Input and Output Impedance (for a CE Amp)

kforte318 · October 13, 2015, 09:20:27 PM

Firstly, thanks again to those of you that helped me get the click out of the LFO for the trem circuit I'm working on. I really appreciate it!

I am trying to stick a final gain stage on the circuit to get it up to proper volume.

http://www.falstad.com/circuit/#%24+1+5.0E-6+16.13108636308289+66+5.0+43%0Aa+192+64+304+64+0+9.0+0.0+1000000.0%0Aw+192+48+192+16+0%0Aw+192+16+304+16+0%0Aw+304+16+304+64+0%0Aw+192+80+192+192+0%0Aw+192+192+208+192+0%0Aw+240+192+208+192+0%0Aw+208+272+240+272+0%0Aw+192+192+192+288+0%0Aw+240+272+304+272+0%0A174+304+128+320+224+0+100000.0+0.9851000000000001+Rate%0Ar+320+176+384+176+0+10000.0%0Aa+384+192+480+192+0+9.0+0.0+1000000.0%0Aw+384+208+384+272+0%0Aw+304+272+384+272+0%0Aw+384+176+384+128+0%0Ar+384+128+480+128+0+100000.0%0Aw+480+128+480+192+0%0A174+512+160+480+224+0+100000.0+0.5+Shape%0Ad+512+160+576+160+1+0.805904783%0Ad+576+224+512+224+1+0.805904783%0Aw+576+160+576+224+0%0Ar+576+160+640+160+0+1000.0%0Aa+640+176+720+176+0+9.0+0.0+1000000.0%0Aw+640+192+640+272+0%0Aw+640+272+384+272+0%0Aw+640+160+640+112+0%0Aa+720+192+800+192+0+9.0+0.0+1000000.0%0Aw+720+208+720+288+0%0Aw+192+288+720+288+0%0Aw+800+192+800+288+0%0Ar+800+288+720+288+0+22000.0%0AR+640+272+672+272+0+0+40.0+4.5+0.0+0.0+0.5%0Aw+720+112+720+144+0%0Aw+720+144+720+176+0%0Aw+192+80+160+80+0%0As+160+80+128+80+0+1+true%0Aw+112+80+128+80+0%0AR+112+80+96+80+0+0+40.0+2.0+0.0+0.0+0.5%0Ax+803+66+833+69+0+12+Pulse%0Ax+806+133+822+136+0+12+Tri%0Aw+368+64+784+64+0%0AS+848+96+784+96+0+1+false+0%0Aw+784+64+784+80+0%0A162+208+272+208+192+1+2.1024259+1.0+0.0+0.0%0A162+240+192+240+272+1+2.1024259+1.0+0.0+0.0%0Ac+640+112+720+112+0+1.0E-6+1.1722871515602344%0Ar+848+96+912+96+0+10000.0%0Aa+912+112+1008+112+0+9.0+0.0+1000000.0%0Aw+912+96+912+64+0%0AR+912+128+912+160+0+0+40.0+4.5+0.0+0.0+0.5%0AO+1008+112+1040+112+0%0Aw+288+80+288+224+0%0Aw+288+224+304+224+0%0Aw+304+64+304+80+0%0Aw+304+80+288+80+0%0Aw+368+64+304+64+0%0Aw+720+112+784+112+0%0Aw+1008+336+192+336+0%0Aw+192+336+192+560+0%0Ar+192+560+304+560+0+10000.0%0At+304+560+368+560+0+1+0.33734020754424776+0.6240634916083598+100.0%0Ag+368+624+368+640+0%0A162+368+464+368+544+1+2.1024259+1.0+0.0+0.0%0AR+368+464+368+416+0+0+40.0+9.0+0.0+0.0+0.5%0Aw+1008+112+1008+336+0%0Ar+368+576+368+624+0+1000.0%0AR+288+464+240+464+0+1+100.0+1.0+0.0+0.0+0.5%0Ar+288+464+352+464+0+10000.0%0Aw+352+464+432+464+0%0Aw+432+544+432+624+0%0Aw+432+624+368+624+0%0Ax+385+510+417+513+0+12+VACT%0A174+432+544+448+480+0+10000.0+0.5594+LDR%0Aw+432+464+448+464+0%0Aw+448+464+448+512+0%0A174+912+64+976+64+0+25000.0+0.9851000000000001+Depth%0Aw+944+48+1008+48+0%0Aw+1008+48+1008+112+0%0Aw+448+448+448+464+0%0AO+448+448+448+432+0%0Aw+448+464+496+464+0%0Ax+505+472+647+478+0+24+GAIN+STAGE%0Aw+656+464+688+464+0%0AO+688+464+704+464+0%0Ao+51+64+0+34+12.528092670535079+6.103515625E-5+0+-1%0Ao+80+64+0+34+0.5846006549323611+4.8828125E-55+1+-1%0A

Here's my circuit so far. Obviously, I am replacing the "GAIN STAGE" text with a CE Amp. Being that I am weak in math, I am using TransistorAmp 1.1. However, I have no idea what to enter for Input and Output Impedance. Any ideas?

PRR · October 13, 2015, 10:02:14 PM

A "teach a man to fish" reply needs 100 hours in class and 1,000 hours of self-study.

Here's two fish:

1) Use an LPB, the all-purpose guitar-chain booster

2) Use an opamp. Trivial to get very-high input impedance, very low output impedance, and arbitrary voltage gain.

kforte318 · October 13, 2015, 10:27:43 PM

I feel less dumb knowing that learning to fish here would take 1,000 hours (given my 0 of class). Thanks for the tasty fish as well!

bloxstompboxes · October 14, 2015, 09:29:28 AM

Quote from: kforte318 on October 13, 2015, 09:20:27 PM
Firstly, thanks again to those of you that helped me get the click out of the LFO for the trem circuit I'm working on. I really appreciate it!

I am trying to stick a final gain stage on the circuit to get it up to proper volume.

http://www.falstad.com/circuit/#%24+1+5.0E-6+16.13108636308289+66+5.0+43%0Aa+192+64+304+64+0+9.0+0.0+1000000.0%0Aw+192+48+192+16+0%0Aw+192+16+304+16+0%0Aw+304+16+304+64+0%0Aw+192+80+192+192+0%0Aw+192+192+208+192+0%0Aw+240+192+208+192+0%0Aw+208+272+240+272+0%0Aw+192+192+192+288+0%0Aw+240+272+304+272+0%0A174+304+128+320+224+0+100000.0+0.9851000000000001+Rate%0Ar+320+176+384+176+0+10000.0%0Aa+384+192+480+192+0+9.0+0.0+1000000.0%0Aw+384+208+384+272+0%0Aw+304+272+384+272+0%0Aw+384+176+384+128+0%0Ar+384+128+480+128+0+100000.0%0Aw+480+128+480+192+0%0A174+512+160+480+224+0+100000.0+0.5+Shape%0Ad+512+160+576+160+1+0.805904783%0Ad+576+224+512+224+1+0.805904783%0Aw+576+160+576+224+0%0Ar+576+160+640+160+0+1000.0%0Aa+640+176+720+176+0+9.0+0.0+1000000.0%0Aw+640+192+640+272+0%0Aw+640+272+384+272+0%0Aw+640+160+640+112+0%0Aa+720+192+800+192+0+9.0+0.0+1000000.0%0Aw+720+208+720+288+0%0Aw+192+288+720+288+0%0Aw+800+192+800+288+0%0Ar+800+288+720+288+0+22000.0%0AR+640+272+672+272+0+0+40.0+4.5+0.0+0.0+0.5%0Aw+720+112+720+144+0%0Aw+720+144+720+176+0%0Aw+192+80+160+80+0%0As+160+80+128+80+0+1+true%0Aw+112+80+128+80+0%0AR+112+80+96+80+0+0+40.0+2.0+0.0+0.0+0.5%0Ax+803+66+833+69+0+12+Pulse%0Ax+806+133+822+136+0+12+Tri%0Aw+368+64+784+64+0%0AS+848+96+784+96+0+1+false+0%0Aw+784+64+784+80+0%0A162+208+272+208+192+1+2.1024259+1.0+0.0+0.0%0A162+240+192+240+272+1+2.1024259+1.0+0.0+0.0%0Ac+640+112+720+112+0+1.0E-6+1.1722871515602344%0Ar+848+96+912+96+0+10000.0%0Aa+912+112+1008+112+0+9.0+0.0+1000000.0%0Aw+912+96+912+64+0%0AR+912+128+912+160+0+0+40.0+4.5+0.0+0.0+0.5%0AO+1008+112+1040+112+0%0Aw+288+80+288+224+0%0Aw+288+224+304+224+0%0Aw+304+64+304+80+0%0Aw+304+80+288+80+0%0Aw+368+64+304+64+0%0Aw+720+112+784+112+0%0Aw+1008+336+192+336+0%0Aw+192+336+192+560+0%0Ar+192+560+304+560+0+10000.0%0At+304+560+368+560+0+1+0.33734020754424776+0.6240634916083598+100.0%0Ag+368+624+368+640+0%0A162+368+464+368+544+1+2.1024259+1.0+0.0+0.0%0AR+368+464+368+416+0+0+40.0+9.0+0.0+0.0+0.5%0Aw+1008+112+1008+336+0%0Ar+368+576+368+624+0+1000.0%0AR+288+464+240+464+0+1+100.0+1.0+0.0+0.0+0.5%0Ar+288+464+352+464+0+10000.0%0Aw+352+464+432+464+0%0Aw+432+544+432+624+0%0Aw+432+624+368+624+0%0Ax+385+510+417+513+0+12+VACT%0A174+432+544+448+480+0+10000.0+0.5594+LDR%0Aw+432+464+448+464+0%0Aw+448+464+448+512+0%0A174+912+64+976+64+0+25000.0+0.9851000000000001+Depth%0Aw+944+48+1008+48+0%0Aw+1008+48+1008+112+0%0Aw+448+448+448+464+0%0AO+448+448+448+432+0%0Aw+448+464+496+464+0%0Ax+505+472+647+478+0+24+GAIN+STAGE%0Aw+656+464+688+464+0%0AO+688+464+704+464+0%0Ao+51+64+0+34+12.528092670535079+6.103515625E-5+0+-1%0Ao+80+64+0+34+0.5846006549323611+4.8828125E-55+1+-1%0A

Here's my circuit so far. Obviously, I am replacing the "GAIN STAGE" text with a CE Amp. Being that I am weak in math, I am using TransistorAmp 1.1. However, I have no idea what to enter for Input and Output Impedance. Any ideas?

Now that's a link.

armdnrdy · October 14, 2015, 09:51:45 AM

Quote from: bloxstompboxes on October 14, 2015, 09:29:28 AM
Quote from: kforte318 on October 13, 2015, 09:20:27 PM
Firstly, thanks again to those of you that helped me get the click out of the LFO for the trem circuit I'm working on. I really appreciate it!

I am trying to stick a final gain stage on the circuit to get it up to proper volume.

http://www.falstad.com/circuit/#%24+1+5.0E-6+16.13108636308289+66+5.0+43%0Aa+192+64+304+64+0+9.0+0.0+1000000.0%0Aw+192+48+192+16+0%0Aw+192+16+304+16+0%0Aw+304+16+304+64+0%0Aw+192+80+192+192+0%0Aw+192+192+208+192+0%0Aw+240+192+208+192+0%0Aw+208+272+240+272+0%0Aw+192+192+192+288+0%0Aw+240+272+304+272+0%0A174+304+128+320+224+0+100000.0+0.9851000000000001+Rate%0Ar+320+176+384+176+0+10000.0%0Aa+384+192+480+192+0+9.0+0.0+1000000.0%0Aw+384+208+384+272+0%0Aw+304+272+384+272+0%0Aw+384+176+384+128+0%0Ar+384+128+480+128+0+100000.0%0Aw+480+128+480+192+0%0A174+512+160+480+224+0+100000.0+0.5+Shape%0Ad+512+160+576+160+1+0.805904783%0Ad+576+224+512+224+1+0.805904783%0Aw+576+160+576+224+0%0Ar+576+160+640+160+0+1000.0%0Aa+640+176+720+176+0+9.0+0.0+1000000.0%0Aw+640+192+640+272+0%0Aw+640+272+384+272+0%0Aw+640+160+640+112+0%0Aa+720+192+800+192+0+9.0+0.0+1000000.0%0Aw+720+208+720+288+0%0Aw+192+288+720+288+0%0Aw+800+192+800+288+0%0Ar+800+288+720+288+0+22000.0%0AR+640+272+672+272+0+0+40.0+4.5+0.0+0.0+0.5%0Aw+720+112+720+144+0%0Aw+720+144+720+176+0%0Aw+192+80+160+80+0%0As+160+80+128+80+0+1+true%0Aw+112+80+128+80+0%0AR+112+80+96+80+0+0+40.0+2.0+0.0+0.0+0.5%0Ax+803+66+833+69+0+12+Pulse%0Ax+806+133+822+136+0+12+Tri%0Aw+368+64+784+64+0%0AS+848+96+784+96+0+1+false+0%0Aw+784+64+784+80+0%0A162+208+272+208+192+1+2.1024259+1.0+0.0+0.0%0A162+240+192+240+272+1+2.1024259+1.0+0.0+0.0%0Ac+640+112+720+112+0+1.0E-6+1.1722871515602344%0Ar+848+96+912+96+0+10000.0%0Aa+912+112+1008+112+0+9.0+0.0+1000000.0%0Aw+912+96+912+64+0%0AR+912+128+912+160+0+0+40.0+4.5+0.0+0.0+0.5%0AO+1008+112+1040+112+0%0Aw+288+80+288+224+0%0Aw+288+224+304+224+0%0Aw+304+64+304+80+0%0Aw+304+80+288+80+0%0Aw+368+64+304+64+0%0Aw+720+112+784+112+0%0Aw+1008+336+192+336+0%0Aw+192+336+192+560+0%0Ar+192+560+304+560+0+10000.0%0At+304+560+368+560+0+1+0.33734020754424776+0.6240634916083598+100.0%0Ag+368+624+368+640+0%0A162+368+464+368+544+1+2.1024259+1.0+0.0+0.0%0AR+368+464+368+416+0+0+40.0+9.0+0.0+0.0+0.5%0Aw+1008+112+1008+336+0%0Ar+368+576+368+624+0+1000.0%0AR+288+464+240+464+0+1+100.0+1.0+0.0+0.0+0.5%0Ar+288+464+352+464+0+10000.0%0Aw+352+464+432+464+0%0Aw+432+544+432+624+0%0Aw+432+624+368+624+0%0Ax+385+510+417+513+0+12+VACT%0A174+432+544+448+480+0+10000.0+0.5594+LDR%0Aw+432+464+448+464+0%0Aw+448+464+448+512+0%0A174+912+64+976+64+0+25000.0+0.9851000000000001+Depth%0Aw+944+48+1008+48+0%0Aw+1008+48+1008+112+0%0Aw+448+448+448+464+0%0AO+448+448+448+432+0%0Aw+448+464+496+464+0%0Ax+505+472+647+478+0+24+GAIN+STAGE%0Aw+656+464+688+464+0%0AO+688+464+704+464+0%0Ao+51+64+0+34+12.528092670535079+6.103515625E-5+0+-1%0Ao+80+64+0+34+0.5846006549323611+4.8828125E-55+1+-1%0A

