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leonard d rock
Silver Member
Philippines
301 Posts |
 Posted - 09/01/2008 : 05:03:11
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hello everybody!
i'd like to try changing the opamp of a ds-1 from the stock m5223al to a jrc4558 by wiring the pins direct to the pcb. monteallum's converter is not available here and expensive by mail.
questions:
1. can it be done?
2. if yes, can somebody point me which pins of the 4558 should correspond to the 5223's. for point of reference of the 5223, pin 1 on left side, pin 8 on right side on its side with the label/markings.
thanks for any help.
LDR
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Dr. Bob
Moderator
Australia
6593 Posts |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 09/01/2008 : 22:26:12
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Actually, I just pulled a TL082 (same pinout as a 4558) out of my DS-1 - the Mitsubishi chip sounds better, IMO!
It will work, but it's a PITA. There's also reduced clearance for getting at surrounding parts.
I actually rigged a socket into mine.
This is the best way I've found to do it:
Get a chip socket. Actually, get a bunch, because you'll ruin a few of them doing this!
Put the DIP8 socket in the 4 holes closest to the side of the PCB. Orient it so that the other 4 socket pins are closest to the backside of the board (where the ac adapter plugs in)...
...Solder those 4 pins WITHOUT having the socket flush, so that you can angle it.
The remaining pins are 1-4, counting from the PCB edge inward. The remaining holes in the board are the OPPOSITE. I use solid core wire to connect between those socket pins and the PCB.
The chip goes in the socket with the "notch" to your right, and the "dot" in the upper right corner, as you look down on the pcb. Basically, the DIP8 chip is upside down.
If you can etch your own adapter board, that would probably be preferable. It's a PITA, otherwise.
I hope this makes sense. |
Edited by - MoonWatcher on 09/01/2008 22:26:47 |
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leonard d rock
Silver Member
Philippines
301 Posts |
Posted - 09/02/2008 : 01:35:09
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hello dr. bob and moonwatcher,
thanks for the replies , i'll try to do this slowly and carefully. don't want to ruin the ds-1 pcb.
mabuhay,
LDR
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 09/10/2008 : 05:28:00
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| I just dropped a JRC4580L in a DS-1 and BD-2, but it's too late to fire them up and see how they sound... |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 09/10/2008 : 17:20:23
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The 4580L is a bust in the DS-1, but is a keeper in the BD-2.
The DS-1 is a funny animal - I've tried TL082 and 1458 DIP8's in it, and they both sounded pretty bad, too.
I think that for the 4580L to work that it has to be biased much more on the cool side, and it can't have a tranny cascaded into it like the DS-1 does.
Funny thing about the DS-1 - it basically runs the 1st half of the op amp at unity gain, but straps the feedback into it via a 1K resistor. It might be better to ditch the preceding tranny and rework the board to use both halves of the op amp. Since pins 1&2 are tied at the board, it wouldn't be fun, though (at least not for most folks ).
I've got my DS-1 socketed now, in the rare event I come up with something better. |
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Topic |
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corresponding pins of 4558 and 5223 opamps
