What is it? [message #20770] |
Mon, 23 June 2014 23:48 ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
Iowa Boy
Messages: 767 Registered: June 2014
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Senior Member |
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Purchased these for $20 from a guy who had stored them in a barn for 20 years. He had no idea what they were only that he thought 2 of the eight speakers were shot. Turns out all four in each cabinet are torn. Speakers are definitely CTS......(137) 47 week of 1972. Speakers have square magnets,(4) 8 inch speakers per cabinet, 16 ohms each, number on speaker is 038-0012-00. Guy I know thinks these are guitar speakers. Anyone know what they are and what the wattage is. I would like to find suitable replacement speakers but not sure what I have. So far, only thing on the cabinet worth saving is the frame and Kustom logo's......everything else is shot. Are the speakers worth having reconed? Would like to use this for Kustom K400B PA/Bass head that I have just ordered. Thanks
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Re: What is it? [message #20772 is a reply to message #20770] |
Tue, 24 June 2014 07:44 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
stevem
Messages: 4759 Registered: June 2004 Location: NY
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Senior Member |
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Hello!
You have the pa cabinets from a K100 pa and at best when new these where pretty poor for pa usage other than for low volume acoustic acts!
Your wish to use them for bass even with all new drivers will not work out well as the cabinets themselves are too small for low frequency reproduction, not to mention that the drivers themselves do not. Go down to low E frequency wise.
At this point you may be best to just sell the drivers off as is on ebay along with the Kustom logos.
[Updated on: Tue, 24 June 2014 07:53] Report message to a moderator
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Re: What is it? [message #20782 is a reply to message #20770] |
Wed, 25 June 2014 07:02 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
stevem
Messages: 4759 Registered: June 2004 Location: NY
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Senior Member |
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A good pick for a replacement speaker is from parts express, part number 294-2471, they are all of 29 bucks and 16 ohms to boot which is hard to find!
That thread you read here on the reverb problem mentions the reverb pan that you need to get that K400s verb up and running again, but go thru that thread for the check out of the amp before wasting your time on getting a new pan.
Amps back than had there wattage rated in regards to peak power, not RMS power like today stuff, so a k200 head had 100 watts rms into a 4 ohm load, or some 60 watts rms into a 8 ohm load.
The K100 head states 60 watts rms on the rear lable, but only has 50 watts rms into a 8 ohm load, or some 28 watts rms into a 16 ohm load.
You can run a K100 into a 4 ohm load, but the amp will run twice has hot at any given volume as compared to running thru a 8 ohm load.
In this light if you ever run a K100 into a 4 ohm load, never run the volume knob over about 4 unless you can place a small fan blowing on the rear of the amp!
In regards to running monitors, the K200 and 400 heads have a RCA jack on the back that is made for feeding a tape recorder.
Its signal level output is quite hot for pumping into another Kustom with out padding it down by about half, other wise you stand a real good chance of popping the first gain stage transistor of whatever channel on the Kustoms you plug it into!
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Re: What is it? [message #20788 is a reply to message #20770] |
Wed, 25 June 2014 13:35 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
chicagobill
Messages: 2005 Registered: April 2003
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Senior Member |
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You are right about wanting to have each speaker cabinet to be 8 ohms so that when two are used, it will be a 4 ohm load on the amp.
Small fans were not very common on amps 45 years ago. Installing them into your amps can be done, but do you think that you really need them?
"Padding" is an old radio term that simply means reducing the level of a signal. It can be done with a few resistors or a variable pot, etc.
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Re: What is it? [message #20793 is a reply to message #20792] |
Wed, 25 June 2014 16:57 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) |
pleat
Messages: 1454 Registered: June 2004 Location: Belding, Mi
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Senior Member |
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Lots of info on this thread, but I think we need to determine what the end results are in mind.
Assuming the 4x8 columns were in perfect working order, each column is 16 ohms. Two columns plugged into the K200 PA head presents a 8 ohm total load to the amp. The K200 heads are designed to run optionally at a 4 ohm total load to achieve the 100 watts RMS. You can always run a load greater than 4 ohms without concern other than lowering the output wattage.
These amps have lasted over 40+ years and they didn't require a fan back in the day, so I'd guess its not needed today as long as the the columns are correct.
If your going to use the 4x8 columns with the K200 PA head and you find you have some bad speakers, you might want to consider just replacing all the speakers with new 8 ohm speakers, wire them in series/parallel for a 8 ohm load for each column, and the two columns to the K200 head will give you the 4 ohm load to the amp head.
pleat
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