Ed,
Thanks for stopping by, taking a peek and taking the time to comment. It sure is appreciated and I'm having a lot of fun sharing it with folks like yourself.
As for the star ground, that was a solution that evolved over the course of the design. I read so much conflicting info about star grounding that in the end I decided since the idea of a star ground is to approximate each grounded part having a single ground point, I ran a separate dedicated ground back to the chassis/earth ground for every single grounded part. Since the layout was symmetrical, I was able to take pairs of separate ground points, tie them together with zip ties and then terminate each pair into a single ring terminal to go on the ground bolt.
Sure seemed to work! Even at full volume with my ear against the speaker cone I hear zippo hum or noise. In fact, I don't have a single shielded wire in the amp and still no hum.
Of course I'm not counting out the fact that I may've simply gotten lucky!
Best,
mr mojo
Thanks for stopping by, taking a peek and taking the time to comment. It sure is appreciated and I'm having a lot of fun sharing it with folks like yourself.
As for the star ground, that was a solution that evolved over the course of the design. I read so much conflicting info about star grounding that in the end I decided since the idea of a star ground is to approximate each grounded part having a single ground point, I ran a separate dedicated ground back to the chassis/earth ground for every single grounded part. Since the layout was symmetrical, I was able to take pairs of separate ground points, tie them together with zip ties and then terminate each pair into a single ring terminal to go on the ground bolt.
Sure seemed to work! Even at full volume with my ear against the speaker cone I hear zippo hum or noise. In fact, I don't have a single shielded wire in the amp and still no hum.
Of course I'm not counting out the fact that I may've simply gotten lucky!
Best,
mr mojo
Wow, what a beautiful amp, what an amazing journey this must have been. It almost seems a shame to cover up the bottom of the chassis. How about a glass table top with a right angle mirror that shows the underneath as well, just kiddin', kinda.
I'm curious, how long from conception to plug in did this project take?
Thank you for sharing.
Stan
I'm curious, how long from conception to plug in did this project take?
Thank you for sharing.
Stan
sklimek,
Thanks for the kind words-I sure do appreciate it!
From the start I wanted the underside to look as good as the top. No one would ever know but myself; but that was more than enough reason for me.
The whole project took around 9 or 10 months from the first time I had the schematic in hand until I listened to it the first time. No doubt this was too hard for a first-time build; in the end it wasn't brains or skill that made it happen as much as patience and persistance.
Best,
mr mojo
kambule,
Thank you as well for the compliments! I knew from the start I wanted this thing to be red-after all, red IS the color of passion-and a fella's got to be passionate about great sound to build a tube amp from scratch.
Plus I think the red makes it "sound" faster!
Best,
mr mojo
Karma,
It's comments like yours that have really made this fun to discuss and share-I really appreciate it.
It took a long time to get it right. There were a LOT of "two steps up, one step back," but in the end it was all worth it.
I came across the cloth covered wire while searching for solid wire with high enough voltage rating. When I found this stuff I just knew I had to use it.
Best,
mr mojo
Thanks for the kind words-I sure do appreciate it!
From the start I wanted the underside to look as good as the top. No one would ever know but myself; but that was more than enough reason for me.
The whole project took around 9 or 10 months from the first time I had the schematic in hand until I listened to it the first time. No doubt this was too hard for a first-time build; in the end it wasn't brains or skill that made it happen as much as patience and persistance.
Best,
mr mojo
kambule,
Thank you as well for the compliments! I knew from the start I wanted this thing to be red-after all, red IS the color of passion-and a fella's got to be passionate about great sound to build a tube amp from scratch.
Plus I think the red makes it "sound" faster!
Best,
mr mojo
Karma,
It's comments like yours that have really made this fun to discuss and share-I really appreciate it.
It took a long time to get it right. There were a LOT of "two steps up, one step back," but in the end it was all worth it.
I came across the cloth covered wire while searching for solid wire with high enough voltage rating. When I found this stuff I just knew I had to use it.
Best,
mr mojo
Congratulation
I would like to congrats you for your wonderfull amp. It is really neat and nice looking. I also appreciate non visible details.
