Hehe. The guitar is still on my lap as I write this. Just tested my little creature... Well, what can I say? It sounds like a Champ, that is until it gets into distortion territory (unknown to the Fender Champ), and when it does I'm rewarded with farty distortion and some oscillation too. Hehe, maybe it should stay inside Champ's territory after all. Or maybe some work still to do.... The thing I'm really surprised about is the lack of hum. This is to date my first SE amp with no audible hum. I can't hear nothing (98dB speaker) and the filaments are AC heated (in series). More to come.
My amp's ready.
Oscillation and farty distortion are gone now. Changed the layout a little.
More than once, as I was building this, I felt I was losing my time, thinking this will turn out to be a toy or a joke of an amp. Well, I was WRONG. Two big surprises: first one was the absence of hum (dead quiet); second one has been the sound....it sounds pretty,pretty good. And it is loud, I reckon too loud for bedroom use. All in all, pretty happy here about this one and I've learn a few lessons too: this amp has taught me something that I'm yet to fully comprehend.
Now it comes the boring part (drawing out the schematic) and the nightmare part (the recording). Not sure about the BOM, a friend of mine gave me 4 6N2N's, I have no idea how much it cost one of these. Nor do I now what would be the normal price for the transformers and chassis ( Toroidal PT and chassis two euros and OT from some 60's junk reel to reel which only cost me the effort to take it home).
I keep trying to post a decent picture but to no avail.
Oscillation and farty distortion are gone now. Changed the layout a little.
More than once, as I was building this, I felt I was losing my time, thinking this will turn out to be a toy or a joke of an amp. Well, I was WRONG. Two big surprises: first one was the absence of hum (dead quiet); second one has been the sound....it sounds pretty,pretty good. And it is loud, I reckon too loud for bedroom use. All in all, pretty happy here about this one and I've learn a few lessons too: this amp has taught me something that I'm yet to fully comprehend.
Now it comes the boring part (drawing out the schematic) and the nightmare part (the recording). Not sure about the BOM, a friend of mine gave me 4 6N2N's, I have no idea how much it cost one of these. Nor do I now what would be the normal price for the transformers and chassis ( Toroidal PT and chassis two euros and OT from some 60's junk reel to reel which only cost me the effort to take it home).
I keep trying to post a decent picture but to no avail.
Attachments
Nice to see the final schematic and a good picture. Not sure if it is worth the bother trying to price out the parts if they are not readily available though.
So what's up with your amp, Printer? I was going to draw the schematic today but it seems there's no hurry to do it so....maybe, maybe not. As for the recording part, I have decided to take the amp to a friend's house, he has a semi-pro recording setup. Although it will take some time -he's always busy.
I like good pictures (see my avatar) that's why I hate these goddamn phones. Again, will have to take the amp upstairs and blah,blah,blah. All this effort to get no votes I'm afraid, maybe Jazbo8's if he's kind enough. Please Jazbo8, I hate zeros and the pro guys really don't need another vote, pleeeeease.
I like good pictures (see my avatar) that's why I hate these goddamn phones. Again, will have to take the amp upstairs and blah,blah,blah. All this effort to get no votes I'm afraid, maybe Jazbo8's if he's kind enough. Please Jazbo8, I hate zeros and the pro guys really don't need another vote, pleeeeease.
Feature creep. I should not have decided to go to my tabletop amp cabinet. Since it is an amp I want to keep around for a long time I hummed and hawed for a while whether to keep it simple and rebuild it later at some time or whether to toss in a few more goodies. I pretty much decided I would not go and revisit it so I did some additions.
Mind you the additions were not planed for and some of the lead dress is not going to be as short as it was first planned. Kind of a confined space I am working in. Hopefully it will not squeal like a pig, I am wiring the board up today. A little late in the day for an amp that has never been tried, hopefully I will get lucky. For the last hour I have been debating on a couple of resistor values, in the end I am going to use what I originally decided on. Hate second guessing myself.
It also did not help with my brother giving me an amp that he found at the side of the road. It is only a couple watt 50C5, 12AX7, 35W4 amp but I started to think about what to do with it and wasted some valuable construction time. I hope to get the amp portion done, the cabinet may need some construction though. Might just use an external speaker.
I really should have stayed simple and saved the cabinet for a future build. The finished circuit is a little more complicated to build than a normal low wattage amp. I did some point to point due to the additions, not pretty. Not really appropriate for this challenge, went a few bucks over anyway. Mind you I am more interested in if some of the features are worthwhile implementing in a future amp.
I sure hope the deadline is not earlier than Nov 15. That's what I've been telling myself, anyway, ever since Cassiel said something of the sort a while back.
Speaking of whom, Yes, it is always a wonderful and happy surprise to discover that one's design has actually WORKED! And worked well!
This is, of course, especially true after turning on the power to hear . . .
--- nothing.
Or to hear awful banshees and other mythical creatures caterwauling from out of the circuit.
It is most very especially true after going through several stages of such extending over several weeks before hearing that magical moment. Oh, Bliss!
Oh, Deadlines!
Thought it was Saturday, and was in a bind with some recordings to upload, but an unfinished circuit. Aaargh! Then I realized that Saturday wasn't the 15th. (What's a calendar?)
So, if it's still the 15th, then I guess I'm approximately on target to submit something.
No more time to post. Changed some capacitors.
Now I gotta go make some new recordings.
Still need a diagram of the power supply, and a BOM.
Gonna give birth to triplets, I think.
Speaking of whom, Yes, it is always a wonderful and happy surprise to discover that one's design has actually WORKED! And worked well!
This is, of course, especially true after turning on the power to hear . . .
--- nothing.
Or to hear awful banshees and other mythical creatures caterwauling from out of the circuit.
It is most very especially true after going through several stages of such extending over several weeks before hearing that magical moment. Oh, Bliss!
Oh, Deadlines!
Thought it was Saturday, and was in a bind with some recordings to upload, but an unfinished circuit. Aaargh! Then I realized that Saturday wasn't the 15th. (What's a calendar?)
So, if it's still the 15th, then I guess I'm approximately on target to submit something.
No more time to post. Changed some capacitors.
Now I gotta go make some new recordings.
Still need a diagram of the power supply, and a BOM.
Gonna give birth to triplets, I think.
It's safe to assume from many of the comments that we have all learned something here. I have always known that for me at least, the construction and implementation of a project are always far more challenging than designing it and making it work. This project has taught me at least a dozen things that don't fit together. One is this amplifier. Right now the chassis is kind of stuck inside the cabinet where I placed it about 2 weeks ago. It doesn't want to come out peacefully either.
The electronics are alive and well and have not changed since I posted the schematic in post #1021. This unit is just the head unit. I have dubbed it "Little Big Head". The speaker cabinet is the one seen in several posts with a Jensen Alnico 8 inch speaker in it. It still looks the same, unfinished.
The front panel escuteon is still missing. It covers up the aluminum where the pots are and extends down to the bottom of the Lexan front (it doesn't fit). The back panel isn't even made yet.
Speaking of deadlines, I have a major project at work that was to be done by Thanskgiving. My wife, Sherri has been away for most of this year but I found some reasonable plane tickets and she flies in next Sunday. So I will be working non stop to finish my project early so that I can take the following week off. I was at work for most of yesterday. This means that I doubt much more will be done on these amps for a while.
Total parts cost for the electronics is about $45. (Within $2). The tubes are 18FW6 input pentode (like a 6AU6) 18FY6 second gain stage (1/2 12AX7) 32ET5 self split output stage. All tubes are $1 each at ESRC with over 1000 of each in stock. They are also available at AES. The power transformer is the Triad N-68X and the OPT is a 300-040 70 volt matching transformer from parts express. The amp delivers about 1.5 watts of clean power (3% dist) and about 2 watts when dimed.
Amp 2.2 is still in pieces. The electronics work fine, the other stuff still doesn't fit together. There are 2 12 inch cabinets for it and it goes to 20 watts with the attenuator off and just fits in the $100 budget.
The electronics are alive and well and have not changed since I posted the schematic in post #1021. This unit is just the head unit. I have dubbed it "Little Big Head". The speaker cabinet is the one seen in several posts with a Jensen Alnico 8 inch speaker in it. It still looks the same, unfinished.
The front panel escuteon is still missing. It covers up the aluminum where the pots are and extends down to the bottom of the Lexan front (it doesn't fit). The back panel isn't even made yet.
