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My gorgeous transformer based passive pre-amp as featured in the DIY thread.
Wonderful natural and clean sound, nice heavy control, one in one out. Simply not needed anymore.
http://s560.photobucket.com/albums/s...stuff/PP17.jpg
http://s560.photobucket.com/albums/s...stuff/PP16.jpg
http://s560.photobucket.com/albums/s...stuff/PP18.jpg
PM me.
Looks gorgeous! :)
I'm being a typical technophobe here (please bear with me!) but how does a transformer-based passive pre work? I notice NVA are now building their pre's with transformer volume controls and wondered how they work.
Sorry for the thread hijack! :o
Cheers!Quote:
Originally Posted by Gromit
Very basically:
At varying points of the transformer windings there are different attenuation values (increasing with the number of windings) and are accessed by the pins on the transformer housing.
http://www.intactaudio.com/images/At...ges/AVC_Lg.jpg
These points are spurred off to the volume switch which is usually a 24 position switch and as each position is selected the attenuation is reduced and the volume increases.
http://www.intactaudio.com/images/At...g-switch-2.jpg
This one certainly works very well indeed and is very natural and transparent. Its only requirement is a low impedance input (say 50 ohms from a source) and a high impedance input on the power amp (say 50 Kohms). The ratio should really be no lower than 100:1 but preferably closer to 1000:1.
Thanks for that - looks like a very elegant and clever way of doing things (and even I understood it). :)
Makes sense that it would sound good. :)
Any offer considered - no matter how daft!
Go on, have a go with it. You'll be amazed! :D
Well I paid £350 for it last year, obviously I'm not looking for that much, around a couple of hundred-ish?
sounded considerably better than the MFA (silver) to my ears. Didn't ring either! (I borrowed briefly before Rob had it)
Sastus,
The original metal case was RS part No. 364-1632
http://uk.rs-online.com/web/search/s...duct&R=3641632
Cheers matey! Sounds like you know more about it than me. LOL! :D
Going up on eBay this weekend.