Yes, I agree - the boards are the cheap bit.
I would definitely have a look at RS Components - you can buy nice semiconductors there, and they stock Fischer Elektronic heatsinks (like this: SK90). The 100mm length is 0.6 K/W and works well and looks nice.
I have had a slightly bad experience with an RS branded transformer, so I get my transformers custom made nearby. I don't think where I get mine from is possible for you. 🙂
I would definitely have a look at RS Components - you can buy nice semiconductors there, and they stock Fischer Elektronic heatsinks (like this: SK90). The 100mm length is 0.6 K/W and works well and looks nice.
I have had a slightly bad experience with an RS branded transformer, so I get my transformers custom made nearby. I don't think where I get mine from is possible for you. 🙂
When it comes to enclosure and heatsinks (and sometimes even power supply) it can be cost effective to buy an odd PA amplifier to recycle
Jean Hiraga's Le Monstre is a great amp, very easy to build. Kits are available on eBay and you can substitute some of the components if you like. In particular, the choice of output transistors to replace the original obsolete Toshibas is well-debated in this forum.
You might want to the check out the Class A Amplifier site and read through the articles there. They cover JLH, Hiraga and other classic designs. The Class-A Amplifier Site
One thing to keep in mind with all these amps is big heatsinks are crucial for stability and to avoid thermal runaway.
You might want to the check out the Class A Amplifier site and read through the articles there. They cover JLH, Hiraga and other classic designs. The Class-A Amplifier Site
One thing to keep in mind with all these amps is big heatsinks are crucial for stability and to avoid thermal runaway.
I second ScottJoplin's recommendation to use SMPS for Class A amps.
They benefit a LOT more than the usual Class B amps from a regulated PSU. They have to be very large on a Class A amp so SMPS is definitely indicated.
On the other sound details, I favour the JLH variants .. especially Rod Elliot's DoZ.
I used to sneer at these but having done a detailed THD analysis of this iconic circuit, I'm very impressed.
It really will sound like a first class valve amp.
Practically all the other Class A amps either ...
Just a bit smaller than what you want ... but 3dB is only 22.5 degrees on the usual volume control 🙂
They benefit a LOT more than the usual Class B amps from a regulated PSU. They have to be very large on a Class A amp so SMPS is definitely indicated.
On the other sound details, I favour the JLH variants .. especially Rod Elliot's DoZ.
I used to sneer at these but having done a detailed THD analysis of this iconic circuit, I'm very impressed.
It really will sound like a first class valve amp.
Practically all the other Class A amps either ...
- attempt to make a Class A amp sound like a Class B transistor amp ... lower THD bla bla
OR - don't have such a nice THD / overload profile
Just a bit smaller than what you want ... but 3dB is only 22.5 degrees on the usual volume control 🙂
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I agree. I'm also a class-A guy, but I can't deny my IcePower Class-D is an excellent amp, especially when the speaker is vintage. With modern speakers, it tends to sound sterile.
Personally, I think PP or SE is more important than Class A or AB. If the amp is PP, I don't really hear much difference between Class A and AB, probably because I simply prefer the sound of SE. 😛
Is there an active used audio equipment website in your area?
A used John Curl designed Parasound amp would produce excellent sound, with excellent re-sale. Even brands like Emotiva use excellent circuits, and get consistent good reviews.
I enjoyed building amps when I could use the machine shop at work, but hand tools is a tough road to greatness.
Pass A40 was the best thing I ever heard that seems to fit your request. I see many others listed too that would knock your socks off...JHL and others. These are old school classic that will not let you down. Cheers and happy hunting!
What do reckon scott? Had this kam kxr1000 laying around. Cant believe this is 500wrms per channel those heatsinks look tiny, nice idea on the fan blowing air through.
The Power Supply looks MASSIVE, could i steal and use parts from here i wonder?
I just want to build a Class A Amplifier Victoriaguy. I'm happy to choose and build any amp design. I'm only chose my list based on reading forums and articles and popular choices of builds.
The enclosure and heatsink i will machine and build myself, i've got an idea on what i want machines and how i want it to look.
Power supply i'm hoping i can use one i have from an old PA amplifier for the moment. Or ill just build one from scratch and source the correct components.
Preamp is whats throwing me off, this is something i am still learning about.
I was hoping i could just directly connect either my ipad, cd player and minidisc straight into it?
I am reading, researching and looking over so many types of builds, schematics etc.
The enclosure and heatsink i will machine and build myself, i've got an idea on what i want machines and how i want it to look.
Power supply i'm hoping i can use one i have from an old PA amplifier for the moment. Or ill just build one from scratch and source the correct components.
Preamp is whats throwing me off, this is something i am still learning about.
I was hoping i could just directly connect either my ipad, cd player and minidisc straight into it?
I am reading, researching and looking over so many types of builds, schematics etc.
Thanks for the link to your thread, now that was an interesting read. I initially thought i could build the amp and because it has RCA connectors i could just connect my ipad to it and hey presto music will come through.
hhhhmmm i will look more into detail for preamp, especially if i want it built into my amp. Or easier to buy a separate unit, although i like the idea of having a built in volume control.
hhhhmmm i will look more into detail for preamp, especially if i want it built into my amp. Or easier to buy a separate unit, although i like the idea of having a built in volume control.
Le Classe A - DIY Jean Hiraga Super 30W Class A Amplifier
Good thread on this gentleman's build.
i am thinking of ordering from Jimsaudio, although he has two types of boards:
Hiraga super 30W class A w/ current source + kubota reg partial assembled kit ! | eBay
Hiraga super 30W class A amplifier kit ! | eBay
Which one should i go for?
Good thread on this gentleman's build.
i am thinking of ordering from Jimsaudio, although he has two types of boards:
Hiraga super 30W class A w/ current source + kubota reg partial assembled kit ! | eBay
Hiraga super 30W class A amplifier kit ! | eBay
Which one should i go for?
That transformer will probably be too high a voltage.
You'll find you won't need a preamp with the Hiraga, a 10k pot on the input will do, buffered if you want to improve it
You'll find you won't need a preamp with the Hiraga, a 10k pot on the input will do, buffered if you want to improve it
🙂 That was my (not-well-thought-out) thought as well. Music did come through- no problem with that, but it wasn't loud enough for me - and I don't play music very loud, usually.
BTW, I'm not sure about the iPad, but I've heard that iPhones have only about half the output (voltage) of a CD player - something to keep in mind if you are going to be in the 'just enough' gain area.
Not an issue if you will be using a preamp with reasonable gain.
It sounds like you have a couple of power amps right now.
One idea would be to focus on a preamp project first -whether simple or complex is your decision. Preamps don't need those 'big' power supplies and heatsinks that are needed to heat up the listening room with a Class A amp, which can help to keep down the weight and cost.
BTW, I'm 'with you' on the 'integrated amplifier' idea - volume (and balance) control is very handy, in the same box with the power amplifier. I'm coming around to the idea of a 'power only' amp with a separate preamp, but slowly.
Lots of choices, for sure. I started on the Class A idea thinking only about the Pass designs, now I'm reading more about Hiraga and JLH, etc.
That's great. You will save money (shipping heavy heatsinks can get expensive) and have something unique.
Also, some of the popular cases with heatsinks aren't as sturdy as they look in the pictures, from what I've heard from a couple of online (email) friends.
I collected a few (bargain) receivers hoping to use the transformers and other parts. Problems:
1) I hate to scrap something that works 🙂
2) Most of the receivers seem to use either chips (STK) or Darlington outputs and have higher voltage rails (+/- 50-60 volts) than the Class A designs I've found.
3) Heatsinks still needed - I got one bargain receiver that has 5 channels @ 100 wpc and the heatsinks will be about big enough for an Amp Camp Amp.🙂
Reading is a lot cheaper than buying (the wrong) parts!!😀
For me, some ideas are gradually sinking in, but I still have thousands and thousands of posts as possible reading...great insomnia cure.😀
Re: preamps - Some of the power amps do have enough gain to just use a volume control between your source (CDP/iPad) and the amp, especially if you are using sensitive speakers. For me, the 'dividing line' for a preamp would be somewhere around 20-25dB of gain in the power amp. Other folks are happy with 15dB, using sensitive speakers.
Used to be the norm, then integrated amps became the new thing for the new modern high tech 1970's 🙄
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