Here's my circuit so far. Obviously, I am replacing the "GAIN STAGE" text with a CE Amp. Being that I am weak in math, I am using TransistorAmp 1.1. However, I have no idea what to enter for Input and Output Impedance. Any ideas?

Now that's a link.

Here Eric....now you can sleep at night.

http://www.falstad.com/circuit/

kforte318 · October 14, 2015, 11:04:29 AM

Quote from: bloxstompboxes on October 14, 2015, 09:29:28 AM
Quote from: kforte318 on October 13, 2015, 09:20:27 PM
Firstly, thanks again to those of you that helped me get the click out of the LFO for the trem circuit I'm working on. I really appreciate it!

I am trying to stick a final gain stage on the circuit to get it up to proper volume.

http://www.falstad.com/circuit/#%24+1+5.0E-6+16.13108636308289+66+5.0+43%0Aa+192+64+304+64+0+9.0+0.0+1000000.0%0Aw+192+48+192+16+0%0Aw+192+16+304+16+0%0Aw+304+16+304+64+0%0Aw+192+80+192+192+0%0Aw+192+192+208+192+0%0Aw+240+192+208+192+0%0Aw+208+272+240+272+0%0Aw+192+192+192+288+0%0Aw+240+272+304+272+0%0A174+304+128+320+224+0+100000.0+0.9851000000000001+Rate%0Ar+320+176+384+176+0+10000.0%0Aa+384+192+480+192+0+9.0+0.0+1000000.0%0Aw+384+208+384+272+0%0Aw+304+272+384+272+0%0Aw+384+176+384+128+0%0Ar+384+128+480+128+0+100000.0%0Aw+480+128+480+192+0%0A174+512+160+480+224+0+100000.0+0.5+Shape%0Ad+512+160+576+160+1+0.805904783%0Ad+576+224+512+224+1+0.805904783%0Aw+576+160+576+224+0%0Ar+576+160+640+160+0+1000.0%0Aa+640+176+720+176+0+9.0+0.0+1000000.0%0Aw+640+192+640+272+0%0Aw+640+272+384+272+0%0Aw+640+160+640+112+0%0Aa+720+192+800+192+0+9.0+0.0+1000000.0%0Aw+720+208+720+288+0%0Aw+192+288+720+288+0%0Aw+800+192+800+288+0%0Ar+800+288+720+288+0+22000.0%0AR+640+272+672+272+0+0+40.0+4.5+0.0+0.0+0.5%0Aw+720+112+720+144+0%0Aw+720+144+720+176+0%0Aw+192+80+160+80+0%0As+160+80+128+80+0+1+true%0Aw+112+80+128+80+0%0AR+112+80+96+80+0+0+40.0+2.0+0.0+0.0+0.5%0Ax+803+66+833+69+0+12+Pulse%0Ax+806+133+822+136+0+12+Tri%0Aw+368+64+784+64+0%0AS+848+96+784+96+0+1+false+0%0Aw+784+64+784+80+0%0A162+208+272+208+192+1+2.1024259+1.0+0.0+0.0%0A162+240+192+240+272+1+2.1024259+1.0+0.0+0.0%0Ac+640+112+720+112+0+1.0E-6+1.1722871515602344%0Ar+848+96+912+96+0+10000.0%0Aa+912+112+1008+112+0+9.0+0.0+1000000.0%0Aw+912+96+912+64+0%0AR+912+128+912+160+0+0+40.0+4.5+0.0+0.0+0.5%0AO+1008+112+1040+112+0%0Aw+288+80+288+224+0%0Aw+288+224+304+224+0%0Aw+304+64+304+80+0%0Aw+304+80+288+80+0%0Aw+368+64+304