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A DIY 500 Watt Bass Head
- Thread starter Passinwind
- Start date
Very Cool Passinwind!
The work you did on the font alone is beyond my capabilities, and I work in print (and a few other industries to get by). I admire your many talents and dedication. I can barely get out of bed in the morning.
Wish I could hear it in person.
The work you did on the font alone is beyond my capabilities, and I work in print (and a few other industries to get by). I admire your many talents and dedication. I can barely get out of bed in the morning.
Wish I could hear it in person.
dHere's how it looks wired up for testing:
I think I'm done with the electronics dweebing for now. Time for tie wraps to neaten up wiring, plumbing in the shield on the top lid that mates with the bottom one, and a few other odds and ends.
What is left there to tidy up ??? This is the neatest bit of electronics engineering I've seen in a long while. Most commercial stuff doesnt compare.
Ah, well, okay, you've been itching to use those cable ties
Nice work, Charlie! Love the purple PCBs. What pots did you use if you don't mind me asking?
The "pros" could take some advice from you on chassis layout/neatness.
I just ordered some transformers for a tube DI project I've been trying to start for a couple of months. I have a circuit in mind but have been too busy to implement it. I got laid off again a few weeks ago so now I have the time. One of the perks of being unemployed with severance.
The "pros" could take some advice from you on chassis layout/neatness.
I just ordered some transformers for a tube DI project I've been trying to start for a couple of months. I have a circuit in mind but have been too busy to implement it. I got laid off again a few weeks ago so now I have the time. One of the perks of being unemployed with severance.
It may seem that this amp has been assembled on a short space of time but Charlie has designed a few solid state and tube preamps over the years and this is the latest iteration packed with all that experience. It is beautifully installed and wired together with a superb power amp,
Unashamedly "Hi-Fi", this is how I think bass amps should be. Enough fixed frequency EQ to suit anyone or almosr any room and a fully parametric EQ to fill in the gaps or suck out the boom. Add a flexible HPF and that is just perfect,
Unashamedly "Hi-Fi", this is how I think bass amps should be. Enough fixed frequency EQ to suit anyone or almosr any room and a fully parametric EQ to fill in the gaps or suck out the boom. Add a flexible HPF and that is just perfect,
- Dec 3, 2003
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- Designer/Toaster Tech @ Passinwind Electronics
The volume, master, and HPF ones are NOS Nobles. The boost/cut is a PEC. The rest are current production CTS more or less as used in classic Fender tube amps, which have a nice feel and aren't terribly expensive. The purple boards are just OSHPark's standard share-a-panel fab spec, but I like 'em too.
Well, production builds are a whole different thing and I have great respect for anyone who can make that work these days! I've had some amazing mentors over the years and only hope to someday approach their impossibly high standards. Baby steps...
I just ordered some transformers for a tube DI project I've been trying to start for a couple of months. I have a circuit in mind but have been too busy to implement it. I got laid off again a few weeks ago so now I have the time. One of the perks of being unemployed with severance.
Nice! A tube DI is definitely on my radar too Mark.
svtb15
Inactive
- Mar 22, 2004
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- I play it all. Whatever works for the gig. Q+
Can't wait to hear this thing at the GTG. I have to keep in mind that I am aiming to buy a house soon, so I can't really spend money, but damn is it going to be hard with this, Duke's cab etc. all floating around!
Lovely piece of kit for sure.
Lovely piece of kit for sure.
Looks great! The only thing I guess I'd question is the location of the power supply relative to the preamp? Typically there is as much separation as possible and shielding between them to keep hum from being induced. I know you said you tested it out and it works perfectly without noise so I guess it's a non-issue.
Great thread!
Great thread!
- Dec 3, 2003
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- Designer/Toaster Tech @ Passinwind Electronics
Thanks, and a point well worth some discussion.
The low voltage supply's toroid is as far away as I could really get it unless I want to take my chances with interference from the power module. The power module's supply is onboard and very well shielded from the preamp side, and absolutely as far away as I could figure out how to get it. The HPF board has big 'ol stitched-together ground planes on both sides and I oriented that board to provide some shielding for the pot wiring. All the other signal wires are shielded cable.
As usual, you take your best shot at identifying the tradeoffs, then pick your poison and see what you've got. There's not even a sniff of hum, but eventually I'll test the noise floor on my friend's Audio Precision analyzer as a reality check anyway though.
- Apr 3, 2003
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- Editor-in-Chief, Bass Gear Magazine
Nice setup! A nicely laid out 3-band EQ, variable HPF and parametric EQ scores nicely on my personal wish list. 
- Dec 3, 2003
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- Designer/Toaster Tech @ Passinwind Electronics
Nice setup! A nicely laid out 3-band EQ, variable HPF and parametric EQ scores nicely on my personal wish list.
