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Could you homebuild a tube amp ar less than vendor rates?

Discussion in 'Amps and Cabs [BG]' started by IamGroot, Nov 10, 2019.

  1. I know very little about tubes except watching my dad fixing the tv and stereo...

    Seems likes lots of talented people here.

    Do folks home build their own tube amps.... say a B15n. How does the price compare to retail?.
  2. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    I can.

    Save a lot of spending money if you are not thinking of paying yourself for time. And that includes time learning how to do it all. It isn't without necessary skills. I don't consider it worth it compared to sorting out high end build little known amps.
    dkelley, miljoneir, Robus and 3 others like this.
  3. abarson


    Nov 6, 2003
    Santa Cruz
    I think you need a firm understanding of electronics first, then you need to delve into tubes specifically. This isn't for the faint of heart and the voltages used for tubes are seriously deadly. Be mindful of precautions if you take this on.
    With DIY you will have an initial outlay to acquire all the necessary tools as well as the time it takes to garner skills. Eventually, you are saving on labor costs, so it comes down to whether this is to be a hobby that you devote yourself to and enjoy. As with any undertaking of this kind, start small and build up. Building a kit first might be a good introduction.
  4. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Pedals is the place to start, you get to learn signal and power supply troubleshooting at merely educational voltages. And you can flip the pedals you made towards parts.
  5. Typically no. The home builder has to buy his/her parts at retail pricing. That adds a lot to the total cost. A vendor gets quantity discounts. Sometimes those parts are made of unobtainium where a vendor can have them specially made. I have enough stock yo build six 50 or 100W amps. These are for my designs for guitar amps. I left tube amps for bass behind years ago. Except for my lovely B15N! :D
    fleabitten, 12BitSlab, gbaker and 5 others like this.
  6. StyleOverShow

    StyleOverShow Still Playing After All These Years Gold Supporting Member

    May 3, 2008
    Couple of guitar players I work with regularly just considered this summer upgrading to custom homemade amps. Both independently came to the conclusion that it was not worth it. They both run Fender Hot Rods amps usually.

    I pal around with one of them and saw the specs and Proto types, including breakdown of costs that were dominated by bench time, soldering. There are no guarantees, warranties or predictable outcomes. as a hobby project, why not!
    dabis and IamGroot like this.
  7. seamonkey


    Aug 6, 2004
    Before you start sourcing parts look into ltspice
    LTSpice Modeling Of Vacuum Tube Amplifiers

    You'll find complete analysis of tube amplifiers you can run in ltspice to understand how they work, and what happens when you make changes.

    There are many amp simulations that actually start this way. They take an old amp, a schematic, put it into spice, do analysis, actually run audio through them them compare that to the real amp.

    The results ends up as a DAW plugin, modeling amplifier, or pedal, but still it's a valid way to understand the electronics and devices used.
  8. JKos


    Oct 26, 2010
    Torrance, CA
    Probably the cheapest way to get into fiddling with tube amps is to find an old tube PA amp in working order. I use to pick them up for free from people just looking to get rid of them.

    Then you change out the input and tone stack to something more common in musical instrument amps. Then maybe the phase splitter. Etc.

    - John
  9. Im not planning to do any electronics . Out of league. I was just wondering if folks are building customized tube amps from scratch.

    I am interested how one designs rheir own amp. Any books youd recommend.
  10. seamonkey


    Aug 6, 2004
    arbitrary and mikewalker like this.
  11. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    The best way is to get an electrical engineering degree, that way you understand how and why amps are designed the way they are to achieve specific results. This is how you determine topology, gain stages, filter stages, feedback, voltage to current and current to voltage conversions, etc.

    There are lots of good text books, most are fairly math-centric. How is your calculus and differential equations?

    I can build just about anything I want, but for prototypes the parts cost more because they are being bought in very small quantities and the labor (both design AND fabrication) is quite high.
  12. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    Depends on how in depth you want to get. The Merlin Blencowe (valve wizard), Rich Kuehnel (amp books) books and sites, or Rob Robinette’s website would be a good start.

    How to design valve guitar amplifiers
    Guitar Amp Books for Professional Builders
    Amp Stuff

    As far as cost - as Paul said the economy of scale works against you. Building from scratch for a one off build will generally not be cheaper than something you can find off the shelf or as a kit. Or even cheaper find a used/broken amp and repair/mod it to your liking.
    ddnidd1, crazyBassClown and IamGroot like this.
  13. Well, here is a b-15 style amp kit for ~$700 US. You still need to assemble, buy tubes for it, and buy a cab option or build one. You decide if it's worth it to you.
    Trinity Trip Top Kit
    DirtDog and IamGroot like this.
  14. seamonkey


    Aug 6, 2004
    IamGroot likes this.
  15. james condino

    james condino Spruce dork Supporting Member Commercial User

    Sep 30, 2007
    asheville, nc
    Remember that every one of those excuses are the same ones Leo Fender was told before he redefined what we all know of as a bass and a guitar and amplification.

