My Charlize2 is coming tomorrrow! Would love suggestions (ideal voltage, etc.)

[fliz]

Hey everybody!  My first post here.

I've had an eXemplar 2a3 amp for years now (3.5wpc) powering eXemplar horns (102db@1w)

Recently, I met some people who make custom Li-Ion battery solutions for industrial applications.  (Including a Li-Ion car battery!)

Needless to say, I immediately started thinking of the audiophile applications of this technology.

It didn't take me long to find out about Charlize from here.  (The first thing I found when searching for battery powered amps was the altmann amp at an insulting 950eu). 

After determining that reviews placed the Charlize as the best of the class-T amps, I got a board and was wondering about how best to set it up.

1) is there any reason I wouldn't want to simply solder wires directly to the board and skip binding posts and rca jacks besides the obvious reason that it's inconvenient if I want longer/shorter wires?  (How difficult would it be to undo if I wanted to?) It'd save me a bunch of money and work, plus the signal would have less stuff to travel through.

2) I understand the TA2020 operates between 8.6VDC and 14.6VDC.  I've heard that SLA batteries sound the best when fully charged (usually above 14VDC) but only stay above 13V for maybe an hour.  I could have a Li-Ion designed that outputs exactly 14.6v and stays above 14v for WAY longer.... Is it safe to run the TA2020 at this voltage for extended periods?  If not, what's the highest I can get away with?  Would I need to attach a heat-sink to the chip?

3) In the meantime, before the Li-Ion is built, what's the difference between using a $20 12v/7ah SLA instead of a fancy Optima Red Top? 

4) can I skip installing a switch and simply attach/remove the wire connected to the + terminal of the battery?

[vt4c]

Hi Fliz,
   Please allow me to answer your questions...

  1.) I encourage you to solder the wires directly onto the pcb.

  2.) Based on the datasheet, the absolute max. operating voltage is 16V...The recommended max. operating voltage is 14.6V....Of-course there is no reason why the chip can't operate at that voltage but there is no guarantee that the power supply will stay fixed at that value.   It's good to play it safe though...

   3.) I never tried the Optima Red Top but some owners of Charlize did try it and reported excellent result

   4.) This is possible.

   BTW, I heard good things about the eXemplar horns designed by Mr. Tucker & Mr. Markwart but never able to listen to a pair in action....Is one of those hi-eff. speaker I wish to own some years back but never able to do so.....I have to ask this....What's your view on this speaker and does it handle bass well?

[CKL]

I power my Charlize2 with 20V. More treble, more sound stage. Of course, you have to take your own risk with such a high voltage. 

[CKL]

Note that I had changed the caps to BGs. Please check if the max voltage of the default caps is 16V or 25V before powering with 20V.

[fliz]

Hey vt4c,

Thanks for your answers!

1) I figured that no connector is better than any connector (especially since the "best" connectors cost ludicrous amounts of money)  I have some of the plastic RCA tips that came with the 47 labs OTA cable kit, so DIY hardwired interconnects should be easy.  I even have a friend that's a jeweler who'll pull some 24 awg pure silver wire for me.

2) 16v? awesome.  I just have a 12v 7.2ah SLA for now, but if I decide I like the amp enough to have the Li-Ion built, I'll make sure to request that's it's 14.6v

3) seems pricey.. I'll hold off and see how it goes

4) I ended up getting a 4p3t heavy duty switch so I can simultaneously switch on two charlize2s in the same box or charge the two batteries connected to it. (with a center off position)

As to your question about the eXemplar Horns.  I love them.  The tops are 750hz up and perfect.  the bottoms are 750-135 via the front horn and 135-50-ish via the rear porting.

I have zero complaints from 135 up, the rest is very room dependent, and unfortunately my room is far from ideal.  My solution is a Bruce Edgar Seismic Sub.

it gets RAVE loud from the 2a3s turned up halfway, so 3.5wpc is probably plenty, but I'm dying to find out what they do if I give them 10wpc.  John Tucker powers his with 300b amps, so he's got 8wpc and says that it makes a big difference in the bass.

I'll laugh my ass off if the little charlize2 bests my John Tucker built 2a3 amps.  (I'll also make a pretty penny selling off these rare beauties!)  If that's the case, I'll definitely by a second and build one box that's a monoblock pair to bi-amp my speakers (20wpc, wow!)

Hey CKL,

What do you use as your power supply?  Also the charlize2 only has the two caps in between the air coils, right? (1000uf 16v), or are you referring to the tiny 47uf 25v caps?

[CKL]

I changed all 4 caps to BGs. Watch out, those two caps are 16V only.

[fliz]

Hey CKL,

would you recommend changing the 1000uf 16v caps to something else?  (2200uf 25v maybe?)


what did you do that allows you to run at 20v?

[CKL]

Can't remember the exact values, the bigger the better. 20V was discovered during an accident. My Paul Hynes' transistor was broken so the 13.8V had become 21V and I discovered it after 6 months! After that, I know the chip can withstand 21V without any problem but with better treble & sound stage.

Note: you have to take your own risk if you power it with 20V.

[fliz]

those are some huge caps! lol...

what are they?  also what's the grey stuff you have in and around your air coils?

[vt4c]

Hi Fliz,
   The grey stuff in and around the coils are toxic! 

BTW, any comment regarding Charlize2 vs the 2A3 amp?