Class D Amplifiers

[keith_correa]

Listened to Iron Maiden, Deep Purple. Sounds sexy.

As mentioned before, this amp is great in sweetening the mids, positioning of the instruments, spot on.

The transient peaks an decay, worthy rival to tube amps.

What it lacks I find is in slam & width of sound stage.Depth is now palpable but I've not been able to expand the sound stage.:sad:

Donno if it is the speaker prob?

Amp may need to be burned in - if you believe that.

 

[captrajesh]

Amp may need to be burned in - if you believe that.

Donno how much of burning in is required.

For the slam, I've read that the PassDIY B1 Buffer pre amp will do wonders with their JFETS. I'm planning to get the kit. Lets see.

Edit:
One good news, one not so good news & one bad news.

Good news first, the toroid has arrived.

Not so good news: It weighs 4.1 kg:indifferent14:

Now the bad news: It doesn't provide a -35 tap. So I cant use it for this amp.:annoyed:

And the whole point to get is: I'm myself to blame.

I mentioned that I need 35V @ secondary, I should've said 35-0-35 @ secondary.

Don't know what to do with it now.

 

[borg]

One good news, one not so good news & one bad news.

Good news first, the toroid has arrived.

Not so good news: It weighs 4.1 kg:indifferent14:

Now the bad news: It doesn't provide a -35 tap. So I cant use it for this amp.:annoyed:

And the whole point to get is: I'm myself to blame.

I mentioned that I need 35V @ secondary, I should've said 35-0-35 @ secondary.

Don't know what to do with it now.

you can change the rectifier to a bridge type and use the tfr, get a bridge rectifier module or use discrete diodes

 

[captrajesh]

you can change the rectifier to a bridge type and use the tfr, get a bridge rectifier module or use discrete diodes

Hi Borg

Thanks but the power supply already has a bridge rectifier. It has three pins, one each for +35, 0 & -35 which lead to the bridge rectifier and the caps.

Someone suggested that the tranny can be used for Class A amp as it doesn't need -35 tap. Is this true?

 

[gobble]

I thought EIs are bulkier and heavier than Toroids ...

Hmmm check with the electronics experts , I have no clue about what kind of acrobatics will make it useable ...

 

[borg]

Hi Borg

Thanks but the power supply already has a bridge rectifier. It has three pins, one each for +35, 0 & -35 which lead to the bridge rectifier and the caps.

Someone suggested that the tranny can be used for Class A amp as it doesn't need -35 tap. Is this true?

Oh, you need a dual supply, that also possible with this by using a doubler configuration, will have to use bigger caps to reduce ripple. you should be able to find the schematic on net

I thought EIs are bulkier and heavier than Toroids ...

Hmmm check with the electronics experts , I have no clue about what kind of acrobatics will make it useable ...

Toroid shape is one of the most electromagnetically efficient shape to make a tfr, the core material available is the best grade (min losses) so it should be possible to make a lighter tfr ,if it is heavier it the EI and toroid may not be of equivalent specs

 

[mathewsyriac]

Toroid shape is one of the most electromagnetically efficient shape to make a tfr, the core material available is the best grade (min losses) so it should be possible to make a lighter tfr ,if it is heavier it the EI and toroid may not be of equivalent specs

Even i think the transformer is overweighted...
My toroidal is a 20 amps 22-0-22 config. It weighs around 5 kg only..
3000+ rupees is also very high for this spec.
In this case its only a 0.4 amps 35v transformer
In your case center tap is a must.. or else, u may face grounding issues.

Don't worry sir, thats all in the game...
I know how much money i have burnt while i was designing my 8-channel amp for my X-fi Platinum Sound Card
So, many IC's blowed up, redesigned and fabricated PCB's hell a lot of times due to ground looping issues.
All this u must consider as a thrill; in the end one day u'll be like :yahoo::yahoo:

 

[captrajesh]

Oh, you need a dual supply, that also possible with this by using a doubler configuration, will have to use bigger caps to reduce ripple. you should be able to find the schematic on net

Thank you very much for the info Borg, will check that out.
Edit:
Checked with Miracle guys, they are suggesting that I connect the +35 lead parallelly to the +35 / -35 terminals of the power supply and connect the '0' tap to the neutral.

Any DIY masters help me please:sos:

Hope Cranky was around.

 

[pragyapriya]

Hi!
In class D, D stands for Dusty Vawter groused.It is actually an analog switching amplifier that modulate the output of the digital input..

 

[keith_correa]

Hi!
In class D, D stands for Dusty Vawter groused.It is actually an analog switching amplifier that modulate the output of the digital input..

Dusty Vawter is the name of the person that owns Channel Islands Audio. "Dusty Vawter groused" means "Dusty Vawter grumbled". In context of the Stereophile article which mentions "Dusty Vawter groused", Dusty was grumbling to the author of that article that the D in Class D did not mean Digital.
The D in Class D does not stand for the D in Dusty if that is indeed what you are thinking :lol:

 

[captrajesh]

I see this thread has gone quiet. I've heard of a couple of members trying to source the amp kits. Any progress?

 

[grubyhalo]

I see this thread has gone quiet. I've heard of a couple of members trying to source the amp kits. Any progress?

Hey Cap! Any luck with the mods on your Class D?

 

[santhosh]

Hey Cap! Any luck with the mods on your Class D?

Why should mods have a problem with class D amps? Are they banned?

 

[grubyhalo]

Ha ha ha! I meant modifications we were discussing for his class D amplifier.

 

[iaudio]

Santhosh,Lol, I think DIY has amplified your witticism too!

 

[captrajesh]

Any luck with the mods on your Class D?

Hey Richie,

Sorry, didn't see the post earlier. No mods yet. Been a bit busy of late. Hope I find some free time.

Rgds


Rajesh

 

[grubyhalo]

Hey Richie,

Sorry, didn't see the post earlier. No mods yet. Been a bit busy of late. Hope I find some free time.

Rgds


Rajesh

No worries at all. Yeah, I know how that goes, good luck...

 

[captrajesh]

Reviving an old thread. I re-visited the amp and mated it to my AP PM1 to drive both AP MS101 and the Cadence Aristas. The class D amp is such seductive midrange and beaten the AP AM1 Power amp so hollow on that account that I want to see how it fares vis-a-vis a tube amp. Looking forward Rajiv. Ball is in your court.

Will come back & tie up with Bala & Rajiv to see how this amp fares with their speakers.

Looking forward to it.