[Moby]

Hi all

I have consoles that use the 301 which is now obsolete in dip8 package (soic seem to stay alive?)
The LM301 is used in a specific way I don't remember to see elsewhere, where the input stage is bypassed and a discrete differential pair is used in place and sent to the output stage via comp/bal pin.

I'm not expert at all in opamp topology/design and like to know what other of opamp is able to be used like that.

Here the idea of discussion is not to replace for "better" opamp, I have no complain about the sound of my 169 and 289, but anticipate a possible substitution when my spare spent out or when NOS stock get completely overpriced...

Best
Zam

LM301 DIP8, how many pieces you need? I think I still can buy it locally.

[robovox]

BGMicro shows stock on these at a reasonable price.

https://www.bgmicro.com/ICSLM301.aspx

[zamproject]

Hello

LM301 DIP8, how many pieces you need? I think I still can buy it locally.

BGMicro shows stock on these at a reasonable price.

https://www.bgmicro.com/ICSLM301.aspx

Thanks to both of you for the help.
I should have enough spare for the moment.

Best
Zam

[diggy fresh]

I'm not good enough to contribute too much but i think the Ward beck m460 and m470 preamps uses the lm301 in a similar way, bypassing some of the limitations of the internal stuff with discrete parts around it. I have dug a little bit around to find a way to upgrade the lm301 because of the bad reputation but haven't come to any conclusive info yet.  I'm very interested to know if anybody has an idea or tried something.

[chrisenglish]

BGMicro shows stock on these at a reasonable price.

https://www.bgmicro.com/ICSLM301.aspx

Has anyone tried these in a Studer 169 - 269 ?

[gridcurrent]

Has anyone tried these in a Studer 169 - 269 ?

yes.
circuit critique welcome.

thanks !
drawing revised.

[JohnRoberts]

yes.
circuit critique welcome.

well that schematic looks wrong... The input LTP (long tail pair) needs to use PNP devices for that PS orientation.

JR
[edit- well now that schematic input pair looks like it was fixed (changed to pnp)... /edit]

[jokeramik]

The NE5534 is not the right substitute. Input offset current and Input bias current are higher (around factor of ten) then the LM 301. The best way ist to use an SOIC to DIP-Adapter.
Alternatively you check the use of the LT1122 with higher slew-rate or the OP42 with higher slew-rate and symmetrical slew-rate.
Best regards!
jokeramik

[jacomart]

yes.
circuit critique welcome.

thanks !
drawing revised.

Honestly the class AB output buffer for me isn't very appealing.
Cheers
J.

[JohnRoberts]

Honestly the class AB output buffer for me isn't very appealing.
Cheers
J.

Class AB output stages are extremely common especially inside ICs to reduce power dissipation.

JR

[jacomart]

Class AB output stages are extremely common especially inside ICs to reduce power dissipation.

JR

I agree, but for a discrete-elements realization I would prefer to use class A, but that's just my opinion.
Cheers
J.

[abbey road d enfer]

The NE5534 is not the right substitute. Input offset current and Input bias current are higher (around factor of ten) then the LM 301.

I don't get it. In this application, the input devices are bypassed and replaced with discrete transistors, so input offset and bias currents are not anymore chip-dependant.
I'm too lazy to ascertain it would work, though.
For most of the circuits in these Studer mixers, the LM301 could be subsituted with 5534 without problems. Even with an order of magnitude higher, input offset and bias currents are not a concern, except in the limiter side-chain, where a FET opamp would be better..

trim pot substitution?

Started by kiira The Lab

74 series IC substitution.

Started by Steve Jones The Lab

1176 VU Meter Substitution Question

Started by Hairball Audio « 1 2 3 » The Lab

IC upgrade for the LM301's and the LF356

Started by dandeurloo Drawing Board