Ultrafast diodes. CanAmp comes with 1N4002 fitted (100V) UF4002 are only marginally more expensive and are ultrafast types with a 50ns reverse recovery time. I didn't have any UF4002 but did have some UF4007 (1000V) which are in circuit as I type this. Do the ultrafasts make an improvement? Yes, a definite improvement in bass being tighter, less rounded and better seperated from the rest of the frequencies (easier to pick out and follow) this word is getting tired but I can't think of another......... "clarity" there's, yet again, an improvement here with another layer of fine mesh having been removed, more detail and nuance creeping out of the mix for sure
Not night and day improvements but definitely an
improvement allowing more through, an area maybe worth considering should the "reference" ever hit the drawing board. Obviously there are even better types of diode which may give even better results over the UF4007 / UF4002.
Hook up wire to the headphone socket could be better, in fact it could be dispensed with altogether in favour of a high quality board mounted headphone socket, I've replaced the stock hook up wire with some thick OFC copper stuff (nothing fancy just good old fashioned OFC copper) and, even though it sounds exactly the same, it just "feels" better knowing the connection is a lot more mechanically sound (thick wire soldered to the board then flooded with epoxy resin topside to ensure integrity, hardwired to the headphone socket, through hole, and then double wrapped with heat sleeve) I was frightened to sneeze on the stock hook up wires incase they blew away
Nah, not
that bad but an area that can be improved on for sure.
I've covered the PSU capacitors in my last post.... more capacitance there most certainly improves things quite dramatically, night and day if you like, I'll be trying the dubilier
DPG series 10,000uF 35V tomorrow (they fit perfectly, no other reason) and will report back. Capacitance is one thing, voltage rating is another.... sometimes it's better going with a higher voltage rated cap (
I agree with Paul Stamler on this one) from experience a 35V 10,000uF can sound better than a 16V 10,000. Obviously we can fit a 16V 22,000uF into this position (dimensions are the same as the 35V 10,000uF 45mmL x 25mmD) another one I'll try after the 10,000uF dubilier. By the way, there's only 11.4V across the PSU caps so 16V rated caps are
well within spec.
10uF coupling caps, I mentioned them in my last post I think? If not, well worth replacing them with non polar varieties..... there's no DC (to speak of) across them so no reason to implement polar 'lytics here. I think I measured around 21mV across them. Vast improvements to be gained using non polars here, obviously even better improvements to be had fitting film caps but a polyprop in a 10uF package would be bigger than the amp itself
(well, almost!)
DC offset. Anything under 50mV is, IMO, good to go. Ideally +/- "0" would be optimum but hard to achieve without DC blocking output caps. I measured 16.7mV LC and 12.8mV RC from cold and after one hour very little change 15.1mV LC and 13.1mV RC. If this is representative of all the CanAmps then pretty good going.... if you
can get it closer to zero, all the better
Somebody mentioned fitting an IEC socket.... Good to go if mains polarity is correct but a bugger if it isn't. One of the main reasons I favour the two pin figure of eight socket, it's a simple case of turning the connector upside down to change polarity, with an IEC this simple "turn it around" procedure becomes a laborious task of swapping over the wires in your mains plug and, by the time you've done that you can't remember what it sounded like in the first place! For those of you who haven't got a scooby what I'm on about
Have a read With the figure of eight lead you can slot her in, turn her upside down and reverse polarity in seconds.....your ears as the judge. With IEC you enter the realms of unnecessary hassle, inflated prices, weirdos selling polarity checkers.............. stick with the captive lead guys as long as "you" get polarity right at the factory
Oooooh, I think I've said enough for one night. Happy Easter (or whatever season it is) to you all
