[geom_tol]

I was talking to an Elantec guy about the el-2000 series buffers.
He told me about a Harris buffer ha-5002 which is what they recommend as a replacement to el2001. (Intersil owns both Harris and Elantec).

The specs look really good, and it is available at around $3 from a couple places.

To find it you need to search for: ha3-5002
That's the ceramic dip version, they have 8 versions of this chip

Any tried it or know ahything about it? I searched the forums and ppl is the only one to even mention this buffer.

 

[morsel]

bump

 

[kevin gilmore]

I used to use these a lot. I think they sound great. I stopped
using them because i could not get them. If they are available
again i will switch back to them.

They do get quite warm in use...

 

[geom_tol]

www.findchips.com is really useful for finding stuff.

Three places seem to have the ha3-5002 in stock.

It's good that you liked this part Kevin, the Elantec guy didn't think this buffer would be discontinued.

 

[morsel]

Kevin, have you (or anyone) compared the HA5002 to the BUF634 or EL2002?

 

[ppl]

Some time ago i posted about this as well as the HA-5033. Both these Buffers are Based upon the Dielectric Isolation Fab technique, The Best Available like the Elantecs and unlike the BUF-634. The HA-5002 like the 5033 Lacks output Short Circuit Protection and as sutch can be damaged by inserting or removing the Phone Plug from the jack if the Program material is loud. i haven't encountered any problems with these parts at normal volume. The 5002 is good for 250-300Ma and can supply peaks of up to 500 Ma. for 2 sec on a non repetitive duty cycle (or Once in a while Required) since these Buffers lack output protection, thay come closest to the High end Ideal! of No Current limiting. Most folks hear might have noticed that Hightly regarded High end Amplifiers for Lounspeakers Boast about not having Current limiting and thus not limiting Dynamic range on Program Peaks. When the current Limit on Amps or IC's employing Current Limiting is activated, the Distortion Produced by the Protection circuit's is worse than clipping and have been Known to fry Tweeters evean though the Amp was seamingly operated within it's Rated power. If you count yourself amoung thoses users that think thay do not need output protection and understand that a Slight oversight like changing Phones or not pluging the phones in unless no signal is present, is you! then Mutch can be gained from this aproach. The HO-5002 if I remember is a 200 Ma/100MHz. Buffer and the HA-5033 a 100Ma/275 MHz. Buffer the 5002 consumes about 4 Ma. Similar to the EL-2002 or a buf-634 with the BW Pin set for 70 MHz. about 4-5 Ma of Icq. for the BUF-634.

Sound quality the HA-5033 is fantastic and the part I based my portable reference Amp around. the 5002 is great in Applications when an Opamp with a 180 MHz GBP is not used like the AD-8065 that i used in this ref, otherwise i would have used the Higher output current lower Icq 5002 rather than the 5033 in my Reference Amp. Let me tell ya Properly done this combo is among the Finest most articulate sound one can get and it could be portable (Large Battery pack Model car Type) why not one for each channel and get dual mono as well as twice the Play time.

I would say go for it

 

[kevin gilmore]

http://headwize.powerpill.org/ubb/sh...20020808060433

new pictures of this unit with the ha3-5002 coming monday
or so. Made adapters that put a 5002 into a buf634 socket.
Lots more listening to do...

 

[tangent]

Quote:

The HA-5002 like the 5033 Lacks output Short Circuit Protection and as sutch can be damaged by inserting or removing the Phone Plug from the jack if the Program material is loud.

Let's say you've got a 6V RMS p-p signal -- damn loud even on inefficient headphones. Since the chip can handle 500 mA for up to 2 seconds, and that's plenty of time to pull a headphone plug out, you could put a 12 ohm resistor on the output to fix this problem, couldn't you? In the META42 design, R9 would fill this need, so from my perspective at least, there's no need to worry about this. Either you trust yourself to remember not to pull the headphone plug when there's music going, or you can add an R9 resistor to protect your output buffers. Seems like a reasonable choice to me.

 

[ppl]

Tangent. like i sed i havent had a problem but i can see som DIY'er having a malfuntioning amp due to a assembly error and have like 6 volts DC upon the outputs and then without testing plug in there phones and poof. so i think this is a buffer that is to be used with caution by the Novice. I like these parts alot and have no problem with lack of output protection because i don't need it and most often don't want it. Oh and no resistor between the Outout stage and the phones for me i just hate giving up damping factor that was so hard to get in the first place

 

[aos]

Didn't I see in datasheets that they tell you how to implement current limiting by use of 2 resistors (not in series with output)?

 

[morsel]

http://www.head-fi.org/forums/showth...threadid=10140

PPL, in this fine thread (the new zenith of smooth and clear) you described the HA5033/OPA633 in great detail, praising its high end but damning it for being totally gutless, even in a 6 deep stack. That was enough to put it out of my mind as a contender.

I am concerned that the HA5002 may also be gutless, as you put it. You say now that the sound quality of the HA5033 is fantastic, which seems to contradict your earlier assessment. Can you shed more light on this discrepency, and also differentiate the two parts?

On the subject of output protection, I would definitely go with a 5-10 Ohm output resistor per Rudy's advice.

 

[ppl]

I thought i covered this I now suspect that the origenal bass defect was the result of using electrolytics that were in storage for years without use. i suspected this because the Current drain of the Amp went down right after the sound Improved what do Ya think. BTW i then soldered a 5033 in a adaptor socket and droped a pair in my Pocket amp and thay sounded better than the 2001's and at least as good as the EL-2002. I paid critical attention to the bass and again at least to my ear on my MDR-V6's both using and not using the bass boost BTW the Amps ICq went from 10.8 Ma with the 2001's 18 Ma with the 2002's and 26 with the HA-5002 and 50 MA with the 5033.

 

[kevin gilmore]

ha5002 to buf634 converter

http://gilmore.chem.northwestern.edu/ha5002.jpg

 

[morsel]

PPL: I must have missed your explanation that the gutless bass was due to defective caps. This is good news. The HA5002 seems more appealing than the HA5033/OPA633 due to lower quiescent current and higher output current.

Kevin: Cute! Clearly cans are easier to kluge than DIPs. The can also has a vastly superior pinout. The DIP is obnoxious, grouping the 4 power leads plus with minus and minus with plus on opposite sides. Ugh, whoever did that was a few Whoppers short of a Happy Meal. It makes routing a mess if current limiting resistors are used, and forces traces across the underside of the chip if they are not used. The can probably dissipates more heat, but does have one significant liability - it is not easy to stack. If buffer stacking is as important for the HA5002 as for the EL2001 and BUF634 then we probably need to stick with DIPs.

 

[aos]

The first question is CAN you stack them? I would think that most buffers are not directly stackable, without use of current sharing resistors. EL2001 happens to work fine, but for the rest, are they?