 is currently offline  cassent5150
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It was one of the ones on the board itself. They're mounted in the square heat sink and soldered in the board.

Steve C
Re: Distortion in an Kasino Club PA head [message #15927 is a reply to message #15669] Wed, 29 June 2011 11:21 Go to previous messageGo to next message
jh45 is currently offline  jh45
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OK yea I saw them too. If I would have really needed a PA head I may have tried to fix this but since I have a Bi Amp 6 channel 300 watt Powered mixer and a 16 channel Ramsa (Panasonic) board and a Peavey CS 800 amp I figured that I would not bother and as long as you can get use out of it great. This way it worked out good for both of us. It was not the best packing job I could not find a box that would remotely even fit so I just surrounded it with cardboard and a pile of tape. Laughing

[Updated on: Wed, 29 June 2011 11:23]

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Re: Distortion in an Kasino Club PA head [message #15928 is a reply to message #15927] Wed, 29 June 2011 16:15 Go to previous messageGo to next message
cassent5150 is currently offline  cassent5150
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Packing was fine enough, they're pretty tuff to tear up. I spoke too soon on the work fine thing. I took it to my music room and hooked it up to real speakers and the reverb only lasted a minute and quit. Got back into it again a hour ago and recaped that section of the board. I just tested her out and pushed the crap out of it. She works good now and I thrashed on it with a guitar for 10 or 15 minutes on 10 the whole time. I have to say it has some really good sounding distortion if you crank the gain up on her. Still nice and clean for vocal use though. I don't know that it will replace my soundtech equipment though. My brother in Kansas has got a pair of 2X12 Kasino speakers that have the same blue Kasino decals so this will probably go back to Kansas as a present to him. It would be fine for small barn parties if ya run just vocals alone with it.

Steve C
Re: Distortion in an Kasino Club PA head [message #15929 is a reply to message #15928] Wed, 29 June 2011 18:48 Go to previous messageGo to next message
jh45 is currently offline  jh45
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Yea should work good for that it did back when it was new. Back then no one miked anything as most PA's were 4 channel lucky you had enough channels for the Mics.
Re: Distortion in an Kasino Club PA head [message #16608 is a reply to message #15684] Fri, 27 January 2012 12:27 Go to previous messageGo to next message
simpson studios is currently offline  simpson studios
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I havent done alot of work on the older amps just because iv never had to but i have the same distortion problem on the same amp. could i get some more info on the switching jacks. thanks Nick
Re: Distortion in an Kasino Club PA head [message #16612 is a reply to message #15687] Fri, 27 January 2012 19:45 Go to previous message
cassent5150 is currently offline  cassent5150
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Hey Pleat, your right on the driver board in the square 4 channel head, but the laydown model has that little 75 watt output board. I want to say PC 5032. I have both models and I just went through another laydown model for a friend. Steve C

Steve C
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