Systems

[jbeckva]

Like the LME49860 but in a quad and a dual 14-pin package?

Hi Mark,

You can try the LME49740, which is basically a quad version of the LM4562. Great specs, etc. But you may have to do some PS decoupling work to make sure it won't oscillate (shouldn't be a prob for ya tho).

http://www.ti.com/lit/ds/symlink/lme49740.pdf

Looks like Mouser has it. Pic's wrong tho (shows an 8 pin DIP when it really is a 14 pin)

 

[Gepetto]

You are being very generous with your "7" Mark. The RC4136 was the first quad op amp as far as I know and it was basically 4 LM741s which are great utility op amps but not very good for passing audio signals.

The RC4136 pinout is very oddball so you will have to obtain some of those small PCB adapters.

 

[mlucitt]

Brown Dog makes an adapter for the 14-pin DIP quad OPAMP but not for the 14-pin dual OPAMP and those are the phono and rear equalization circuits. I will order 2 of the OPA2134 surface mount OPAMPs to use with the Brown Dog adapter. I'll let you know if there is an improvement.

https://02b9b87.netsolstores.com/audiou ... pters.aspx" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Mark

jbeckva,
Thanks for the recommendation, I was on the Mouser page, the opamp is $5.32 and probably sounds great but the pins are all wrong and I would have to do major surgery with a wire wrap tool and a DIP socket to make it work!

 

[jbeckva]

Good snag, Mark!

 

[Gepetto]

The OP2134 is my favorite Mark. Have the dual version in my old Realistic TM-1001 tuner and it sounds great. Very rich and full sounding.

 

[laatsch55]

I have some mounted up on the adapters already with surface mount 2134's. I had bought a bunch to upgrade the 2000's. How manmy ya want Mark??

 

[laatsch55]

I had contemplated doing the mount work myself but ordered some mounted first. Glad I did as the surface mount op-amp is very small. For another 8.00 or so it was a no-brainer.

 

[Gepetto]

I have an SMT microscope and SMT iron if you need a few done up

 

[laatsch55]

That's what it takes e??

 

[NavLinear]

Yeah - IMO Joe's right. As soon as you begin using small footprint components (surface mount) things can get a little dicey. Where I work we develop unique designs - one off so to speak - and most of the work (on my projects) is hand soldered. Not by me but by someone that does this for a living and I swear she can solder two molecules together!

Ok - maybe she can't quite do that but the components we use today have close spacing and we use microscopes to solder and to QA the workmanship. I cheat and use a higher magnification level than what is called out in the present specification we're following and I am amazed at what someone can do with a soldering iron.

Just keep this in mind if you deceide to solder the smaller surface mount components yourself. The microscope and surface mount soldering iron / adaptors are not cheap and will take some time to amortize. The bottom line (as I see it) is this - by using an outside source to do this soldering it may keep your cost down and keep you from having to procure new equipment - unless the numbers work out for doing this in house. My opinon only - good luck!

Nav

 

[speakerman1]

I found this site awhile back.

http://www.chipquik.com/

Larry

 

[mlucitt]

Lee,
Is there anything you don't have? Thanks for the offer, I may take you up on that. But first I want to try and see if I can do it myself. I have a good soldering station, the venerable Weller WTCP with a new 700 degree 1/32" tip. I took a class in the Navy about a thousand years ago on surface mount technology and I will practice first. I also bought two adapters, just in case. I'll send pictures if they turn out OK, no pictures if I butcher them.

If I can make this work, I might try to find modern OPAMPs in a TO-5 style and go after the Crown IC150 preamp (with Joe's help).

 

[Gepetto]

That would be the other Lee, Mark

 

[laatsch55]

We have 2???????

 

[laatsch55]

Joe, I'll round up mthe orphan adapters and let you have at it. I think I bought ten of each. Mark you'll dig the care package I sent.

 

[laatsch55]

Got some TO-5 op-amps too.

 

[laatsch55]

Dennis I couldn't justify the AP either, that's half the fun.

 

[Gepetto]

OK Lee, give me instructions on what you want installed on which. Thx.

 

[laatsch55]

The 2134's on the brown dog adapters, I have the components just have not tried soldering them as it appeared the equipment I had was like a 20 lb sledge to remove a sliver.

 

[mlucitt]

This thread never disappoints.