Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

Passively Equalized RIAA Tube Phono Preamp Based on ECC83 ECC82 & Fake NAGRA Chassis
Passively Equalized RIAA Tube Phono Preamp Based on ECC83 ECC82 & Fake NAGRA Chassis
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 16th May 2019, 02:08 PM   #11
AVWERK is offline AVWERK  United States
diyAudio Member
 
AVWERK's Avatar
 
Join Date: Jan 2004
Location: So Calif.
Very nicely done and Thanks for showing us your work !

Regards
David
  Reply With Quote
Old 16th May 2019, 04:10 PM   #12
analog_sa is offline analog_sa  Europe
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Cascais
Passively Equalized RIAA Tube Phono Preamp Based on ECC83 ECC82 & Fake NAGRA Chassis
Quote:
Originally Posted by bbp View Post
So, please give an example for non-loop feedback design based on passively RIAA equalization, especially use ECC83/12AX7 as amplification tube.
There is nothing remarkable about ECC83 other than availability. Personally not a fan of the sound and even objectively it is not such a great valve. As for examples, these come to mind starting with the letter A. Some indeed use ECC83s.
6moons audio reviews: Acousticbuoy Scorpio
Aesthetix : Products : Saturn Series : Rhea Phono Stage
Allnic Audio H-1202 Phono Stage — Audiophilia

Audionote
Talos Mk2 Reference phono system - Aries Cerat
6moons audio reviews: Art Audio Vinyl Reference

Audio Tekne
https://www.audiovalve.info/shop/pre...fiers/sunilda/
https://www.ayonaudio.com/products/p...stage/spheris/
  Reply With Quote
Old 17th May 2019, 05:19 PM   #13
waltube is offline waltube  Italy
diyAudio Member
 
waltube's Avatar
 
Join Date: Feb 2005
Location: roma
The schematic in post 2 is quite similar to my phono built 25 years ago. I always use this topology for different reason. First af all the use of a low Z riaa network help for s/n. second you can change the gain simply using the bypass cap of each gain stage without any changes on specs mainly for accuracy of the network. Now I am using different tube in the gain circuit with lower Rp and good Mu, this always to reach a good s/n

Walter
  Reply With Quote
Old 18th May 2019, 06:01 PM   #14
bbp is offline bbp  China
diyAudio Member
 
Join Date: Sep 2005
Quote:
Originally Posted by analog_sa View Post
There is nothing remarkable about ECC83 other than availability <snip>
Thanks for so many good equipments information share with us.

The reason why I use ECC83:
1. It is a challenge for using the classic ECC83 as PHONO PREAMP amplification. Especially challenge in how to deal with its high noise due to nothing special about filament noise and microphics. Thatís why some other DIYer chose E283CC, ECC808, for these tubes are made for low noise application. When you look at the commercial products, modern tubes like ECC88, D3a, C3g, 6H30, 6C45 are very popular. They feature in low impedance, low noise, some of these tubes are in good availability.
2. Availability. Yes, we can find TFK ECC83 smooth plate, ladder plate, ECC803S; Simens ECC83, triple mica E83CC; Mullard short plate, long plate and box plate; Brimar long plate, half box plate; Marconi; RCA; GE; PHILIPS; AMPEREX; JJ; TESLA; EI; RUSSIA EH; JAPAN tubes; Chinese SG, TJ; etc.
3. I like the sound produced by the classical ECC83. Nothing special but almost all the guitar amps are using it. Maybe the musicians know why.
4. Just for a DIY project, I am not intend to make it into commercial production. I am not afraid of the availability for those good ECC83 I like.
5. I have a turntable ^_^

Paul

Quote:
Originally Posted by waltube View Post
The schematic in post 2 is quite similar to my phono built 25 years ago. <snip>
Itís a pretty common design based on two very common common cathode circuits. So many designs are using it. Happy to hear that I made a similar choice as yours in 25 years before, and you may using it today! So, this choice is not bad.

Choosing the right Z for RIAA network, the amount of capacitors and distortion of 1st stage should be considered. Nobody want to using lots of capacitors in parrallel and no one want to customize special value caps from pro manufactures, the cost is toooooo high. 10K loading for ECC82, it is a good balance point.

Thanks for the advice about changing bypass cap to change gain. I tried to remove 2nd stage bypass cap to get lower gain and lower distortion. But I failed to get different capacitance in a same foot print. ROE capacitors are out of production in 10-20years before. Maybe a voltage divider is not a way.

Itís a pretty common design based on two very common common cathode circuits. So many designs are using it. Happy to hear that I made a similar choice as yours in 25 years before, and you may using it today! So, this choice is not bad.

Choosing the right Z for RIAA network, the amount of capacitors and distortion of 1st stage should be considered. Nobody want to using lots of capacitors in parrallel and no one want to customize special value caps from pro manufactures, the cost is toooooo high. 10K loading for ECC82, it is a good balance point.

Thanks for the advice about changing bypass cap to change gain. I tried to remove 2nd stage bypass cap to get lower gain and lower distortion. But I failed to get different capacitance in a same foot print. ROE capacitors are out of production in 10-20years before. Maybe a voltage divider is not a way.

Have a nice day.
Paul
__________________
Tuber, Vinyler
  Reply With Quote
Old 19th May 2019, 02:16 AM   #15
bbp is offline bbp  China
diyAudio Member
 
Join Date: Sep 2005
The transformers and shielding case.
__________________
Tuber, Vinyler
  Reply With Quote
Old 19th May 2019, 04:27 AM   #16
bbp is offline bbp  China
diyAudio Member
 
Join Date: Sep 2005
Quote:
Originally Posted by bbp View Post
The transformers and shielding case.
Permalloy sheet, hand made shielding case.
Hand winding transformer.
Exceptional frequency response results in perfect 20kHz square wave response with proper RC damping.
Attached Images
File Type: jpg TRANS1.jpg (234.4 KB, 129 views)
File Type: jpg TRANS2.jpg (271.8 KB, 129 views)
File Type: jpg TRANS3.jpg (301.1 KB, 128 views)
File Type: jpg TRANS4.jpg (187.6 KB, 126 views)
File Type: jpg TRANS5.jpg (248.2 KB, 126 views)
File Type: jpg TRANS6.jpg (255.1 KB, 36 views)
__________________
Tuber, Vinyler
  Reply With Quote
Old 19th May 2019, 11:46 AM   #17
jackinnj is online now jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Passively Equalized RIAA Tube Phono Preamp Based on ECC83 ECC82 &amp; Fake NAGRA Chassis
Quote:
Originally Posted by bbp View Post
It seems that hardly no commerical Phono Preamp on the market features in non-loop feedback design. Because matching tubes are too difficult? or too expensive?
Probably because the first stage requires high gain, low noise, absence of microphonics and low output impedance. In the passive network, the output impedance and a passive resistor value form the "R1" of the Lipshitz network.

As a tube ages, rp will change. By making the stage with low output impedance and a higher buildout resistor you mitigate the effect of changing rp.

By using the cathode follower you've achieved low output impedance. Several triode-strapped pentodes can achieve the same effect.
  Reply With Quote
Old 11th June 2019, 08:08 AM   #18
SemperFi is offline SemperFi  Wake Island
diyAudio Member
 
Join Date: Jan 2002
Location: nowhere
Nice work!
  Reply With Quote

Reply


Passively Equalized RIAA Tube Phono Preamp Based on ECC83 ECC82 &amp; Fake NAGRA ChassisHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Need RIAA phono preamp based on octal or ST Greg Hyatt Tubes / Valves 56 23rd April 2019 07:19 PM
A passively equalized OpAmp RIAA preamp Razorblade Analogue Source 13 13th May 2009 10:25 PM
Passively Equalized Pre-amp schematic HKC Solid State 0 27th May 2007 10:58 AM
FS : Car tube preamplifier (ECC83 + ECC82) ANALOG GUY Swap Meet 0 21st June 2006 03:57 AM
RIAA phono preamp using single ECC83 DJG Tubes / Valves 19 29th March 2003 02:27 PM


New To Site? Need Help?

All times are GMT. The time now is 04:08 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki