Hello!
I've been building a small amp for the past week... and now it is nearly finished (finaly) :)
Here are some photos and comments ;)
First I drilled the alu chasis (hammond 1444) according to my plan:
(http://www.shrani.si/t/2Q/G2/VPPsRvF/chasis.jpg) (http://www.shrani.si/?2Q/G2/VPPsRvF/chasis.jpg)
Then I designed the power supply and the jfet splitter (which I later ditched):
(http://www.shrani.si/t/1U/V0/43QyKYFm/psbs.jpg) (http://www.shrani.si/?1U/V0/43QyKYFm/psbs.jpg)
Assembled power supply:
(http://www.shrani.si/t/2n/uH/1VnVpMAr/psfinished.jpg) (http://www.shrani.si/?2n/uH/1VnVpMAr/psfinished.jpg)
(18V for the amp and 15V for the preamp, both regulated)
I then fiddled with the global layout and stuff:
(http://www.shrani.si/t/46/Qt/43L0yaxN/layout.jpg) (http://www.shrani.si/?46/Qt/43L0yaxN/layout.jpg)
Next was choosing a handle and wood type... and then drawing a plan in 3D (google sketchup):
(http://www.shrani.si/t/3M/yX/3i0zGuhf/materials.jpg) (http://www.shrani.si/?3M/yX/3i0zGuhf/materials.jpg) (http://www.shrani.si/t/c/Pd/4vnJJu5n/sketch.jpg) (http://www.shrani.si/?c/Pd/4vnJJu5n/sketch.jpg)
This was the internal pcb layout...
(http://www.shrani.si/t/3e/lM/4CsJKj9L/layoutfotka2.jpg) (http://www.shrani.si/?3e/lM/4CsJKj9L/layoutfotka2.jpg)
...until I wired it and plugged it in :'(
There was just no way in hell my dr.Boogey would cooperate with my small dpdt switch. I used shielded&grounded wire, but the proximity of I/O wires at the switch caused it to oscilate. I then ditched the second preamp and wired the Boogey differently. It is now a "one trick pony" amp, but it sounds really good 8)
Also, I wired the volume from tonestack directly to amp input. I had some trouble with the splitter, I might try it again later.
This is from today's testing:
(http://www.shrani.si/t/1k/UT/3x744TIp/working.jpg) (http://www.shrani.si/?1k/UT/3x744TIp/working.jpg)
After three hours the heatsinks (scavenged from a dead PC PS) were just slightly warm. Transformer was a bit warmer, but still at lower than body temperature... yay :tu:
Now I'll have to wait until monday for my wood to continue :)
Comments are as always most welcome!
WOW !!
Congratulations !!
:tu: :tu: :tu: :tu: :tu: :tu:
Really nice! What its power rating??
Power amp is TDA2003 running at 18V, so it has approx. 5W into 8 ohm, according to datasheet. It was born as as a practice/recording amp and it does it nicely. Plugged into my 1x12 cab it reaches "max. bedroom level" at around half volume. Into my 4x12 with V30s it is loud enough to tear my ears of from a meter or so, hehe.
Just this moment the wood arrived, two days early! :o
(http://www.shrani.si/t/Q/Sn/2USlppzN/woodcheck.jpg) (http://www.shrani.si/?Q/Sn/2USlppzN/woodcheck.jpg)
I will probably glue it together tomorrow :tu:
Hello Alexius II,
Very tidy workmanship :tu:
Watch out Mr Fahey might have you working in his factory before you can blink :-*
Phil.
Lovely Work!!
Very nice work. I have to ask though, why did you regulate the voltage on the power amp chip?
Thanks! :tu:
As for the regulation: I first intended to use a 12V transformer which would give me about the right voltage after smoothing caps... but then I decided to just use the 15V, 1A transformer, which I already had. And since the TDA2003 datasheet said 18V is the max. operating voltage - I regulated it down to that ;)
I'm still deciding about the wood though... to stain or not to stain ::)
Quote from: Alexius II on August 01, 2011, 12:02:39 PM
Thanks! :tu:
As for the regulation: I first intended to use a 12V transformer which would give me about the right voltage after smoothing caps... but then I decided to just use the 15V, 1A transformer, which I already had. And since the TDA2003 datasheet said 18V is the max. operating voltage - I regulated it down to that ;)
I'm still deciding about the wood though... to stain or not to stain ::)
If you don't stain I would recommend using Linseed oil to finish it with.
Ha, I just found some "leftover" clear acrylic based lacquer for wood from a previous (non music) project :tu:
I have just about enough for a few coats... so I'll go with it ;)
Who said a "metal" amp should be black... it's gonna be bright and pretty :P
QuoteWho said a "metal" amp should be black...
You are right, it can also be Red ..... dripping
Blood Red, that is :grr
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You could always use a torch to darken it up a bit first, then put the laquer on. I think the burnt look would be badass on a metal amp.
While dripping blood is not a bad idea :D burnt look would be even better.
The only problem is... my wood won't do that. It is not a solid piece of wood, but is made from smaller (2 inch wide) parts glued together. I tried that yesterday on a small leftover piece to see if the glue would hold, but it does not :-\
Also, this spruce wood burns faster than I can say "fire extinguisher" :o
I also tried to stain it with my fountain pen ink and achieved a really nice effect ;D so I'll try it on a larger piece to see if it works.
Personally, I'm getting a bit tired in the generic hardwood cab -look but each to his own I guess. Too bad that the heat ruins the glue, as the burned wood -look wasn't such a bad idea. The burned wood effect looks nice also when you sand out the top layer, sort of brings out the wood grains like a stain would.
(http://g-cdn.apartmenttherapy.com/1976074/111610_rg_IKEARusticDesk_03_rect540.jpg)
Nevertheless, looking forward seeing how that amp looks when finished.
Wow, this really looks good :tu:
The trick might also be in the high flame temperature of that "torch"... what I have is more of a orange-ish flame "burner", so the wood (and glue) heats up too much before actually turning black.
Well, I've tried another of my inks which I like best so far.
After a rough sanding it with a small piece of wet-sanding paper, this spruce suddenly looks a bit older, half rotten and beaten up ;D
I believe this decadent look could be just dirty enough for the sounds coming out this amp ;)
Here is the sampled surface (lower left part):
(upper part is overburned and not sanded... don't mind that)
(http://www.shrani.si/t/2y/uY/ac7BweA/ink-stained-wood.jpg) (http://www.shrani.si/?2y/uY/ac7BweA/ink-stained-wood.jpg)
Looks great! Are you going to coat it with anything after the inking (polyurethane, linseed oil etc) ?
I tried that transparent acrylic stuff on it and it looks nice.
It even gives it a tiny hint of green-ish shade which is even cooler 8|
I'll report back in a few days, hopefully with some nice photos :tu:
The amp will have to wait a few days, because I have to finish another thing first... until then: here is the first sample (http://www.box.net/shared/z4g9hk61bayp0ipfq79a).
Recorded on a 1x12 openback cab, center mic, one guitar on the left, one on the right, my random chugga riffs ::)
Settings were somewhere around: a bit too much gain, bass and treble :loco ;D
Sounds great. I gotta learn some metal riffs...love the chugga chuggas :tu:
It took me a whole day, but it's finally finished (construction-wise) :tu:
This is the final photo before getting my hands dirty with black ink, hehe...
(http://www.shrani.si/t/L/8t/316mMsr4/hcamp.jpg) (http://www.shrani.si/?L/8t/316mMsr4/hcamp.jpg)
One thing I noticed is, that I have more and more random "waterfall" hum/noise. I'm sure the bias trimpots are the source, since adjusting them a bit helps for a while... looks like I will have to replace them with fixed resistors :-\
I would always suspect pots or trimmers with DC across them, in a signal path, specially if high gain.
Measure and replace them with closest standard value.
You are right.. I guess I should have thought of this earlier.
Nevertheless, I found THIS (http://www.coolcircuit.com/tools/resistor_closest/index.php) nice tool that will help me match the resistance easier :tu:
Nice tool :tu:
Any way, nearest 10% value is more than good enough.
Not forgetting that the actual value will not be more than 5% away ;)
I have achieved the desired look of the wood... and made a matching logo :)
Only one thing missing now: the labels for input, outputs, pots and switch.
Latest pic with my simple logo:
(http://www.shrani.si/t/3f/NG/1SYHmkCG/hcampnolabels.jpg) (http://www.shrani.si/?3f/NG/1SYHmkCG/hcampnolabels.jpg)
Wow, that looks seriously killer, great job!
Great. I especially like the small details like the bigger (volume?) knob that's still the same style as rest of the knobs, and the black-colored shaft of that switch.
I don't know how well it would work at this point when everything already seems pretty much assembled but you should really consider an option of etching the labels. The etched, kinda "corroded" looking labeling on the chassis might fit rest of the scheme perfectly.
Thanks!
This is my first amp "head", so I really appreciate all the positive feedback :tu:
About the details. Well yeah, friends often call me... I believe the English translation is "nitpick" ;D
I always find inspiration in smart simplistic designs that just plain work. Both functionally and aesthetically.
Lots of pre-planning and attention to details are a great part of that, of course. ::)
I would love to etch the symbols/writing, I even have some ferric chloride, but I don't think I have the balls :lmao:
I never etched aluminum before, but intend to try it on my next stompbox. This chassis is only 1mm thick and I'm afraid of ruining it. I do have on the other hand a 2mm aluminum sheet. Hmm, I have some more thinking and drawing to do.
Since I'll be taking it apart to replace trimpots with fixed resistors, I might as well do something more challenging than simple stickers/labels ;)
This also means it's going to take a few more weeks until finishing it. Patience.
EDIT: yeah, the big one is the volume knob.
From left to right they are: gain, bass, mids, treble, presence, volume.
Well, *if you dare* you may take the Silkscreening route.
Now there are also Laser etched anodized aluminum labels, maybe you have access to somebody who does them.
The service is usually provided by shops who engrave Sports trophies and the like, so check that.
There are two basic flavors:
1) silver aluminum, covered in a transparent special varnish, which gets "toasted" by the laser: dark brown to almost black letters on a silver background.
2) anodized aluminum (any color but black, blue or red is best) where the laser evaporates that color: silver letters on colored background.
Results are impressively professional.
Exams are over, time to wrap this one up :tu:
I've tinkered with the unused switch for the past few days and ended up using it for diode clipping. I know everyone using a boogey is going "wtf" :loco but it sounds good for my ears, so that's it. I experimented with clipping inside the tone stack after reading this cool AMZ article (http://www.muzique.com/lab/tclip.htm) and ended up using two (3mm) green LEDs for treble and two 1N914 for mids, leaving bass as it is. This compresses mids and tames treble a bit, making a darker, smoother, and a bit more compressed sound. I like it on a V30 and hate it on a CL80 :)
Now that this is sorted out, the labels can be created. I think it's time for me to learn aluminium (khm, aluminum for those in US ;D) etching. I don't want to etch the enclosure (removing all the pots and switches :() but instead create small "Alu labels" and glue them onto the enclosure (epoxy should do the trick). I think this is the safest way... and should look cool too :tu: I already have ferric chloride, I'll get an aluminium sheet tomorrow ;)
Quote from: Alexius II on September 17, 2011, 07:01:57 AM
Exams are over, time to wrap this one up :tu:
I've tinkered with the unused switch for the past few days and ended up using it for diode clipping. I know everyone using a boogey is going "wtf" :loco but it sounds good for my ears, so that's it. I experimented with clipping inside the tone stack after reading this cool AMZ article (http://www.muzique.com/lab/tclip.htm) and ended up using two (3mm) green LEDs for treble and two 1N914 for mids, leaving bass as it is. This compresses mids and tames treble a bit, making a darker, smoother, and a bit more compressed sound. I like it on a V30 and hate it on a CL80 :)
Now that this is sorted out, the labels can be created. I think it's time for me to learn aluminium (khm, aluminum for those in US ;D) etching. I don't want to etch the enclosure (removing all the pots and switches :() but instead create small "Alu labels" and glue them onto the enclosure (epoxy should do the trick). I think this is the safest way... and should look cool too :tu: I already have ferric chloride, I'll get an aluminium sheet tomorrow ;)
Keep us posted as this sounds like a really great way to label an enclosure.
Will do!
I just noticed that tomorrow is sunday :duh so aluminium obviously comes the day after tomorrow ;D
Very nice work on your amp, and very nice playing. Congratulations! :tu:
Wow! Very nice job on this amp. Your sample sounded great! Love the look you did for the cabinet. Very inspirational. :tu: Did you use the Dr. Boogey circuit for your preamp?
I have a chip-amp kit (from Ebay) based around the same chip. I was thinking of building it into a chassis with 2 "bays" in which to plug in different preamps. (thinking the ROG circuits, ie: Professor Tweed in Ch 1, Matchbox in Ch 2, etc...) Was thinking of being able to plug in preamps sort of PC sound card style. Kind of a modular analog "modeling" amp.
Did you solve your problem with the drift in the trimpots? That worries me a bit. Has anyone had problems like this with the other ROG circuits? I guess it's worth measuring voltages and going to fixed resistors.
Yes, I suggested that.
I don't like a trimpot (or any potentiometer) carrying DC in my signal path, much more so if it's a high gain circuit, because a mechanical contact on a carbon track is a bad contact, by definition.
Conductive plastic pots are better in that aspect .... but best connection is a soldered one ;).
As of your plug-in preamps, I suggest you do not rely on edge connectors (as in PC boards) but normalize on a certain regular connector with an "universal" pin assignment.
PC board makers can get away with edge connectorsw because they can gold plate them, which is beyond what we can do within our means.
As an example, *all* of my instrument amps which I build commercially have the same connector:
+15/-15/signal out/ground/+B (usually +40V) for the LED or anything else which does not run on +/-15V
That way, I have already built cabinets+60/100W power amps+PSU, and by plugging the approppriate preamp the customer can carry any amp he chooses in a jiffy.
I usually have a Bass preamp, a simple 3 channel Mic/Keyboard one, a regular (clean/distortion) Guitar preamp and a Jazz sound one.
That covers most bases with a minimum effort... and minimum inventory.
The power amp+PSU is also plug-in so somebody with a burnt one can trade it for a new one in about 5 minutes for a fixed price.
Modular is a very practical concept.
All of my 60/100W power modules have had the same connectors and are mounted with the same 2" separation 1/8"bolts (and have about the same footprint) for the last 30 years, so somebody with an old workhorse can have it running like new with no problems at all.
That has given them some legendary reliability status, not bad as a selling point.
It also means that somebody in a far away Province or neighbouring Country can order a new module and revive his burnt amp without moving its bulk back and forth.
Quote from: J M Fahey on October 06, 2011, 06:38:52 AM
All of my 60/100W power modules have had the same connectors and are mounted with the same 2" separation 1/8"bolts ...That has given them some legendary reliability status, not bad as a selling point.
Ok, that's not fair. Stop telling us how awesome your amps are when we can't get them here in the US! :trouble
Hi joecool, I didn't use the word "awesome" :lmao:
It's just that I have the funny idea that things should last , providing good service to their owner along the way.
And just between you and me, it also had a lot to do with not wasting perfectly good stuff I had already built, at a high cost to boot, not in $$$$ but in man-hours (mine) which is an even scarcer stuff.
So when I design, say, a new power amp, for example going from TO3 devices to plastic transistors, or from bipolars to MosFets or from discrete to chipamps (I'm road testing TDA7294), if I make them mountable to the aluminum back panel (my heatsink) with the same two screws, same holes, it means that if I still have 60 backpanels left from the last 100 unit run, I can keep using them, and viceversa.
And if an old client shows up with a PCB "repaired" by somebody who lifted half the pads and traces, ruining it beyond repair, I just slap a new one , even a different technology one.
In fact, anybody who shows up with a pre-2006 board with TO3 2N3055 gets the TIP141/142 one, even if only one output transistor is dead and nothing else, because counterfeiting has made them unusable.
Now I'm in Brazil setting up shop here, going tghrough all the paperwork, red tape, etc. , and one homework I'm having to complete is designing a "packaged"power amp (yes, you guessed right, still mountable with those old screws), similar to those ILP modules used by many British SS amp makers, so if a guy has a problem 3000 miles away I just mail him a new one, together with a little silicon grease, so he drops the old one in the junk, wipes old grease, applies a little new one, bolts the new power pack, plugs 3 connectors and is home and running again, no soldering.
