F2 Initial Listening Impressions

[audiotux]

Steen , i mail the plan direct to you ,
its a other typ of enclosure , but very nice
and with good WAF , hope your room is not to small


Jürgen

 

[steenoe]

i mail the plan direct to you

Thanks, Jurgen. Looking forward to take a look at it🙂 Its not that the Corals sound bad, they are just a bit box'y to listen to. I dont know if anyone cares😉 but here is the last pic😀 Its the Fairchild Stealth diodes on their own heatsink. The heatsink shields the main circuit from the trafo's a little bit. Or so I want to think at least😉

Steen🙂

 

[mdlover]

hi Steen,

your F2 looks great. 🙂

i have mine completed too. 😀

An externally hosted image should be here but it was not working when we last tested it.

i'm using c-l-c filter instead of active regulation though. it's powered by a 25V x 2 625VA toroid.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

some of my DIY friends are interested to build one after hearing this wonderful amp. and yes, they use full range speaker too. 😉

thanks again, Nelson.

btw, i'm using Coral Flat 6 II as well. they are mounted in a folded quarter wave pipe.

An externally hosted image should be here but it was not working when we last tested it.

apart from Coral, i'm using the F2 to drive Lowther in "Singular" cabinet, a design from Netherlands. 😀

An externally hosted image should be here but it was not working when we last tested it.

cheers and Merry Christmas! 🙂

 

[steenoe]

your F2 looks great.

Thanks again🙂 The pics you inserted, loads really slowly I cant see them yet.

they use full range speaker too.

None of my friends does, sad enough I would love to connect the F2 to a pair of Lowthers, just for the heck of it😀 I am sure it would be great, though🙂

i'm using Coral Flat 6 II as well. they are mounted in a folded quarter wave pipe.

I am looking for something like that, any drawings to share? Thanks🙂

Steen😎

 

[mdlover]

hi Steen,

here come the pics. 😀

 

[mdlover]

the clc filters. each channel has 4 x 10000uF, so total 80,000uF. the inductor is 2mH.

 

[mdlover]

the 625VA toroidal transformer

 

[mdlover]

and my coral flat 6 II. 🙂

 

[mdlover]

and lastly, my current system and the Lowther.

 

[audiotux]

Hi mdlover ,
nice amp , i like the techno-style .
Maranz-Caps in a Pass amp is very exotic !

Greetings from Germany

Jürgen

 

[steenoe]

and lastly, my current system and the Lowther.

My Goodness, fantastic pictures🙂 How do you rate the F2 compared to those tube amps? May I ask, did you design the boards for the F2 yourself? Very nice system you got there😉

Steen😎

 

[mdlover]

Thank you, Jurgen. 🙂

I like those Marantz caps too. 😀


Hi Steen,

Thank you.

Yes, I draw the PCB myself but the CCS is different (Aleph type) coz I don't have P channel MOSFET at hand so I change the design a bit.

I prefer F2 over the tube amp. 😀

And I have just done a quick search but I could not find the drawings of my Coral cabinet.......

cheers

 

[steenoe]

Mdlover😎 Designing the boards and everything, you did a great job🙂 Hats off, Gents😉

And I have just done a quick search but I could not find the drawings of my Coral cabinet.......

Easy enough, take them apart and do some mesauring😀 😀 Did I spell that right😀 😀

Steen🙂

I am wondering; could I get Jon Van Der Halen to give me a nice offer on a pair of Lowthers?? They are way too excpensive, here in Europe😀 😀

 

[mdlover]

Easy enough, take them apart and do some mesauring😀 😀 Did I spell that right😀 😀

Will do. 😉
I mean it coz I want to re-build the cab with better material.

 

[Zen Mod]

Here is another without the lid on🙂

messy!

 

[Zen Mod]

I am wondering; could I get Jon Van Der Halen to give me a nice offer on a pair of Lowthers?? They are way too excpensive, here in Europe😀 😀

contact Miroslav Ivanek at Hornet (something as www.hornet.hr) or Andreas Mau-Lowther club of Deutschland
you will be surprised with prices,I think.
few years ago Andreas have lower prices than Lowther directly

😉


btw,your amp is ugly!

 

[zygibajt]

>mdlover

How do Corals compare to Lowthers and which Lowthers are you using?

I know Lowther sound very well, but never heard Corals.

Bartek

 

[apassgear]

I prefer F2 over the tube amp. 😀

cheers

MDlover,

You and Steen have some really jaw dropping F2 clones, congrats!!!

 

[apassgear]

messy!

Envious?

Choky, it shows alright

 

[apassgear]

Now that Steen has ironed out some last glitches of the circuit I have updated the schematic for anyone interested on this fabulous current source amplifier.

At 1 Ohm R13 is now burning arround 8W so make sure you have plenty of spare thermal capacity just to avoid resistor noise.

R4 has been changed to 1M so I would suggest :

First, set R4 for symetrical clipping at full power using a scope when amp is hot (after a couple of hours).

Secondly, when you finish playing arround with the pot (R4) desolder and measure the ohmic value, then replace with fix resistors.

Cheers,