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Kustom K200B, Pics and Question Regarding Speaker Cab

C

Commodore 64

Sep 12, 2012
49
1
Kent, OH
#1
Last week I nabbed a cool Kustom Tuck N Roll bass amp.
Kustom%20200.jpg


These amps were designed to use 2 cabs at a 4-ohm load. I have one cab, with two 16-ohm speakers in it. I understand this will use ~65 watts RMS. If I can put two 8-ohm speakers in there, it will do the full 100w RMS at 4-ohms. The amp is plenty loud as is, I think, but I did notice that Partsexpress has some factory sellout Celestion 15-inch woofers for a decent price, and I'm wondering if they would work in my cab.

Can these be used in a bass amp cab?

[Invalid or Expired Link Removed]

Specifications: • Power handling: 300 watts RMS/450 watts max • VCdia: 2.5" • Impedance: 8 ohms • Re: 5.44 ohms • Frequency range: 46-4,000 Hz • Fs: 46.9 Hz • Sensitivity: 98 dB 1W/1m • Vas: 6.18 cu. ft. • Qms: 5.18 • Qes: 0.55 • Qts: 0.50 • Xmax: 3.5 mm • Dimensions: Overall diameter: 15.16", Cutout diameter: 13.86", Depth: 6.38".
Click to expand...
 
#3
For starters, recap that amp before playing out much with it...those old power supply caps (the big silver cans at the bottom of your last picture) are far past their prime. And remove the "death cap" and put in a 3-prong power cord.

That cab (which appears to be actually from a later K250 rig) sounds best with JBL D140F's or similar speakers. I put Eminence Delta 15's in mine (after somebody stole my JBL's which I had taken out at the time), they sounded good in that cab. Personally I would not match Celestions with that cab, just from my general opinion of Celestion "sound".
 
#4
What value caps should I look for? I've seen people mention stiffer caps, like 12k uF @50v, and I believe to stock values are 4500uF @50v.

Also, if the cab is a K250, is it still likely an 8-ohm cab (2 16 ohm speakers)? My cab does say Kustom By Ross, so I took that to mean it was an older cab.
 
#5
the stock cap values are just OK, you could add more, though much over 10,000 uF is diminishing returns for the amount of power that amp generates.

+1 on the JBL D140Fs in there. They're likely run you over 200 a piece these days, though.

I can't comment on the Deltas myself, no experience with them, but it looks to me they like a pretty big box if they're ported. Sealed might be better w/those as well as the Beta's, another fav for vintage replacements. Both the Delta and Beta get good reviews (see above), worth looking at.

If you're looking for that particular tone the JBLs generate, and they're rather unique, the Faital 15PR400s are very nice modern (and neo) near-substitutes. But they're also just over 200 apiece.
 
#6
Now that I've sold my old Kustom K250 rig, I no longer have their website bookmarked, but I think it's www.vintagekustom.com They have all the old brochures from the late 60's and early 70's. The K250 cab (which dates to around 1971) had the chrome flared ports like your picture, they differ from the earlier cabs.

Kustom was sold out a few years after the K250 cabs came out and the versions after Bud Ross sold the company were no longer tuck-and-roll.

I concur with the cap size, I recall the stock ones were 4500 in mine. I put 10,000 ufds in mine (I think) but I upsized the bridge rectifier.
 
#7
The reference to the Vintage Kustom is correct.

With the serial #, I can tell you within a few months of when it was made, but I can't make out the serial # on your head. I can tell you that it is late 60's and the cab appears to match it. The first generation logos had Kustom by Ross, Inc. and later changed to Kustom Electronics, Inc. Standard speakers for the cab were CTS. I've had a number of those that sounded great in that cab and others that didn't. The optional speakers were the aforementioned JBL D140 F's and the Altec 421A's. I personally like the Altecs a little more than the JBLs. :o
 
#8
Serial number is 37067. Thanks so much for the info!

You know, I just assumed those CTS were 16 ohm and that it was an 8-ohm cab. Maybe I should measure them.

NAshvillebill, do you happen to have a schematic? I do need to replace the power cable, so I'd like to get a list of parts I should order. I assume the bridge rectifier is a set of diodes. Do I need to change those out if I put a set of stiffer filter caps in there?
 
#9
I see that you found your way to the Vintage Kustom site. Lots of good folks there and information.

Serial #37067 indicates a build time between April and June 1969. If you can give me the numbers on the frame from the speakers, I can tell you when they were made too, and confirm the rig as a matched pair. The number should start with 137 followed by four more numbers if they're CTS. If not, still should be a grouping of numbers usually on the outer frame edge from which we can probably determine the maker and time frame. I believe that those cabs were wired for 8 ohms providing for adding a second 8 ohm cab (note the second speaker jack on the back of the head) for full benefit of power and air movement. I can attest to that being a nice setup.

I have the schematics for the 200 head that were faxed to me several years ago. I can only fax them too. Probably be readable for you. If not, someone on the Kustom site will probably have some. If you have access to a fax, PM me the number and I'll send you what I have. If you're a bit of a purist like me, I can direct you to a Bissel site that has the exact 3 prong cord "storage" clip just like Kustom. A bit pricey, but... There are also directions for replacing the cord on the Kustom site using the search function. :cool:
 
#11
Oren,
Thank you for the info. I will get the speaker numbers tonight if I have time before a gig, or failing that, tomorrow. I may take you up on the schematic fax if I can't find a digital copy. Also, would like the Bissel part # (or link) if you don't mind.
 
#15
As original owner of 1971 K 200-B, I have some questions...

bACKGROUND: In mid 80's I took my head in for service. The "Brite" side would go dead when I engaged the "brite" switch. Ths was my fave tone; Brite-side: Brite switch: ON. Bass: Full, Treble: Full. Volume between 2-4. Any volume beyond this resulted in distortion equal to Jack Bruce/ Felix Papplardi. I have one cabinet with 2- CTS; total ohmage @ 8 OHMS. Head is rated @100watts R M S; 50WATTS WITH

In those days, my Lifetime Waranty was still inm effect; service was completed for free..no questions asked. However, that service tech is no longer around and Lifetime Warnty is no longer in efffect.

Questions:
1) Does anyone know which/ what component is at fault in my Brite Switch Section? [ very low volume is discernable when Brite Switch is engaged, BTW]

2) Is there any remedy/ upgrade of component to make my head sound "better" ? I have always heard that Kustom heads were "loud", but Loud on mine means uncasseptable distiortion levels. It has never been able to compete with any guitar amp beyond say..Fender Super. Also, head is noisy. People say it's old school Solid state.."nature ofthe beast".

PS: Mine still has the original 2-prong cord; never any shock issues with mine, but y'all have me scared, now...LOL..
 
#16
Mine is not overly noisy. There is some buzz, but it is certainly less than that of my 5E3 build.

As far as max volume, it will rattle the walls pretty good. I mean it's freakin' loud. I cranked everything and banged a few notes. The speakers farted out big time and there was definitely some distortion. I dunno if it was the speakers distorting or the transistors clipping or what. In general use, I do keep the treble pretty low, though. Bass maxed, treble just on a hair. Still getting to know the amp (and bass guitar in general) so that may change.

I also have a Peavey Max 115 and a Kustom KBA100 to compare with...and this old K200 seems right where it should be from a volume standpoint.

Fed Ex seems to have lost one of my replacement speakers for the time being, so I'm in a bit of a holding pattern on that front.

As far as your Bright input issue, I'd look at the caps and resistors on the jack and the ones associated with the bright/lo switch.
 
#18
Small update: Finally located my lost package. Kudos to Fed Ex and Parts-Express, they've handled it the way they should. I should have the other 15 tomorrow, so I should be able to swap out the speakers tomorrow night. The silver lining in all this is I've had a good chance to get to know the amp and cabinet while trying to track down this rogue package. I've been using it for both guitar and bass, and liking it a lot. I feel like I will be able to make an informed decision as to which speakers I prefer.

zon6c-f: This rig will be gigged. I'm in a 7-piece oldies/covers/few originals band. I can't honestly tell you the last time I saw a full or even half-stack at a gig. I usually play a 15w Pro Jr or 12w 5E3...if that gives any idea of the type of gigs I'm talking about it. I'm pretty sure this rig can hang with that.

Also, Oren, I see you posted at Vintage Kustom. I cannot seem to log in there. Even resetting my password, it doesn't seem to take. I want to ask stevem about his rectifier diode set-up. I have the diodes and tag strips, and I'd like to recap it, as well, since I plan to gig this puppy.

THis may be a dumb question, but I have come across people "jumpering" the channels on these. Does that involve putting a pigtail in the inputs on one channel to the other? Also, if I make my single 2x15 cab run at 4-Ohms, will the amp output properly, just to that 1 cab?
 
#19
Well C-64, you've surely had the crap on that second speaker. Over soon maybe.

zon6c-f I've completed the rehab and posted some pics of the Kustom X1-18B folded horn cab on the Acoustic site.

Back to C-64 Yea, I normally look at the Kustom site once daily and post as needed. I just visited and didn't have any problems. I even started a thread last night. You might want to contact the moderator or something for assistance with logging on.

Daisy chaining is popular on tube amps. Taking a short cord and running from the unused jack on the channel you're plugged in to to one of the open jacks for the other channel. I use that trick on my Ampeg B25B and Fender Bassman tube heads with great success. I just tried it on the Kustom 250 rig that I have for sale for my friend. It made a little difference, but bumped up the ground hum too much. Give it shot on yours. For testing purposes, just use a guitar cord to chain the channels.

Yes on the 4 ohm cab. Most of those Kustom heads are 4 ohm. The head doesn't care how it gets it, it just needs the total of 4 for maximum power and performance. The perceived volume will be greater with two 8 ohm cabs, particularly if both are multiple speaker cabs. Long answer as to why that is. Bottom line - on the smaller powered heads, you want every bit of it used, so make sure you put 4 ohms to it. :cool:
 

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