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

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

The Kuartlotron - keantoken's simple error-correction superbuffer
The Kuartlotron - keantoken's simple error-correction superbuffer
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 22nd September 2018, 08:47 PM   #941
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
The Kuartlotron - keantoken's simple error-correction superbuffer
Yeah I think it’s at min value, so essentially r9 is jumpered. Not sure what to make of it. On start up, tp slowly goes to 5v and offset to1-2mV.
  Reply With Quote
Old 22nd September 2018, 08:48 PM   #942
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
The Kuartlotron - keantoken's simple error-correction superbuffer
Quote:
Originally Posted by silasmellor View Post
Ok, using the 1M trimmer without the series 1.8M also works, so I suspect I’m just at the end of the travel for the pot, probably at low R. Would it make sense to try something even higher, like 2.2M for the Series resistor to R9? Is Avery low resistance for R9 a problem?
Sorry, that post should have said “without the 1.8M series resistor...”
  Reply With Quote
Old 22nd September 2018, 10:22 PM   #943
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
The Kuartlotron - keantoken's simple error-correction superbuffer
Ok I think my benchtop psu might have been the issue. I switched over to the intended psu, 10v bipolar using Nisbeths standalone whammy psu boards. Added another 500k in series with the 1.8M one and offset is only a few mV without any trimming. I can play music through it so I guess it works, but I will try the fft to check distortion (though I doubt I can trim much as my interface won’t go below 0.006%.

Sorry for the confusion, not sure why the benchtop psu was giving odd results, it has +/- and gnd taps, but measuring gnd to either + or - showed 0V so something must have been off there...
  Reply With Quote
Old 12th November 2018, 09:59 PM   #944
Zoran is offline Zoran  Serbia
diyAudio Member
 
Join Date: Jan 2004
Location: Belgrade
Hi Ken. Could You transcribe superbuffer to Germanium transistor version?
(I have one full Ge amp and it need buffer to drive input transformer...)
I know that old Ge-s are maybe inferior against contemporary Si BJTs but I just dont like idea to mix...
thanks
__________________
###
  Reply With Quote
Old 6th December 2018, 05:59 AM   #945
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Sorry, for some reason I tend to stop getting notifications from this thread.

I could take a stab at it, but I need to have datasheets for the parts you have available.
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!

Last edited by keantoken; 6th December 2018 at 06:02 AM.
  Reply With Quote
Old 6th December 2018, 06:48 AM   #946
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
I tried the Kuartlotron in the simulator with AC127/128 models, it does surprisingly well. Unfortunately not all Ge transistors are as useful as these.

The OC70 has a transition frequency of 15KHz. If I heard of a modern transistor with a Ft of 15KHz, I would assume it weighs about 100LB and is used only in special super high power applications.
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!
  Reply With Quote
Old 24th December 2018, 05:42 PM   #947
Zoran is offline Zoran  Serbia
diyAudio Member
 
Join Date: Jan 2004
Location: Belgrade
Quote:
Originally Posted by keantoken View Post
I tried the Kuartlotron in the simulator with AC127/128 models, it does surprisingly well. Unfortunately not all Ge transistors are as useful as these.

The OC70 has a transition frequency of 15KHz. If I heard of a modern transistor with a Ft of 15KHz, I would assume it weighs about 100LB and is used only in special super high power applications.
Thanks for answering Ken
(I need Ge buffer, t match with old restored Ge amp. Just to stay in a same "mood"...)
Westrex 2404-C Germanium Amp Restored
But I dont have experience how to transcribe to Ge. Biasing and other things. I am from vacuum tubes world mostly.
...
I will try to find some AC127/8
.
I have next Ge-s
.
Type Designator: 2G339
Normally replaceable-slightly different: AC127
Material of Transistor: Ge
Polarity: NPN
Maximum Collector Power Dissipation (Pc): 0.15 W
Maximum Collector-Base Voltage |Vcb|: 15 V
Maximum Collector-Emitter Voltage |Vce|: 10 V
Maximum Emitter-Base Voltage |Veb|: 2 V
Maximum Collector Current |Ic max|: 0.3 A
Max. Operating Junction Temperature (Tj): 100 C
Transition Frequency (ft): 5 MHz
Forward Current Transfer Ratio (hFE), MIN: 150
Noise Figure, dB: -
Package: TO5
.
Type Designator: 2G381
Polarity: PNP
no datas
.
Type Designator: OC83
Material of Transistor: Ge
Polarity: PNP
Maximum Collector Power Dissipation (Pc): 0.6 W
Maximum Collector-Base Voltage |Vcb|: 32 V
Maximum Collector-Emitter Voltage |Vce|: 20 V
Maximum Emitter-Base Voltage |Veb|: 3 V
Maximum Collector Current |Ic max|: 0.5 A
Max. Operating Junction Temperature (Tj): 80 C
Transition Frequency (ft): 0.4 MHz
Collector Capacitance (Cc): 100 pF
Forward Current Transfer Ratio (hFE), MIN: 40
Noise Figure, dB: -
Package: TO1
...
thanks again
cheers
.
__________________
###
  Reply With Quote
Old 24th December 2018, 06:19 PM   #948
Zoran is offline Zoran  Serbia
diyAudio Member
 
Join Date: Jan 2004
Location: Belgrade
A have also
AC187-AC188
__________________
###
  Reply With Quote
Old 24th December 2018, 06:24 PM   #949
Zoran is offline Zoran  Serbia
diyAudio Member
 
Join Date: Jan 2004
Location: Belgrade
I found some datas for small Ge already have
.
Type Designator: 2G381
Polarity: PNP
Maximum Collector Power Dissipation (Pc): 0.25 W
Maximum Collector-Base Voltage |Vcb|: 20 V
Maximum Collector-Emitter Voltage |Vce|: 20 V
Maximum Emitter-Base Voltage |Veb|: 3 V
Maximum Collector Current |Ic max|: 0.5 A
Max. Operating Junction Temperature (Tj): 85 C
Transition Frequency (ft): 1 MHz
Collector Capacitance (Cc): 50 pF
Forward Current Transfer Ratio (hFE), MIN: 75
Noise Figure, dB: -
Package: TO1
__________________
###
  Reply With Quote
Old 25th December 2018, 12:45 PM   #950
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Try it with the AC187/188. The 2G339 is fast but the Vce limit is not quite where I would like it to be.
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!
  Reply With Quote

Reply


The Kuartlotron - keantoken's simple error-correction superbufferHide 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
New error correction amp PMA Solid State 101 4th January 2011 12:00 AM
error correction et al' sq225917 Digital Source 4 7th August 2007 11:16 AM
Visual error correction? Circlotron Everything Else 4 15th September 2003 05:17 PM


New To Site? Need Help?

All times are GMT. The time now is 10:12 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