Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

Replacing Dead Phono Opamp...What to Use??
Replacing Dead Phono Opamp...What to Use??
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 26th October 2003, 11:19 AM   #31
Christer is offline Christer  Sweden
diyAudio Member
 
Join Date: Sep 2002
Location: Sweden
Quote:
Originally posted by EchoWars
I always like to follow up with what I did/what I found, although it seems no one ever reads it.
I am sure a lot of people read it, but they might perhaps be
satisfied with just reading about your findings withoug making
any further comments. Having been involved myself in the
thread and trying to help you, I appreciate that you report
the results.
  Reply With Quote
Old 26th February 2005, 04:23 PM   #32
Monsterle is offline Monsterle  Germany
diyAudio Member
 
Join Date: Feb 2005
Location: Stuttgart, Germany
Send a message via ICQ to Monsterle
Hello folks,
does anybody out there have a datasheet of the HA1457 OpAmp?
Following the nomencaltura of this circuit I would suppose that it was made by Hitachi... It was used 4 times in my Telefunken receiver TR550...

Best regards, Monsterle
  Reply With Quote
Old 26th February 2005, 04:30 PM   #33
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Replacing Dead Phono Opamp...What to Use??
Quote:
Originally posted by Monsterle
Hello folks,
does anybody out there have a datasheet of the HA1457 OpAmp?
Following the nomencaltura of this circuit I would suppose that it was made by Hitachi... It was used 4 times in my Telefunken receiver TR550...

Best regards, Monsterle

perhaps you neighbor in Aachen has one:
http://john.ccac.rwth-aachen.de:8000...550/index.html
  Reply With Quote
Old 9th January 2010, 06:41 PM   #34
SoNic_real_one is offline SoNic_real_one  United States
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
You need a device that can take +/-22V on supply (44V in total) since that's your supply. Or you will need to use some voltage regulators too...
  Reply With Quote
Old 9th October 2019, 04:05 AM   #35
Cataudio45 is offline Cataudio45  United States
diyAudio Member
 
Join Date: Sep 2019
Location: Florida
Quote:
Originally Posted by EchoWars View Post
I always like to follow up with what I did/what I found, although it seems no one ever reads it.

Anyway, reworked the regulator to supply +/- 16V, and built my own adapter since I couldn't get ahold of the guy who apparently has some premade ones. Replaced the inverting and non-inverting input coupling caps with a new Panasonic FC caps of the same value, and popped in a OPA2134. Seems the 2134 is as good as the 2604 for DC precision, as offset at the output is under 1mV. So I replaced the output cap with a jumper wire.

Sonically, the 2134 sounds peachy. But what is most noticeable about the change is how much quieter the 2134 is than the original Hitachi part. Truly a dramatic difference.

Again, thanks for the help guys. Got a great bunch of transistor geeks here.
Hello, I just found this thread. I know it is old... but I have a similar project. You guys gave good ideas here. Thanks. But what happened to the 20 pF capacitor connected between pins 3 and 5 in the original HA1457 (pic attached)? I understand it is ignored / unnecessary. Thanks.
Attached Images
File Type: jpg Image2.jpg (70.9 KB, 92 views)
  Reply With Quote
Old 9th October 2019, 11:00 PM   #36
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Quote:
Originally Posted by Cataudio45 View Post
...what happened to the 20 pF capacitor ....
"It's in there".

The HA1457 required an external compensation cap. The OPA2134 has the compensation built-in.

There's history behind this change but you don't need to study it.
Attached Images
File Type: gif HA1457-comp.gif (17.0 KB, 68 views)
File Type: gif OPA2134-comp.gif (4.1 KB, 68 views)
  Reply With Quote
Old 9th October 2019, 11:33 PM   #37
Cataudio45 is offline Cataudio45  United States
diyAudio Member
 
Join Date: Sep 2019
Location: Florida
Quote:
Originally Posted by PRR View Post
"It's in there".

The HA1457 required an external compensation cap. The OPA2134 has the compensation built-in.

There's history behind this change but you don't need to study it.
Ok many thanks. That explains well. I've seen that diagram in OPAx228 (it is very low noise 3nV/SQRT(Hz) but doesn't use FET inputs). I will use the OPA134 to replace the HA1457. Thanks.

There is an HA1457 to OPA134 Upgrade Adapter here for those interested:
HA1457/HA12017 Upgrade Adapter | BrownDog 140901 | Cimarron Technology
  Reply With Quote
Old 10th October 2019, 06:38 PM   #38
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
Quote:
Originally Posted by JoeBob View Post
You could use two AD797s, it's rather low noise. Although I don't know how much these cost
No, its not low noise, its low _voltage_ noise. Alas the current noise is correspondingly poor making it a mismatch for a MM preamp where the impedances are much higher than the AD797 is designed for.

NE5534A will perform better, as will any good JFET or CMOS input opamp.
  Reply With Quote
Old 10th October 2019, 07:49 PM   #39
stocktrader200 is offline stocktrader200  Canada
diyAudio Member
 
Join Date: Jan 2008
Location: Calgary
The HA1457 is actually pretty good, close to NE5534. The component values chosen in some of the systems were not optimal.
  Reply With Quote

Reply


Replacing Dead Phono Opamp...What to Use??Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
folded-cascode FET/opamp MC phono Werner Analogue Source 33 17th January 2010 10:22 AM
nad 3020. Aux works, phono left dead? hostarn Solid State 13 2nd August 2009 03:54 AM
RIAA opamp phono stage advice mp741 Analogue Source 19 7th February 2006 08:49 PM
replacing phono cable kazoo Analogue Source 1 20th June 2005 08:22 PM
CDM9 servo/control pcb.....replacing the opamp tbla Digital Source 6 30th September 2004 01:28 PM


New To Site? Need Help?

All times are GMT. The time now is 11:46 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki