Switchable Hi-Z input impedance, how ? - Page 9 - diyAudio
Go Back   Home > Forums > Live Sound > Instruments and Amps

Instruments and Amps Everything that makes music, Especially including instrument amps.

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 14th December 2011, 01:52 PM   #81
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by Nigel Goodwin View Post

Some people (yourself included) seem to like the lower qualty sound that valves give you, there's no accounting for taste..
Nigel, you draw too fast conclusions
  Reply With Quote
Old 14th December 2011, 02:10 PM   #82
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
Quote:
Originally Posted by tinitus View Post
Nigel, please notice I said bass guitar only

not quite the same thing as guitar
I was referring only to bass, although the exact same thing applies to guitar as well.
__________________
Nigel Goodwin
  Reply With Quote
Old 14th December 2011, 02:14 PM   #83
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
Quote:
Originally Posted by tinitus View Post
Nigel, you draw too fast conclusions
Hardly, as you've been discussing valves throughout this thread, and endless weird configurations of valves and FET's.

Presumably you're looking for lower quality sound for a bass?.
__________________
Nigel Goodwin
  Reply With Quote
Old 14th December 2011, 04:17 PM   #84
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by Nigel Goodwin View Post
Presumably you're looking for lower quality sound for a bass?.
depends what you mean by quality

distortion seem to be a key element of good quality guitar sound

but the question is, how to differ between low quality and high quality distortion
and the difference really is there, we know that
but its still distortion
and often exstreme
  Reply With Quote
Old 14th December 2011, 07:35 PM   #85
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
Quote:
Originally Posted by tinitus View Post
depends what you mean by quality

distortion seem to be a key element of good quality guitar sound

Except we're talking bass, not guitar - remember?

Quote:

but the question is, how to differ between low quality and high quality distortion
and the difference really is there, we know that
but its still distortion
and often exstreme
There's no such thing as 'quality' distortion, by definition it lowers quality. Some guitarists want distortion for some styles of playing, I've no problem with that at all, in fact I'm all for it - heavy metal would be a sad thing wihout it

But it's far rarer for bass, not many want distorted bass, even the heavy metal crowd.
__________________
Nigel Goodwin
  Reply With Quote
Old 14th December 2011, 07:46 PM   #86
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by Nigel Goodwin View Post
But it's far rarer for bass, not many want distorted bass, even the heavy metal crowd.
thats my point

bass guitar needs only small amounts of distortion
and not really audible when playing with others
a very different from what a guitarist needs

non distorted is really not a possible option, is it ?
  Reply With Quote
Old 15th December 2011, 01:16 PM   #87
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
Quote:
Originally Posted by tinitus View Post
thats my point

bass guitar needs only small amounts of distortion
No, it's needs none at all, unless you're aiming for some specific effect?.

Quote:

and not really audible when playing with others
a very different from what a guitarist needs

non distorted is really not a possible option, is it ?
Distortion well below the range of hearing is easily possible, and most bass amps provide that.
__________________
Nigel Goodwin
  Reply With Quote
Old 15th December 2011, 03:44 PM   #88
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by Nigel Goodwin View Post
No, it's needs none at all, unless you're aiming for some specific effect?.

Distortion well below the range of hearing is easily possible, and most bass amps provide that.
what instrument are you playing
  Reply With Quote
Old 15th December 2011, 05:39 PM   #89
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
ahhh

found this on Alan Kimmel site

Because most MOSFETs are enhancement-mode types and cannot be self biased, we must supply fixed bias to it. This does not compromise the performance in any way. We want the MOSFET's source terminal lobe at about half the B+; therefore, our fxed bias must also be half the B+. We can derive this bias voltage by using a simple voltage divider of two equal-value (say, 220k)) resistors in series. Connect one end of the voltage divider to B+ and the other end to ground with a 1-5uF capacitor across the lower resistor.

The junction of the two resistors will be the fixed bias supply point to which gate resistor Rg2 will he connected. This simple arrangement has given excellent results. However, if you do not want a voltage divider, you can use a zener string for Q1's fixed bias voltage source. Operate zeners at about 20% of their maximum current rating and use a 10uF capacitor to bypass the zener string. If you build a stereo pair or a push/pull pair of Mu Stages, the same voltage divider (or zener string) can serve both. No interaction will result.
  Reply With Quote
Old 15th December 2011, 08:04 PM   #90
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
Quote:
Originally Posted by tinitus View Post
what instrument are you playing
I don't play anything, but my daughter plays bass, piano, keyboards, flute, guitar, piano accordian, drums, and she sings - and has gigged on them all.

I just do the PA

I've seen, used, and repaired MANY bass amps and combos, they don't add distortion.

Often we just DI the bass directly in to the PA, no on-stage monitors either.
__________________
Nigel Goodwin
  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
Switchable balanced / unbalanced input buffer nigeljking Analog Line Level 4 12th September 2011 12:03 PM
How to design input stage with specific input impedance/pot value mahleriana Tubes / Valves 0 16th November 2009 09:37 PM
Input Impedance Bengali Analog Line Level 7 15th August 2007 10:24 PM
Input impedance nhuwar Tubes / Valves 24 23rd July 2007 11:11 PM
Input pot and input impedance Bricolo Parts 1 19th March 2003 01:59 PM


New To Site? Need Help?

All times are GMT. The time now is 01:56 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