Adcom 5800 - Nelson Pass, others - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 2nd May 2008, 10:23 PM   #1
diyAudio Member
 
Join Date: Apr 2008
Default Adcom 5800 - Nelson Pass, others

I'm baffled as to why my 5800 is having such a tough time driving my ML CLS2A's(glary mids and tizzy treble). Granted, the CLS impedance dips to less than 1 ohm @18-20kHz but I always thought the beefy power supply and 16 output devices/ch of this beast could handle the job. Can this be remedied by bias adj or some other relatively easy tweak? Appreciate any input?

Jerry
  Reply With Quote
Old 2nd May 2008, 10:55 PM   #2
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
I think you at least want to check on the bias value of the 5800.

The prototype had a lot of capacity and a very healthy bias, which
ordinarily would allow it to do the job. I had a pair of ML Monolith
variants at the time it was developed, so I know it worked well
into them.
  Reply With Quote
Old 2nd May 2008, 11:41 PM   #3
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
The Martin Logan CLS went through a few changes during its lifespan and I didn't hear all of them, but to be quite frank with you I never found them acceptable. Why? Exactly what you describe--glassy, forward upper midrange and less than optimal top end.
In other words, are you sure it's the amp that's the problem?
Speaking only for myself, I wouldn't take a pair of CLSs on a silver platter. They were actively offensive to me. Yes, I know they reviewed well and some people swore by them, but to me...well, you get the idea. Don't blame the amp if it's the speaker.

Grey
  Reply With Quote
Old 2nd May 2008, 11:54 PM   #4
diyAudio Member
 
Join Date: Apr 2008
Hi Grey

I know it's the amp because my VSP Trans/Mos 200w works very well with the CLS. A friends Hafler 9505 Transnova also was quite good. BTW, one must use tubes somewhere in the chain of amplification when running CLS'S. I use an AL MOD 2D pre. Perhaps your listening experience with the CLS was affected by incompatible power amplification. You should'nt go all solid state.

Jerry
  Reply With Quote
Old 2nd May 2008, 11:56 PM   #5
diyAudio Member
 
Join Date: Apr 2008
Thanks Nelson. How high should I reset the bias?

Jerry
  Reply With Quote
Old 3rd May 2008, 01:35 AM   #6
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Is yours the version with the fan?
  Reply With Quote
Old 3rd May 2008, 03:47 AM   #7
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
Quote:
Originally posted by CLS2ASTAT


Perhaps your listening experience with the CLS was affected by incompatible power amplification. You should'nt go all solid state.


The first thing to know is that I adore tubes. The second thing to know is that I own tubes. The third thing to know is that I've designed with tubes. That said...no speaker should force you to listen to use tubes in order to sound tolerable.
If you're trying to use a warmish sounding amp to tame the aggressive mids and highs of the CLSs, consider an Aleph.

Grey
  Reply With Quote
Old 3rd May 2008, 04:08 AM   #8
diyAudio Member
 
Join Date: Apr 2008
Yes, it has the fan.
  Reply With Quote
Old 3rd May 2008, 04:31 AM   #9
diyAudio Member
 
Join Date: Apr 2008
Quote:
Originally posted by GRollins



The first thing to know is that I adore tubes. The second thing to know is that I own tubes. The third thing to know is that I've designed with tubes. That said...no speaker should force you to listen to use tubes in order to sound tolerable.
If you're trying to use a warmish sounding amp to tame the aggressive mids and highs of the CLSs, consider an Aleph.

Grey

I love tubes also. In fact I Wish I could afford a high powered tube amp to drive my CLS but I think you're missing the point. Their notoriously tough load can give many so called "high end" solid state amps a hard time. And oddly enough, just for grins we tried a Berenger Euro that my friend uses strictly as a sub amp. It did a respectible job sonically(this amp is NOT euphonic sounding), because it could deliver enough volt/amps to handle the nasty impedance of the ML. The hard aggressiveness is not a speaker issue, but rather an amp issue.

Jerry
  Reply With Quote
Old 3rd May 2008, 04:55 AM   #10
diyAudio Member
 
Join Date: Dec 2005
Location: Seattle, WA, USA
>>BTW, one ohm speaker can design only moron
Upupa Epops, 4\2006

http://www.diyaudio.com/forums/showt...944#post898944

  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
Measurements of an Adcom GFA-5800 mjarve Solid State 23 1st January 2014 09:52 AM
Adcom 5800 ROY'S Solid State 1 21st October 2012 09:37 PM
Adcom 5800 ROY'S Solid State 7 5th August 2012 04:18 PM
Adcom 555II - Nelson Pass ? thylantyr Solid State 53 29th October 2010 07:13 PM
adcom gtp 500ll tuner problem, Nelson Pass maybe? crippledchicken Pass Labs 11 21st January 2004 11:36 PM


New To Site? Need Help?

All times are GMT. The time now is 04:03 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