Class D Amp Photo Gallery

My Class D amplifier.

An Iraudamp1 derivative. Onboard bias regulator, low side current sensing, adjustable osc freq., adjustable trip current. All through hole components.

Power supply: +-35VDC to +-75VDC (25A), 12VAC (2A) aux supply

1 Pair IRF(x)4227/ IRFB4127
IR2110/IRS2110/FAN7392
HEF4069
LF356N/TL071
PCB Size 3 x 4.7"
T157-2

Power measurements to follow.

You selling this on ebay :p
JLAMP1000D 500W RMS 4OHMS Class D Amplifier PCB | eBay
 
Peerless is not expensive in Denmark the 12" XXLS 4 Ohm Alu is approx 270 US dollar (a cheaper alternative is 150 US dollar). A 12" JL Audio 12W0v3-4 is 220 US dollar

Hi Kjeldsen

Yes, you are correct saying that in Denmark its cheap, also if I buy a Peerless subwoofer anywhere overseas, shipping costs are almost near the price of a JL Audio W6V3 woofer also note the tax duty on the import is not handled by the supplier so I the buyer needs to handle that as well...

do you know of any cheap places that offer Peerless with cheap shipping ?

The main question is does the W6V3 outperform ANY Peerless woofer i think so just glancing over the construction i do feel the JL Audio is a winner even for home audio.
 
A small 2x100 watt amp I have built for my HGV. I work away slot and wanted something that sounds good for when I work away. Plugs directly into the 24v cigarette socket rated at 20amp so plentiful power available. Sounds great through a pair of celestion 6ohm speakers. Amp is a Sure Electronics module costing 15 quid off eBay
An externally hosted image should be here but it was not working when we last tested it.
 
Following up on yesterdays posts, here is the little amp working in the truck. It's certainly not audiophile but does pack a punch thru celestion KR10 lightweight pa speaker's and is ideal for getting good sound 60m into the air as I spend most of the day working on windfarm turbine blades. So simple yet very effective with surprisingly powerful sounds. Enjoy
IMAG0888_zps90a3fe55.jpg
 
Did you do any measurements on those modifications?

I actually can't understand why someone is changing caps "just because". Whats wrong with this SMD-Type caps?

Don't get me wrong, i'm just asking to understand why someone, or in this case you, changed this.

Circuit design/improvement is alot more than just changing some caps/inductors and "sure electronics" are doing a good job on this.

:) Cheers
 
My ears were my guide, the amp now makes the sounds beautifully, that's enough for me. I bought two of those and made the changes only on one, and always compared the one to th other during improving.

SMD electrolytic caps and other passive SMD parts are not thought to be as good as regular ones. Also, I added some capacitance and their voltage is now 63V, and not 50V as before. Just look at the boards on PE website - the 220uF caps are all regular, I got one of the boards with SMD 220uFs.
 
SMD electrolytic caps and other passive SMD parts are not thought to be as good as regular ones.

:snoopy:

Wow dude! Who told you that? SMD caps and "regulars" are made the same way. They just differ from the connections. SMD passives have alot less inductance, thanks to the missing connection-legs. So ESL is a way lower.

If you want "better" electrolytic, go for "solid-polymer". -> Super low ESR, highest ripple current rating, super long life. You could also go for massive parallel MLCC ceramics. (Which have some other disadvantages)

Business | Industrial Devices | Products | Passive & Electromechanical

But well then, if your ears like it - go for it. ;)
 
Did you do any measurements on those modifications?

I actually can't understand why someone is changing caps "just because". Whats wrong with this SMD-Type caps?

Don't get me wrong, i'm just asking to understand why someone, or in this case you, changed this.

Circuit design/improvement is alot more than just changing some caps/inductors and "sure electronics" are doing a good job on this.

:) Cheers
I find this practice a re-occurring theme for many DIY'ers. The perceived improvement by changing components is either anecdotal, or subjective. I find very few who offer any kind of metrics to substantial their claims. But then there's this whole school of thought that pit specifications against the sound that you hear - often concluding the two have no absolutely no bearing on each other. There are entire threads that support these theories. But, I've quit trying to argue either way, and look at any component level change with a very skeptical eye - realizing that no serious double-blind testing was ever done, and hence the conclusion of the observation is flawed from the beginning. I think someone aptly called it 'expectation bias'. :)
 
I just wonder about so many "misleading" informations around. I mean, there is a difference between i.e. MKP & MKS capacitors - they made differently. :) But the question is always, will the different params affect my needs in the right way.

I actually call it "there is a problem for every/any solution" as nowadays everyone is trying to sell "problems".

OT: For the blind test - some weeks ago a couple of guys and me speculated about different "cable-sounds" and we simulated alot of params which lead to cause this. Well, cables sound "different" BUT the problem mostly is not the cable, it's the outputstages/prestages/bufferstages/inputstages which causes the variation in sound as they are mostly balanced and/or calculated to a specific cable in the test-rig. At the final stage we went into alot of mathematics and complex cable models. Conclusion: A significant improvent can be done with an active ground-driver.. i.e. via jfet-circuit when there is no way to change the interface at all.

But thats a way to offtopic to this thread.

Cheers
 
:snoopy:

Wow dude! Who told you that? SMD caps and "regulars" are made the same way. They just differ from the connections. SMD passives have alot less inductance, thanks to the missing connection-legs. So ESL is a way lower.

If you want "better" electrolytic, go for "solid-polymer". -> Super low ESR, highest ripple current rating, super long life. You could also go for massive parallel MLCC ceramics. (Which have some other disadvantages)

Business | Industrial Devices | Products | Passive & Electromechanical

But well then, if your ears like it - go for it. ;)

I am not an expert. I just followed Trevor's advice and replaced the SMD caps and resistors in the input and output stages of the TDA7498. I replaced the 220uF/50V SMD electrolitics with 470uF ones I just had at hand. I am not in position to discuss the rest of your comments.