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

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Iron loaded preamp, any thoughts?
Iron loaded preamp, any thoughts?
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 6th December 2009, 01:07 PM   #1
hollow_man is offline hollow_man  Europe
diyAudio Member
 
Join Date: Nov 2004
Location: Athens
Default Iron loaded preamp, any thoughts?

After much frustration with a 6H6Π LTP design intended for SE to balanced conversion, this is my new line stage plan. Please openly comment/suggest!
Attached Images
File Type: gif Clipboard01.gif (24.1 KB, 558 views)
__________________
'in acts and works
bigger than a great wale's tail'
  Reply With Quote
Old 6th December 2009, 01:28 PM   #2
hollow_man is offline hollow_man  Europe
diyAudio Member
 
Join Date: Nov 2004
Location: Athens
Mind you, them 6j5's, they don't go cheap eh? Not to mention the god**mn Lundahls, but will it play music?
__________________
'in acts and works
bigger than a great wale's tail'
  Reply With Quote
Old 6th December 2009, 01:44 PM   #3
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Iron loaded preamp, any thoughts?
did you calculate gain ?

anyway - I like big xconductance tube in that position .....

WOT preamp and battery charger
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 6th December 2009, 01:59 PM   #4
hollow_man is offline hollow_man  Europe
diyAudio Member
 
Join Date: Nov 2004
Location: Athens
x19 from 6j5 = 25.5dB
-2.5dB from shunt volume control
-13dB from tranny
=9.6dB, if I am correct.
__________________
'in acts and works
bigger than a great wale's tail'
  Reply With Quote
Old 6th December 2009, 02:21 PM   #5
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Iron loaded preamp, any thoughts?
Quote:
Originally Posted by hollow_man View Post
x19 from 6j5 = 25.5dB
-2.5dB from shunt volume control
-13dB from tranny
=9.6dB, if I am correct.
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 6th December 2009, 04:31 PM   #6
martyh is offline martyh  United States
diyAudio Member
 
Join Date: Feb 2004
Location: Wisconsin
HI,

I built a transformer coupled pre that was originally going to use 6j5Gs but sticker shock got me to wire it for ˝ 6sn7. I still used two tubes but set it up so that the two channels used opposite triode sections. That actually worked out pretty well as I was able to get some good tube matches by swapping channels.
  Reply With Quote
Old 6th December 2009, 05:14 PM   #7
hollow_man is offline hollow_man  Europe
diyAudio Member
 
Join Date: Nov 2004
Location: Athens
I thought of that too Martyh, and I think it's a sound idea if you have access to good 6sn7's. How is the sound? and what trannies did you use?
__________________
'in acts and works
bigger than a great wale's tail'
  Reply With Quote
Old 6th December 2009, 06:26 PM   #8
martyh is offline martyh  United States
diyAudio Member
 
Join Date: Feb 2004
Location: Wisconsin
Quote:
Originally Posted by hollow_man View Post
I thought of that too Martyh, and I think it's a sound idea if you have access to good 6sn7's. How is the sound? and what trannies did you use?
I used a couple of types of vintage transformers, originally some rcas that were built by utc. They were very nice in the midrange but were limited on the bottom end, I switched them pretty quickly for utc ha133s which were much better in that regard.

My long term commercial reference is an ARC LS2, compared to that the sound was warm and full bodied but not in a bloated way. More musical is probably a good way to describe the difference. Vocals in particular had an uncanny realism compared to my reference, more of a “they are here” than a “you are there” presentation if that makes any sense

I listened to it until my marginal filament supply died and rather than rebuild it I am using the output transformers for a version using the 26. I’ve set that up so that if I can’t get the 26s quiet I can switch back to 6sn7s using the unregulated supplies and call it a day. I’m hoping that the 26s give me more of the more I got with transformer coupling but I really enjoyed the 6sn7s and if I need to switch back I’m ready to call it day in my preamp search.
  Reply With Quote
Old 6th December 2009, 07:23 PM   #9
Bandersnatch is offline Bandersnatch  United States
diyAudio Member
 
Join Date: Jul 2003
Location: Ann Arbor, MI
Quote:
Originally Posted by hollow_man View Post
After much frustration with a 6H6Π LTP design intended for SE to balanced conversion, this is my new line stage plan. Please openly comment/suggest!
What about the LTP 6H6Π circuit frustrated you so thoroughly? Just curious, I'm currently listening to a linestage with 6S4Π-EB as LTP and loaded with 20k:600 output TX's and find it quite nice.
cheers,
Douglas
__________________
the Tnuctipun will return
  Reply With Quote
Old 6th December 2009, 10:11 PM   #10
zigzagflux is offline zigzagflux  United States
diyAudio Member
 
zigzagflux's Avatar
 
Join Date: Oct 2006
Location: Charlotte, NC
Ditto, currently listening to a PP 6n6p linestage into amorphous Lundahl. Sheer bliss. What kind of problems? Those little tubes are like tanks; no noise, hiss, or hum, and never had a problem with RF or oscillation. They like their current, tho.

Not meant to distract from your topic.
  Reply With Quote

Reply


Iron loaded preamp, any thoughts?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
thoughts about a 'universal' preamp ErikdeBest Tubes / Valves 16 30th March 2010 08:56 PM
I want to build a preamp for my dad.. thoughts? 240z4u Tubes / Valves 32 22nd April 2009 01:32 AM
Any thoughts on this Philly Audio preamp design. Wtlng Tubes / Valves 8 14th January 2006 12:59 AM
Quick help needed! LOTs of noise in BBMCCCS loaded /0A2 regulated preamp! stigla Tubes / Valves 17 12th May 2005 12:02 PM
Best BOSOZ preamp parts selection thoughts hifimaker Pass Labs 94 23rd March 2005 06:47 PM


New To Site? Need Help?

All times are GMT. The time now is 05:06 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki