AMB Laboratories DIY Audio Forums

[SonusBonum]

Thanks Daniele.
Room temp is 21C now in winter, 30C max in summer. Just measured the heatsink temp: 37C after 5 hours of normal playing.
This is the heatsink I used: http://www.deltourheatsinks.com/heatsink/def75/

[daniele86]

Thanks Daniele.
Room temp is 21C now in winter, 30C max in summer. Just measured the heatsink temp: 37C after 5 hours of normal playing.
This is the heatsink I used: http://www.deltourheatsinks.com/heatsink/def75/

Is not too high the difference between heatsink and D7, D8, D9, D10 - Q33, Q35, Q35, Q36 ? 70°C vs 37°C .. 70°C is high with your room temp and heatsink..or not?

Do you think that you will try to go little upper with bias current?


Thanks

[SonusBonum]

Do you think that you will try to go little upper with bias current?

I don't know whether that's usefull Daniele, maybe Ti can say something about that...?

[amb]

1.4A quiescent already guarantees pure class A operation at full output power into 8 ohms. Any more bias will just create more heat.

[SonusBonum]

Goodmorning Ti,

I listened to the β24's for a week now and all of us (wife, kids and some friends) agree that your amps sound better than my 4 (bridged, mono-ed) 12.000 dollar Burmesters.
There is much more detail in the mids and highs and lots more control over the lows. I had to bypass the top woofers of both stacks to normalise the levels.

So to wrap this up:

FOR SALE: 4 BURMESTER 956MK2 POWER AMPS...

Thank you for baring with me and developping this beauty...

pic-01.jpg

[amb]

That's music to MY ears!
Congratulations, and that's a gorgeous looking setup.

[poseidonsvoice]

Sonusbonum,

Wow! You must a very large disposable income! The Burmester 956mk2, is a beautiful stereo amplifier that can be bridged mono and is USD$ 19k each at the dealer below. But I have seen it at Euro 11k as well.It has some nice specifications but no real measurements I could find. It does have a whopping low 1.8K ohms input impedance using the XLR input!

http://www.rutherfordaudio.com/products ... amplifier/

It is very nice to know you prefer the Class A build of the AMB B24. Please keep us in the loop regarding your sonic impressions...

Best,
Anand.

[SonusBonum]

Hi Anand,

I remember your system, been looking at it a while ago. Nice...! Thanks for your comments.

So far so good...! The β24's are breaking in nicely. Never heard anything like it. More people listened to the system and were impressed by both the speakers, the amps and the combination. Since I bi-amp the 1.8kohms input impedance you mentioned was a bit of a problem. That's why I (also) build a couple of α24's. With the 10k of the β24 that's no real problem anymore. The most important improvement over the Burmesters is CONTROL by means of the damping factor. I even had to replace both top woofers by 32 ohm 50W wire wound resistors to tone down the lows a bit and keep the same impedance (expensive filter parts) at the same time. Most listeners claim they hear way more of the stick hitting the cymbals. I do know for a fact that my ribbons are extremely fast and responsive, but combined with the control of the β24's it gets even better.

As you can see, I am passionate about the musical truth.
Oh and guess what... The four Burmesters are sold to a guy in Germany. So there's no way back...

Greetz,
Ronald

[lugili]

Really like your casing with the shiny toroidy transfomer sitting on top! Looks like a being from outer-space.
Great job, sonusbonum. Keep us updated on how it all sounds and your experiences.

[SonusBonum]

Thank you Lugili. Here's your update. It sounds so extremely good that I sold my four Burmesters WITHIN A WEEK. My new amps are better by far. Faster, stronger, clearer. My audio friends all agree, this is the best amp we've heard so far...!