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Author Topic: Customized Kustom 12 Gauge  (Read 959 times)

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Customized Kustom 12 Gauge
« on: March 23, 2020, 07:36:35 PM »
Hi everyone...

I would like to start by sharing this guitar amp project.  I bought and modified a Kustom 12 Gauge over 10 years ago, and happened upon another one recently on Ebay.  So I bought it, planning to modify it and document the mods as I go.

My idea is to request modification suggestions from anyone interested, then document and share the trials and tribulations of each modification with 3 goals:

1.  Modify any and all aspects(within cost and reason) of this amp, driven by popular suggestions.
2.  Document and share everything from the purchase of parts and materials, construction and fabrication techniques, any and all challenges, failures, and successes of each modification, and the effects to the amp's tone, volume, gain, ease of use, weight, "playability", etc. etc.
3.  Produce a unique amplifier that nobody else has, share ideas and experiences to help others with their own modifications, and even give the amp to a deserved individual after the mods are complete.

I will be documenting this project both here and on YouTube.  Most of the content will be within the YouTube videos, but I will be sure to keep this thread going with new pictures, descriptions, updates, and links.  Feel free to respond to me here or on YouTube.

The first mod will be relatively easy: the speaker. 

Please suggest what speaker you would like to see installed in this thing.  The current speaker is a 12" 8 Ohm "Expertly Made In China" cheap POS that I find can be made to sound OK-ish, but is harsh, thin, and is heavy on the treble.  I figure the budget for the replacement is about $100, give or take, so please don't suggest something that costs more than $125 or less than $50.  The goal here is to find out what most of you think is good or would like to hear, and share the results.  Also not looking to polish a turd, rather take something from mediocre to respectable.

Once the speaker is done, we'll move on to other things, similar to what I've already done with my old one.  I will consider just about anything, but reserve the right to determine where the "crazy" threshold begins and ends.

So thanks for following along and making suggestions, asking questions, making rude comments, whatever.   I'm not sure how long it will take to finish, but it will likely take months... this isn't a rush job, just a hobby(for now )

Thanks and best regards,


YouTube video:  https://www.youtube.com/watch?v=DrLrTWQD1tE







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Re: Customized Kustom 12 Gauge
« Reply #1 on: March 24, 2020, 11:05:16 AM »
First of all, welcome aboard SSGuitar!

Second, I'd like to put in the first speaker vote.  Eminence Legend 1275.  8|
Life is what you make it.
Still rockin' the Dean Markley K-20X

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Re: Customized Kustom 12 Gauge
« Reply #2 on: March 29, 2020, 08:12:43 PM »
Thanks for the welcome and speaker vote!  Duly noted.



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Re: Customized Kustom 12 Gauge
« Reply #3 on: March 31, 2020, 09:10:46 AM »
Regards Speakers.
 Years ago i read an article in a El magazine, I can't recall details now of course but the writer made the observation that it is better to design from the speaker back to amplifier.
He was referring to hifi but over the years I've come to understand why he made that observation.

The reality of this Amp/speaker thing is complex.
Many pages on guitar forums are filled with Spk debates and observations.
I can tell you that even though many amp circuits might look similar one only has to alter a 20cent passive in a circuit and it can have big impact on the outcome.

Much like Valve shootouts, they always give me a giggle.
Someone swaps a whole lot of valves in a particular amp circuit and gives an observation of which one is best.
Even some educated folks entertain this stuff.
Yes in one particular amp circuit Valve X might work better than Valve Y.
But that does not mean that valve X is better for every circuit. In another circuit design the opposite might be the case.
Same goes for speakers.
I may have told this little story before but years back a mate brought me his Trademark 60 combo.
He said do whatever you can but if it does not work I'll dump it. It's way wrong, too harsh, brittle. Dist ch is not usable.
After a few days of pondering what could be done I decided to try a few old speakers I had laying around.
OK the Hot rod Eminence special design speaker that was in the trademark might have higher SPL and make the amp sound a lot louder than another similar 50 watt chip amp design but those big name fancy pants drivers that promise so much will often peak at higher freq and hence sound Louder. (they know the kids will often buy the loudest unit) ;)
Problem with that is they are excessively bright when using heavy distortion, All sweetness is lost when you do that.
To overcome that issue one would have to dig deep into the circuit and change a lot of stuff.
As Trademark goop all the circuitry that I would need to change,, well it's just not worth all the fuss when all that was needed was a more balanced (Flatter SPL freq response driver)
My mate could not believe the huge difference.
the speaker was a $10 junk sale purchase. 8|

Just my observations,, Phil.
« Last Edit: March 31, 2020, 09:16:30 AM by phatt »

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Re: Customized Kustom 12 Gauge
« Reply #4 on: April 05, 2020, 02:20:08 PM »
A quick update... I will pick the speaker to go with next weekend, so if anyone else has a suggestion, now is the time!   :duh


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Re: Customized Kustom 12 Gauge
« Reply #5 on: April 21, 2020, 11:29:04 AM »
Hello all,

Sorry it's been a while since I posted an update, but I decided to install a Celestion Greenback.

Here are links to the latest videos of the purchase and installation.  I'll post pictures and create another sound comparison video at another time.




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Re: Customized Kustom 12 Gauge
« Reply #6 on: April 22, 2020, 04:42:32 AM »

I have a question: is this model the same as 'Tube 12A" but with 12" speaker ?