LH0002CH -- what is inside?
« on: April 22, 2008, 09:46:12 PM »
Here is a datasheet:

http://www.datasheetcatalog.org/datasheet/calogic/LH0002.PDF

It says "0.1% THD on 1 KHz 5V rms". Had anybody used them for audio? Unfortunately I can't find schematic to see how prone they are to crossover distortions...


bcarso

LH0002CH -- what is inside?
« Reply #1 on: April 22, 2008, 09:51:38 PM »
They were originally a National Semi part.  IIRC they are hybrids with cascaded complementary emitter followers.  Slightly less than unity voltage gain, and were touted as buffers to incorporate inside the feedback loop with an opamp driving.  Opamps of the day were slow enough that the LH part added negligible phase shift.


EDIT:

In fact:

http://www.datasheetcatalog.org/datasheet/nationalsemiconductor/DS005560.PDF

Freq Band

LH0002CH -- what is inside?
« Reply #2 on: April 22, 2008, 10:33:03 PM »
Audio by Van Alstine had a kit for a headphone amp which used the LH0002 as a buffer/output booster.

Here it is described, and schematics (parts layout, pc board).
(scroll mid-way down)
http://www.avahifi.com/root/audio_basics/ab_pdf/ab1994-04-05-06.pdf

I built it using point-to-point, but used the LH0002 can  instead of the DIP.
Sounds fine. I have not yet A/B it with my more recent HP amps.....to see if I can hear any differences, or done any measurements.

They're obslte, but show up on ebay at a good price once in a while I bought 20 of them for about...??.....$20 ??

App note 227
http://my.ece.ucsb.edu/bobsclass/2C/tutorials/App%20notes/an-227.pdf



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LH0002CH -- what is inside?
« Reply #3 on: April 23, 2008, 12:34:50 AM »
Thanks a lot for the info!

LH0002CH -- what is inside?
« Reply #4 on: April 23, 2008, 03:01:05 PM »
I have 20 of them, let's use for a headphone distribution amp...

guy_4

LH0002CH -- what is inside?
« Reply #5 on: April 24, 2008, 08:02:14 PM »
Hi,
It is used as a video output driver on the SSL E/G computer...probably good enough for a headphones amp  :grin:
Guy
"If you think it is expensive to hire a professional, wait until you hire an amateur ! "   Red ADAIR

Dan Kennedy

LH0002CH -- what is inside?
« Reply #6 on: April 24, 2008, 11:59:42 PM »
I use a variation of the circuit in a high pass circuit in my EQ, simple to build with a pair of 4403's and 4401's and a couple of SIP resistor networks.

Use 47 ohm and 6K8 to start.

LH0002CH -- what is inside?
« Reply #7 on: April 25, 2008, 12:01:50 AM »
Quote from: "Dan Kennedy"
I use a variation of the circuit in a high pass circuit in my EQ, simple to build with a pair of 4403's and 4401's and a couple of SIP resistor networks.

Use 47 ohm and 6K8 to start.


Thanks, it is exactly what I was thinking about today, to use them in crossovers.  :cool:


 

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