|galaxiex||6/5/2018 7:37 PM|
|The making of an eyelet board...|
So here we go...
This will eventually become a conversion on a little amp I have, that has a pcb circuit board.
Here's the fiberboard and eyelets.
Holes punched, not drilled.
Place eyelets in holes...
Tape to hold in place, now off to the eyelet press.
Dri...err... I mean, eyelet press.
|galaxiex||6/5/2018 7:43 PM|
|oops, it's easy to split the eyelets, less pressure please.|
|Bill Moore||6/7/2018 9:30 AM|
I prefer turrets, and generally use Garolite for the board, so I drill the holes. My friend Pete made some tools for me to stake the turrets. (not pretty, but functional). My "press" is similar to yours!
|galaxiex||6/7/2018 6:13 PM|
Ya, I can see how it might be difficult to use a punch on those boards.
My plan is to build something "Fenderish" looking, so I went with the eyelets and fiber board.
I know the circuit can't tell the difference.
This is my first attempt at this type of build, (I've done home etched pcb's before).
Also have worked on a few eyelet type amps, Fender, Traynor, etc, and like the ease of modding them.
Never worked on a turret board type so nothing to compare.
|galaxiex||6/20/2018 6:43 PM|
|So that first board was a test since I have never worked with this stuff before.|
Here's the final version I will be using to convert my Blues Junior to hand wired.
Started populating the board...
To get to this point the board went thru about 2 dozen iterations.
I added a tube so it will have tube driven reverb.
Here it is a little farther along. Still waiting for some parts...
Edit; Hummm, I was going to edit the first post to change the title to include "For Blues Junior Conversion"...
but I see that it times out for editing.
Did not know that... as some other forums I am on allow you to edit posts basically forever.
Oh well, if some kind mod sees this maybe they can change the title for me?
|galaxiex||6/21/2018 12:05 PM|
|A few more pics.|
It's getting there...
|galaxiex||6/28/2018 7:13 PM|
|Finally got this wired up.|
Not the neatest wiring job, probably going to howl like a Banshee.
Smoke test next!
|The Dude||6/28/2018 7:29 PM|
|Looks good to me. Good luck with the smoke test!|
|galaxiex||6/28/2018 10:03 PM|
Smoke test went well.
Plugged in my lamp limiter, no tubes, checked voltages, all seemed ok. B+ 355
Installed tubes, again lamp limiter, still no smoke.
Took it off the limiter... annnnnd.... Ta freakin Da!
Tweaked the bias (I installed 1 ohm cathode resistors) for about 28ma.
Worked way better than I expected.
Very little noise, (back shield panel still not on, amp on bench).
A little hissy but not bad, certainly no worse than my stock 1978 SFDR.
I have a hum balance control on the heater string, tweaked for least hum.
Played it for 1/2 hour, sounds great to me, considering this is my very first build of anything like this...
Reverb is incredible, absolutely cavernous, too much even, I think it's the med decay Belton tank, I'll get a short delay tank and see.
Happy, Happy, Happy,
|Greg_L||6/28/2018 10:15 PM|
|galaxiex||6/29/2018 11:28 AM|
|galaxiex||6/29/2018 2:58 PM|
|Here it is back in the box.|
I need to make a new back panel for it.
|dmartn149||6/29/2018 10:09 PM|
this is my very first build of anything like this...
|J M Fahey||6/30/2018 6:52 AM|
The first "musical instrument amplifier dedicated" tool I bought back in 1969 was a bench eyelet press "to make boards like those on Fender amps" .
It still works flawlessly 49 years later, have made thousands of boards , even used it for my early SS amps and even today use it regularly for quick projects such as speaker crossovers, simple supplies and such.
It´s a twist type, similar to this one:
Still saves my bacon often.
|galaxiex||6/30/2018 12:26 PM|
There is quite a bit of wiring on the back of the eyelet board...
I thought to make the top side wiring less "busy"
So what you see there is mostly power and grounds and a little bias wiring.
I'm not sure if you're "supposed to" do this... or not...
Never seen it done before so IDK.
I'm sure this will come back to bite me in the a**....
Indeed it already has...
I mounted the eyelet board with spacers above the insulating card...
and with the volume and bass turned up the eyelet card "buzzes" with the low E string.
