| batee |
Built Marcello's headphone amp last evening. Sounds great except for a faint hiss (sounds like white noise).
Details:
Measures about 5mVPP at the output terminals when connected to paused source (a Sony DVD player) measuring 0mVPP.
Sony 75 Ohm headphones.
Don't have it in an enclosure yet - part's on the truck. Did connect ckt ground to line ground via 100 Ohm resistor.
Noise disappears when I short the input terminals of the amp boards.
Amplitude is constant regardless of bias settings or source level.
Used a few cheap (RS) carbon comp resistors in non-power situations (I live in a small town).
FETs matched to 300uV.
Thanks in advance for any assistance,
Bryan A. Thompson
batee@roadslessphotographed.com |
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| Nat Riscica |
Hello Batee,
I have had the same problem. I solve it by adding a o.oo1 ceramic capacitor across the base-collector of the ztx 450 like the original Zen schematic.:D
Nat Riscica |
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