6V6 line preamp - Page 164 - 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 2nd April 2013, 02:07 PM   #1631
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
Nice Bas. Ikea cutlery box? Whats your config and hows the sounds and measures?
Yep. Ikea cutlery box. Essentially the Salas 6v6 preamps standard. Without shunt reg. Sounds goods. I have never done any measurements on my amps. Because I don't have any facilities to test it with tools. Always use my ears as the final arbiter. Transforms my computer room gainclone by giving it a nice big bold tone. And sounds transparent with that big bottle tone in my main system.... if that means anything. I'll post some pics of the inside and some minor details that differ....simply because I had different stuff in my ports box. Solid state rectifiers with a damper tube after that...and elaborate snubber before the solid state rectifiers....small little chokes in the primary followed by a "standard" snubber..cap->resistor->cap.


Quote:
Looks good Bas!
Thanks.

Quote:
Did you compare it with cap out?
Also how did you wire ll1660?
Yes. I started off with cap input. Essentially it sounds pretty much the same. I mean the main character of the amp does not change really. But I did not want to worry about this cap or that cap anymore and I had no current use for my Lundahl's. Wired them up 4.5:1. In essence I moved to transformer output because I could. And I found that the background had less "noise" with the output transformer. Also I preferred the lesser gain of the transformer output.

Last edited by Bas Horneman; 2nd April 2013 at 02:15 PM.
  Reply With Quote
Old 2nd April 2013, 03:14 PM   #1632
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by Bas Horneman View Post
because I could.
That line reminds the classic Nelsonian argument. Can't be wrong using stuff in hand when fitting the bill. I.e. giving proper gain and Zo for a given system in this case. Technically it can add the odd ringing on a square wave if not tuned with primary series resistor and RC across secondary. Cutting some bandwidth also. But to know exactly it takes a gen and CRO. Very nice wooden realization Bas, true diy. Congrats.
  Reply With Quote
Old 2nd April 2013, 03:19 PM   #1633
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
Very nice wooden realization Bas, true diy. Congrats.
Thanks. Thank you again for the design!
  Reply With Quote
Old 2nd April 2013, 04:50 PM   #1634
stajo is offline stajo  Sweden
diyAudio Member
 
Join Date: Jun 2011
Location: Stockholm
Quote:
Originally Posted by iko View Post
Captain Ahab, a great battle awaits thee...
Captain Ahab had forgotten to throw the anchor

Ripple was bcs ct was not grounded to mother earth. I usually let my poweramps tie both them and pre audioground to earth. Now all measurable ripple is gone, ie scope shows small microvolt noice but no waveforms. Some 10th of a volt slow fluctuation , but I dont think thats oscillation, just tempdrifts and normal linear PSU behaviour.

285 V at 2*38 mA current means that the SSHVS gonna eat 20ish and Im eding up at 260ish (ca 20+20 mA/rail) on the anodes for choke CF. Worth a try.
  Reply With Quote
Old 2nd April 2013, 06:09 PM   #1635
stajo is offline stajo  Sweden
diyAudio Member
 
Join Date: Jun 2011
Location: Stockholm
Quote:
Originally Posted by Bas Horneman View Post
Solid state rectifiers with a damper tube after that...
Damper tube? A diode? How does that work?
  Reply With Quote
Old 2nd April 2013, 06:32 PM   #1636
massimo is offline massimo  Italy
diyAudio Member
 
Join Date: Dec 2002
Location: Milan, Italy
Quote:
Originally Posted by stajo View Post
Damper tube? A diode? How does that work?
In series, i guess, it provides a nice slow turn on
  Reply With Quote
Old 3rd April 2013, 03:31 PM   #1637
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
Damper tube? A diode? How does that work?
Click the image to open in full size.

Quote:
In series, i guess, it provides a nice slow turn on
Correct. Even though cathode stripping does not occur apparently when HT is present without the heaters being warm. I still like the slow ramp up.
Attached Images
File Type: png GM70bridgeSupply.png (12.6 KB, 221 views)

Last edited by Bas Horneman; 3rd April 2013 at 03:34 PM.
  Reply With Quote
Old 3rd April 2013, 03:38 PM   #1638
stajo is offline stajo  Sweden
diyAudio Member
 
Join Date: Jun 2011
Location: Stockholm
Common mode choke?
  Reply With Quote
Old 3rd April 2013, 03:43 PM   #1639
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
Common mode choke?
I did not use a common mode choke. That was just to demonstrate the use of a tube damper diode after a ss rectifier.
  Reply With Quote
Old 10th April 2013, 05:08 PM   #1640
stajo is offline stajo  Sweden
diyAudio Member
 
Join Date: Jun 2011
Location: Stockholm
Heloo

I putted some stuff together today to do some tests. Its a choke loaded cathode follower version with 110 H chokes. Its still ragedirag and I have some absent ground hum but it sounds decent.

I did some measurments and for compareness I took an old Rozenblitz Grounded Grid that I built long ago. 6V6 to the left and GG to the right.
10Hz, 20Hz, 50Hz, 100Hz, 1kHz, 5kHz, 10kHz and 20kHz. No wiggle at least
Attached Images
File Type: jpg 6V6 006 (3000x2000).jpg (889.2 KB, 137 views)
File Type: png 10Hz.png (26.2 KB, 131 views)
File Type: png 20Hz.png (27.6 KB, 119 views)
File Type: png 50Hz.png (27.9 KB, 21 views)
File Type: png 100Hz.png (27.4 KB, 20 views)
File Type: png 1kHz.png (23.5 KB, 21 views)
File Type: png 5kHz.png (27.7 KB, 21 views)
File Type: png 10kHz.png (27.3 KB, 18 views)
File Type: png 20kHz.png (27.3 KB, 18 views)
  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
Help me design my DAC/Line Preamp. kuroguy Tubes / Valves 7 2nd April 2009 08:31 PM
preamp line ctt richwalters Tubes / Valves 1 7th March 2008 04:34 PM
Preamp for Line In and Mic blur Instruments and Amps 1 4th January 2007 04:02 PM
Line stage preamp, based on SY's "Heretical Unity gain line stage" Danko Tubes / Valves 23 18th July 2005 04:07 AM
Line preamp for 2A3 amp Petman Tubes / Valves 0 24th May 2002 03:11 PM


New To Site? Need Help?

All times are GMT. The time now is 12:25 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