Search found 33 matches

by KMN
Tue Apr 16, 2019 5:17 pm
Forum: Pro Audio Design
Topic: Op amp matching
Replies: 40
Views: 1223

Re: Op amp matching

Indeed. Though, while appreciation of the NE5532 seems fairly ubiquitous, the NJM2068 seems to fly under the radar for many. I have recently been gaining quite a healthy respect for it in some low noise circuits. When it is the winner it often beats out parts I didn't think could be beat. I am still...
by KMN
Mon Apr 15, 2019 10:17 pm
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 393
Views: 150600

Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851

Of course, my eyes are terrible but it is hard for me to see exactly how you dealt with the transistor thermal coupling problem. Are they face to face..bonded somehow? Do you have any close up shots of that? I was thinking maybe if you planned to insert the TO92's 90 degree bent, the flat faces coul...
by KMN
Sat Apr 13, 2019 10:22 am
Forum: Pro Audio Design
Topic: Op amp matching
Replies: 40
Views: 1223

Re: Op amp matching

Wow. The little engine that could.
by KMN
Fri Apr 12, 2019 11:34 pm
Forum: Pro Audio Design
Topic: Op amp matching
Replies: 40
Views: 1223

Re: Op amp matching

I've been amazed lately at how much bang for buck an OP07 seems like in integrator circuits. Maybe they aren't THE best but they seem pretty good.
by KMN
Fri Apr 12, 2019 9:22 pm
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 393
Views: 150600

Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851

Holy cow, you are an animal! I think that may be the fastest turn around I've ever seen. Nice work!

What schematic capture/layout tools are you using? if you don't mind my asking, that is...
by KMN
Wed Apr 10, 2019 9:05 pm
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 393
Views: 150600

Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851

I am fully aware of the EMI-prone, latch-up prone, rectifying and sometimes very noisy, LM4562/LME49720 and now-discontinued LME49860. Does anybody know if this is also a problem for the current production LME49724? I was kinda eyeballing that thing after seeing it's data sheet. This thread is shoc...
by KMN
Wed Mar 27, 2019 6:54 pm
Forum: Pro Audio Design
Topic: Op amp matching
Replies: 40
Views: 1223

Re: Op amp matching

OK Im at work should be working on non audio simulations but since I'm an ijit and wanted the whole internet to know...went back and had another quick look. For me, in an integrator such as the one I posted above, the OPA335 was horribly noisy even with a ton of LPF. On the contrary. The OPA2189 is ...
by KMN
Wed Mar 27, 2019 6:38 pm
Forum: Pro Audio Design
Topic: Op amp matching
Replies: 40
Views: 1223

Re: Op amp matching

actually, just to be clear. I believe it was the opa335 I didn't like and not the OPA2189. I don't recall if I ever did the noise simulation on that one. 2189.
by KMN
Wed Mar 27, 2019 6:11 pm
Forum: Pro Audio Design
Topic: Op amp matching
Replies: 40
Views: 1223

Re: Op amp matching

When I tried this with the OPA2189 and when it was still making my circuit noisy I gave up. Notice it way over at the right hand side. How much LPF is it going to take? lol

LMP2021 was looking perfect until I noticed the limited rails. The cost is really nice too. It's too bad.
by KMN
Tue Mar 26, 2019 5:50 pm
Forum: Pro Audio Design
Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
Replies: 393
Views: 150600

Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851

Thank you for replying, JR. I figured this is one of the few places where someone might have an opinion or first hand knowledge of such things as they relate to audio.