Had to shove some foam in there to stop the buzz.
OR... a short or broken wire under there will cause no end of grief... I'm sure...
|galaxiex||6/30/2018 12:28 PM|
That's a cool vintage press.
I've never worked with eyelets before and I'm finding lots of uses for them.
|J M Fahey||6/30/2018 6:56 PM|
I only use aluminum for chassis and such, since I buy it by the sheet (in fact in 10 sheet packs, since I know I use it for everything), and cut/punch/bend as needed.
But... aluminum can´t be soldered (in practical terms) so preferred assembly way is by riveting parts together.
I use nickel plated 3.5mm (~1/8") by 7 to 9 mm (almost 3/8") hollow rivets/eyelets to assemble heat sinks, chassis reinforcements, double thickness areas for better heatsinking, the works.
Plus repairing belts, etc.
|galaxiex||7/1/2018 8:20 AM|
|Here's the schematic I made for this conversion.|
It's basically a mish-mash of the AB763 Deluxe Reverb effects channel minus the tremolo,
and the Blues Junior from the Master Volume to the power tubes.
Plus a few tweaks like the added Mid pot, etc.
The stock BJ uses a 50k MV, I didn't have one, so used a 100k instead.
Stock BJ transformers plus the replacement TX for the reverb.
|Chuck H||7/1/2018 9:13 AM|
|galaxiex||7/1/2018 10:58 AM|
I thought about all that when I made the decision to do this.
In the end my desire for a "pretty" board won out.
...and it's not all that much "more pretty" anyway....
First time it gives me trouble
I'll probably snip off all the under board wires and put them on top.
|galaxiex||7/1/2018 6:20 PM|
|Got started on a new back panel for this that allows access to the fuse, speaker jack and hum balance. |
Now waiting for some tolex to arrive.
|galaxiex||7/1/2018 7:46 PM|
|...and a little update on the schematic.|
I forgot to add the 2000pf cap on the grid of the reverb recovery tube.
Moved some other stuff around to make it a little easier to read.
|galaxiex||7/2/2018 1:27 PM|
|So I've been playing this for a while now and like it very much. |
Nice cleans and great crunch when cranked.
Tone controls very effective, can dial in whatever I want.
Honky mids to thick thunderous bass, great scooped sound, glassy treble, etc.
Sure couldn't do all that with the stock BJ.
The only minor issue is the reverb.
When cranked to "12" the reverb is on the edge of feedback, and waaaaay too much reverb.
I know I can just dial it down/not turn it up so much, but how would you go about taming this?
What component value changes would you look at making?
Edit; This seems to be a problem on almost anything I "build". Way over the top reverb, on amps that have it. SS or tube.
I don't actually design anything... I just kinda "paint by numbers" and copy existing schematics.
Sometimes, like this one, I mish-mash different circuits just to see....
|galaxiex||7/4/2018 8:23 PM|
Updated the schem with voltages...
I seem to always forget to do this, (add voltages to schem) for some weird reason, even tho I know it's kinda important. (insert embarrassed smiley here)
|galaxiex||8/3/2018 7:37 PM|
|A small update on this,|
I removed C18, the 22uf bypass cap on the reverb recovery.
The reverb was waaaaaay over the top on this amp, bordering on feedback.
Pulling the cap tamed it to a reasonable level.
Before, reverb on 3 and it was lots, but nudge the knob and it became too much.
Now reverb on 4 and it's good, and much smoother increase with knob rotation.
|Chuck H||8/4/2018 7:40 AM|
|galaxiex||8/4/2018 8:05 PM|
I never even thought to try a smaller cap there.
As is the reverb now sounds pretty good, but it won't hurt to experiment.
|J M Fahey||8/4/2018 10:23 PM|
I would cut a long narrow strip of said material (maybe from the routed out oblong strip material), say 1 cm narrower on top and bottom so it´s invisible, 2 or 3 cm shorter at each end so it clears the mounting cleats, and glue it along the bottom strip for added strength, on the inside of course.
Leo would have cut two smaller oblong holes instead, leaving center untouched for strength but you already cut, so ....
|Chuck H||8/4/2018 11:15 PM|
EDIT: Here's an image.