Thanks Tom. A lot of people tried it out at the Seattle GTG and the response was surprisingly great for something home built to my notoriously quirky personal tastes. When I arrived up there the glue was just about dry on the wood trim I added to an old DIY rack case to make it fit right, and as soon as the weather cooperates I'll add a clear coat on the trim and call it good for now.
Photo by Fritz Marial
Charlie,
I know I told you this at the GTG, but I wanted to post it up here as well.
That "little" head is a killer. I seriously need to convince you to make me one. For my main gig, I don't need the power section at all, but for my side stuff it'd be nice to actually move away from pre/power setup.
The power and tone from that was stellar, to say the least. I loved how super responsive it was to my playing, and also how much movement there is available in the EQ. Previous to that, as you know, I was thinking I needed much more "control", but after hearing that thing, I was blown away. I liked it best, I think, when we pushed it through the TC118. I don't know how close we were to the limit output wise, but kneeling next to the cab was dizzying - yet so much clarity at the same time.
So much GAS now after that GTG...
I know I told you this at the GTG, but I wanted to post it up here as well.
That "little" head is a killer. I seriously need to convince you to make me one. For my main gig, I don't need the power section at all, but for my side stuff it'd be nice to actually move away from pre/power setup.
The power and tone from that was stellar, to say the least. I loved how super responsive it was to my playing, and also how much movement there is available in the EQ. Previous to that, as you know, I was thinking I needed much more "control", but after hearing that thing, I was blown away. I liked it best, I think, when we pushed it through the TC118. I don't know how close we were to the limit output wise, but kneeling next to the cab was dizzying - yet so much clarity at the same time.
So much GAS now after that GTG...
- Dec 3, 2003
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- Designer/Toaster Tech @ Passinwind Electronics
GTGs are like that, for sure. There's always so much great sounding stuff and never enough time to do it all justice.
The TC118 cab is 8 ohms, so the amp would be running out of gas at 250 watts or so in that situation. The TC112 cab I built it to use with is 4 ohms, so max output would likely be pretty similar in each case. The TC118 was my favorite cab of anything I heard at the GTG, I think. It just laughed at whatever EQ choices you cared to dial in and dished it right out perfectly gracefully.
Ah, but see, you assume I'd only be using one cab.
Yes, it was crazy good. Everything I did came right through, and man your amp sounds SWEET too. I love the EQ points and how they all interact. I don't think I had it fully grasped... I might have to make a weekend trip south so I can give it a whirl for a few days
I should've hauled my rack over and tried Duke's cab with that, but it would've been difficult given the limited room and mass of bodies between points . First I'm getting a TC118, which my QSC will pump full of 600W. Dang, I just realized I could use 4 of the TC118s off my QSC... 2 per side, with 1800W going into them. Might need a much bigger space next GTG...
- Dec 3, 2003
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- Designer/Toaster Tech @ Passinwind Electronics
You know I have a DIY 15/15/6/1 cab too, and a PLX1804 as well, right?
I have no real idea how my new amp's EQ all works together yet myself Ray. I just kept spinning knobs until I found something I liked.
Haha! Love it. Though, I liked Duke's cabs better than the various fEarfuls/nEarfuls that were there. But, that's just my preference, not knocking those.You know I have a DIY 15/15/6/1 cab too, and a PLX1804 as well, right?
I have no real idea how my new amp's EQ all works together yet myself Ray. I just kept spinning knobs until I found something I liked.
Too bad we can't bridge our PLXs
.I didn't do a whole lot of twiddling after you stopped. I think I tweaked the HPF a little more and a couple of twists here and there. Not a bad sound to be found in there. I wanted to really just dime it out and see what it did when pushed, but I think that would've been pretty brutal to everyone within earshot. Did anyone put their pedalboards through it? I know it played awesome with my active basses, just curious how it deals with dirt and compression mostly.
- Dec 3, 2003
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- Designer/Toaster Tech @ Passinwind Electronics
Haha! Love it. Though, I liked Duke's cabs better than the various fEarfuls/nEarfuls that were there. But, that's just my preference, not knocking those.
Too bad we can't bridge our PLXs
I didn't do a whole lot of twiddling after you stopped. I think I tweaked the HPF a little more and a couple of twists here and there. Not a bad sound to be found in there. I wanted to really just dime it out and see what it did when pushed, but I think that would've been pretty brutal to everyone within earshot. Did anyone put their pedalboards through it? I know it played awesome with my active basses, just curious how it deals with dirt and compression mostly.
My cabs are quite a bit different from Dave's thing and sound a lot more like my TC112 in a lot of ways, but I dig Dave's thing a lot too.
The older version of the preamp section works great with my modeler and tube noise toy, especially in the EFX loop, and I expect this new one to be better if anything. I'll take this to email as far as all the specifics. All my preamp designs are heavily optimized for active basses BTW (since that's all I own or use), and I'm always surprised that they work OK with passives too.
