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

Solid State Talk all about solid state amplification.

Nikko HB-18005  (inside a STA-1101)
Nikko HB-18005  (inside a STA-1101)
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
Thread Tools Search this Thread
Old 18th March 2012, 10:18 PM   #1
flambart is offline flambart  Italy
diyAudio Member
Join Date: Sep 2009
Default Nikko HB-18005 (inside a STA-1101)

Hi, yesterday I've got a nice Nikko STA-1101 receiver. Really a strange, massive 40 years old boy, very very well built (wiring apart...), in excellent conditions.
Unfortunately, the right pre-amp channel does not work. I've discovered a faulty IC, labeled "Nikko HB-18005", that is mounted inside the first stage ("Flat amplifier" card, immediately after the volume potentiometer). This component is a 8 pin custom IC, and it's no more available , of course.

I think it's not so complicate to replace it with something equivalent, but neither schematics nor datasheet seem to be available

Anyone has any idea or documentation about ? I've also realized that the power amp transistors have been replaced , and now the right channel mounts two 2SC1030 and the left two 2SD551. Which are the proper ones ?

Thanks so much to everyone

Ciao, Paolo
  Reply With Quote
Old 19th March 2012, 10:19 AM   #2
east electronics is offline east electronics  Greece
diyAudio Member
east electronics's Avatar
Join Date: Jan 2006
Location: Athens GREECE
as about the buffer IC you may ID the pins 4 is - V 8 is +V or so, inputs and outputs install a base for the IC you then you can try anything you want starting from 4558 or 5532 ...I would say not to go to anything extreme of the OPA series unless you have instruments and knowledge to verify present oscillation.

For outputs you need obviously to replace only if blown also there you may put anything you like ...example will be MJ150003-4 .... non though will be drop in replacements you need to run bias set up procedure from scratch

All changes need to be symmetric you have to replace both N and P transistors working or not .... both channels also for symmetry reasons

then you need to recap the all amplifier

some info here vintage amplifier repair/upgrade manual
  Reply With Quote
Old 20th March 2012, 11:09 PM   #3
flambart is offline flambart  Italy
diyAudio Member
Join Date: Sep 2009
Thank you so much Sakis, your interventions are always wise and gentle

In the meantime, I've found in Internet (Analog Alley) the official "IC replacement bulletin" from Nikko, about the subsitution of my HB-18005

It's based on 2 normal npns, and few other components. I'm preparing the PCB

I'll let you know

Thanks a lot again, Paolo
  Reply With Quote


Nikko HB-18005  (inside a STA-1101)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
Where to place amp: Inside a common cab or inside speakers? goldyrathore Chip Amps 3 3rd September 2010 01:39 PM
Realistic STA-7 receiver rpapps Solid State 8 17th May 2005 02:49 AM
FS: RCA HB-3 Tube Handbooks Milkduds Swap Meet 1 7th March 2005 03:04 PM
PANASONIC capacitors TS-HA or TS-HB! Other caps? ulysse21 Parts 2 25th March 2004 08:10 PM

New To Site? Need Help?

All times are GMT. The time now is 05:17 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio