Kustom Mysteries [message #10161] |
Fri, 02 January 2009 22:20 ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
LesS
Messages: 477 Registered: December 2002
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Senior Member |
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Hey everybody,
Here are a few Kustom Mysteries - anyone have any comments or possible answers?
想: Why are only 21xxx serial numbers over-struck to make 23xxx serial numbers, and why were they over-struck? (This happened approx Jan/Feb 1968.)
A? : Maybe Kustom had received some defective components and had a high number of failures?
想: Why were aluminum front panels used (from approx July 1967 to Sept 1967)?
想: Were any of the top handles you see on K200’s and some K100’s actually done at the factory? This happened from Aug to Dec 1968. Most appear to be added-on.
想: In approx August 1971, Kustom cabinets went from slant to straight and Kustom amps went from straight to slant.
想: Are the K25 and K50 the same output power?
想: It is amazing how many Kustoms fade evenly to a different color or shade. White with silver sparkles fades to light gold. Charcoal fades to charcoal with a gold cast. Fading/discoloration is not always even.
想: Commonly found in Kustoms is a speaker rated as "8 - 16 ohms" - should it be considered to be 8 ohms, or 16 ohms?
A: A speaker rated as "8 - 16 ohms" should be considered to be a 16 ohm speaker.
The 8-16 ohms rating means "16 ohms but a little on the low side".
A speaker rated as 8 - 16 ohms with a meter will measure about 10 to 10.5 ohms - where the average 16 ohm speaker will measure 11 to 14 ohms.
So it is no big deal - just consider it to be 16 ohms.
想: Why does my Kustom cabinet with chrome ports have the earlier "by Ross" emblem? (The chrome ports normally came in the later "by Kustom Electronics" cabinets.)
A? : My guess is that they simply had extra "by Ross" emblems left over when they switched to the Kustom Electronics cabinets.
想: Why does some Kustom 2x12 cabinets have a rear center brace and some do not?
A: It seems like the 2x12’s without a center brace have guitar speakers – so maybe only the bass cabinets got a center brace.
想: Why did the K100 2x10 combos come with two 8 ohms speakers wired in series which caused the amp to only put out about 35 watts RMS?
A? : Maybe the speakers were easier to obtain than 16 ohm speakers. Also the Eminence speakers were not high power, so maybe the 16 ohm load resulted in fewer blown drivers/warranty claims. (The later K150 2x10 combos came with more powerful 16 ohm speakers wired in parallel.)
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Re: Kustom Mysteries [message #10194 is a reply to message #10161] |
Mon, 05 January 2009 07:07 ![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: 4768 Registered: June 2004 Location: NY
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Senior Member |
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A possible reason for question #4 is that when Kustom made the folded horn 1-18" cabinet which had to be squared off, they made the whole cabinet line up look like a match more or less of continuity.
Also they needed more room in the 2-15" bass driver loaded cabinets no less the 3-15" models for quite sometime. Just the fact that they went to a 1-18" horn cabinet was a sign that they where looking for more bass output with less amp wattage.
Also I would venture a guess that not having to make that angle cut for each side of the cabinet, saved on some production cost!
Question #7
The impeadance of a driver skyrockets way above what it is rated at when the driver is powered at its resonate FQ, after that it drops down again untill about 2000hz where it starts to rise sharply again.
When we test, and when even amp companys test thru a resistive load, this is no where near a real world test, like what the amp will see when its driving speakers.
In fact probibly close to 70% of the time the driver is putting out a load well above what ever impedance it was rated at, so in effect a 8 ohm driver would average closer to 16 when in use.
Question #10
Yea, I bet it was due to the drivers not being made to handle the amps wattage, and what sucks with just two drivers hook in serise is if one blows the other one goes dead also from the lack of signal feed.
This is what took out a whole lot of Celestion 25 watt 12" drivers in there early cabs when drivin by their new 100 watt head.
The 4 drivers could barely handle the 100 watts, and then when one driver blew the other one wired in serise with it went dead also and then you had just 2 25 watt drivers trying to carry the 100 watt load for about 20 seconds before they blew also.
In the end you wound up with one good driver left, the one that went dead when the first driver popped!
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Re: Kustom Mysteries [message #10198 is a reply to message #10161] |
Mon, 05 January 2009 11:56 ![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) |
pleat
Messages: 1454 Registered: June 2004 Location: Belding, Mi
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Senior Member |
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To help out in some of the mysteries.
10 of us kustom amp collectors met with Bud Ross Nashville in Dec.2000 and spent the weekend with him at a guitar show where we had over 110 pieces of vintage Kustom amps on display. Some of your questions were answered by Bud at dinner.
Serial #'s Bud stated that they were trying to gain some financing and they restamped amps as added inventory as the bank was using inventory as colateral. So there are a lot of amps out there with altered #'s.
The Aluminum etched face plate is a mystery to Bud. He didn't ever remember them using the face plate. Altough the aluminum face plate was used for the pre amp section of the kombo 1 organ which is another story.
December 2008 we again met with Bud in Nashville, and he brought up speaker impedance. He stated that Kustom had custom wound voice coils of 12 ohms. Even though they were stamped 16 ohms. He also stated it was easier to order just one impedance speaker and had better parts inventory control when installing speakers on the shop floor.
The K25 and K50 are different amps. The K25 is 12.5 watts rms and the K50 is 25 watts rms.
Looking at the schematics you will see the difference in the output stage.
I still play a K50 on stage and with a processor pedal in front of it will rip your head off. It is my go to amp for just about any size venue I play.
The newer non slant kustom cabinets, I agree, it was after Bud sold the company to Baldwin and I think it was easier for production to cut straight sides and easier to cover. That era saw a lot of changes to cut costs, cabinets made with particle board, no insulation, The name badge was a dull die cast off set logo.
On another note on the metal slant face square blue light Kustom amps are the white molex connectors kustom used to make connections from board to board, is they failed quite often. I was a kustom dealer in the 60's and 70's and we finally got a tech update from Kustom saying to cut the plugs off and solder the wires direct to the boards. It was a good idea for using plugs, for the fact kustom could make field repairs on the pre amp boards by a plug and play, but it backfired. I have owned several of the Baldwin era Kustoms and when they don't work, the molex plug is the first thing I look to, to fix the problem. Well I guess I've covered everything I can think of for now.
pleat
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Re: Kustom Mysteries [message #10233 is a reply to message #10161] |
Thu, 08 January 2009 12:48 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) |
stevem
Messages: 4768 Registered: June 2004 Location: NY
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Senior Member |
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The reason for #8 has to be just to use up inventory, just like new Fender company did in 1965 after CBS took over. When Leo owned the company the control panels said Fender electronic instruments, latter in 65 after CBS used up all of those panels( and came darn near to having a law suite on their hands from the get go)in inventory the new ones said Fender musical instruments.
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