The seller responds with the following model number:
04-07-8512 on MCI
Any help here is really appreciated!
Poor design, VERY poorly wired, wooden chassis, be very afraid. Look dude, I'm not trying to bust your chops, but you should ask this so called amplifier builder for a refund. If he refuses, file a complaint with paypal, or your credit card company. Better to be safe than sorry.
No, I don't feel offended by anyone here. I'm honest when I say I know enough about this and am asking for help here. I'm going to have a friend of mine that builds custom tube guitar amps look at this thread and give me his opinion as well. Its not that I don't trust you guys, I just need to know for sure because sending it back and getting a refund is likely easier said than done. I need to make damn sure I understand the issues here and not go off all half-cocked because of a couple posts on a forum.
Does that make sense?
So far I've got one guy making what sounds like an educated statement on the technical safety of the way the transformer is wired, based upon experience in a similar design. Everyone else just seems to be developing opinions about it's worth on the way it looks, expecting to see a bread board or something? I understand that ideas don't always make their way through the internets the way intended so I understand that I may be misinterpreting....which is exactly why I'm trying to be thorough and clear and damn sure.
So please bear with me and if possible help me understand more by giving me verifiable, empirical information.
The sellers reply when I asked him about the apparent misuse of the transformer, please refer to the scematic linked at the beginning of this thread if needed:
IN5400 it 5A 500V diode, its hot but no problem, any item will hot but save, except the Transformer, if the transformers hot, the item will be problem, like the tube, always hot. if dont like that, ship back and must before Monday.
Also, if you scare IN5400 hot and not save, you can take it out and just use AC filament, I like AC Filament, AC filament will be more musical but just little bit hum. But, if you return it back to me, dont going to modify, I will not accept money back if you modily.
From this page
its clear that the design uses one of the primaries as
the secondary. Clearly against all the UL rules and regulations
for safety on dual bobbin transformers.
A 35 watt transformer running at half power.
6.3 volts @ 2.5 amps is 15.75 watts
plus another 9 watts or so for the output
tube plate current. Plus the input tube power.
Absolutely running 20 to 30% over the ratings.
Not as bad as singlepower, but still...
half wave rectification of the filament, and a cap
way to small.
Definitely has singlepower written all over it.
I would monitor the temperature of the transformer carefully
while listening to it, and never EVER leave it turned on unattended.
Edit: there are some things about the new forum software that don't
make any sense. like you can't delete your own post or edit it
some of the time.
The problem with that 5 amp diode wired like it is, is the fact that
the current peaks are in the 12 amp range. Same problem with
other singlepower amps, go and find those threads.
This is not the way to do DC filaments.
To the OP : Dr G is an expert in the field. I'd trust his advice/analysis without question.
To answer your question about the parts quality used...none of the parts that I can make out are high quality....the entire amp uses low grade caps and resistors (sorry to say). Maybe 20 bucks worth of parts (if that) excluding the transformer, vol pot. This thing would require a complete rebuild that would end up costing you more than you paid for it IMO. The best course of action is to return it and re-order that Bottlehead kit rather than risk using this amp any further.
would be funny if peoples safety wasnt at stake... Man poor guy... trying to get a deal on a tube amp and ends up with something that could kill him or his house... or both..
Good luck! After you get your money back you should consider Bottlehead's Crack if you're willing to build a kit. Looks really nice
P.S. How did you pay or your amp? If it's paypal or your credit card, you can always file a complaint if this guy give you a hard time refunding your money