All he needs is a screwdriver and a little tissue paper.
Shipping costs here are *outrageous* and the Country is huge, not to mention that Mail service is poor, to say it politely.
PS: if things go well here, maybe I get in the mood and setup something on the US side, as we already talked.
Just give me some time.
:tu: :tu: :tu:
Hello after quite a long time!
I now finally have some free time to finish my "almost finished" projects, and this is one of them. Some time ago I replaced those trimpots with fixed resistors and all the strange "noise artifacts" (scratching) are gone. I also replaced two bad pots and that ugly power switch (green led light instead of red/orange ac light). While doing that, I temporarely removed the buffer - and while testing the amp - found out it doesn't need one (for now). I might add a switched buffer at some point, as the line-out after tone stack without an buffer is not very nice.
I also have all the materials for the labels, which should be finished until the end of the week.
Will post photos and samples when it's done :tu:
EDIT:
Quote from: Puguglybonehead on October 06, 2011, 02:38:10 AMDid you use the Dr. Boogey circuit for your preamp?
Yes, the preamp is a Dr.Boogey. I made the PCB from gaussmarkov blog :tu:
Today I tried to do a few different label designs and came up with something like this:
(http://shrani.si/t/b/t/4UfXJk1u/hcamplabels.jpg) (http://shrani.si/?b/t/4UfXJk1u/hcamplabels.png)
Each sign represents a letter: I for input, G for gain, B for bass, M for mids, T for treble and P for presence, while maintaining the original sharp/linear theme from the logo. I am just now drawing theese in autocad, so that I can take them to a nearby workshop tomorrow (abrasive waterjet cutting). I have some 1mm and 2mm aluminum plates, so two different label types will be made: labels cut from 1mm aluminium plate, painted in black - and labels from 2mm aluminium plate with just the sides painted in black, like in the sketch above. If it turns out not to be what I immagined, the design will be changed. If all is ok, final pics should come soon ;)
No comments.. I guess no one likes my design :tu:
Anyway, today I got the aluminium plate back:
(http://shrani.si/t/3C/hJ/2BoG3eq0/labels1.jpg) (http://shrani.si/?3C/hJ/2BoG3eq0/labels1.jpg)
And here is a quick ugly photo with raw unfiled labels placed on the amp:
(http://shrani.si/t/1h/W7/2DIXHoWt/labels2.jpg) (http://shrani.si/?1h/W7/2DIXHoWt/labels2.jpg)
It does look kind of strange to some people, but it turned exactly as I hoped.
I will continue on monday (filing, sanding, painting...) :)
EDIT: Also, all the visible screws have been changed to black hex type, as I like the look of them more.
I think it's great. Though it's not quite my style, I love the machined aluminum. Was it expensive to get done?
congratulations man...
Its looks very professional finish, maybe it should called "tiny recto" ?
kerraankkk...
Thanks :tu:
The cost for the waterjet cutting was 8€ (around $10). Not a lot, considering one unique amp, but not really cheap if I would want to do similar things often ;)
The main problem was, this being a huge machine, the little letters would easily get flushed away as "debris" so we had to modify my drawing a little. Solution was to add a tiny line, few mm long and around half mm thick, that would not get cut - connecting the symbol to the rest of the plate. Worked like a charm, but some filing and sanding will be required. (just like some small model airplanes that have all the plastic pieces attached from the molding process)
el nino: since the "Mini Rectifier" already exists :-X I choose another name: Black Mesa.
This name tells us, that the amp was inspired by M/B - and that I am a serious computer geek (Half-Life anyone?) :lmao:
Etching the name on a small plate (that was also cut from the same aluminium as other labels) will hopefully be the final task, thus concluding my work on this amp ;)
Nice stuff! That is a very unique and original look you've got going on there. Not an easy thing to achieve, nowadays. I like how it looks almost Cold War Industrial. Your labeling technique is clever. Very cool!
So, those labels are attached to the front somehow...superglue? I thought at first they were all one piece, etched into the front, then I noticed the two separate pictures and figured out why you were referring to them as "labels".