monoblock vs. one chassis? - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 20th February 2003, 02:03 AM   #11
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default URBAN MYTHS.

Hi,

Quote:
I guess monoblocks can cause a ground loop problem.
Nah, only if designed wrongly.

I have used monoblocks (physically two separate chasis) for poweramps and have never experienced any problem with them.

My preamp is dual mono, not two monoblocks, so ground is common to both channels.

Monoblock design should be superior to integrated left and right channel.

Cheers,
__________________
Frank
  Reply With Quote
Old 20th February 2003, 02:22 AM   #12
diyAudio Member
 
Steve Eddy's Avatar
 
Join Date: Sep 2002
Location: Sacramento, CA
Quote:
Originally posted by Ryder
I've read where it works to keep the safety ground connected to the poweramps chassis (safety first)- but "float" the signal ground above the chassis gnd with a decent sized (min. 2W) 10-50 ohm resistor

What works best??
Getting rid of that damned AC power supply, that's what.

Actually, the method you mention above can be effective, though I prefer placing a 0.01uF cap in series with the resistor. That provides greater isolation at power line frequencies and the cap alows for a low impedance path to the chassis at high frequencies so that the chassis can work well as an electrostatic shield.

se
  Reply With Quote
Old 20th February 2003, 02:28 AM   #13
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default AC GROUNDING.

Hi,

Quote:
Actually, the method you mention above can be effective, though I prefer placing a 0.01uF cap in series with the resistor. That provides greater isolation at power line frequencies and the cap alows for a low impedance path to the chassis at high frequencies so that the chassis can work well as an electrostatic shield.
Absolutely, this method has been used for what...fifty years already?

Clever little trick,that one.

Cheers,
__________________
Frank
  Reply With Quote
Old 20th February 2003, 02:42 AM   #14
diyAudio Member
 
Steve Eddy's Avatar
 
Join Date: Sep 2002
Location: Sacramento, CA
Default Re: AC GROUNDING.

Quote:
Originally posted by fdegrove
Absolutely, this method has been used for what...fifty years already?
Wouldn't surprise me. I first saw it at least 20 years ago.

Quote:
Clever little trick,that one.
Yup. Another clever trick (short of ditching the AC power supply completely) is to use a Class II double insulated chassis and ditch the !@#$% safety ground.

Sadly, there are probably a lot of commercial products out there whose chassis meet Class II specs but because the 3 conductor power cord has become so ubiquitous, the manufacturers just tack on an IEC socket out of habit and to be compatable with all the aftermarket IEC power cords.

se
  Reply With Quote
Old 20th February 2003, 02:49 AM   #15
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default DITCHING THE EARTH.

Hi,

Quote:
Sadly, there are probably a lot of commercial products out there whose chassis meet Class II specs but because the 3 conductor power cord has become so ubiquitous, the manufacturers just tack on an IEC socket out of habit and to be compatable with all the aftermarket IEC power cords.
No big deal for a DIYer though.
As long as you play it safe,easy enough to solve IMO.

Cheers,
__________________
Frank
  Reply With Quote
Old 20th February 2003, 03:15 AM   #16
diyAudio Member
 
Brett's Avatar
 
Join Date: Jan 2002
Quote:
Originally posted by Steve Eddy
Getting rid of that damned AC power supply, that's what.
Wow, what an idea. My monoblocks are looking like weighing about 50kg ea when the chassis are finished, so if I go battery power to give me 900V, maybe I'll just add on an extra room for them all. Seventy four truck batteries if I want to keep them monos. Batteries R us are gonna love me. No one light a match when they're recharging.
  Reply With Quote
Old 20th February 2003, 03:29 AM   #17
diyAudio Member
 
Steve Eddy's Avatar
 
Join Date: Sep 2002
Location: Sacramento, CA
Quote:
Originally posted by Brett
Wow, what an idea. My monoblocks are looking like weighing about 50kg ea when the chassis are finished, so if I go battery power to give me 900V, maybe I'll just add on an extra room for them all. Seventy four truck batteries if I want to keep them monos. Batteries R us are gonna love me. No one light a match when they're recharging.
That's the spirit!

se
  Reply With Quote
Old 20th February 2003, 07:04 AM   #18
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Default Re: URBAN MYTHS.

Quote:
Originally posted by fdegrove
Nah, only if designed wrongly.

I have used monoblocks (physically two separate chasis) for poweramps and have never experienced any problem with them.

My preamp is dual mono, not two monoblocks, so ground is common to both channels.

Monoblock design should be superior to integrated left and right channel.
I think in fact it's technical impossible to get ground loop problems if the monoblocks don't have protective earth. But you can surely get hum. I think everyone can agree that monoblocks are the easiest way to get problem free amps.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 31st March 2003, 01:42 PM   #19
Account Disabled
 
Join Date: Nov 2002
Location: hong kong
But pls remember that in one chassis if u use full triode version to push 300B. very easy to cross the noise.
this is the problem must be careful to handle.
If U like to use one chassis but near monoblock powerful swing.

one power trans with use seperate chokes ( every channel use one choke) & rectifier cap.
this will better.

thanks

Thomas
  Reply With Quote
Old 31st March 2003, 03:08 PM   #20
diyAudio Member
 
Join Date: Dec 2000
Location: 3rd rock from the Sun
Default Which is better.

Quote:
Shorter speaker cables yes. - But then your interconnects would be eaqualy longer. I don't know which is worst.
I would say probably the shorter speaker cables are better. They are more difficult to have ( heavy) shielded braids with low impedance and generally their dc resistance will be lower if they are shorter.
For balanced low level signal lines especially at 600 ohms , frequency response, damping (?) shielding etc will be much better.
So I hazzard a guess that this might be a better way to go. It also avoids the ground loops mentioned earlier - or can be avoided with careful planning.

Balanced lines here we come !
__________________
Fantastic
  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
Class-A Monoblock Amplifier Chassis (qty 2) tstrafford Swap Meet 8 14th February 2009 05:19 PM
Chassis for DIY MonoBlock Tube Amplifier sgerus Swap Meet 1 20th January 2009 07:40 PM
How to star ground to Chassis without a Chassis?? Minion Chip Amps 10 5th November 2006 04:28 PM
Where to get chassis or chassis parts in Vancouver? Prune Parts 1 7th July 2004 05:37 PM


New To Site? Need Help?

All times are GMT. The time now is 11:13 AM.


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