Go Back   Home > Forums > >

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

EL34 Baby Huey Amplifier
EL34 Baby Huey Amplifier
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
Old 9th January 2021, 10:02 PM   #981
zintolo is offline zintolo  Italy
diyAudio Member
 
Join Date: Sep 2012
Quote:
Originally Posted by Francois G View Post
Thank you also for your reminder about CFB transformers - I forgot about the additional drive requirements with them. I will have to learn LTSpice to play with and balance these things and devise a proper drive circuit for those Toroidy TTG-CFB6600PP transformers in the closet.
LTSpice is an useful tool, but it's really only part of it. I use it during the week, when I cannot push the amp to its limits and hear how it sounds. Then details must be defined by hear IMO.

Quote:
Originally Posted by Francois G View Post
I don’t know if it is a simulation artifact, or some other cause, but I am dubious about the “optimal CCS current” result of >6 ma for two 12AX7 triodes. See the chart below.
I was probably not clear in my explanation, but the current I was talking about is through the leds of the CCS, not through the NPN (so not passing through the PI). It is clear that a current flowing through the triode would change its working point and so its harmonics, but here I'm talking about the current through the leds.
  Reply With Quote
Old 10th January 2021, 10:28 PM   #982
zintolo is offline zintolo  Italy
diyAudio Member
 
Join Date: Sep 2012
This is again a cascoded version of the BH with KT88.

In attachment there's the schematic in image and LTSpice format, here below the THD at 70 Wrms with no gnfb:

Code:
Harmonic	Frequency	 Fourier 	Normalized	 Phase  	Normalized
 Number 	  [Hz]   	Component	 Component	[degree]	Phase [deg]
    1   	1.000e+03	3.341e+01	1.000e+00	   -3.54°	    0.00°
    2   	2.000e+03	9.127e-03	2.732e-04	  -93.13°	  -89.59°
    3   	3.000e+03	2.083e-01	6.237e-03	 -146.94°	 -143.40°
    4   	4.000e+03	9.812e-04	2.937e-05	  -90.02°	  -86.48°
    5   	5.000e+03	2.459e-01	7.362e-03	 -177.65°	 -174.11°
    6   	6.000e+03	6.152e-04	1.842e-05	  -86.21°	  -82.67°
    7   	7.000e+03	2.082e-02	6.231e-04	  162.87°	  166.41°
    8   	8.000e+03	5.356e-04	1.603e-05	  -82.22°	  -78.68°
    9   	9.000e+03	3.107e-02	9.300e-04	  174.51°	  178.06°
Total Harmonic Distortion: 0.971709%(0.971996%)
Attached Images
File Type: jpg 12AX7&KT88 - cascoded-BHEL34.jpg (144.7 KB, 86 views)
Attached Files
File Type: asc 12AX7&KT88_Shunt_Hi-Fi.asc (10.1 KB, 9 views)

Last edited by zintolo; 10th January 2021 at 10:52 PM.
  Reply With Quote
Old 11th January 2021, 10:43 PM   #983
zintolo is offline zintolo  Italy
diyAudio Member
 
Join Date: Sep 2012
Another trial of the cascoded version of the BH, this time with KT120.

In attachment there's the schematic in image and LTSpice format, here below the THD at 110 Wrms with no gnfb:

Code:
Harmonic	Frequency	 Fourier 	Normalized	 Phase  	Normalized
 Number 	  [Hz]   	Component	 Component	[degree]	Phase [deg]
    1   	1.000e+03	4.177e+01	1.000e+00	   -2.91°	    0.00°
    2   	2.000e+03	1.047e-02	2.507e-04	  -91.83°	  -88.92°
    3   	3.000e+03	1.350e-01	3.232e-03	  -71.34°	  -68.43°
    4   	4.000e+03	5.792e-04	1.387e-05	  -71.50°	  -68.59°
    5   	5.000e+03	2.946e-01	7.053e-03	 -168.55°	 -165.65°
    6   	6.000e+03	2.006e-04	4.803e-06	  -76.50°	  -73.59°
    7   	7.000e+03	1.674e-03	4.007e-05	 -112.26°	 -109.35°
    8   	8.000e+03	1.510e-04	3.615e-06	  -79.49°	  -76.59°
    9   	9.000e+03	2.552e-02	6.109e-04	  175.67°	  178.58°
Total Harmonic Distortion: 0.778626%(0.778689%)
Attached Images
File Type: jpg 12AX7&KT120 - cascoded BHEL34.jpg (140.1 KB, 59 views)
Attached Files
File Type: asc 12AX7&KT120_Hi-Fi.asc (10.1 KB, 5 views)
  Reply to this post

Reply


EL34 Baby Huey AmplifierHide this!Advertise here!
Thread Tools

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
Baby Huey GB PCB - EL34 Build Thread spaceistheplace Tubes / Valves 22 5th March 2020 02:59 PM
FS: partially populated Baby Huey EL34 PCBs Abszero Swap Meet 2 18th June 2018 03:40 AM
First time baby Huey amplifier build mossmamc Tubes / Valves 131 21st November 2011 08:18 PM
Building the Baby Huey EL84 pushpull amplifier Bas Horneman Tubes / Valves 0 19th October 2009 09:21 PM


New To Site? Need Help?

All times are GMT. The time now is 08:22 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki