rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
My first post so please, new friends, bear with me. Just got a 1970 Kustom K200-B2 amp and 2-15" cab. Head has been serviced and works perfectly, however it has two mismatched speakers. One is a 1984 Eminence and the other is a mystery. Anybody that knows what the factory Jensens were and can offer a suggestion what to use to replace these with would be appreciated. The "mystery speakers" are working fine but have to be tired after 33 years of age...ROCK ON....Dave.
If you look at the back of both speakers, they often times have code numbers stamped on them that will tell you the manufacturer and the date that they were made.
As for replacements, it will depend upon what you are playing through the cabinet, guitar, bass, keyboards, etc. Different uses will suggest different replacement drivers.
rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
Thanks for the come back, chicagobill....I am a Rhythm guitar player who plays a little lead sometimes. This amp will not be gigged out, just used in my home studio. The back of the amp is stuck in place (I have read on this site the difficulty of breaking the seal.) which I will have to do eventually. I snaked a trouble light in the front vent holes and used a mirror to get the speaker numbers. Bottom has 67-8410 on it so that should be an Eminence built the tenth week of 1984. The top has three rows of # and letters as follows: Top row: 00-9200-830, second row: 4317 731, third row: SWHO 4. Gobbeldy gook to me!! A Florida amp guy recommended Eminence 1518 speakers. Your help much appreciated...Dave.
pleat Messages: 1452 Registered: June 2004 Location: Belding, Mi
Senior Member
Welcome to the site. The Jensen cabs used P15L 16 ohm speakers originally wired in parallel for an 8 ohm load to the K200 amp head. Kustom did this so adding a second 2x15" 8 ohm cab would present a 4 ohm total load to the amp head which would produce 100 watts RMS.
As far as removing the back of the cabinet, the foam gasket over the years turns to a black tar like goo. I removed the speaker jack nut, and you can place a 2x2 piece of wood or bass ball bat through the port holes and hammer the wood or bat to break loose the back panel. One thing to check since you have to different brands of speakers in the cab, is to check to insure both speaker cones move in the same direction to be in phase. Small flashlight battery across the terminals will show the cone movement.
Quick question, are you also part of the Gibson les paul owners page on FB? I just saw a post very similar to yours. The amp I saw has replacement grill cloth.
rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
Thank you, pleat for the comeback, and yes...the ad you saw on the Gibson Les Paul owners group site is me!!! When I get the back off of this beauty, I will post what I find. Any other info you need to help me out will be provided. Amp serial is 55973. Thanks again!!
stevem Messages: 4739 Registered: June 2004 Location: NY
Senior Member
Greetings to you!
Since your only using the amp at home adding 20 more pounds to its weight is not a issue and keeping that in mind I would search out 2 EVM15L drivers , these will all be the needed 8 ohm type more then likely so you can have the preferred 4 ohm load.
Note that if you can find 2 blown EVM15B models ( Bass model ) you can get them reconded into the L model.
The sound and punch of your amp with these drivers in it will have folks that play or hear it drooling!!!
My next pick in regards to installing new drivers would be from Jensen.
One of there C15N drivers and a C15K in 8 ohms would be the way to go !
Any new Jensen drivers and even many good new ones I have seen need to be broken in for 12 to 24 hours, visit the uncle spot site for info on how to due such.
Note that many times you can find the C15K model used in great shape on EBay.
Other chooses for drivers would be used JBL K130 or E130 models, Altec 418 models or new versions of these two from Weber speakers, either way used or new they will not be cheap.
You may also beable to turn up used blown Jensen models like the C15N , P15N or the C15L and get them reconded.
The C15L model has a heavier cone and would would need to be reconded into the N model.
rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
Thank you, stevem, for your reply...I am a complete amateur to speaker terminology: Driver,tweeter,wolfer are all Greek to me. I'm not even sure of the wattage output of this amp, but I think it is 100W. I gather that I need two 15" 8 Ohm 100 watt bass speakers. You mentioned using 1 C15N and 1 C15K speaker.What is the difference in the two? I looked up these speakers and they are rated 50watt. Isn't that too low? You are dealing with a 65 year old guitar player who just bought popular amps (Fender, Vox) and just plugged in!!! Any thoughts on the Eminence 1518 speakers? Thanks, Dave.
stevem Messages: 4739 Registered: June 2004 Location: NY
Senior Member
All of the speakers / drivers I listed for you are for guitar which is what I thought you posted up that you played?
These are not Bass speakers / drivers , if you play Bass I will need to post different model speakers / drivers!
The will output very close to 100 watts of clean power into a 4 ohm load, or 50 watts of clean power into a 8 ohm load.
For home usage speakers that handle 50 to 75 watts of power will work and live just fine, if you need Bass speakers you can do a search and find many post on the site for that usage.
The Eminence speaker that you already have may be perfectly good for guitar if it's 8 ohms ,but I can not tell unless or untill you pull it and post up a picture of the cone,
A Eminence 1518 will have dull overtones as its frequency responce takes a nose dive right at 5K cycles, if you like chime in your guitar tone this speaker will not put out much of it!
Go look at its frequency responce chart on the Eminence site and then go look at the chart on the Jensen site for the C15N and compare.
You can always turn down uneeded treble with the tone controls, but if the speaker can't put it out in the first place your done!
rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
Thanks, stevem....sorry for the confusion....I will be playing 6 and 12 string electric guitars only through this amp. I know a few guys that play through Fender bassman amps, and, since I think I stole this amp for $275, thought I'd upgrade speakers. I have never played a guitar through a bass amp, but had the bass amp Eminence speakers recommended buy my luthier that is a Fender tube amp guy. Thanks again....Dave.
Two 8 ohm speakers wired in parallel will give you a 4 ohm load, which will get the most power out of the head.
For years I played guitar through Fender Bassman amps. Both original 4x10 combos and 2x12 head and cabinet models. In fact the amp most recorded with by the Beatles was a white Fender Bassman.
Technically, the Kustom K200B amps are designed with modules for the power amp and the preamp sections. The different models have different combinations of modules. That being said, there really isn't much difference in a head that is designed for guitar and one that is meant for bass. Most players don't use reverb and tremolo for bass, so a lot of people consider the Model-1 amps to be bass amps, but they sound great as guitar amps.
The biggest difference that Kustom amps had between models were the types of speakers that people bought to use with them. Most CTS speakers were used in bass cabinets and most Jensen cabinets were used as guitar amps.
rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
Thanks again chicagobill,pleat, and stevem....as soon as I carpetbomb the back off of the amp and install the new speakers, I will post the results....rocknrolldave!!!
stevem Messages: 4739 Registered: June 2004 Location: NY
Senior Member
Put down a good wide area of cardboard when you pop the back off the cab as that old sealer is a tuff sticky mess to get off you or your carpet and furniture unless you use Naphtha.
Use new gray foam type door and window weather strip to seal things back up.
Kustom amps do not have output transformers, very few solid state amps do. They are designed to work best with a speaker load of 4 ohms. They will work with higher output loads, but will have a reduced power output.
stevem Messages: 4739 Registered: June 2004 Location: NY
Senior Member
If it was your quote unquote" amp guy "who did not know that most SS amps do not have output transformers then it's a good thing that you came here for help as he sounds like a Tube swapper in regards to competence level!
rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
Right, stevem, I know what you're saying, my "AmpGuy" is a luthier by trade and he does set-up and restrings on all of my guitars. But he also builds guitars and tube amps from scratch. Go to "Granville Guitars" in St Petersburg, Florida for his site. And yes, I am very grateful for the info and help I received here. Dave.
rocknrolldave2 Messages: 15 Registered: January 2017 Location: Largo, Florida
Junior Member
Finally got the back off of my Jensen 2-15" cabinet and found two mismatched speakers (Eminence and CTS) wired in series! Any problems forseen for K-200B head because of this? Getting ready to install tw0 C15N Jensens in series!! Thanks, rocknrolldave2!