Converting the AKSA 55N+ to allow balanced operation?

ShinOBIWAN · « **on:** 6 Nov 2005, 12:53 am »

Hi folks, first post here and I must say there's some wonderful looking AKSA products that others have built here.

I really hope I can produce something similar when my AKSA 55N+ kit arrives.

I'm really wanting to convert the input section of the AKSA into balanced using XLR's. I'd have liked to pose this question to Hugh but since its actually unrelated to the kitset and the fact that he's already far too generous with his time, I thought it would have been rude to do so. But I do know there's many passionate folks on here that would possibly have the answers I need.

There's also a nagging thought that I may actually cause damage to the sonics by doing so. Is this unfounded?

Geoff-AU · « **Reply #1 on:** 6 Nov 2005, 01:02 pm »

try the search button mate.. already been answered in this very section of the forum!

JohnR · « **Reply #2 on:** 6 Nov 2005, 01:08 pm »

Hi, I think this is the thread:

http://www.audiocircle.com/index.php?topic=21302

ShinOBIWAN · « **Reply #3 on:** 6 Nov 2005, 06:19 pm »

Thanks for link John.

AKSA · « **Reply #4 on:** 6 Nov 2005, 09:44 pm »

Hi Anthony,

To add to this thread; Keith has not come back to us on this yet, but doubtless will fairly soon. It can be done, but at the expense of input impedance, which drops hugely from 47K single ended to around 2.2K balanced. To accommodate a higher, balanced input impedance a buffer would be needed, and this could damage the sonics just a little.

While balanced input is not something I believe is necessary, I know the market says otherwise, and I cannot ignore that. However, a quick and easy way of doing balanced is a transformer; in UK, your man is Brian Sowter; in the US, it's Jensen Transformers. These little transformers are very good, too, used right through the recording industry, but they are rather expensive, typically 50 quid each.

I hope this is some help - try getting the rig going as it stands before you take the (expensive) decision to move to balanced lines!

Cheers,

Hugh

keithvv · « **Reply #5 on:** 7 Nov 2005, 05:44 am »

Hi all,
I have not yet had the time to make the conversion to balanced operation, so nothing to report as of yet. The project ahead of this one has taken longer than expected....... don't they all?

That said, I should get to the conversion by next weekend, and have a preliminary result to post.
For the record, the output impedence of the driving pre-amp is less than twenty ohms, so Hugh's concern in that arena (the converted AKSA will have an input impedence of only around 2K ohms) should not be realized.
Look for a response within the week.
Cheers,
Keith