Kustom 100 Guitar Amplifier Repair

A story about a guitar amp.
I borrowed this Kustom 100 around 2006 from a friend, and it broke while I was putting it to use. I took it to several repair shops, none of which were able to bring it back to life. I returned it back to the friend, still broken, several years later. Then in the Spring of 2024 I reached out to them and asked if I could get that amp and try to bring it back to life- they agreed and let me take on the project. I was able to repair it and this video provides my troubleshooting methods and describes my repairs. Thanks for watching!

[@johndrx165]

I first saw this amp at a music store in our town in about 1969 and just thought it was the coolest amp ever! Never bought one, but it always holds a place in my heart/memory bank. So 60's.

[@killertimes]

They have such a distinctive, and charming aesthetic- I can totally relate to that kind of lasting impression!

[@davidmarks6042]

Nice work!

[@BadChizzle]

You did well. Trouble shooting skills are key… and it looks like you’ve got em. Thanks for the video.

[@killertimes]

Thank you! I'm glad you appreciate the video- I definitely enjoyed the project and valued it as an addition to my troubleshooting experience. I've got some more repair projects lined up and will be putting videos up on them in the future. Cheers!

[@DeadKoby]

I've fixed several of these old Kustoms... There's some fun charm about them.

[@killertimes]

I agree. Their aesthetics and circuit design have really hooked me. If more come my way, I'm definitely going for them!

[@lifegettingintheway2710]

The cover over the reverb can sag and droop low enough to touch the delay springs. I also used an LED substitute for the On lamp so it would never fail again. The reverb is always on unless you put a plug in the reverb jack. Or use the reverb foot switch if one is available. On the more powerful Kustoms the hiss is unacceptable. The orange gumdrops with the polarity indicated are electrolytics. And be sure the connections to the reverb tank are not over the transformer. John Fogerty had a love afair with these tuck and roll amps.

[@killertimes]

I could definitely see that stiff foam doing that. I really like the character of the this amps reverb, I kind of wish the tremolo came after the reverb though. The LED is a good idea. What do you think the hiss on those more powerful units was coming from? Bad caps? Aged transistors? I had a feeling some of those larger, orange caps were electrolytics. Everytime I look at this Kustom amp, theres a flash thought of Fogerty, and Creedance runs through my head.

[@scarysad]

I dig the uncle doug pointy stick action 😁. Very interesting. I was wondering what had come of this bad boy.

[@killertimes]

Spudgers...all the cool electronics youtubers use them.

[@colincampbell4505]

Rarely, especially in guitar circuits, are the transistor parameters tightly spec'd. The transistors of the day were probably +-50% or more on most of the parameters. Anything roughly equivalent should work, especially if the circuit is well designed.

[@killertimes]

The more I dive into projects like these, the more I'm discovering that point. I'm also getting more familiar with the key specs (and what they mean) of transistors just by hunting for substitutes/equivalents. It's acutally kinda fun having 15-20+ tabs open at once and comparing datasheets, looking for the best choice. Thanks for watching and I appreciate the comment!

[@edcherney]

Great video! Great job! Great history and description! As, other have said a nod to Uncle Doug (not even mentioning the cat!:) and I would say Also, Lyle of Psionic in your use of "adequately gauged wire" And, your humble, honest telling of mistakes made, as well as, your soft spoken, easy going descriptions ala Brad the Guitologist! I would be pretty sure you yourself watch many of the same channels I do. Not all are guitar or amp repair channels Like This Old Tony, Ave and others. Anyway, Loved the reverb and feedback demo! Subscribed right away! Not even sure what your channel is mainly focused on, as I am writing this before looking at your about info and other videos. I feel, after looking at number of views, number of comments, and number of subs, that I am lucky enough to have gotten in early on what I am sure is going to be an awesomely successful channel! Of course it took, by your providing the dates and, a little math on my part, of events on this particular repair video, about eighteen years to actually have been able to make this one! LOL! But, I think that things have come sufficiently together with your knowledge and ability and, of course, the all important, all powerful, and mysterious "KZbin Algorithm" that it probably wont, and hopefully doesn't, take as long to put out another good one! Congrats! And I look forward to your future content!:)

[@killertimes]

Thank you so much! I have some more equipment that I’d like to present in this way, some need repair, most just some tlc. Either way, I look forward to the challenge of making more videos showcasing various audio electronics. My youtube channel is a mix of content, but generally I use it to share my projects, whether they’re creative endeavors (music) or my electronics work/ journey. Thank you for subscribing!

[@edcherney]

@@killertimes, Thanks so much for the reply to my comment! I used to couldn't spell electri can now, I R one! Sparky, that is. I am an electrician, guitar player, keyboard/piano/and organ noodler, and occaisional inventor. Most all of the things I have invented/created or dreamed up have been for my own desires or wants or needs, as the old saying goes, "necessity is the mother of inventions!" and I have a generaly curios mind. Physics, Astronomy, Philosophy, Humor and obiously E-Lec-Tricity! So, to make now, a long story shortEd out, Your channel mix is right on for me! Thanks again man! And looking forward to future content! Happy Fourth!🎉🎇🎊

[@killertimes]

@@edcherney Cheers!

[@voornaam3191]

Thank you! Bought a secondhand Kustom KG1. But this one is built in China. And it does not need a repair. I can talk and talk and talk, though.

[@killertimes]

Absolutely! I can understand that- if I get onto certain topics, I can really get goin' too. I want to channel that kind of energy and use it to make more videos like this one- I've got more gear to fix and talk about. Rock-n-roll!

[@meisenman]

Can you post a link to where you found the serial number/date chart? I bought my K-100 bass amp in 1970 and had a tech replace the two-prong power cord with a three-prong grounded cord (I was getting buzzed when I touched the power switch).

[@killertimes]

I found that info through vintagekustom.com, if you search "vintagekustom.com date serial number" in your browser, you'll find links that have info on dating your amp with the serial number. I'll copy and paste the url of the page I was taken to with the list of serial #/dates: www.vintagekustom.com/FUDforum/pdf.php?th=2115&rid=0&S=454342cbd8498704deba8766e2730840 I hope that helps!

[@meisenman]

@@killertimes Thanks. Got it. 👍🏻

[@Shim267]

Unfortunately the realm of guitar amp repair is a very transient industry. Some of the work I've seen being done at a premium is bad enough to make your head spin. It's also plagued with many that possess a lot of valuable experience but are generally lacking in a fundamental understanding of what in the heck is actually going on from an electronics standpoint. You'd think it'd be the opposite case considering we have the internet to help us out these days but the signal to noise ratio on that information can be abysmal at times. There's great people that do it but there's a lot of goons out there as well (even on youtube) so trust but verify. Also, funny that one guy was trying to say that those BJT's were some kind of magical vintage unobtanium parts... In many cases a lot of these transistors are configured as such where their gain/special characteristics really aren't that important. You may have altered the characteristics of the input slightly with a newer transistor with different hfe/impedance but I mean come on... No ones going to notice or care and your result is WAY better than it not working at all. Putting that aside, good for you for figuring out the problem. You wound up falling back on some very essential electronics repair principles (thou shalt check voltages!) and some (not so) common sense. Great work and I'm looking forward to more videos :)

[@killertimes]

Thank you very much! The internet, as a resource for learning about electronics, has provided me with so much useful knowledge. However, half the work is sifting through the quantity/ quality to find the info I’m looking for. I really value how much knowledge is being shared, especially here on youtube. Hearing and seeing things explained can really expedite the learning process, and I’ve been inspired to contribute in the same way. I just hope to not be, or rarely be one of those goons :)