Hi, this is probably a cuestion asked and answered a couple of times but reading through a thread with over 1200 posts could take a while so i'll ask again instead.
How great is the is the sonic difference between using the AD8620 version VS the standard one? I found a sweet deal on the regular but had my heart set on the AD-version at first.
How great is the is the sonic difference between using the AD8620 version VS the standard one? I found a sweet deal on the regular but had my heart set on the AD-version at first.
Hi KMJ
Depends a little on the application, but I can tell you this.
If you have a high resolution (High-End) audio chain, there is no other road than the 8620. IMHO.
It is neutral and transparent at the same time. 5532 is rather neutral, but a little grey and not very transparent. 2134 is more transparent than 5532 , but has a special sonic signature that it impose on everything. First spotted it is hard to ignore.
Just my 20øre ;-)
Koldby
Depends a little on the application, but I can tell you this.
If you have a high resolution (High-End) audio chain, there is no other road than the 8620. IMHO.
It is neutral and transparent at the same time. 5532 is rather neutral, but a little grey and not very transparent. 2134 is more transparent than 5532 , but has a special sonic signature that it impose on everything. First spotted it is hard to ignore.
Just my 20øre ;-)
Koldby
ok, thanks.
Can one change directly between different op's or must i change other components on the modules as well?
It would be nice to buy the basic version and then be able to test different types just by changing the op's (without changing resistors and such)
Can one change directly between different op's or must i change other components on the modules as well?
It would be nice to buy the basic version and then be able to test different types just by changing the op's (without changing resistors and such)
It is mandatory that you change two zener didoes as well, as the 8620 dosen´t tolerate +/-15V .......
If you have coupling capacitors in your version, it will be beneficial to remove (shortcircuit) them .
Koldby
If you have coupling capacitors in your version, it will be beneficial to remove (shortcircuit) them .
Koldby
so it's not especially difficult then.
then i'll go for the basic and later perhaps upgrade.
thanks for the quick reply.
then i'll go for the basic and later perhaps upgrade.
thanks for the quick reply.
koldby said:
It's not mandatory to change the diodes. The stock UcD module supplies +/- 14.3VDC to the opamp, which is only slightly above the maximum spec for the AD8620. I've been running my AD8620 w/the stock diodes for several months and haven't had any problems. Maybe I'm just lucky. 🙂
As the other op amps (5532 and 2134) are equally happy working off 12V we will be changing the zeners to 12V on all modules. Easier for us (less parts) and for experimenters.
Personally I can't think why anyone would want to go back after trying the 8620.
Personally I can't think why anyone would want to go back after trying the 8620.
mac:
I would still say it is mandatory.!
I know of at least one instance where a precious (and expensive) AD8620 blew up in a UcD module where the Zeners were 15V types.
I can´t find the post, but as far as I remember , it was in one of the UcD threads.
The guy just dropped in the AD8620 and in one of the modules , it blew up. The other one worked ok.
The long time stress on th AD isn´t a good thing either. Besides it is a very easy and inexpensive operation.
Koldby
I would still say it is mandatory.!
I know of at least one instance where a precious (and expensive) AD8620 blew up in a UcD module where the Zeners were 15V types.
I can´t find the post, but as far as I remember , it was in one of the UcD threads.
The guy just dropped in the AD8620 and in one of the modules , it blew up. The other one worked ok.
The long time stress on th AD isn´t a good thing either. Besides it is a very easy and inexpensive operation.
Koldby
I fact here is the explanation from Hypex (Jan-Peter) to the blown up UcD.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=38199&perpage=10&pagenumber=40
It was worse than I remembered:
The hole UcD module blew up!
Better change those zeners!!!!
Koldby
http://www.diyaudio.com/forums/showthread.php?s=&threadid=38199&perpage=10&pagenumber=40
It was worse than I remembered:
The hole UcD module blew up!
Better change those zeners!!!!
Koldby
koldby said:
From Jan-Peter:
"I guess it'safe to use the 15V regulator, normally you will have 14.3VDC and the absolute maximum for the AD8620 is 13.65V. But I can't guarantee!!!"
I'd wager that Matjans' failure occurred immediately upon first power-up.
I don't have to tell you that a failure can be caused simply by removing and reinstalling the SMD opamp on the board. The pads are very tiny and even if you're experienced and have the right tools to perform SMD soldering it's still a tricky proposition.
In any event, I do have some 12v zeners that I plan to install the next time I have the hood off. 😉
Cheers, mac.
Damn, there smd's?
The thing is that the version with ad8620 is gonna cost me atleast twice as much as the regular version, but i guess that i can get someone to change the op for me later when the fingers start to itch.
once again, thanks 😀
The thing is that the version with ad8620 is gonna cost me atleast twice as much as the regular version, but i guess that i can get someone to change the op for me later when the fingers start to itch.
once again, thanks 😀
kmj said:
Yes sir. The opamps are SMD and so are the zener diodes. The latter are the size of an engorged flea. 🙂
Not much. The amps are designed to operate well using unregulated supplies.kmj said:
Actually you're likely to shoot yourself in the foot by regulating the supply because most regulator circuits can only source current whereas class D amplifiers are liable to send current back into the power supply from time to time. This is most obvious in half-bridge amplifiers but also occurs in full-bridge amps with strongly reactive loads (few people know about the latter). What would happen with a regulated supply is that during a current source phase the regulator would produce a low impedance rail and in the sink phase the rail impedance would become high (equal to the local capacitance only) so you'd get some sort of a rectified audio wave form riding the power rail.
I have used 15 volts for AD8610 for two years now and it works still. 13.65 V is the abolute maximmum rating if you manufacture an unit but if you make one single item and it won't brake right away it will probably last if you have constant environment. This is nothing I recommend though. If you want to be 100% don't use the AD8620 over it's ratings.mac said:
I like being intentionally lazy, but if I do go through the trouble of replacing the standard opamp, I might as well replace the other little bugger (the diode) as well 😉peranders said:
I have still no idea how to appoach this SMT problem: I have bought a new soldering tip with a very fine tip, but every time I practise on leftover components, I manage to solder a few legs together instead of seperately to something else... Any tips/pointers? I'm seriously considering buying conducting glue...
Flood solder the row of pins then use desolder braid to soak up the excess from between the gaps -- just place it across the row of pins and run your iron along the braid. No need for a fine point tip.