Suggestions? - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 29th October 2008, 01:09 AM   #1
diyAudio Member
 
Join Date: Oct 2008
Default Suggestions?

Im looking into possibly building a set of monobloc chipamps. I will be using a tube pre that has approx 22db of gain. The speakers are a pair of Klipsch RB-81 bookshelfs that have a sensitivity of 97db and are 8 ohms. I am also using a powered sub a Klipsch RSW-10d but that is run off the pre.

What would you suggest for a chip that would sound the best to drive these speakers? What voltage?

Schematic and BOM?
  Reply With Quote
Old 29th October 2008, 08:26 AM   #2
diyAudio Member
 
Join Date: May 2008
Something like this?
__________________
If you've always done it like that, then it's probably wrong. (Henry Ford)
  Reply With Quote
Old 29th October 2008, 11:48 AM   #3
diyAudio Member
 
Join Date: Oct 2008
Nope. That is a tube hybrid integrated of sorts. It already has a preamp or buffer that is using tubes. I already have the tube preamp. Just looking of r a good sounding power amp or mono bloc design to build.

There are soooo many designs out there. Just looking for what most people think is the best as well as the best power supply design.
  Reply With Quote
Old 29th October 2008, 12:19 PM   #4
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
most amp systems use near 0dB to +12dB gain in the preamp, then 23 to 30dB gain in the power amp, followed by speakers of 84dB/2.8V/m to 90dB/2.8V/m.
Your system has 22dB of gain @ the pre, >=20dB gain in the power and 97dB/2.8V/m.
This equates to an extra 7dB to 32db of gain from the input of the pre to the speaker output compared to the norm.

This will demand that the input attenuator will always be at low to very low settings. Many resistive track attenuators do not operate well at low levels. The optical attenuators cannot work at very low levels.

I suggest you use a special switched attenuator adjusted to give fine resolution at very high attenuation levels or to abandon the idea of combining all these high gain stages in one system.
+42dB of gain driving 97dB speakers is exceptional!!! So exceptional that a conventional power amp is not required. By that I mean a power buffer after the preamp would give +22dB of gain into your 97dB speaker and still match the gain of +6dB pre into +23dB power into 90dB speakers.

Does anyone else agree that a power buffer may be the solution?
__________________
regards Andrew T.
  Reply With Quote
Old 29th October 2008, 12:52 PM   #5
diyAudio Member
 
Join Date: Oct 2008
Ya know what. I am sooooo mistaken! The gain the tube pre was way to high around 20 or so untill I changed the 1st and 2nd stage tubes ftom 12AX7 to 12AU7. the AX has a MU of 100 vs. the AU with a MU of if I remember correctly 17 this decreased the gain to under 12db or at 12db. I am also using a 250K stepped attenuator for the control. here is a schematic of the pre. It has three outputs 2 for the mono blocs and 1 for the sub. Click the image to open in full size.
  Reply With Quote
Old 29th October 2008, 03:49 PM   #6
Nuuk is offline Nuuk  United Kingdom
diyAudio Member
 
Nuuk's Avatar
 
Join Date: Feb 2003
Location: Somerset, SW England
Use something like the OPA549 with a gain under 10.
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant.
  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
First DIY. Suggestions are welcome. RomanSivers Multi-Way 3 19th December 2006 04:29 PM
SET Suggestions nogoodboyo Tubes / Valves 37 11th March 2006 08:38 AM
need suggestions please.. oface Full Range 2 23rd March 2005 04:46 AM
DAC Mod Suggestions? Flappytango Digital Source 24 4th February 2004 04:25 PM
Any suggestions jaybird Multi-Way 3 15th January 2004 09:12 PM


New To Site? Need Help?

All times are GMT. The time now is 04:41 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