The Amp Garage

Dave Jones, around 2005 put out a schematic for the Octal One which was based on the 5c1 but with the 6sj7 cathode biased. Colossal recently built one and i built one a number of years ago using a 6aq5 for the power tube. Mine i played around with the 6sj7 values and settled on this. http://i216.pho...

Even less widely known is that you can add a bipolar transistor and a couple of other parts and make that circuit also have a current limit. This can be useful when you want to reduce current surges into a filter cap at power on or when changing off standby. London Power's Power Scaling circuit as ...

I've done it in the amps i've built with 6AQ5 output tubes

dave

"The Ultimate Tone" series of books from Kevin O'Connor have been worth buying to me in addition to the books and authors listed above, but they do have one aspect to them that bothers me...the chicken scratch hand-drawn schematic and layout illustrations are terrible. A frequent complaint, I'm oka...

Dave - thank you for the lead. I'll check out the Octal One - I see it's pretty well detailed on SEWATT.com Did you have a thread here on your project? Cheers, Greg Hi Greg, I did and i even found it. Was back in 2010. Also made their Savage Croaker which is 6U8/6AQ5. Octal One build thread http://...

I built up an Octal One with the 6AQ5 for the output tube quite happy with that one. The Octal One is a derivative of the 5C1 so uses 6sj7 for the preamp.

dave

The two heatshrinked parts at the far end are inductors, part of an RFI filter on the power line. Under them are two caps across the power line (rated for the application). Lettering is waterslide decal that required touching up and no matter what i tried with the waterborne lacquer i was using, i c...

Been sitting for months, plain jane 6aq5's and i paralleled sockets for the 12ax7's with 6eu7's. No idea when i'll get back to it. [IMG:800:800]http://i216.photobucket.com/albums/cc305/davent/CUVH3886_zpsaiiywlcd.jpg[/img] [IMG:800:450]http://i216.photobucket.com/albums/cc305/davent/667b2547-bf42-41...

Also, not shown, but with 5879's, always ground pin 6! You had me curious on this as the datasheet says no connection for pin 6 (&2), but at the end of the datasheet it does recommend 2&6 to ground. Thanks for shedding the light. I've an almost completed HoSo56 to make a couple additions to. https:...

Here's another option that I've used on some projects. Cheap, easy and looks good but a bit industrial. Bigger than the Heyco though. Comes in several different sizes and even a 90° version. http://www.ebay.com/itm/3-8-NPT-Strain-Relief-Cord-Grip-Cable-Gland-w-nut-gasket-NEW-/271307829316?hash=item...

I use ExpressPCB for schematics as well. Pretty basic in appearances, one font, black & white only. But all the pluses already mentioned and free. If i do want a better looking presentation i print the schematic to PDF then open the pdf in Inkscape (freeware) and replace all the lettering with nicer...

Secure the cable to the chassis so it can't flop about and there should be no strain on the soldered joints. And... PTFE coax like pictured, is a joy to work with, i've some Teflon/Kapton that's terrific.Very small outer diameter, maybe 26awg inner conductor. Been using for years, never an issue. dave

Hello Chris, Good to see you 'round. 6U8 into a 6AQ5, power scaling and single tone control. Savage Croaker that was a communal effort sussed out at Wattkins.

dave

Faceplate to cover or a 3/8" black nylon hole plug, if that's the size.
dave

Hi Chris, I've always just cut small 'L' brackets from 1 1/2" "L" channel (Home Depot maybe Cdn Tire) and used those to hold a piece of garolite or the like. One "L" back and front.

[IMG:800:600]http://i216.photobucket.com/albums/cc30 ... 5e2373.jpg[/img]
dave