Just when you thought there could be no more EZ questions
I understand the basic schema for attaching a single-ended (SE) input to the EZ headphone amp......
....and I'm simplifying this for novices.
For example, one channel/one EZ board/ stock LMExxxxx chips :External SE
+ signal goes to EZ IN
+ (pos).
External Ground to Ground.
EZ IN
- (neg) jumpered to Ground.
EZ Out to right or left headphone jack pin.
Ground to headphone jack.
(assume a star ground for all)
The 4 Resistors....R3 and R5 are the same value for a gain of 2 (keeping the pair R3,R5 under 5000 ohm each)
R2 = 100 ohm
R4 = 100,000 (100k) which gives the circuit a 100k input impedance.
Now my questions....A) Level control: I have an Alps 10k (LOG/dual/stereo) potentiometer....to be added just before the EZ boards (standard volume pot configuration). Do these resistor values still make sense for typical "studio line level" signals ? (+4dB, around 1.75Vpp) (not the consumer -10 dBV)
B) If I use this as a permanent headphone amp module inside my "eurorack synth", where levels are hotter (up to 10Vpp). How do the resistors change ?
(Eurorack synth modules "typically" have a 100k input impedance, and a 100 ohm resistor at the output.)
C) If I want this headphone synth module to have an extra set of "thru" jacks, how does that affect the impedance/loading ?..... say if I just passively "mult" (split) the input ? Basically I would be tapping the synth signal to listen on headphones, as it goes elswhere in that system.
(edit: I don't want someone to just "tell me" the gain and input resistors, I'd like to learn "how and why", but some examples would be nice..... plus the simple math.)
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Edited by user Friday, October 7, 2022 1:41:12 AM(UTC)
| Reason: specifics/format
