I am working on an old vintage mixing console which uses the 'discontinued' LF351.
http://cache.national.com/ds/LF/LF351.pdf
I have a tube full of LF356 which looks to be a good sub. Any thoughts? Other suggestions?
http://web.mit.edu/6.301/www/LF155.pdf
Each of the balanced mic channels are transformer coupled input connected to selected NE5534 then the LF351.
I just finished digging into one of the potted transformers and was able to repair it.
Now I find a few bad LF351 discontinued parts.
Cold weather projects...
http://cache.national.com/ds/LF/LF351.pdf
I have a tube full of LF356 which looks to be a good sub. Any thoughts? Other suggestions?
http://web.mit.edu/6.301/www/LF155.pdf
Each of the balanced mic channels are transformer coupled input connected to selected NE5534 then the LF351.
I just finished digging into one of the potted transformers and was able to repair it.
Now I find a few bad LF351 discontinued parts.
Cold weather projects...
Yes I've got one comment re:LF356. I seem to recall that Walt Jung did an article on op-amps in the 1970s and there was a discussion of slew rate and sound quality etc. I'm pretty sure that he didn't like the LF356 and I believe it was something to do with the circuitry where there was some sort of "enhanced" design. Anyway it wasn't just subjectivism. He gave his reasons. The article was in "Audio". I'll check his website as he's got some of his material there. Again from memory the Texas "071" series got better auditions.
Hi danielm. I just done my "homework" You'll find the reference if you chase up the following. Put "Walt Jung's website" in Google. then go to "Library" on the LHS, then "Classic Articles" There is stuff from AA which would almost certaintly cover it but the thing I recalled is in a three part art' called "An overview of SID and TIM" AUDIO 1979 co-authored with Stephens and Todd. The listening tests are summerized on page 9 of the second section IE Part II (It was "asymetry" that was the issue.)
I'm intrigued to see on the page I mentioned that the far left column list a number of op-amps that appear "transparent" on listening tests. I'm sure you've seen some of the comments that are passed on the sonics of various electronics in this forum and while I am sure that there are differences I think some of the reactions could have been submitted to a creative writing contest. Sorry, I'm just going thru' a "bitter and twisted" phase. There is an "Audio grade" model in the 071 series from TEXAS isn't there? That will be new since the Jung art. Best wishes, Jonathan
So far I have two input channel strips installed and going. In one I installed a 351, the other a 356.
Panned one left one right and listened to a variety of music.
I noticed when driven hard the 356 is less... open sounding. Maybe a tad less detail.
I swapped ears (headphones) to verify. It is ever so slight and if didn't know it would be a tough call.
I have sockets so its easy enough to try a few different ones.
I did find one strip oscillating. Closer inspection with the scope revealed it was a 357 (LM357, not the firearm) in place of the original 351. A 356 solved this problem.
I'm OK with the performance of the 356 in a couple or more chans that need them. I will be using this for FOH live.
I think it will be a good console for hostile RF environments with its transformer inputs.
We'll, I better get back to it...
Panned one left one right and listened to a variety of music.
I noticed when driven hard the 356 is less... open sounding. Maybe a tad less detail.
I swapped ears (headphones) to verify. It is ever so slight and if didn't know it would be a tough call.
I have sockets so its easy enough to try a few different ones.
I did find one strip oscillating. Closer inspection with the scope revealed it was a 357 (LM357, not the firearm) in place of the original 351. A 356 solved this problem.
I'm OK with the performance of the 356 in a couple or more chans that need them. I will be using this for FOH live.
I think it will be a good console for hostile RF environments with its transformer inputs.
We'll, I better get back to it...
Tle2071 Tl051 Tl071 Lf351
Jonathan,
maybe you refer to this one:
The best direct upgrade replacement for TL071 from Texas
would be TLE2071 ( TLE207x )
http://focus.ti.com/docs/prod/folders/print/tle2071.html
http://focus.ti.com/lit/ds/symlink/tle2071.pdf
Texas also has got the TL051 ( TL05x ).
But in my opinion TL051 is not very much of an upgrade for TL071.
Anyway, very slightly better data, if looking to specs only.
And, of course, if answering this topic,
TLE2071 would be a very good replacement for LF351, too.
Regards
lineup
Jonathan Bright said:
Jonathan,
maybe you refer to this one:
The best direct upgrade replacement for TL071 from Texas
would be TLE2071 ( TLE207x )
http://focus.ti.com/docs/prod/folders/print/tle2071.html
http://focus.ti.com/lit/ds/symlink/tle2071.pdf
Texas also has got the TL051 ( TL05x ).
But in my opinion TL051 is not very much of an upgrade for TL071.
Anyway, very slightly better data, if looking to specs only.
And, of course, if answering this topic,
TLE2071 would be a very good replacement for LF351, too.
Regards
lineup
Jonathan Bright said:
Hi Jonathan Bright ( middle aged professional )
I wonder if you maybe think of TLE2071
It is one of Texas best for replacing TL071
* The TLE207x family of BiFET amplifiers are Texas Instruments highest performance BiFETs,
with tighter input offset voltage and ensured maximum noise specifications.
Would that make any sense to you
I guess you missed my post above.
lineup
Half Bright ( older age true amateur )Lineup Audio Research Lab
http://lineup.awardspace.com/
danielm said:
LF356 appear very different from LF351 (which, in turn is very similar to TL071; the latter has better noise specification but this may be due to a different measurement parameter and not a really better performance).
