Well my short problem came back on the amplifier I thought I had fixed. And I even got some smoke from Q1 - I'll have to tear that side of the amp apart to see where I messed up. And I ordered another pair of IRFP240s. Funny that the first amp has been problematic while the second works perfectly.
kstagger,
Post some pics (close up) of the misbehaving amp and also your working amp for comparison sake if you like. I am a bit surprised if this all came about from a pin hole crack or break in the thermal insulators. The insulators should be comfortably oversized compared to the MOSFETS themselves, and only the thin rubbery pink stuff (no brown backing). Make sure there aren’t any shorts between the MOSFET pins.
Best,
Anand.
Post some pics (close up) of the misbehaving amp and also your working amp for comparison sake if you like. I am a bit surprised if this all came about from a pin hole crack or break in the thermal insulators. The insulators should be comfortably oversized compared to the MOSFETS themselves, and only the thin rubbery pink stuff (no brown backing). Make sure there aren’t any shorts between the MOSFET pins.
Best,
Anand.
I think it looks great!!! I have seen some companies do the stereo / mono with ´groupings´, I think it looks a bit cleaner and its much more intuitive, you get it all by one look instead of reading each block of text.
Also, is there a chance to center the DC label?
Something like this (sorry if this is unasked for intrusion!):
Anyways, I think yours is just as good and it will certainly give it an extra nice touch!
Best regards,
Rafa.
I was going to suggest the exact same thing but was too lazy to draw. hahahah
Additionally, I'd circle the word mono, and also circle the mono binding posts + and - signs.
halitun, how do you like the Aikido with the ACA as far as the gain is concerned? Do you find you're limited on the volume control at all?
Reason I ask is I've had a 9 pin Aikido pcb with the PS-1 kit sitting around for a couple years unbuilt. I kind of went another direction with my audio and can't decide whether to build the Aikido or sell the parts.
I've always liked the idea of having panels engraved with graphics. For one, it just looks classy if done well. It also makes it easier to restore should anything bad happen later.
As a long-time restorer of vintage radio gear I can recall quite a few instances where a successful complete restoration of a given (not-too-valuable) "boatanchor" would hinge on whether or not the panel was engraved, rather than simply silkscreened. Collins R-390As were particularly vexing in that regard; some front panels were etched and some weren't, depending on the firm doing the actual manufacturing.
If you can do it, I say go for it!
As a long-time restorer of vintage radio gear I can recall quite a few instances where a successful complete restoration of a given (not-too-valuable) "boatanchor" would hinge on whether or not the panel was engraved, rather than simply silkscreened. Collins R-390As were particularly vexing in that regard; some front panels were etched and some weren't, depending on the firm doing the actual manufacturing.
If you can do it, I say go for it!
I hesitated about this myself... maybe if the engraving device can do 'colors' these 'mono' sections could be engraved in a different color? Red contrasts nicely with black.
I don't like the circle idea that much. I think it is clear enough with the 'siding' of the + and -, so I would avoid the circle.
I've been listening to my new amps this week and they just sound sweeter and sweeter.
My preamp is a Schitt Freya with three modes - passive, JFET buffer and a tube gain stage. The specs on the Freya state the tube gain is 5 or 14db.
One thing that I've noticed is that I seem to enjoy music much more on the JFET buffer mode. When I had the preamp hooked up to a class D amp I enjoyed it much more with the tube gain.
Perhaps the tube gain of 5 / 14db is too high or just a mismatch for the amp? The highs seem a bit broken up and the bass isn't as present and full. I did order some NOS tubes to try out.
These amps just sound so damn good compared to my class D's I had before. I'm repeatedly blown away listening to different music and how good it sounds.
My preamp is a Schitt Freya with three modes - passive, JFET buffer and a tube gain stage. The specs on the Freya state the tube gain is 5 or 14db.
One thing that I've noticed is that I seem to enjoy music much more on the JFET buffer mode. When I had the preamp hooked up to a class D amp I enjoyed it much more with the tube gain.
Perhaps the tube gain of 5 / 14db is too high or just a mismatch for the amp? The highs seem a bit broken up and the bass isn't as present and full. I did order some NOS tubes to try out.
These amps just sound so damn good compared to my class D's I had before. I'm repeatedly blown away listening to different music and how good it sounds.
Hi Bloozestringer, The Aikido preamps and power supplies are great! I've built several of them. One thing I've learned is to use a chassis with plenty of space so that you can more easily avoid introducing secondary power supply hum. Also, the low voltage designs he has are super easy because then you use an external PS brick. Of course, trying different tubes also is fun and will result in finding the best sound. I highly recommend them and the two that I've tried with the ACA have been perfect. No limit on volume - I have the 20k A3 stepped attenuator in the 5687 (also from tubeCAD). My 5687 based Aikido is my best build because it uses the PS-1 which has the regulated high voltage supply as well as the regulated heater supply and the A3 attenuator helps too. The combo of the PS-1 and Aikido pre makes a very low noise preamp. You won't be disappointed. I'm really enjoying the Tube pre-amp with the solid state ACA power amp combo.
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I’ve wondered how the Schiit preamps would sound with the ACA. I bought a Saga a while ago, but returned it because I couldn’t stand the volume clicking. If I could get past that, I’d be tempted to try Freya balanced into a pair of ACAs.
Thank you guys! Rafa made a great step and the others finished it. Unfortunately I only have the laser etching the anodized layer. It will turn white. I will try to adjust the back panel using simple signs.
I also need to wait until the kit arrives to measure al the components to see how much space I really have to center and space text and graphics.
I also need to wait until the kit arrives to measure al the components to see how much space I really have to center and space text and graphics.
Yet another noob into the dark art of class A
Hello everyone!
I have just got delivered my ACA 1.6 and boy i am quite exited!
For me this is like a dream come true. Since 2000 that i read about class A power amps and dream about building one for me.
2 things have prevented this: first i was unable to afford the parts needed nor the cash/expertise to have decent speakers.
As a portuguese that worked hard all time but never knew how to do to have a decent salary, i just kept this love on the back all these years. the other thing is that i have rudimentary electronics knowledge so i always been afraid to tackle this kind of quest.
Now, after changing to another country and getting the chance to improve my life, i finally am able to afford buying a kit and dream about some decent speakers after it.
Not a lot of cash available but just the right to start toreach for my 18 year old dream.
So now, with this amazing kit in hand and the courage to tackle this project, i am going to do my best to achieve my goal - have my 1st class A amp and from Mr Pass brain
Probably i will be making a lot of rudimentary and stupid questions but i will try my best, i will try to learn as i go and have this done and working like i dream about.
Hello everyone!
I have just got delivered my ACA 1.6 and boy i am quite exited!
For me this is like a dream come true. Since 2000 that i read about class A power amps and dream about building one for me.
2 things have prevented this: first i was unable to afford the parts needed nor the cash/expertise to have decent speakers.
As a portuguese that worked hard all time but never knew how to do to have a decent salary, i just kept this love on the back all these years. the other thing is that i have rudimentary electronics knowledge so i always been afraid to tackle this kind of quest.
Now, after changing to another country and getting the chance to improve my life, i finally am able to afford buying a kit and dream about some decent speakers after it.
Not a lot of cash available but just the right to start toreach for my 18 year old dream.
So now, with this amazing kit in hand and the courage to tackle this project, i am going to do my best to achieve my goal - have my 1st class A amp and from Mr Pass brain
Probably i will be making a lot of rudimentary and stupid questions but i will try my best, i will try to learn as i go and have this done and working like i dream about.
