Hi Wayne,
I'm interested in the head amp. But you are to far to order the pcb. Could you please share the layout I will order in my town?
I'm interested in the head amp. But you are to far to order the pcb. Could you please share the layout I will order in my town?
Check here: http://www.diyaudio.com/forums/pass...ss-diy-headphone-amp-guide-4.html#post5402963
The one sale at diyAudio store is a revised version. However, I use the previous version PCB to build mine without issue.
It is turning out to be a great pre as well...I love my B1 buffer very very much, but I am finding this amp quite interesting
Switched over to the OPA2134 opamp last night. I can hardly tell any difference between it and the LM4562 in terms of sound quality; they both sound great. I'm keeping the OPA2134 in because my offset voltage is very low with the jfet opamp.
I was wondering whether the idea is to keep the PS for this amp floating, I have not explicitly grounded the circuit to the power earth except the RCA jacks ground connected via .01uF cap to avoid oscillations in the circuit. Since there is no direct provision to ground the circuit via 10 ohm thermistor to the chassis and eventually link to power ground (like other FW circuits), not very sure if this should be implemented...
One option is a loop breaker like in figure 4 here Earthing (Grounding) Your Hi-Fi - Tricks and Techniques
Bridge rectifier is the main new thing. You already have capaciotor.
Bridge rectifier is the main new thing. You already have capaciotor.
Thanks, I am aware of this, however I wanted to know if it should be implemented in the first place...if I use headphones, then I don’t foresee any need as headphones are passive...but if I use it as a pre and hook it to the amplifier then I suspect there is a need
as long as you have a good ground to the chassis for safety the other parts are optional if you are getting the performance you want.
Hi Guys,
I have a second WHAMMY board that I'm thinking of using as just a Pre-Amp. What mods would I need to make to use it a just a Pre-amp. I'm assuming some resistance on the output to limit it to ~1v or 2v p-p?
Mark.
I have a second WHAMMY board that I'm thinking of using as just a Pre-Amp. What mods would I need to make to use it a just a Pre-amp. I'm assuming some resistance on the output to limit it to ~1v or 2v p-p?
Mark.
I'd only turn the bias down a bit.
Some amps need more gain, don't worry about output voltage. Plus you now have a perfect excuse to build a MoFo or F4. 😀
Some amps need more gain, don't worry about output voltage. Plus you now have a perfect excuse to build a MoFo or F4. 😀
"WHAMMY" Pass DIY headphone amp guide
Yes 10K resistors would give a comfortable bias
Yes 10K resistors would give a comfortable bias
???
Bias is a function of the source resistors in the output stage, R16 R22 R29 R32, and increasing their value will reduce the bias, as shown on the schematic.
I'd probably try 18ohm or so to start.