In my opinion LF356 circuitry appear to be otpimized for speed and instrumentation application, not for linearity or generic audio.
Hi
Piercarlo
Re: Re: LF351 substitute
Hi Peircarlo
You maybe missed my post about TLE2071 from Texas.
I don't know whay you talk about older OP-Amps
like those in LF35x series.
They are about from same age as LF351.
When we have other modern Op-Amps directly replacing LF351 - Tl071.
Myself have a bunch of LF353 in TO5 capsule at home.
From recycling old PCBs.
Still I would not consider them for my Audio circuits.
When there are so many good modern ones out there.
For a good price and with excellent performance in compare.
If we thing OPA134 is too expensive .. there are plenty of others.
TLE2071 a bit higher quality JFET Op-Amp
Regards
lineup
Piercarlo said:
Hi Peircarlo
You maybe missed my post about TLE2071 from Texas.
I don't know whay you talk about older OP-Amps
like those in LF35x series.
They are about from same age as LF351.
When we have other modern Op-Amps directly replacing LF351 - Tl071.
Myself have a bunch of LF353 in TO5 capsule at home.
From recycling old PCBs.
Still I would not consider them for my Audio circuits.
When there are so many good modern ones out there.
For a good price and with excellent performance in compare.
If we thing OPA134 is too expensive .. there are plenty of others.
TLE2071 a bit higher quality JFET Op-Amp
Regards
lineup
TLE2071 TLE2072 LF351 substitute
Hi Peircarlo
You maybe missed my post about TLE2071 from Texas.
I don't know what and why you bother talk about older OP-Amps
like those in LF35x series.
They are about from same age as LF351.
When we have other more modern, even from Texas Intruments,
Op-Amps directly replacing LF351 - TL071.
Myself have a bunch of LF353 in TO5 capsule at home.
From recycling old PCBs.
Still I would not consider them for my Audio circuits.
When there are so many good modern ones out there.
For a good price and with excellent performance in compare.
If we thing OPA134 is too expensive .. there are plenty of others.
TLE2071 a bit higher quality JFET Op-Amp
Regards Not a Milan football fan
lineup
Piercarlo said:
Hi Peircarlo
You maybe missed my post about TLE2071 from Texas.
I don't know what and why you bother talk about older OP-Amps
like those in LF35x series.
They are about from same age as LF351.
When we have other more modern, even from Texas Intruments,
Op-Amps directly replacing LF351 - TL071.
Myself have a bunch of LF353 in TO5 capsule at home.
From recycling old PCBs.
Still I would not consider them for my Audio circuits.
When there are so many good modern ones out there.
For a good price and with excellent performance in compare.
If we thing OPA134 is too expensive .. there are plenty of others.
TLE2071 a bit higher quality JFET Op-Amp
Regards
Not a Milan football fanlineup
Re: TLE2071 TLE2072 LF351 substitute
No, I don't miss it; rather I've download the datasheet!. But i've think about that is more suitable for new design than older. However I suppose that the IC, being employed as a second stage, is used essentially for equalizing purpose where a FET input is a noticeable plus.
For general purposes new TLE 207x are better replacements for TL07x with a big exception: TL070/80 which permit, with it's open compensation feature, a better flexibility than new devices, especially in tailoring maximum open loop bandwidth, gain e, last but not least, offering a tricking possibility of bypassing it's output class B stage with a more "personal" kind of output stage(fully class A if desired!), especially in preamplifiers, where the high (but not too...) output current capabilities are often not used at all!
I'm not a football fan at all!
Hi
Piercarlo
lineup said:
No, I don't miss it; rather I've download the datasheet!
. But i've think about that is more suitable for new design than older. However I suppose that the IC, being employed as a second stage, is used essentially for equalizing purpose where a FET input is a noticeable plus.For general purposes new TLE 207x are better replacements for TL07x with a big exception: TL070/80 which permit, with it's open compensation feature, a better flexibility than new devices, especially in tailoring maximum open loop bandwidth, gain e, last but not least, offering a tricking possibility of bypassing it's output class B stage with a more "personal" kind of output stage(fully class A if desired!), especially in preamplifiers, where the high (but not too...) output current capabilities are often not used at all!
Regards
lineup
I'm not a football fan at all!
Hi
Piercarlo
I used the 356 to replace the stock 351 simple because I had a tube of 'em here.
The TLO2071 looks to be a good candidate for this project.
There were a few problems on the console I wanted to address before putting much $$$ into several more expensive devices.
Re-amping a large console can add up money, current and noise. Those limiting factors are listed in order.
There's maybe 200+ opamps. BB134s would brake the bank here.
So far she's sounding good. I'm down to one chan strip yet to repair.
I'll let it cook for a few days then maybe order some 2071s.
Thanks guys.
The TLO2071 looks to be a good candidate for this project.
There were a few problems on the console I wanted to address before putting much $$$ into several more expensive devices.
Re-amping a large console can add up money, current and noise. Those limiting factors are listed in order.
There's maybe 200+ opamps. BB134s would brake the bank here.
So far she's sounding good. I'm down to one chan strip yet to repair.
I'll let it cook for a few days then maybe order some 2071s.
Thanks guys.
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