Lets have it the Class A way

[omishra]

Congrats :clapping:

Oh yes, i didnt think of that
saves you the running cost of a heater ! and we get excellent quality amplification alongside :clapping:

Now I am facing it just warm while ambiance is 20 deg C here. But over the heatsink you can melt coconut oil to be applied to scalp.

 

[pranavkumar]

Congrats :clapping:


Now I am facing it just warm while ambiance is 20 deg C here. But over the heatsink you can melt coconut oil to be applied to scalp.

Easily easily !
in hotter places like Delhi.. it could replace a Toaster

 

[pranavkumar]

Finally, i procured the power supply capacitors today !
Somehow the electronics market didnt have 10,000uF caps. So i got 12,000uF, the bigger the better

Just the transformers left now.

and this :

 

[kaushik]

Indeed they do get really hot !
yup, i might just put a Cooler Master CPU fan at the outside to shoo away all the heat !

the tiny winy water coolers are silent and compact some work here My 8Kg water cooling 75W Class A Mono block - diyAudio

Making some thing in class A , but cooler.

 

[heliumflight]

the tiny winy water coolers are silent and compact some work here My 8Kg water cooling 75W Class A Mono block - diyAudio

Making some thing in class A , but cooler.

The green fluid makes me think of Hulk.

 

[pranavkumar]

the tiny winy water coolers are silent and compact some work here My 8Kg water cooling 75W Class A Mono block - diyAudio

Making some thing in class A , but cooler.

Brilliant built !
Lets see how "dry" heat dissipation works first

 

[Thad E Ginathom]

Amazed by that water cooling.

 

[pranavkumar]

After a busy busy month, i finally completed the two channels and got the transformers.
Listening to the amp on my DIY 2 way speakers (4" Goldwood driver and TangBand Tweeters) in different setups, with different sources, was a pleasureful experience.

The Amplifier case is what is up as of now, here are some pics of the bare frame.

With the top, back and front panels designed, just waiting for the milling machine guy to do the work.

Cheers!

 

[pranavkumar]

And after about a month, the stuff's getting all put together!
With the black powder coating done, it'll all about nuts and bolts now.

Here's what is up!

Cheers!

 

[pranavkumar]

After today's work!

With the PSU's mounted, all that needs to go is the amplifier board itself!
Stay tuned.
Cheers!

 

[pranavkumar]

As time progresses, more and more work is done!.
Here are some pictures of the amp when it was being biased.

The Input Wires being wound by my handy bosch screwdriver!

Temporary arrangement for mounting the I/O connectors.

All Wired UP!

Biasing Time!

 

[diesel engine]

Pranav,

I am inexperienced, pardon my simple question. Is 10,000uF too low for Class A operation?

Thanks
Balaji

Hi Balaji,
Calculate the required capacitance Like this:
Suppose your amp consumes 5A @60V at full load.
then the impdance is 60/5=12 Ohm
The reactance of the capacitor at 120Hz (Full wave ripple frequency) should be one tenth of load impedance. ie, 1.2 Ohms.
This can be calculated From the formula Xc=1/2xPi x f x C
ie, 1.2= 1
____________
2x 3.14 x 100 x C
Value of C is what you should calculate.
add anything around 25% as a margin.

do some maths and have fun:licklips:

 

[diesel engine]

Still, I wonder why people are behind these power burning monsters of Class A amps since one can make better performance with a good design of Class AB amp? I dont see any significant advantage with Class A.

 

[anilva]

Still, I wonder why people are behind these power burning monsters of Class A amps since one can make better performance with a good design of Class AB amp? I dont see any significant advantage with Class A.

Many have wondered before about this question. But if you have a good Class A amp like Nelson's you will understand what is the difference between Class A and AB. I hope you had a chance to listen to Pass Amps.

 

[pranavkumar]

Many have wondered before about this question. But if you have a good Class A amp like Nelson's you will understand what is the difference between Class A and AB. I hope you had a chance to listen to Pass Amps.

i agree totally.
Although the F5 is class A only till a first few watts, but never the less. It Sound wonderful!

And if you are thinking about being environmentally friendly, then why stop at Class AB? Class D's are really good sounding too.

But then, Class A's have a character of their own, i feel.

 

[diesel engine]

i agree totally.
Although the F5 is class A only till a first few watts, but never the less. It Sound wonderful!

And if you are thinking about being environmentally friendly, then why stop at Class AB? Class D's are really good sounding too.

But then, Class A's have a character of their own, i feel.

I did not mean to hurt any feelings. my point is, the money invested in the huge heatsinks, big trafos and the power it wastes dosent' justify Class A's performance. I have listened to Nelson and other Class As. with good drivers, well designed spkr enclosers, good Class AB amps give better listening experience at very redused investment. (and I am not a sworn enemy of ClassA)

 

[anilva]

I did not mean to hurt any feelings. my point is, the money invested in the huge heatsinks, big trafos and the power it wastes dosent' justify Class A's performance. I have listened to Nelson and other Class As. with good drivers, well designed spkr enclosers, good Class AB amps give better listening experience at very redused investment. (and I am not a sworn enemy of ClassA)

If you have listened to the Pass amps and feel some good Class AB amps are better then you must be in the minority or the Class AB amps are really top class ones. However everyone is entitled to his own opinion and buying preferences.

If one were to bring money into the picture, people have blown way more money on other paraphernalia compared to amps in pursuit of good sound. Amount of money one spends on DIY of Class A amp particularly F5 will be lower than a decent NAD amp. Money cannot be the reason here.

 

[pranavkumar]

I did not mean to hurt any feelings.

not at all, we are just putting our views and maybe learn a few things here.

Every amp has a character of its own, be it a class A, B, AB, D or T.
Hi-Fi amps are designed to give the most linear frequency response. But then the design and the kind of components used play a vital role.

Its true that Class A requires a rather large investment and probably has more maintenance costs. No doubts about that.

If one were to bring money into the picture, people have blown way more money on other paraphernalia compared to amps in pursuit of good sound. Amount of money one spends on DIY of Class A amp particularly F5 will be lower than a decent NAD amp. Money cannot be the reason here.

yes, a brand would definitely cost a bomb. But DIY efforts are not exactly cheap either (if one goes for highest possible components/HW and stuff).

 

[Staxxx]

Personally I have owned both Class A and Class AB amps too. I have had terrible Class A amps that have just not made for a good system and I have had pretty good ones to...but the same with AB. I agree a little with Deisel Engine that a blanket recommendation of Class A amps is not really correct.
I initially thought my current amp was Class AB but apparently it is a Class A amp (300 watts per channel into 8 Ohms, 600 into 4 and 1200 into 2) with a regulated (sliding) bias control. It therefore has the power consumption closer to that of a Class AB amp apparently. One of the other reviewers stated it as being Class AB. So not sure which, but regardless IMO it is the best amp I have had in comparison with the various Class A (and AB amps) that I have previously owned.

Your project however looks very interesting and I am following eagerly. Regards

 

[pranavkumar]

A blanket recommendation of Class A amps is not really correct.
Your project however looks very interesting and I am following eagerly. Regards

I agree, no one should just buy an amplifier for the very reason that its class A or any other for that matter.
The very sound that it produces should be the concern.

And thanks! Stay tuned.. more pictures coming in this week!