    If you have the interest or desire, there is a way. Start small and work your way up. If I told you it would take 400 hours for your first amp build, that would scare away almost everyone here....yet if I said you could only spend 400 hours this year watching videos or on the world wide waste of time, everyone would agree that is a crazy minimalist amount......
    Last edited: Nov 10, 2019
  16. An old friend of mine has been building his own since college. He's built some amazing stuff.... Cleveland Amplification
    IamGroot likes this.
  17. Tommyc


    Nov 11, 2015
    From what I’ve read about Leo Fender he had neither a degree in electrical engineering nor any kind of formal electronics training of any kind other than the radio tinkering he did as a youngster and later, the radio repair business he opened. I think his only training was that of a bookkeeper. I don’t recall what radio or what circuit, but I think his very earliest amplifiers were based on, wait for it, radio circuits. Still, I do think that Fender was probably a genius and geniuses tend to find their own way. I would probably, if I were so inclined, try to build an existing well known circuit such as has been suggested, a well known pedal or even something simpler before entertaining the idea of designing something original unless I had my own Steve Wozniak handy.
    Oobly likes this.
  18. I dunno, I've got an epiphone valve junior that I've been VERY slowly modding over the years. Put it into a combo cab, then moved it back into the head cab, added a cheap digital reverb unit with a pot, and once I find a cheap soldering iron I'll probably get a switchable negative feedback loop going. Might at some point try to get an octal socket and a 6V6, see if one can get a switch going to go between the EL84 and the 6V6 or something. But honestly

    Guitar amps tend to be easier because a single-volume control, single ended class A amp with five watts or less makes a very simple (and cheap by comparison) circuit that actually sounds really good. While I love the way this amp sounds for bass, it's not what I'd call conventional by any means. But yeah, from the get-go, it's easier to build or buy and mod a tube amp for guitar than it is for bass. Once you get into the push-pull range I'd say a bass amp isn't too far off of some guitar designs.
    IamGroot and b-b-b-bass like this.
  19. thetragichero


    Jan 4, 2019

    when you stumble onto stuff like this for free (to haul away) on Craigslist you could probably get away with a build costing about a hundred bucks (some filter caps, whatever resistors and coupling caps you can't salvage from inside, jacks, pots, iec socket and fuse holder, whatever materials for head shell). i prefer brand new micalex tube sockets because the old ones don't seem as rugged
    IamGroot likes this.
  20. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Correct, most electronics education at this time (this was in the early 1930's) was either through the power industry, the telephone/telegraph/signaling industry the radio industry or the military. While there were engineering degrees that folks working on cutting edge development received, much of this education was more of the trade school variety where training for being a technician, repairman, junior designer, troubleshooter was both common and high paying. My grandfather went through this (night school) program (in mechanical "engineering") at Cooper Union in New York around that time and would have been a contemporary of Leo Fender's as they were close to the same age. Night school was common as many of these people had returned home from WW1 and worked full time to support their families as there were few financial assistance programs at that time. I believe that some of my grandfather's school costs were paid for by the military as he was in the Army Air Corps and had earned some special benefits by the very nature that the planes he flew were not very reliable. Pilots were just as likely to die flying as being shot at.

    These guys in general were very smart, very driven and read everything they could get on the subject. They also tended to surround themselves (formally or informally) with people who had the skills that they didn't have, which made up for their gaps in education. A great modern example of this is Hartley Peavey who was also limited in his electronics knowledge but hired Jack Sondermeyer early on do handle the engineering. Jack had been an engineer at RCA and was at that time one of the semiconductor industry experts in silicon power transistor applications. IMO, he was a brilliant engineer who enjoyed designing audio products (both electronic and mechanical aspects). He also had ~30 patents covering a wide range of technologies so he wasn't a "one trick pony".

    Music Industry Remembers Peavey Chief Engineer Jack Sondermeyer

    Fender had George Fullerton, who had studied electronics at night school and continued self study for years afterward. One of my clients (who is in his early 90's) grew up in the electronics industry much the same path as George Fullerton did and knew both Leo and George from the early 1950's through the 1970's. My client worked for one of the large connector manufacturers, made some sales calls to Fender but they didn't really use what his company manufactured. They remained acquaintances until Leo's passing, he had nothing but kind words about him and described him as intense, smart and deeply "scrappy".

    Electronics has become unbelievably more complicated these days, 4 year engineering programs are now often 5 or even 6 years because of the sheer amount of information to learn. (Yes, it took me 6 years to get my EE degree but to be fair I also have a minor in AgE) In fact, while computer engineering used to be part of electrical engineering when I was in school, the computer based digital side of things split off to become either ECE (electrical and computer engineering) or just computer engineering (which can be called different things at different institutions).

    Yes, with enough effort you can learn the basics of "standard circuits", how they work and how to use them IF you are willing to study and read and study some more. The challenge is when you need something different, or you need to troubleshoot why something isn't working as expected, or you need to improve the performance or operation of a circuit. This requires a more in depth understanding of general electronics and the math the underlying the operation of the circuit. The more you know, the more clear the system operation becomes (designing electronics is the assembly of smaller basic circuits or operational blocks into functional systems).

    This is far different than copying existing circuits, copying or cloning existing products, building a kit, modifying an existing product, etc. I see well intentioned people modifying products without even the slightest idea of how it works or is supposed to work, often enough with disastrous results that sometimes causes me to shake my head. What's even more challenging is when they call asking for "advice" then tell you, the guy who designed the product, how wrong you are because "of something they read on the internet so it must be true". This is why I caution folks who are buying used gear to avoid modified gear. I would say 90% of all modified gear either doesn't do what they hope, they have mostly ruined an otherwise perfectly good piece of gear that may not be repairable, or have created a reliability nightmare with new problems. In my shop (not at Mesa), any modified gear automatically costs more to repair because there is more to inspect and test, and usually the policy is to restore everything back to the manufacturer's stock condition because this has a documented history of working correctly.

    These are some thoughts regarding this subject based on decades of working in this industry. I'm sure some will disagree, but my perspective is pretty broad on this subject.

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