Go Back   Home > Forums > >

Chip Amps Amplifiers based on integrated circuits

Modulus-86  build thread
Modulus-86  build thread
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
Old 5th January 2021, 08:36 AM   #5331
hunterst is offline hunterst  Spain
diyAudio Member
 
Join Date: Jun 2014
Is anyone else here experiencing buzzing from the transformer? I'm using the Hammond 1182N22 and it is making a very annoying buzz whenever the amp is turned on.
  Reply With Quote
Old 6th January 2021, 06:06 AM   #5332
tomchr is offline tomchr  Canada
diyAudio Member
 
tomchr's Avatar
 
Join Date: Feb 2009
Location: Calgary
It could be because of DC on the mains. That can happen when the mains voltage is distorted. It would be an even-order harmonic distortion then, but it doesn't sound good.

Solution: Mains DC and Transformers
See fig. 8:
Click the image to open in full size.

The rectifier bridge could be a KBPC3510 or KBPC2510. The caps don't need to be fancy. They should be able to handle some ripple current, though. At least as much as the expected primary current, but more is better.

Tom
__________________
Modulus-86, 186, 286, & 686: 40-240W (8Ω), <-120dB THD. HP-2 Headphone Amp: 660mW, <-130dB THD. Taming the LM3886.
Neurochrome : : Audio - www.neurochrome.com - Engineering : : Done : : Right
  Reply With Quote
Old 6th January 2021, 07:30 AM   #5333
hunterst is offline hunterst  Spain
diyAudio Member
 
Join Date: Jun 2014
Thanks Tom, that looks like a quick and easy build. I'll give it a try.
  Reply With Quote
Old 6th January 2021, 04:45 PM   #5334
BrianL is offline BrianL  United States
diyAudio Member
 
Join Date: Mar 2002
Location: USA
Modulus-86  build thread
There are, or at least were, some simple commercial products with essentially this circuit inside. I think Emotiva has/had one. The price was reasonable. It may be an option if you don't want to do the building.
__________________
bel
  Reply With Quote
Old 6th January 2021, 07:20 PM   #5335
Halauhula is offline Halauhula  United States
diyAudio Member
 
Join Date: Feb 2014
Location: Bethesda MD
Quote:
Originally Posted by BrianL View Post
There are, or at least were, some simple commercial products with essentially this circuit inside. I think Emotiva has/had one. The price was reasonable. It may be an option if you don't want to do the building.
I believe the Emotiva product is a very different animal: it is to safely break a ground loop while allowing shorts to conduct to safety ground. The ground loop breaker usually consists of a large bridge rectifier or a low value (around 2-10 ohms) large wattage, heat-sinked resistor inserted between signal ground and safety ground.


Tom's suggestion, by contrast, is intended to prevent "effective DC" from entering the amplifier' power supply via the AC line. Effective DC, as I understand it, can result where another load on the isle does not place demands on the hot and neutral lines, or where there is an imbalance of loads on each side of the 220 line (110+110=220). The link that Tom has provided provides a discussion of this problem, but there are other sources available on the web which discuss this issue of DC on AC power lines.
  Reply With Quote
Old 7th January 2021, 05:46 AM   #5336
tomchr is offline tomchr  Canada
diyAudio Member
 
tomchr's Avatar
 
Join Date: Feb 2009
Location: Calgary
I've seen both in commercial amps, actually.

Tom
__________________
Modulus-86, 186, 286, & 686: 40-240W (8Ω), <-120dB THD. HP-2 Headphone Amp: 660mW, <-130dB THD. Taming the LM3886.
Neurochrome : : Audio - www.neurochrome.com - Engineering : : Done : : Right
  Reply With Quote
Old 7th January 2021, 05:47 PM   #5337
BrianL is offline BrianL  United States
diyAudio Member
 
Join Date: Mar 2002
Location: USA
Modulus-86  build thread
Look at Emotiva CMX2 - It looks like the DC blocker plus a ground missing/fault detector (similar to one of those plug-in tester gizmos with 3 Neon bulbs that electricians use) plus some noise filtering.
__________________
bel
  Reply to this post

Reply


Modulus-86  build threadHide this!Advertise here!
Thread Tools

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
Modulus-86: Composite amplifier achieving <0.0004 % THD+N. tomchr Vendor's Bazaar 2475 28th November 2020 05:02 AM
Build Thread: OBEOS Tytte71 Multi-Way 15 1st October 2011 07:02 PM
Dome's Build Thread. joe58 Full Range 12 1st September 2010 05:05 PM
SE - Build Thread soundengine355 Solid State 6 27th June 2009 01:19 AM
New Project Build Thread ryoung Multi-Way 5 19th April 2008 02:15 AM


New To Site? Need Help?

All times are GMT. The time now is 10:42 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki