Buzz Hum Aleph 5 with computer as source, no good results with GLI - 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 17th February 2008, 04:48 AM   #1
zigo3 is offline zigo3  Italy
diyAudio Member
 
Join Date: Feb 2007
Location: italy
Default Buzz Hum Aleph 5 with computer as source, no good results with GLI

Hello
I use computer as source with RME digi 96/8.
When I connect the analog output to my Pass Labs Aleph 5, when it begins be warm, appears a buzz on both channels, when it's cold nothing.
I tried with a Melos triode 200+ (200 wpc class A/B tubes) the same problem.
With NAD 3020i , Hypex 400, Hypex 180 , Trends TA10.1, (maybe I forget other...) , nothing.

I put a ground loop isolator and the buzz is a little attenuates, but remain.

I tried using the RME digital output (toslink or coaxial) with a Constantine DAC and the buzz becomes a kind of "wave" that don't attenuate neither with the ground loop isolator between the DAC and the powamp.

Somebody have suggestions?
And why with this 2 poweramps and not with other?

Thanks in advance
  Reply With Quote
Old 20th February 2008, 06:08 AM   #2
diyAudio Moderator Emeritus
 
Iain McNeill's Avatar
 
Join Date: Oct 2007
Location: Santa Cruz, California
Do the amps all have the same gain? Maybe the big power amps got more gain, making the noise floor louder?

I had to pad one amp way down to get hum/hiss acceptable. It was still plenty loud!
  Reply With Quote
Old 20th February 2008, 07:55 AM   #3
diyAudio Member
 
vitalstates's Avatar
 
Join Date: Jan 2006
Location: uk
Hi Zigo

I had a very similar problem with my studio set up when using my layla 3g. I found buzz when feeding my EL34 or my F4 with analaog outs(pseudo balanced) but no buzz when feeding my aura integrated with analog outs.

I got round the problem by putting Lite DAC-AH between layla and EL34, using layla digital out. No buzz at all and the best sound I have got.

I guessed that the aura didn't show buzz because of the volume pot...perhaps if I turned the volume pot all the way up it would mimic the EL34 connection and might buzz. I use the digital volume in this machine, in all cases.

just a couple of thoughts, but it might be worth investigating the digital out a bit further because that should remove any ground loop probs you might have(use toslink obviously).

Ed
  Reply With Quote
Old 20th February 2008, 12:26 PM   #4
zigo3 is offline zigo3  Italy
diyAudio Member
 
Join Date: Feb 2007
Location: italy
Quote:
Originally posted by Iain McNeill
Do the amps all have the same gain? Maybe the big power amps got more gain, making the noise floor louder?

I had to pad one amp way down to get hum/hiss acceptable. It was still plenty loud!

Quote:
Originally posted by vitalstates
Hi Zigo

I had a very similar problem with my studio set up when using my layla 3g. I found buzz when feeding my EL34 or my F4 with analaog outs(pseudo balanced) but no buzz when feeding my aura integrated with analog outs.

I got round the problem by putting Lite DAC-AH between layla and EL34, using layla digital out. No buzz at all and the best sound I have got.

I guessed that the aura didn't show buzz because of the volume pot...perhaps if I turned the volume pot all the way up it would mimic the EL34 connection and might buzz. I use the digital volume in this machine, in all cases.

just a couple of thoughts, but it might be worth investigating the digital out a bit further because that should remove any ground loop probs you might have(use toslink obviously).

Ed
Thankyou very much for your suggestions.
About the volume, I had no problem feeding directly the Hypex400 (200 wpc powamp),Hypex180 (100 wpc powamp) and using NAD 3020 as powamp. Using it as pre and feeding both Melos and Aleph the buzz grown up...mystery...

About DAC-AH (or maybe other DACs too) it could be an idea: maybe the DACs filter in some way the signal. I tried Constantine and the hum was really attenuate, it becomes a kind of "wave", like those old radios.

I tried other trics (before my Melos Looking for Melos triode 200+ schematics and Aleph HELP Aleph 5 is burned? burned ) and the last ones took good attenuation, like put all the power imput cables on the same multi outlet or use good shielded power cables or try to isolate more as possible the signal cable between computer and pre or powamp, and I seen good attenuates results. The hum was not disappeared, but did'nt compromise the listen.
I tried other, like isolate more as possible the sound card, change the signal cables with shielded cables, disconnect the computer devices, but did'nt take results.
  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
Computer to Amp Buzz Funky971 Solid State 60 26th September 2008 04:21 PM
Melos triode and computer as source: BUZZ BUZZ BUZZ zigo3 Tubes / Valves 4 28th November 2007 02:11 AM
Buzz in gainclone, looking for source. kmj Chip Amps 31 19th October 2006 10:21 PM
What Pre-amp has given you good results with your T-Amp? Charged Chip Amps 1 12th September 2006 08:18 AM
Help on Aleph 5 buzz. protos Pass Labs 3 27th September 2002 10:13 AM


New To Site? Need Help?

All times are GMT. The time now is 11:44 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