I am new here and I was surfing the forum for discussion about tube amp that one can easily drive to full power with any line-level source like a CD player.
I let myself suggest to build the Voss-Ellis amplifier with triode connected 6CA7/EL34 tubes ("A New Triode Amplifier", Audio mag, 1964 July). The phase splitter is similar to the amp you have built, but the Voss-Ellis amp uses a triode tube as the initial gain stage. The disadvantage of the triode amp is that its input sensitivity may not be sufficient for use with a passive preamp. The 35-Watt Stereo amp has a pentode front-end, and considerably more gain. What is your appreciation after 3-4 months or so.
Kindly,
Mike
I would like to congrats you for your wonderfull amp. It is really neat and nice looking. I also appreciate non visible details.
I am new here and I was surfing the forum for discussion about tube amp that one can easily drive to full power with any line-level source like a CD player.
I let myself suggest to build the Voss-Ellis amplifier with triode connected 6CA7/EL34 tubes ("A New Triode Amplifier", Audio mag, 1964 July). The phase splitter is similar to the amp you have built, but the Voss-Ellis amp uses a triode tube as the initial gain stage. The disadvantage of the triode amp is that its input sensitivity may not be sufficient for use with a passive preamp. The 35-Watt Stereo amp has a pentode front-end, and considerably more gain. What is your appreciation after 3-4 months or so.
Kindly,
Mike
Thats one nice amp, very very nicely laid out and looks like you spent alot of time on it.
My next question is would you happen to have some schematics on hand of the amp, i would love to try to recreate this masterpiece. How much power at what ohm does it actually put out as well?
Again beautiful amp, i think i'm going to do my wiring like you did, very smart and visually stunning move.
Thomas.
My next question is would you happen to have some schematics on hand of the amp, i would love to try to recreate this masterpiece. How much power at what ohm does it actually put out as well?
Again beautiful amp, i think i'm going to do my wiring like you did, very smart and visually stunning move.
Thomas.
Mr Mojo:
Wonderful amp!
Safetyman:
Since everybody is complimenting the author (with reason) and nobody advices you, I will take the liberty to point you to the project that I would do IF I had the time and money to build a tube amp:
http://www.diyhifisupply.com/diyhs_ella.htm
Appart the fact that the name of the amp is great, it comes from Hong Kong, not far from you
I hope this helps...
Good luck
M
Wonderful amp!
Safetyman:
Since everybody is complimenting the author (with reason) and nobody advices you, I will take the liberty to point you to the project that I would do IF I had the time and money to build a tube amp:
http://www.diyhifisupply.com/diyhs_ella.htm
Appart the fact that the name of the amp is great, it comes from Hong Kong, not far from you
I hope this helps...
Good luck
M
Hi Dido,
So far so good, the amp has performed flawlessly and the sound is better than any amp I've heard so far, but then I've yet to hear a good DIY SET amp...
I've used JJ 7591s as well as EH. The JJs are a bit brighter, a little more detail, the EH a little fuller, more well-rounded sound.
I prefer the sound of the EH, but the JJs have less drifting of bias over time-either way they both sound better-to my ears at any rate-than the closely matched quad of GEs I've got on hand.
I guess the best praise I can give the project is: I'd like to build another amp because I enjoy the creative process and the pride of a working, finished project-but I can't tear myself away from listening. I'm just enjoying the amp so much I can't get motivated enough to start a new project.
I'll try to scan the text tomorrow and post a link to our FTP server-I've been trying to get it scanned for a fellow member but have been covered up at work for the last few weeks...
Karma,
Thanks for checking out my amp-I sure appreciate it.
demon,
Thanks so much for the kind words-this was a big project to bite off for a first-time build. The amp puts out 34.6 watts at 8ohms.
So far so good, the amp has performed flawlessly and the sound is better than any amp I've heard so far, but then I've yet to hear a good DIY SET amp...
I've used JJ 7591s as well as EH. The JJs are a bit brighter, a little more detail, the EH a little fuller, more well-rounded sound.
