Mar-Kel70 in Sweden

The Sure amp can be improved with modifications, right? Since it's so cheap i might try to modify it if i buy one...

Yep - There's a pretty big thread over at the Class-D forum about this.

(I'd start with China-made types though; They have better components and design, to start with so they give A) better sound straight away, B) more bang for the buck. Modding is fun though :) )
 
Yep - There's a pretty big thread over at the Class-D forum about this.

(I'd start with China-made types though; They have better components and design, to start with so they give A) better sound straight away, B) more bang for the buck. Modding is fun though :) )

So you would not recommend the Sure board?

And what power supply will i need for powering an amp like this?
 
So you would not recommend the Sure board?

And what power supply will i need for powering an amp like this?

Oh, sorry - I would recommend any of these amps, including the Sure, but I would bet on the other types myself. They're just a little more nicely made, you know? Like 30% more nice for 10% more money.

There are very suitable switching supplies for these, for example Meanwell, around 300W. Those you will find links for in the Class-D forum!
 
Oh, sorry - I would recommend any of these amps, including the Sure, but I would bet on the other types myself. They're just a little more nicely made, you know? Like 30% more nice for 10% more money.

There are very suitable switching supplies for these, for example Meanwell, around 300W. Those you will find links for in the Class-D forum!

Thanks. I will take a look at those when i have time to read. Could you possibly link to places i could buy those from?
 
Thanks. I will take a look at those when i have time to read. Could you possibly link to places i could buy those from?

Hmmm ... I'd start by checking lavpris-elektronik.dk. Their switchmode supply page looks like it's full of Meanwells: Strømforsyninger - Switchmode moduler - Elektronik Lavpris ApS

Not all types by Meanwell are equal, but this one looks very similar to the supplies people have been using, ~300W, 27V: SPS Case 315W PFC 27V/11,7A | SP-320-27 - Elektronik Lavpris ApS
 
Sure boards

Hi, actually the Sure is made in China also. The advantage of getting them through PartsExpress would be that they are an excellent vendor and handle returns and exchanges quickly, honorably and efficiently. A great vendor to deal with.

Plus, their price on the Sure is unbeatable. They also sell the accompanying Meanwell 27V power supply for $48... your 4ch amp boards + power supply would cost about $100USD before shipping.

The Meanwell would also work well on the 41Hz amps and has been getting very good comments on diyaudio for the good sound quality.

Yes, power supplies make up a BIG part of the overall sound... I've been using 24V/20A SLA batteries with a marine charger, and more recently have been using a RedWine Audio BlackLightning LFP 25.6V supply, and THAT makes these amps sound incredibly good.


OK, about the frequency response: it's actually quite flat in the audio band (within less than 1/2 dB) and you can extend the bottom end by replacing the crappy input cap for a good quality 2 to 10uF paper in oil, or foil, or whatever good quality cap you choose.

Many people change the caps and obtain big differences in sound according to the type they use... I have a friend who has a multiple selection stereo selector switch with 6 (!!) different types of matched capacitors on each channel so he can pick the sound he likes best according to the music he is playing and his preference of the moment.... pretty wild!

BTW, I just looked at the 41Hz site, and it looks like they are now selling some of their boards pre-assembled (hooray! they heard the voice of popular demand!), and at reasonable prices. Have another look with them, they also have very good sonic reputation!

Judging by your responses, it would seem almost as if you are very suspicious and pre-disposed against class D. Keep an open mind!
While it's true that most of the older and some of the newer classD amps are not audiophile material, SOME of these, like the Sure, 41Hz, Helder... and especially the Virtue amps... are really incredibly good sounding regardless of price. And they probably will push your CSS drivers to unreasonably loud levels, if you so desire. IMO these Tripath amps also sound better than most any Hypex or ICEpower units. And when they are hot-rodded and modded with good quality caps and coils... well, it's amazing.

Now, when you factor in the low, low, low price of entry, and availability of inexpensive but good sounding power supplies, ease of use and so on, you have amps with simply remarkable value. I hope you will actually try some. Your ears and pocketbook may very well thank you for it.

Good luck.
 
Power supplies

The Meanwell SP-320-27 supply you referenced is the 27V version of the 24v unit Parts Express is selling for $48USD

Sure 24 VDC 14.6A 350W Regulated Switching Power Supply

The extra 10% voltage will give you a little more power into 8 Ohms, only about 1.6 db extra headroom.

For $48USD vs $135....I would save the money and get the 24V unit, with these amps it's really the extra current capability that seems to make the most difference.

Enjoy!
 
Well, I am finally starting to assemble cabinets Rullknufs, so maybe in a couple weeks I can let you know how a twin EL70 sounds. Given my experience with the mMarS I am hoping for great things.

I will start a new thread once I have some pictures and progress worth posting. Expect that to take far longer than necessary though.