|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
||Thread Tools||Search this Thread|
|7th March 2008, 05:32 PM||#1|
Join Date: Sep 2003
Location: Alps:Tube amp designs over 150W, SMPS guru.
preamp line ctt
Glancing through my 1960's dusty amp files, I came up with this preamp circuit and lashed it up using modern components.
The 2nd stage ECC83 bootstrap is a bonus upping the input Z and with gain control in cathode, the 3rd stage uses AC (36dB) nfb strapped back to cath 2nd stage. I have to tabulate the b/w performance and other issues.
For those who can't abide with true signal triodes, I used two EF86's as triodes an by golly it gave the b/w results I was after. Even with ECC83 it's good.
1V AC rms in and 18V rms at 3rd stage at only 0.15% thd 2nd harm. The THD drops proportionally with level. With such dynamic overhead performance, this would make a template for a line amp and with a Baxandall tone control stage + cathode follower o/p an excellent piece of kit..
Noise level using EF86's as triodes typ -90dB (pretty quiet).
The 2nd +3rd stage physics is pretty obvious, but I've only seen this config in one other preamp. Why not ?
The only other preamp I've seen anywhere near this is the Old Brimar/Thorn VP10 using obsolete ECC807's.
Anyone else tried sim ?
|Thread Tools||Search this Thread|
|Thread||Thread Starter||Forum||Replies||Last Post|
|6V6 line preamp||Salas||Tubes / Valves||2730||19th November 2015 08:50 AM|
|Help me design my DAC/Line Preamp.||kuroguy||Tubes / Valves||7||2nd April 2009 09:31 PM|
|Preamp for Line In and Mic||blur||Instruments and Amps||1||4th January 2007 05:02 PM|
|Line stage preamp, based on SY's "Heretical Unity gain line stage"||Danko||Tubes / Valves||23||18th July 2005 05:07 AM|
|Line preamp for 2A3 amp||Petman||Tubes / Valves||0||24th May 2002 04:11 PM|
|New To Site?||Need Help?|