an observation about RIAA preamps - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

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 11th September 2014, 09:54 AM   #1
diyAudio Member
 
bullpeters's Avatar
 
Join Date: Apr 2009
Location: Right next to beach, a potatoe toss to the whitewater
Default an observation about RIAA preamps

I have built three valve phono pre amps. All from kits so I didnt design any. They have always had hum. Recently I went MC and step up transformers. The noise floor went up and the hum was to much to bear. Not loud but annoying. So I bought a 25 dollar SS preamp for comparison. My partner, she has great ears, she picked it better, blind test. Even so, a very simple battery operated solid state system, I spent a couple hours with lead dress to get ZERO noise. Battery operated!!
What chance that I could get valvels to sound so quiet?
I have a valve amplier and will never let it be pried from my hands but big gain MC phono stage?? To difficult or immpossible
  Reply With Quote
Old 11th September 2014, 10:54 AM   #2
diyAudio Member
 
bullpeters's Avatar
 
Join Date: Apr 2009
Location: Right next to beach, a potatoe toss to the whitewater
My point (I am cooking as I post) is that the noise and distortion in a power amp sounds warm and lovely, but when u lift 350mv up to you. 3.5V!, then there is just to much noise. I think its more trouble then its worth and it makes no sence.
Just my thoughts
  Reply With Quote
Old 11th September 2014, 11:03 AM   #3
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Quote:
Originally Posted by bullpeters View Post
What chance that I could get valvels to sound so quiet?
100%. It's a matter of care in the design, proper layout, and most important, proper grounding. The tube MC stage I use is dead quiet.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 11th September 2014, 02:01 PM   #4
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
I have three diy phono stages, all vacuum tube, and all extremely quiet. It does take considerable care in construction and a certain level of design competence to end up with a quiet phono stage. Most of the kits offered on eBay are neither competently designed nor laid out for good noise performance.
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 11th September 2014, 03:00 PM   #5
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
I use Salas Valve Itch + Jensen 1:10 step up MC transformers, zero noise and zero hum Valve Itch phono
  Reply With Quote
Old 12th September 2014, 01:48 AM   #6
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

Quote:
The tube MC stage I use is dead quiet.
SY, are you referring to your SUT + MM phono or did you build a fully fletched valve headamp?

To TS, I can only concur with the other posters, I too run a LO MC amplified by valves only, no noise (not audible anyway) and 0 hum. Just bliss.

Cheers,
__________________
Frank
  Reply With Quote
Old 12th September 2014, 01:58 AM   #7
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Quote:
Originally Posted by fdegrove View Post
SY, are you referring to your SUT + MM phono or did you build a fully fletched valve headamp?
My MC preamp would not make a great MM preamp if the SUT were removed. I suppose my MM preamp (also dead quiet) would also work as an MC stage with the SUT.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 12th September 2014, 02:27 AM   #8
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

That's actually quite a clever design decision if you opt to use a SUT.

Cheers,
__________________
Frank
  Reply With Quote
Old 12th September 2014, 06:39 AM   #9
diyAudio Member
 
bullpeters's Avatar
 
Join Date: Apr 2009
Location: Right next to beach, a potatoe toss to the whitewater
Please believe me, I am not trying to be argumentative, and I am no electronic engineer. I guess my point is: valves are inherently unlinear and are "noisy". Maybe that makes a warm sound in your power amplifier, but if you are trying to make a tiny voltage bigger, perhaps there are better ways?
FWIW I have a john broskie tetra RIAA preamp, which was ok till I got an MC cart and SUT. Balanced inputs, all kinds of grounding schemes, when it was past 10 oclock gain, there was noise!
I am prepared to be schooled on this. I dont pretend to know much
  Reply With Quote
Old 12th September 2014, 07:02 AM   #10
diyAudio Member
 
bullpeters's Avatar
 
Join Date: Apr 2009
Location: Right next to beach, a potatoe toss to the whitewater
Seriously confused. Looked at the "valve itch" schematic layout and enclosure. Why is yours quiet and mine not? I have spent months twisting tucking and earthing to no avail. Its quiet at low gain but never ever "silent".
  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
Just an observation tvrgeek Power Supplies 0 4th February 2010 09:35 PM
Just a senseless observation... ptwining Class D 1 13th September 2006 11:11 AM
A curious observation alexmoose Tubes / Valves 1 28th April 2006 02:09 AM
Overload considerations in RIAA preamps ashok Solid State 17 11th March 2004 12:03 PM
Simple RIAA phono preamps Optical Solid State 81 26th November 2002 10:27 PM


New To Site? Need Help?

All times are GMT. The time now is 09:03 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