• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

The most instructive video I have found on tube amplifiers online.

I watched some videos last night on resistors on the input tube of a tube amplifier by Uncle Doug. Excellent teacher as well. He got more into the subject of how the components react in a specific circuit than the above video. There are 3 videos totaling slightly over an hour total by Uncle Doug about resistors just in one stage of amplification. There are many excellent videos by some very talented people online but what I like about Roger's video is how in his presentation he talks in general terms about a lot of components in tube amplification. One of the best videos for someone just getting into the hobby.
 
high level theory is a fair bit different than nitty-gritty detail about very specific components. Personally I find its useful to get at least a high level view of the whole thing first before "zooming in" on a specific area just so I already have at least an idea of where that is in the overall chain.
 
Talking about solder again. I bought two brands of Chinese solder the last few weeks and they both suck. One MAIYUM 63-37 with glowing reviews on Amazons sucks as much as the Chinese brand I bought on Ebay. Neither one flows but rather clumps up. Dries dull and and not shiny like Kester. All I can say is the reviewers on Amazon have never used Kester. Worthless as far as I am concerned. I hope the old stock military Kester is as good as what I have been using from Kester. Trying to save a buck is costing me more money. The case many of times. Wish now I had just bought what I have been using for a decade or more at the increased price.
 
Mr Boochie said:
I like the smell of vintage flux smoke mixed with lead, in the morning. :thumbsup:

Really, if these things work and don't cause me reliability pains, I'm a happy camper.
Click to expand...
I love the smell of vintage flux with lead in the morning.

One time I re-capped a board,
for twelve hours,
And when it was all over I hooked it up,
I couldn’t find one of them… not one stinking volt on the rail,
But the smell,….that metallic piney smell….the whole shop, smelt like…..

Victory.

Some day this supply’s gonna end.
 
Last edited:
I criticized this MAIYUM 63-37 solder too soon. I can work with this solder. Yesterday when I received it I tried soldering a wire to some 14 gauge solid wire and had problems with it flowing when posting what I did. Probably my fault, not enough heat or whatever. This MAIYUM seems to be working good making normal connections flowing nicely. I wanted to correct myself. Too hasty a judgement.

Stay clear of JINHU brand being sold on Ebay. As far as I am concerned junk. Nothing but trouble. This is after trying to solder with it for days.
 
have any flux you could try it with? wonder if its the metal mix or the flux thats the problem. Some known-good flux in the mix would answer that question, if it still sucks its the metal.

not that having to manually flux things is ideal but maybe it could be used in spots where you'd have to do that anyway, just to use the stuff up.
 
I'm perfectly happy with good old 60/40 solder using a hot iron at 650°F to
700°F. Hot and fast.
 
I thought Roger's discussion on designing the smallest possible output transformers was most interesting! Goes against everything I thought I knew about "big iron"...
 
well, it does and it doesn't. For bass response in a standard transformer that carries DC you need a lot of inductance, and that means big size, especially if its flowing a healthy amount of current. He's doing parafeed stuff where the big iron is a choke feeding DC to the plate. The small transformer doesn't need to carry any current, which allows it to be much smaller for a given inductance value. That gets you the bottom end, and since its not enormous thanks to the thinner wire that can be used it doesn't have the parasitic capacitance problems that affect the high end.

so there is still big iron involved, its just not the output transformer. If you're not doing parafeed and try to get good bass out of a teeny little transformer while making any significant amount of power, its just not going to work.
 
Most of use do not have the ability to do some of things he did with transformer. He wound his own. Interesting talk though.
 
You must log in or register to reply here.
Back
Top Bottom