PDA

View Full Version : Practical Op-Amp Help Please.



DaveK
04-08-2009, 13:58
Hi Guys,
I have 'invested' in a 4562HA (metal capped) op-amp, circular with 8 very long thin legs. Would any of 'Santa's Little Helpers' be willing to bend and trim the legs for me so that it would be a 'drop-in' fit inot my 7520? I would be happy tp cover any costs, including Artisan craftsman rates and return postage :).
Not in any hurry - got enough going on at the moment to keep me occupied for a while :).
Any willing volunteers, please PM me.
Thanks in anticipation.
Cheers,

Gints
04-08-2009, 14:44
Hi DaveC,
I am sure that after one more beer (I see that you taking one already) you will have courage to do it yourself. Yesterday I manage to desolder drop-in sockets. That took an hour and half for the first one and 10 min for the second one :)
So that is only just matter of starting. Aaaa, but have only one, otherwise I definitely volunteered :)

Mines were already formed and cut but I can not see where you can go wrong. Legs are quite elastic, so there is no need to be very precise. If you worry about lenght just go shorter gradually. You should take on count that they are quite high, can be difficulties to close lid (otherwise board is so close to caps below it). I soldered mines directly on board.

Gints

Dave Cawley
04-08-2009, 16:38
Great op-amp, but no difference to the DIL 8 pin version, unless you are going to fly it in space? Make sure you use a proper gold plated socket of the turned pin variety. And check it with a scope to ensure that the extra gain has not caused any ultrasonic instability which could destroy your amplifier or tweeters?

Dave

StanleyB
04-08-2009, 16:54
Great op-amp, but no difference to the DIL 8 pin version, unless you are going to fly it in space?
Got to disagree with you there Dave. The HA is very much better sound wise. I use a pair myself and have two identical audio boards kitted out with the HA and the NA. With the NA I need to switch on the subwoofer I got off you. With the HA I can safely turn the subwoofer off.

Stan

Gints
04-08-2009, 17:34
And check it with a scope to ensure that the extra gain has not caused any ultrasonic instability which could destroy your amplifier or tweeters?
Dave

Do we really need to worry about this? Many people already using them and I did not read any warnings about this earlier.

Dave Cawley
04-08-2009, 18:47
Why would it be any diffrent? and how would it make your speakers produce more bass?

Dave

leo
04-08-2009, 23:21
I compared the LM4562NA against the LM4562HA, there is a small but noticeable audible difference between the two with the HA being the better.

Maybe the clue is in the different material? better thermal matching of the IC? the HA does run warm (no instability issues measured)

I'm going to compare the plastic LM4562NA against the LME49720NA, supposed to be the same chip

Alex Nikitin
05-08-2009, 13:09
Why would it be any diffrent? and how would it make your speakers produce more bass?

Dave

Dave, the difference is in the thermal time constants and it could indeed affect the perceived bass performance.

Alex

alb
05-08-2009, 13:14
I'm going to compare the plastic LM4562NA against the LME49720NA, supposed to be the same chip

Oh good. let us know the outcome. I tried them both in a phono stage, and was to indecisive to arrive at any meaningful conclusion.:)