AD8610 and HA5002 Buffer/HeadAmp

[abid_rehan]

Due to exorbitantly high priced chips from T.I (OPA627 and BUF) I had been on the look out for an alternate thats not that high priced and sound good too, so ultimately i came up with AD8610 and HA5002 both SMD type, later is a buffer amp from Intersil.
I did take some time in coming up with schematics and PCB, however, as i got the prototype running last day. I am pretty impressed with its performance.
Here are the PCB layouts it only about 3inchh by 3 inch.

[paulb]

Have you got a schematic to show us?

[abid_rehan]

Sorry I was busy in a few meetings:
Here are the schematics of my buffer, basically this an SMD type buffer, coz both AD8610 and HA5002 are SMD devices, since i couldnt get a decent DS PCB therefore I decided to use a single sided PCB, with a few arangements, firstly i used Tantalum or Polyester type capacitors to ensure good quality capacitance, also used 1% metal film resistors only electrolytic/film capacitors were used at the main DC supply terminals. PCB measures only about 3 inches by 3.6 inches, the size could have been reduced further but its alright with this size too. After burning in the chips for about 2 days the results are pretty good, bass is pretty tight, high frequencies sound good.
In order to have a comparison i used BUF634/OPA627 buffer with OPA549 Gainclones for two front channels and AD8610/HA5002 for the rear channels with OPA549 Gainclones after a while interchanged the buffers from front to rear and vice versa.
Input signal were generated from SB Live Audigy2, and afterwards from my DVD player, and playing for hours i could hardly distinguish between the sound quality of both buffers, so in my opinion (not imposing upon others) quality of this buffer comprising of AD8610/HA5002 is no less than that of OPA627/BUF634 buffer, but with a fraction price, only catch difficult to make and solder PCB.
BTW i used toner transfer method to make PCB and doing the same after couple of years I found it pretty effective.
So whats next, sending PCB designs to local prodcution house for future use, but with slight modifications of pure DS PCB with power planes on other side and usage of SMD components i.e; capacitors and resistors (found an excellent shop for SMD components here).
Great advantage of my home country is that there are retail shops here, from wher i could buy components in a minimum quantity of 1s even no need to bulk purchase. He he he.

[abid_rehan]

Heres REV1 of the PCB

[setmenu]

I have also built 8610/5002 based amps and enjoyed their sound.

Check Tangent's site for slightly different approach to using the same chip combo.
Depending on your phones or music preferences the 'bass boost' can be very handy.

http://tangentsoft.net/audio/ppa/

For the dedicated headphone enthusiast these sites have great info and diy sections.


http://headwize.com/index.htm


http://www5.head-fi.org/forums/index.php?

[abid_rehan]

Nice projects, but probably lack schematics:
I am sure that having used this buffer and compared it with OPA/BUF buffer i havent found much difference between the performance of both.

[setmenu]

These schematics?


http://tangentsoft.net/audio/ppa/amp...schematic7.pdf


I much prefer the sound using the 5002 over the 634.



.

[Nisbeth]

....but keep in mind that the 5002's have no current limiting and might be damaged by a shorted output. The BUF's are limited to 250mA or so (this could explain at least part of the difference in sound quality, which I have also observed)


/U.

[abid_rehan]

As per data sheets of HA-3-5002 page 4, under heading SHORT CIRCUIT PROTECTION, it is mentioned how to limit the output current of HA-5002, i have used the same technique to limit the output current of HA-5002 and its working fine for me.