Good starting gain for an instrument preamp input stage--do I have this right? - 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 10th October 2011, 05:24 PM   #1
diyAudio Member
 
Join Date: Oct 2010
Default Good starting gain for an instrument preamp input stage--do I have this right?

I'm building up a couple of AMB's a20 discrete line stage amps as input stages for a "boutique-ish" stereo instrument preamp I'm working on:

The alpha20 Line Stage Amplifier

They're configurable gain from unity to 20.

Specifically, my NS/Stick uses EMG FT active pickups, which output .52V RMS, .75V Peak, according to the specs:

EMG Pickup Specs

I thought I'd like to run the internals of the preamp at a nominal +4 dBu level, 1.228V nominal or 1.737V peak (I run pro-referenced power amps).

This suggests a gain of about 7 whether I calculate from nominal or peak levels. Does this sound normal for an instrument preamp?
  Reply With Quote
Old 10th October 2011, 11:02 PM   #2
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
I get voltage gain of 2.5 which seems to be within spec. What is an NS/Stick EMG FT active pickup? My moving magnet phone cartridge, or "pickup" puts out about 25 mv.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300
  Reply With Quote
Old 11th October 2011, 12:03 AM   #3
diyAudio Member
 
Join Date: Oct 2010
Quote:
Originally Posted by indianajo View Post
I get voltage gain of 2.5 which seems to be within spec. What is an NS/Stick EMG FT active pickup? My moving magnet phone cartridge, or "pickup" puts out about 25 mv.
The "NS/Stick" is a multi-mode tapping instrument created by Emmett Chapman and Ned Steinberger:

www.stick.com - NS/Stick

The EMG FT's are active stacked humbuckers:

www.stick.com - NS/Stick - Electronics

Quote:
I get voltage gain of 2.5 which seems to be within spec.
Thanks! See..that's what I get for "cheaping out" on my math (in my case misusing an online calculator).

Actually doing the math I ended up with similar values.
  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
6SN7 operating points input gain stage and concertina DrewP Tubes / Valves 13 14th July 2009 11:03 PM
12vdc gain stage or preamp dublin78 Solid State 0 30th March 2008 10:41 PM
12vdc gain stage or preamp dublin78 Class D 0 29th March 2008 11:58 AM
How to calculate the gain of an input-driver stage? Antonio Tucci Tubes / Valves 0 8th October 2004 12:25 PM


New To Site? Need Help?

All times are GMT. The time now is 03:04 AM.


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