+64+0%0Aw+720+112+784+112+0%0Aw+1008+336+192+336+0%0Aw+192+336+192+560+0%0Ar+192+560+304+560+0+10000.0%0At+304+560+368+560+0+1+0.33734020754424776+0.6240634916083598+100.0%0Ag+368+624+368+640+0%0A162+368+464+368+544+1+2.1024259+1.0+0.0+0.0%0AR+368+464+368+416+0+0+40.0+9.0+0.0+0.0+0.5%0Aw+1008+112+1008+336+0%0Ar+368+576+368+624+0+1000.0%0AR+288+464+240+464+0+1+100.0+1.0+0.0+0.0+0.5%0Ar+288+464+352+464+0+10000.0%0Aw+352+464+432+464+0%0Aw+432+544+432+624+0%0Aw+432+624+368+624+0%0Ax+385+510+417+513+0+12+VACT%0A174+432+544+448+480+0+10000.0+0.5594+LDR%0Aw+432+464+448+464+0%0Aw+448+464+448+512+0%0A174+912+64+976+64+0+25000.0+0.9851000000000001+Depth%0Aw+944+48+1008+48+0%0Aw+1008+48+1008+112+0%0Aw+448+448+448+464+0%0AO+448+448+448+432+0%0Aw+448+464+496+464+0%0Ax+505+472+647+478+0+24+GAIN+STAGE%0Aw+656+464+688+464+0%0AO+688+464+704+464+0%0Ao+51+64+0+34+12.528092670535079+6.103515625E-5+0+-1%0Ao+80+64+0+34+0.5846006549323611+4.8828125E-55+1+-1%0A

Here's my circuit so far. Obviously, I am replacing the "GAIN STAGE" text with a CE Amp. Being that I am weak in math, I am using TransistorAmp 1.1. However, I have no idea what to enter for Input and Output Impedance. Any ideas?

Now that's a link.

Yeah, sorry about that. Falstad's "Export as Link" gives those ridiculous things, and tbh I don't know how to hyperlink in forums. . .

kforte318 · October 14, 2015, 11:13:16 AM

Quote from: PRR on October 13, 2015, 10:02:14 PM
A "teach a man to fish" reply needs 100 hours in class and 1,000 hours of self-study.

Here's two fish:

1) Use an LPB, the all-purpose guitar-chain booster

2) Use an opamp. Trivial to get very-high input impedance, very low output impedance, and arbitrary voltage gain.

So I tried the LPB circuit which seems like exactly what I want, and the signal seems to be clipping quite a bit. Is that normal?

ubersam · October 14, 2015, 03:06:30 PM

Quote from: kforte318 on October 14, 2015, 11:13:16 AM
So I tried the LPB circuit which seems like exactly what I want, and the signal seems to be clipping quite a bit. Is that normal?

That sounds about right. I don't know the exact values but imagine the LPB having a voltage gain of 10. If you feed it a 1v input signal, the circuit will try to amplify the signal up to 10v but it will hit the 9v power supply limit giving you clipping. Something like that.

News:

Input and Output Impedance (for a CE Amp)