Bottleneck Headphone Amp Repair
Since it was built as a kit he is very familiar with it. Open it up and very closely examine all parts for heat related stress, maybe a bad tube was drawing to much current. Also check every solder connection, even reflow them, especially if this was his first kit build. Unless he is experienced with soldering, this is a common problem with first time kit builders. Report back with what you find. BillWojo |
I built the Bottlehead Crack with the Speedball enhancement. First things first... low hanging fruit easy to test/solve toward more complicated troubleshooting approach: 1. I am not sure about other non Bottlehead Crack amps, but it is well known that you MUST let the Bottlehead Crack warm up BEFORE you plug in your headphone. If he hasn’t been doing this, he could have blown his headphones. Easy test...borrow another set of headphones and test. I make sure I do this religiously with my Sennheisers...too expensive to blow up! 2. Make sure the tubes are good. If he has spares that are known good, then swap those in to do fast test. Don’t have spares? Many shops in the Bay Area will test your tubes for a fee. If your in the San Jose / South Bay, you can go to Keith Holland’s Guitar Shop / Hospital that repairs both guitars and tube amps. The guy that fixes tubes amps has a tube tester there. I have been using the same tubes, btw, that originally came with the kit; I am not a tube roller, but just saying the tubes can last a long time. 3. If tubes are good, then it is time to get the volt ohm meter out and go back through the manual and test the voltage test points. It has been 7 years since I built mine (and I still use it today while working at my workstation) but I believe at the very end of the instruction build manual there are explicit places to test voltages before using the amp. They tell you exactly what points to test and the voltage you should read. If your not getting the right voltage, then you know your getting close to the problem and work backwards from there = divide conquer to isolate issue. The fact that it ran for awhile could possibly rule out cold solder joints, but maybe a dodgy wire got loose since the amp did operate? The BottleHead forums and HeadFi forums have a lot of people who post very specific problems and people have posted numberous solutions. By the time I built my unit, there were no unknown issues = someone has probably encountered the same issue your son has = probably someone has posted a solution. You just have to search and read. I live in the South Bay (Bay Area) San Jose. There are two shops in the South Bay that I can recommend; I am not sure if they specifically work on BottleHeads but they are excellent with tube amp repair, in general, and these BottleHeads are NOT that hard to troubleshoot. For my Wavestream Kinetics and Moore Franklin & Associates tube gear...I go right to the designer/ builder....the legendary Scott Frankland. He still does tube repair work and solid state work on non Wavestream and non MFA gear....I saw a LOT of different gear in there for repair ...Macs, Levinson, etc. Scott’s shop in in North San Jose: Scott Frankland Associates 706 Charcot Ave San Jose, CA 95131
TEL: 408-432-1500 Email: scottfrankland@att.net Website: www.scottfrankland.com Scott just serviced and updated my MFA 200Cs tube amps as well as my Audio Research D100 M3 solid state amp. His shop edifies serious work and engineering going on in that place Highly recommended. -------- I have also used True Sound in Campbell a long time ago when I had Dyna ST70 tube amps needing recap work. https://www.tsound.com/ Highly recommended ...... Alas, debugging your own equipment is half the fun and satisfaction with DIY gear. Push / encourage your son to debug it....it will serve him a lifetime of courageous learning and curiosity! Good luck! -stu |
