R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: "Discrete Sound from an IC Op-amp"  (Read 14183 times)

JGreenslade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 824
"Discrete Sound from an IC Op-amp"
« on: September 07, 2006, 08:48:08 am »

http://www.profusionplc.com/

What say you? Is this the breakthrough THAT claim it to be?



Regards,
Justin
Logged
Audio is a vocational affliction

"there is no "homeopathic" effect in bits and bytes." - HansP

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1105
Re: "Discrete Sound from an IC Op-amp"
« Reply #1 on: September 07, 2006, 10:31:51 am »

More marketing hoopla to sell new semiconductors. They don't discuss MO resistors that are sonically poor compared to discretes. These parts sound ok, but the SSM2019 is sonically clearer with less hf hype. Most of the time the discrete opamps have far less open loop gain, higher THD, lower bandwidth and these "errors" are what most audio folks are enamored with. A great opamp coupled with very good discrete transistors can beat this chip sonically and on the Audio Precision. Not too hard to do. Put it all in an 8 pin dip and it's very hard to do.

This is more to do about cost/convenience than quality.
Logged
Jim Williams
Audio Upgrades

danlavry

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 997
Re: "Discrete Sound from an IC Op-amp"
« Reply #2 on: September 07, 2006, 01:42:56 pm »

thermionic wrote on Thu, 07 September 2006 13:48

http://www.profusionplc.com/

What say you? Is this the breakthrough THAT claim it to be?

Regards,
Justin


The IC's at the web you mention have very little specification  
You can find out more about THAT at their web, and the datasheets are complete and detailed, as should be.

http://www.thatcorp.com/datashts.html

My general impression is (based mostly on the data sheets but somewhat limited hands on experience with those IC's):

THAT has some nice IC's. They are one of the very few semiconductor houses that offers low noise voltage and noise current capabilities, as well as other features that are suitable for good audio work.  

Regards
Dan Lavry
http://www.lavryengineering.com

Logged

Schallfeldnebel

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 816
Re: "Discrete Sound from an IC Op-amp"
« Reply #3 on: September 07, 2006, 04:08:33 pm »

Has anyone familiar to the sound of the INA 217 done AB tests comparing the THATcorp 1512 with INA217 or SSM2017?

Erik Sikkema
Logged
Bill Mueller:"Only very recently, has the availability of cheap consumer based gear popularized the concept of a rank amateur as an audio engineer. Unfortunately, this has also degraded the reputation of the audio engineer to the lowest level in its history. A sad thing indeed for those of us professionals."

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1105
Re: "Discrete Sound from an IC Op-amp"
« Reply #4 on: September 08, 2006, 10:40:06 am »

Yes, one customer has the D.A.V. BG-1 preamp which uses a BurrBrown INA217. I installed a socket and the owner can play as he has all three of the top contenders at his disposal. He reported that the Burrbrown part is the poorest performer while the that1510 has a bit of top end hype and the AD SSM2019 is the most natural of the three. I didn't get a chance to deep test it with the Audio Precision but they do test more alike than not with simple THD+noise tests.

BTW, trench isolation has been around a long time, it's used on FET input opamps as the FET transistors need to be overlayed to the silicon substrate as the bipolar process won't do FET transistors. Look to the BurrBrown OPA627 for an example.
Logged
Jim Williams
Audio Upgrades

Schallfeldnebel

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 816
Re: "Discrete Sound from an IC Op-amp"
« Reply #5 on: September 20, 2006, 05:43:53 pm »

Today I received from the THAT company two samples of 1510 and 1512. I understand the 1510 is very good in having low noise at low gains.

Erik Sikkema

Logged
Bill Mueller:"Only very recently, has the availability of cheap consumer based gear popularized the concept of a rank amateur as an audio engineer. Unfortunately, this has also degraded the reputation of the audio engineer to the lowest level in its history. A sad thing indeed for those of us professionals."

Schallfeldnebel

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 816
Re: "Discrete Sound from an IC Op-amp"
« Reply #6 on: September 27, 2006, 10:36:52 am »

I have done several listening tests comparing the THAT 1510 with the INA 217 opamp, and have to conclude that the differences are very low, and if I have to choose I would prefer the THAT 1510.

I did not hear anything of a high frequency hype as was stated earlier in this thread; IMHO there is a lower distortion in the higher midrange from the THAT 1510, which opens up that part a bit, which make the top end seem to be sharper, but this certainly does not cause a hype in the higher tonal band.

On very dynamic vocal material it seems to be the THAT 1510 handles that better, the INA 217 leaves you with some kind of pressure on the ears.

The SSM 2019 I have not heard, on paper this one has the highest distortion compared to the others. Maybe higher distortion in the low end makes it sound more warm.

Please any opinions are welcome.

Erik Sikkema
Logged
Bill Mueller:"Only very recently, has the availability of cheap consumer based gear popularized the concept of a rank amateur as an audio engineer. Unfortunately, this has also degraded the reputation of the audio engineer to the lowest level in its history. A sad thing indeed for those of us professionals."

danlavry

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 997
Re: "Discrete Sound from an IC Op-amp"
« Reply #7 on: October 11, 2006, 04:12:18 pm »

Schallfeldwebel wrote on Wed, 27 September 2006 15:36

I have done several listening tests comparing the THAT 1510 with the INA 217 opamp, and have to conclude that the differences are very low, and if I have to choose I would prefer the THAT 1510.

I did not hear anything of a high frequency hype as was stated earlier in this thread; IMHO there is a lower distortion in the higher midrange from the THAT 1510, which opens up that part a bit, which make the top end seem to be sharper, but this certainly does not cause a hype in the higher tonal band.

On very dynamic vocal material it seems to be the THAT 1510 handles that better, the INA 217 leaves you with some kind of pressure on the ears.

The SSM 2019 I have not heard, on paper this one has the highest distortion compared to the others. Maybe higher distortion in the low end makes it sound more warm.

Please any opinions are welcome.

Erik Sikkema


All of those devices are "special purpose" in the sense that they yield lower noise (input referred noise) at higher gains, but as you lower the gain, the noise grows way above levels of very noisy opamps. The reason for that is in the internal circuitry of those INA218 SSM2017 and THAT 1510, they have a pair of input transistors, and part of the gain control calls for running different amount of collector current (the more gain, the higher the current), therefore at high gain the noise goes down. But when you use such a device at unity gain (or very low gain), the noise is very high!

One can argue, and somewhat properly, that we need lower noise at high gains, and we can "live with" higher noise at low gains, when the signal is already high. This argument is good to a point. For example, I would not use such devices in a fixed low gain applications. I would consider such devices for high gain applications.

Regards
Dan Lavry
http://www.lavryengineering.com
Logged

berniechap

  • Newbie
  • *
  • Offline Offline
  • Posts: 1
Re: "Discrete Sound from an IC Op-amp"
« Reply #8 on: October 26, 2006, 11:41:16 am »

Hi.

I am an amateur, doing non-professional recordings of our choir concertos. The microphone preamp of my mobile Sony DAT Recorder TCD 7 is quite noisy. So I am considering to build my own battery-operated stereo preamp on the basis of two THAT 1510. I don't need phantom supply as I use dynamic microphones. I would like to use the preamps also for recordings with my MP3 player/recorder which only has a line level stereo input (3.5 mm).

Does anybody know if there is a kit available where you can use the THAT 1510? Where can I buy it? Or do I have do design it myself?

Or do I have to by a ready-made product, probably at a price that is too high for my amateur-level recordings? Which battery-operated micro preamp would you recommend then?

Regards,

berniechap
Logged
Pages: [1]   Go Up