The Amp Garage

you can always use higher rating cap where physical size permits

Hey'all, I finished AX84 4-4-0 which is a 2w version of express with 6SN7 output tube and 12AY7 PI. A few pix: [img:800:320]http://diy-fever.com/wordpress/wp-content/gallery/4-4-0/board.jpg[/img] [img:800:600]http://diy-fever.com/wordpress/wp-content/gallery/4-4-0/bias_board_1.jpg[/img] [img:800:600...

I spoke too soon. Inside that 500V 20mF cap was a Samsung 400V 22mF cap. Had the leads cut very short than had this much thicker wire soldered on to it. Made it appear from the outer cap that the leads were very robust. When in fact the leads were actually quite thin and wimpy. They probably didn't...

Well,this example is not so bad. At least the voltages are the same. Unless there's another surprise inside of that Rubycon. yes, but bear in mind that the inside cap is most likely used. Leads are so short which indicates it's probably desoldered from a PCB. I think that's the main motivation for ...

My DMM reads caps and usually I do check before installing one, but after seeing all this I think I'll be checking every cap from now on!!! :P Thanks for posting this heads up. I had no idea this was going on. Just measuring them with DMM won't help in most cases because they usually put caps of si...

One thing about zeners - they can die easily, even with loads lower than rated. Their power rating deteriorates very fast as temperature increases so it's not a bad idea at least to put it somewhere where air flows and not to cut leads too short because they will dissipate heat too.

Cheers

yeah, those tubes run their heaters at much higher voltages than tubes we're used to so they are feeding right from the mains. B+ is rectified directly from mains too. I'd add a simple isolation transformer just to be safe. Older fender amps had "death cap" from mains to the chassis. If you have som...

here's what I found in mine. The third cap is obviously a pull from used equipment with new leads soldered to the old ones

[img:800:600]http://diy-fever.com/wordpress/wp-conte ... _cap_2.jpg[/img]

I agree, most of the amps we're building and playing are variations of the same basic ideas that are 50-60 years old. That's why it's so lame to go around and patent everything without any real innovations.

The Reason for the success of the Dual Recto was partly this......... The sound of the music industry was changing the 80's were over and grunge took off, For the heavy type player a channel switching amps that was Rock solid, channel switching and covered sloppy playing because they didn't have th...

Randall Smith from Mesa Boogie tries to create hype around him and surprisingly many people are buying it. My favorite line For example, the great top end of the Dual Rectifier has an aggressive bite but avoids the harshness by the way two very important traces are laid out on the board. One trace i...

AX84.com 4-4-0 project, which is a 2w version of the Express uses that cap. Haven't heard any complaints.

I may be the victim of this crap too. I built a SLO using mostly those ELON caps I got from Weber. Since I built it I had problems with sound suddenly changing and recently it started motorboating when I hit the strings which probably means that cap can't provide the current when there's signal. [im...

fully sealed doesn't have anything to do with that. Pot body/shaft is metal and it makes connection to chassis which is grounded.

This is very cool, congrats!
I'm in the middle of making a Mesa MarkIIC+ preamp with 6112 tubes and graphic EQ.
Cheers