I prefer the sound of the EH, but the JJs have less drifting of bias over time-either way they both sound better-to my ears at any rate-than the closely matched quad of GEs I've got on hand.
I guess the best praise I can give the project is: I'd like to build another amp because I enjoy the creative process and the pride of a working, finished project-but I can't tear myself away from listening. I'm just enjoying the amp so much I can't get motivated enough to start a new project.
I'll try to scan the text tomorrow and post a link to our FTP server-I've been trying to get it scanned for a fellow member but have been covered up at work for the last few weeks...
Karma,
Thanks for checking out my amp-I sure appreciate it.
demon,
Thanks so much for the kind words-this was a big project to bite off for a first-time build. The amp puts out 34.6 watts at 8ohms.
That is first class work. As you are from Iowa, we'd expect you to be a master of tractor colors but your build quality is as good as it gets, anywhere. Speaking of color, I'm pleased to see that you also know that Sprague caps are the best. Because they are blue. And also, because they are orange.
I've been designing and building amps for a long time and your layout and wiring makes mine resemble Nest of Rat!
I've been designing and building amps for a long time and your layout and wiring makes mine resemble Nest of Rat!
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Sheesh, mojo... I just finished installing new orange-drop capacitors in my old Scott 222 D, and I was feeling a real sense of pride and accomplishment 
... until I saw a picture of your strikingly gorgeous first amp ever
... Now I feel as though I have acheived nothing 
I am, of course, being dramatic. Your project actually has inspired me to build my own amp. I've thought about it, and thought about it; but now that I see your beautiful creation I'm going to go for it.
First, though, I'm going to have to build my maple stereo rack that I've been mumbling about lately; I'll post pictures of it when I'm done. After that; homemade amp.
... until I saw a picture of your strikingly gorgeous first amp ever ... Now I feel as though I have acheived nothing I am, of course, being dramatic. Your project actually has inspired me to build my own amp. I've thought about it, and thought about it; but now that I see your beautiful creation I'm going to go for it.
First, though, I'm going to have to build my maple stereo rack that I've been mumbling about lately; I'll post pictures of it when I'm done. After that; homemade amp.
Mojo, not really sure if you'd like to disclose this, but total any idea how much you spent on building this amp, and what your starting budget was.
I really want to build my own tube amp, very much like yours, but find that budget is the biggest problem and fear of going extreemly wild with parts and goin really over budget.
If you would rather not say thats cool. I sure wish my first project when it happens looks 1/2 as good as yours.
I also worry that i don't have the appropriate equipment and knowledge to test for Square waves, actual output power and such, just to make sure the amp is running like it should......Dunno of any tube guys in my area at all.
I really want to build my own tube amp, very much like yours, but find that budget is the biggest problem and fear of going extreemly wild with parts and goin really over budget.
If you would rather not say thats cool. I sure wish my first project when it happens looks 1/2 as good as yours.
I also worry that i don't have the appropriate equipment and knowledge to test for Square waves, actual output power and such, just to make sure the amp is running like it should......Dunno of any tube guys in my area at all.
demon2091tb said:
As others will no doubt point out the voltages inside a tube amp can be lethal. Read the thread here about safety and be extremely careful. Don't work on the amp when you are tired, etc.
Now some good news- you can build a tube amp without having a bunch of test equipment. Basically what you need is-
1- A place to work
2- A good digital multimeter
3- A good soldering iron (or better yet, soldering station)
4- Some basic hand tools like needle-nose pliers and a wire
stripper
5- Some tools to cut holes in metal to make your chassis
6- A schematic you want to build
7- Some money
In addition to those things I like to have an adjustable work light, and a self-supporting magnifying glass. (I just got one that clamps to my bench and has a light in it, wonderful!)
You use the DVM to check voltages and current. Those two things will tell you if your amp is operating within limits. If it operates within limits and sounds good do you really care what its performance is with square waves, absolute power output etc?
As for money. You can, with careful shopping build a nice tube amp for under $200. But you need to decide a few things like how much power you really need etc.
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