Hi Anand,
Good description from X.
The global feedback of the ALPHA is set by R123 to R126, and is 15, (330k/22k) which is 23.5dB. You can alter R123 to set the global feedback with little change to the DC conditions. However, you will change dynamic parameters, particularly damping factor/Zout.
Changing feedback in audio amps goes to the heart of the design. You are changing blood pressure and pulse, with diverse effects, particularly compensation/stability. You need to be aware of this!
Hugh
Good description from X.
The global feedback of the ALPHA is set by R123 to R126, and is 15, (330k/22k) which is 23.5dB. You can alter R123 to set the global feedback with little change to the DC conditions. However, you will change dynamic parameters, particularly damping factor/Zout.
Changing feedback in audio amps goes to the heart of the design. You are changing blood pressure and pulse, with diverse effects, particularly compensation/stability. You need to be aware of this!
Hugh
Last edited:
This build is now on the table, going to start ordering parts. I have the PCBs for a dual mono and just ordered two Antek 400VA 22V trannies. I have a case on the way (the one with the isolation between sides. I have 2 SLB boards here too.
I'm stoked!
JT
I'm stoked!
JT
Quality is remembered long after the cost is paid........
DIY is always more expensive than buying from China - this is a fact which is destroying most western manufacturing. Be assured your amp will be the best you have ever built, and likely the best you've ever heard.
Hugh
DIY is always more expensive than buying from China - this is a fact which is destroying most western manufacturing. Be assured your amp will be the best you have ever built, and likely the best you've ever heard.
Hugh
I completely agree with you AKSA! I also wish I could find some less expensive chassis not made in China...
I started my audio DIY adventure because the lab I used to work at had a lot of older/unused components laying around which I tried put together into something that sounded good. I thought I would be able to build something cheaper/better than something off the shelf. Learned that it 100% won't be cheaper but will sound just as good if not better!
I started my audio DIY adventure because the lab I used to work at had a lot of older/unused components laying around which I tried put together into something that sounded good. I thought I would be able to build something cheaper/better than something off the shelf. Learned that it 100% won't be cheaper but will sound just as good if not better!
The BOM for Alpha Nirvana is actually very reasonable and probably much less than other amps of the same class and category. Note that no rare unobtanium unicorn dust parts are used. IIRC, the BOM for one channel was like $45.
But the amp is usually the little guy and big hitters are the chassis and PSU. We are trying to help there by having a cap Mx that avoids 8 big bulk caps.
But the amp is usually the little guy and big hitters are the chassis and PSU. We are trying to help there by having a cap Mx that avoids 8 big bulk caps.
Wow, okay, it's going to cost about $1k to build the DM version. (with all the bells and goodies, case 2 SMBs) Ya, know I typed a book,(then deleted it) but suffice it to say, I don't appreciate the defensiveness.Ya might want to review previous posts before you talk/comment without reference. Please refrain form knee/jerk comments without knowing the person you are talking too.
JT
JT
Last edited:
Or mine?
Your response seems a bit extreme; no one was taking a pot shot at you, but rather at defending the cost of building a very high quality Class A, which by definition is always expensive, particularly in power supplies and heatsinks.
No one is holding a gun to you, TT, you are not obliged to build it. Heck, I have a mate with very little money who just bought a $20k speaker, it really depends on what you consider value. Every five years some people buy a $100k Benz, and people regularly buy $1M homes, not to mention travel.......
I really don't get it. I have spent half a million dollars developing amps over the last 25 years and while it's not for everyone, it's been a blast and I consider it good value. I've learned a lot, kept a lot of people happy, and found satisfaction in the design experience. And I've got a garden shed full of unused pcbs which will make terrific coffee tables in my dotage........
Hugh
Your response seems a bit extreme; no one was taking a pot shot at you, but rather at defending the cost of building a very high quality Class A, which by definition is always expensive, particularly in power supplies and heatsinks.
No one is holding a gun to you, TT, you are not obliged to build it. Heck, I have a mate with very little money who just bought a $20k speaker, it really depends on what you consider value. Every five years some people buy a $100k Benz, and people regularly buy $1M homes, not to mention travel.......
I really don't get it. I have spent half a million dollars developing amps over the last 25 years and while it's not for everyone, it's been a blast and I consider it good value. I've learned a lot, kept a lot of people happy, and found satisfaction in the design experience. And I've got a garden shed full of unused pcbs which will make terrific coffee tables in my dotage........
Hugh
I am still impressed that people can build their own amps. Man, I look at you guys that do this stuff like gods. No kidding. Its really cool what you guys know and can do.
A Class A amp that you can make and you gets TONS of Support from people to help you build it? Man... Is there a Better time to be living or what!
Now... I have to admit. Some of you Smart dudes are sort of like...Oh... Overly sensitive? I know some of you get passionate about stuff, but.... its just words. Who cares.
About the Budget stuff? I get that Parts can be expensive. But there is always a way around that. If you look into AVionics gear, they use tons of Top end parts, and many times they surplus the stuff. Or old gear that has never been used since they no longer use the parts anymore.
There is always a Way. And I to be honest? MAN... A CLASS A AMP that you can build for cheap with support to build it? That's sort of unheard off from normal folks like me.
Anyways, I'm just glad that folks that make this gear are around and share it. Its really cool!
THank you all! Look forward to start building a cool amps soon.
A Class A amp that you can make and you gets TONS of Support from people to help you build it? Man... Is there a Better time to be living or what!
Now... I have to admit. Some of you Smart dudes are sort of like...Oh... Overly sensitive? I know some of you get passionate about stuff, but.... its just words. Who cares.
About the Budget stuff? I get that Parts can be expensive. But there is always a way around that. If you look into AVionics gear, they use tons of Top end parts, and many times they surplus the stuff. Or old gear that has never been used since they no longer use the parts anymore.
There is always a Way. And I to be honest? MAN... A CLASS A AMP that you can build for cheap with support to build it? That's sort of unheard off from normal folks like me.
Anyways, I'm just glad that folks that make this gear are around and share it. Its really cool!
THank you all! Look forward to start building a cool amps soon.
Nah, just a bunch of older gents having a bit of OCD fun with an obsolete technology.......
Gotta do something, can't watch Star Trek all our lives........
Hugh
Gotta do something, can't watch Star Trek all our lives........
Hugh
Funny you should say that, I find it less fun now that I know the dialogue to every series and movie. Well, all except DS9 😀
The fluid is basically distilled water with anti-corrosion, freezing and other additives to inhibit bacteria etc. I think they dye it blue to make it look cool. 🙂 Do a search for replacement options, and yes, you will want a fan, or I would, you can replace the sink as well. They aren't all that expensive, depending on model and name, so don't spend to much mucking with it.
Last edited:
Make sure it's distilled water and add a bit this.
EDIT: THERE IS A WARNING ABOUT ADDING TO SOME TYPES OF FLUID! I would drain it all out and flush it, add distilled and some of the stuff I linked. You don't know what the hell is in there right now.
I'm sure ya know, but on the off chance... Pure water does not conduct... it's the minerals in water that make it conduct. This way, if at some point you get a leak, it won't short out your ****. 🙂
I should say it doesn't conduct well. 😛
Last edited:
CPU coolers with heat pipes never leak and don’t require water changes. It’s fun to play with water cooling but might be messy. Also, that copper block will only hold one MOSFET. Make sure the pump in that copper block is not too noisy.
The radiator can be saved but maybe you might need a new pump/copper block.
The radiator can be saved but maybe you might need a new pump/copper block.