Extreme Peavey RAGE mod!

[mshilarious]

OK, here's today's progress. Unlike the ugly rear-mounted stock speaker, I wanted the Eminence flush with the front, hi-fi style It will be more of a pain to swap in the future, but I'm not the type to blow a speaker (I'll be testing the circuit with the stock unit!)

So I had to route the front to fit it in--first time with a router, not too bad for me, I think (woodworking and me do not get along )

It's an Eminence Front

 

[mshilarious]

Here's the rear view:

 

[mshilarious]

Next came the grille cloth. That was harder to work with than I thought. I wanted it to run diagonally for the extreme look, but those of you experienced with the fabric arts know that it's a pain in the ass stretching on the bias

So I retreated to the conventional look:

 

[JazzMasterWil]

Looking good

 

[Jamal Bucket]

Next came the grille cloth. That was harder to work with than I thought. I wanted it to run diagonally for the extreme look, but those of you experienced with the fabric arts know that it's a pain in the ass stretching on the bias

So I retreated to the conventional look:

man that looks AWESOME!..nice work ...have you plugged it in yet??

 

[mshilarious]

man that looks AWESOME!..nice work ...have you plugged it in yet??

Nope, haven't done the circuit mods yet. First I need to make the PCB for the tube stage . . . maybe tomorrow!

 

[IronFlippy]

So I retreated to the conventional look

What's conventional about that? The lines go up and down rather than at a diagonal, big deal, look at the colors, man! Diagonal would be pretty extreme though.

 

[mshilarious]

Bump for this thread . . . I've done all the mods to the mainboard this week, there will be more pictures on Sunday. I've etched the tube stage board, still need to drill & stuff it. Then I just have to wire up the power cable, transformer, and reverb tank, and punch a couple of holes in the chassis

In the meantime, I sketched out a tube gain pedal to use up some spare parts. I have everything for this except the footswitch. It's a pedal using a 6GM8 tube which runs off a 6V supply--heaters and plate! Dunno how it sounds, but to my knowledge it will be the only tube pedal that can run off 4 AA batteries (for around 6-8 hours ). I also added a pair of LEDs for soft clipping (I did that in the RAGE too, among other changes), and I'm gonna add a treble/bass EQ circuit:

 

[apl]

So is this like a distortion pedal?

 

[mshilarious]

So is this like a distortion pedal?

Yeah, probably more like an overdrive. If you wanted overdrive + distortion, you could change each LED to 2x 1N4148. Obviously I haven't tried this yet, so build at your own peril!

Once I get the bugs out, it would be a pretty cheap pedal to make, 6GM8s are not particularly sought after tubes, you can score them for $3 or less. I really don't know how it will sound, most of what I've read is people trying to make low-voltage hi-fi pres, which doesn't appear to work that well. But this is not a hi-fi application! The tube was designed for radio frequencies (for a car radio, powered off the car's battery), so who knows?

Add a 6V power supply (to avoid constantly changing AA batteries ), a box, a footswitch, four pots, two jacks, and about $5-10 in small parts and you're good to go. A lot cheaper than an EH tube pedal!

 

[oh_the_blood]

is it working yet?

 

[mshilarious]

is it working yet?

Nope, gimme another week and she'll be fired up!

 

[zer0sig]

very cool. i have an old rage that i haven't been using.. once you get that bad boy together, i'd love to hear what it sounds like. maybe i'll try something similar.

 

[mshilarious]

Here's a pic of the modded circuit with the highlights labeled. I should be able to finish the tube circuit board today too

I've also made some revisions to the tube pedal design, I'm gonna start a separate thread for that.

 

[jimistone]

I have done a couple of mods to my guitar rig as well.

I have a fender hot rod deville and I clipped the end of a resistor which smoothed the reverb out very nicely (and made it not quite so touchy). I soldered a 220 uf siver mica capacitor accross 2 posts of the clean volume pot (takes away the "tubbyness and accents the bite on the clean sound), soldered a 330 uf silver mica capacitor across 2 posts of the drive pot (takes away the tubbyness and accents the bite on the overdrive sound), and switched out the liner volume pot with an audio volume pot on the Master volume (makes the volume not so touchy in the drive mode.....with the liner pot you get 1/2 of the available volume between settings 0 and 1....now the same amount of volume is spread out evenly frome 0 to 5)

Bottom line....this amp simply rocks now. Fender clean tones to die for.


Also, I did the "brent mason" modification on my boss blues driver 2 pedal. There is no noticable bass loss when I engauge the pedal and the overdrive is much more pleasing to the ear now....it's an awsome pedal now and was "so-so" before.

Im glad i can solder....it would have cost me a bundle to pay a tech to do all this....the total cost was 10 bucks with me doing it.

Man, my '66 strat going into this rig is soooo sweet now.....blues and hard rock heaven baby!

 

[mshilarious]

Bottom line....this amp simply rocks now. Fender clean tones to die for.

Yeah it surprised me in this amp how it was designed to shed some lows, and of course nearly all the caps were ceramic or crappy electros.

Tonight's progress: I ran out of solder I got this far on the tube board:

Tomorrow (hopefully) will be final assembly

 

[mshilarious]

So very close . . . smoke test in maybe an hour!

 

[mshilarious]

So very close . . . smoke test in maybe an hour!

After stupidly blowing a couple of fuses, voltages check out OK everywhere

Audio test tomorrow. Then there's still some hardware work to do cutting holes, and it's done

 

[mshilarious]

OK, staying up late so why not play with high voltages? After fixing an embarassing problem with the power supply (I left out a jumper, what was supposed to be ground was -14V ) the clean channel passes audio and sounds pretty good, although buzzy, since the circuit boards are totally unshielded at the moment and I have the dimmers down. Definitely that stock speaker was crap, and the improvements in the opamp and caps help a bit too, I'm sure.

Of course it ain't saying much that the clean channel works, that was more or less straight part swaps.

The tube stage does not pass audio at the moment DC voltage on all the pins is good, so I probably crossed a wire somewhere between plates and grids, or something. It'll have to wait for tomorrow.

 

[mshilarious]

The tube stage does not pass audio at the moment DC voltage on all the pins is good, so I probably crossed a wire somewhere between plates and grids, or something. It'll have to wait for tomorrow.

OK, found that problem--the heater ground was not properly soldered Fixed that, played around with it. It sounds pretty good, but as I suspected a few resistors are off. The first tube stage is getting hit too hard, so there isn't a clean tube tone available, and it gets way too distorted too fast. Actually when I looked at that, R50 and R57 (voltage divider going into grid) weren't done properly on the PCB, so they aren't doing anything.

Also I clamped down too hard on the second stage plate output, there isn't enough volume available from the tube stage. I'm gonna try 470K for R56 as a fix.

But my big problem is that my 12vreg keeps going into overload. I suspect it's because the transformer is putting out higher voltage than rated. Thus I have 37v on what is supposed to be 28v. That ends up OK for all components except that vreg, which is supposed to be max 35v input. I put some resistors in front of it, and the total draw should only be ~400mA, and I put a heatsink on it, but it hates me It's my fault for trying to use the same rail for the bias and the heaters Since there is no easy way to fix that vreg, I think I'm going to have to build a separate power rail for the heaters