Speaking of deadlines, I have a major project at work that was to be done by Thanskgiving. My wife, Sherri has been away for most of this year but I found some reasonable plane tickets and she flies in next Sunday. So I will be working non stop to finish my project early so that I can take the following week off. I was at work for most of yesterday. This means that I doubt much more will be done on these amps for a while.
Total parts cost for the electronics is about $45. (Within $2). The tubes are 18FW6 input pentode (like a 6AU6) 18FY6 second gain stage (1/2 12AX7) 32ET5 self split output stage. All tubes are $1 each at ESRC with over 1000 of each in stock. They are also available at AES. The power transformer is the Triad N-68X and the OPT is a 300-040 70 volt matching transformer from parts express. The amp delivers about 1.5 watts of clean power (3% dist) and about 2 watts when dimed.
Amp 2.2 is still in pieces. The electronics work fine, the other stuff still doesn't fit together. There are 2 12 inch cabinets for it and it goes to 20 watts with the attenuator off and just fits in the $100 budget.
Attachments
I will miss the 15th. Going slow and methodical over the amp as I build it since it will not be very serviceable once made. I sometimes refer to ship-in-a-bottle builds but this one is more than most. I was going to spend much of tomorrow night on it and thought I could finish it up on Tuesday but I got a late diner invitation for that night with some instructors I used to work with. We do not get together very often so I am taking the opportunity to see them. I should have something to post later in the week though (please don't squeal, please don't squeal). Parts list done a while back, schematics, I may even have one without errors. We'll see how the rest will go.
I thought Sunday was the 15th (deadlines can play tricks on your mind). It seems no-one is going to be on time. Maybe Tubekit will show up with all his homework done. I will post a decent picture and the schematic. No sound samples (yet) and no BOM.
This challenge is going off rails so I have an idea. Let's imagine Tubekit is the only one to show up on time with all his papers in order, mods can't open up a poll with only one amp. It would be ridiculous. No poll, no fun. So.....post your project and wait for others. When there is at least three projects posted the fun begins. In case of a tie, the first amp posted wins.
YES. To me the real headache is to make up my mind, then the construction and implementation; the rest is the easy part.
BINGO!!!!!You win the prize!!!!!!
I was actually asked to leave the public school system in the 4th grade because I was "disruptive". We now know this affliction as ADD or ADHD and I had it bad. I have wrestled with it all my life and generally have it stuffed back into a small corner of my mind, but......simple decisions are SCARY THINGS. The line between genius and insanity really is thin and hard to see at times.
Matters get worse when you think about something for a while, come up with a dozen ideas, and can't choose one. After finally making a choice and starting the build.....then damn, it doesn't fit. I have trashed more than a few projects at that point.
The electrical stuff is easy, just sit down with a bunch of parts, a few clip leads, and a power supply. That is my playground and everything done there is fun.....even if it blows up.
"What's wrong with you boy? You got ants in your pants?"
I have my suspission that a lot of people who end up in the technical field are ADHD/ADLD/ whatever the current term is for it.
I consider myself undiagnosed. My son was diagnosed ADHD/ADLD when he was 5. There is most likely a genetic predisposition.
I have my suspission that a lot of people who end up in the technical field are ADHD/ADLD/ whatever the current term is for it.
I consider myself undiagnosed. My son was diagnosed ADHD/ADLD when he was 5. There is most likely a genetic predisposition.
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Well you certainly get my vote for creativity with the keypad
Love to hear some clips, we are all waiting...Jaz
Down to the wire . . . (A little solder helps, too.)
Actually, it's still a tossup. Here's the basic circuit and psu. Working on the BOM. Made some recordings today, but not the best. Still need to edit them and turn them into MP3s. But there are still a few hours left in November 15, 2011. We'll see.
Got a decent batch of recordings of the five-tube unit the other day, but I doubt it will meet the price target.
Okay. Let's do that.
Actually, it's still a tossup. Here's the basic circuit and psu. Working on the BOM. Made some recordings today, but not the best. Still need to edit them and turn them into MP3s. But there are still a few hours left in November 15, 2011. We'll see.
Got a decent batch of recordings of the five-tube unit the other day, but I doubt it will meet the price target.
