• 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

Akai Guitar Amp Project - Round 3

sloober

sloober

Super Member
Man this is getting fun. Since I just about buttoned up the last version, and have more to make, I decided why not try something different? Got a free organ last week and the output tx is made for 6v6 PP. So with room for 2 more tubes in this chassis without doing any extra work, I decided to try a take on the Fender 5E3 "Deluxe". Again, subbing 6CA5A tubes for the 6V6, and using a 6X4 for a rectifier. Heck I have a bunch, why not?. Going to do it right this time as last time I had 3 wrong value resistors. Bought a 17 section plastic parts box and loaded all the parts after checking them. Also decided to make a wiring diagram using the stock board from the Akai. Here it is so far, just making sure it is right and all parts have room. I did it in Pages on my Mac. After I made a few parts, and the board, it was just a matter of placing them where they go. John
Diagram PDF
 
Register to hide this ad
Nice choice! The 5E3 is a classic, gets really obnoxious (in a good way!) when cranked way up. I believe it's what Neil Young plays. I don't know about 6CA5As... I think the 6V6 is a lot of what gives the Deluxe it's magic, but try it!

I just looked up the 6CA5 (my book doesn't have the "A") and it showed a max plate voltage of only 130V. Will you be able to use that?
 
The A has a higher plate voltage rating. I was worried about this with the single ended one I just made in part 2. But it works great. I am also, using the Akai power tx which is a little less voltage. I have heard they can be pushed way past max and still do fine. So far so good. I was going to try some real 6V6 tubes, but it is so much easier to use sockets that already fit. John
 
Last night I stripped another chassis and cleaned off the board. Lots of slinging solder.
photo1.jpg

The other night I filled and painted a faceplate. Now I just need to drill 2 holes. This amp has 2 volume controls and a tone control. Have to select some knobs...
photo2.jpg

Tonight I finished up the drawing I started last night. See PDF above. Made it a snap to build this tonight. Have it all in place but little is soldered until I'm sure.
photo3.jpg

photo5.jpg

photo4.jpg

photo6.jpg

Now to start figuring out the wiring. Is pretty easy as most of the bottom connections go a short distance to the tubes. The tone/volume/input wires were a bit trickier. I left extra slack so I can unbolt the face and flip it down to work on. I routed all those wires to one side.
 
Yes!

Well I am proud to say it worked almost perfectly. Missed one solder joint that caused some intermittent noise. I ended up using a 6CA4 rectifier on the recommendation of a friend. Lots of pictures I will try to address all here. I drilled 3 holes in a row on the faceplate. The Fender Deluxe has 2 input channels, so you need 2 volume knobs, and a tone knob. Was hard to get them all in using these knobs. They are from an Akai M7 if I am not mistaken. I like them because they are marked, so I don't have to do the chassis. I cut the center rail out of the top window. Looked better on the other chassis with the faceplate over it. Not so sure now. I may add screen, or clear Lexan. Or just open. The 2 side screens are from speaker grill from one of the RTR chassis. Cut easily and glued with JB weld. It is directionally perforated so it lets air in, but hides the jacks that are right by the opening.
A buddy gave me the vintage cap for the tone stack. Said it makes a huge difference there. I was considering having a pot to control the VU meter. I bagged it and just used a 22kΩ resistor to calm it down. With nothing it pegged very easily with the single ended amp... this should be 2x the power.
I may use the left over hole for a switch to turn feedback on and off. Right now there is none. The output transformer seems perfect for these tubes. When I showed it to my guitar amp buddy he **** as it is a Schumacher marked 1957. Could easily be what Fender might have used for the Deluxe.
I can't really judge the sound yet, but it does have much more kick. Tone control works well as it should and having different sounding inputs is cool.
I think this is the one I will offer in the blue enclosure with the 10 inch driver as it is better suited. I will make another case and put the single ended in there with an 8 inch driver. I think I have one in my Leslie unit from another organ. I want to build a box for that and install a 10 incher. Enough for this weekend!
photo7.jpg

photo8.jpg

photo9.jpg

photo10.jpg

photo11.jpg

photo12.jpg

photo13.jpg

photo14.jpg

photo15.jpg

photo16.jpg

photo17.jpg

photo18.jpg
 
Looks fantastic! I wish I could try one of these out. Probably sound terrific as well.
 
deaner33 said:
Coolest knobs ever for an amp!
Click to expand...

While very cool, I still think the ones from the M8 Akai are the coolest. Machined aluminum in a sort of pyramid kind of way. I'll post a photo later. Of all of these things I have, I am not parting out the one M8 I have had since 1983. I stupidly sold the amps from one to a buddy before I realized their potential.
Amp is working pretty well, but think I need to check it on a scope. At some points I can get the controls set just so and I think I am getting oscillation. Can't hear much, but the VU needle moves to half way so I think it is outputting something. Still...very close. I think the PP Deluxe schematic is the way to go on these. John
 
Yeah, but what other knobs give you Sabbath if turned upside down & Stryper if turned up? :thmbsp:
 
JonL said:
Looks fantastic! I wish I could try one of these out. Probably sound terrific as well.
Click to expand...

You might try the little Wollensak, Jon. Some are better than others, but my last one is pretty good. I had one around 1966 with my p90 sg special and I can get some good stuff with my current cheap Turser p90.

This clip is from a heavily clipped wav with MIC in front of the unit's 5' speaker, Volume at 8. It did good with a fulldrive in front, too.
 

Attachments

You must log in or register to reply here.
Back
Top Bottom