Feedback Loop help - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 30th November 2002, 11:58 PM   #1
diyAudio Member
 
Join Date: Oct 2002
Location: Winnipeg MB Canada
Default Feedback Loop help

Hello Everyone,

I have a Rotel RA930AX integrated amplifier. I have completed numerous upgrades such as:

-discreet bridge built with soft recovery diodes.

-bypassed all tone controls and hardwired with Nordost cable from input to volume control. (now only one source can be used).

-replaced all applicable caps with Elna Cerafine.

-added 22000uf Elna Cerafine caps to power supply.

-Changed op-amp to AD827.

-Replaced all resistors with Roederstein metal film.

-Paralled .1UF Solen and .01 Teflon(russian) cap in power supply.

-Removed plastic covers from all caps including the 22000uf ones and put a damping material on the caps.

-Replaced speaker outputs with better Vampire units (hard wired to board with Nordost cable. Also replaced RCA inputs.

That is about the extent of the upgrades so far.

I plan on upgrading the volume control.

What I want help with is identifying which components are in the feedback loop. I want to replace these components with better resistors/capacitors.

Does anybody have a schematic and can help me identify them?.

I am not too good with circuit topology.

Also, what would be the next logical upgrade to do to this amp.

Thanks for reading all this.

Cheers
KevinLee
  Reply With Quote
Old 1st December 2002, 12:16 AM   #2
halojoy is offline halojoy  Sweden
On Hiatus
 
Join Date: Nov 2002
Default Feedback localisation

Feedback always comes from the output.
Usually before the output relay
and between the output transistors.
But I guess you can not see the bottom side of the circuit.
So a schematic would be best.
  Reply With Quote
Old 1st December 2002, 12:23 AM   #3
diyAudio Member
 
Join Date: Oct 2002
Location: Winnipeg MB Canada
Thanks Halajoy.

My amp does not have relays.

I can trace the circuit if you can help me with what I am looking for.

KevinLee
  Reply With Quote
Old 1st December 2002, 01:36 AM   #4
halojoy is offline halojoy  Sweden
On Hiatus
 
Join Date: Nov 2002
From the output point,
there should be 1 or two small resistors going
in direction to the input transistors.
Often is a small capacitor right beside the resistor.
They are in parallell.

It can also be a track that goes halfway from the output
back towards the input.
and then the resistor/cap is closer to the input.
The input is mostly one or two pairs of transistors,
with close body contact to eachother.
  Reply With Quote
Old 1st December 2002, 01:39 AM   #5
diyAudio Member
 
Join Date: Oct 2002
Location: Winnipeg MB Canada
Thanks again halajoy!

I will check it out and let you know how I made out.

KevinLee
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
feedback loop rmenger Instruments and Amps 4 21st October 2006 07:04 PM
Electrolytic in the feedback loop yup Tubes / Valves 30 9th September 2006 07:56 PM
feedback loop rmenger Parts 0 29th July 2004 01:24 PM
Zen V4 Feedback Loop Extension dcmohs Pass Labs 1 14th March 2003 05:35 PM
ZEN V4 without feedback loop Selfmade Pass Labs 8 20th February 2003 03:38 PM


New To Site? Need Help?

All times are GMT. The time now is 04:47 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2