Hey my builds been done for quite a while and I love it with less sensitive cans.
Just wondering about one thing, there's this extremely low volume hiss on extra sensitive cans like the AD2000X.
The hiss doesn't increase in volume with pot position at all.. does this mean it's coming post the amplification? What would be the best solution to this?
I was thinking of trying the output ground to the chassis too.
Or is it due to some other reason
Just wondering about one thing, there's this extremely low volume hiss on extra sensitive cans like the AD2000X.
The hiss doesn't increase in volume with pot position at all.. does this mean it's coming post the amplification? What would be the best solution to this?
I was thinking of trying the output ground to the chassis too.
Or is it due to some other reason
Hi all. The guide on page 1 says "25VA 22V+22V is best and used in this guide.". There is discussion in the thread about using a 15V with no LEDs. The advantage of the 15V is that is runs cooler. Any advantage to the 22V over the 15V? I'm building yet another WHAMMY for a friend, and ordering parts. Given the voice, which to build with?
Yes it will run without these. It provides a lower impedance to drive the outputs and shorts potential noise from the optocouplers.
The middle two 10K resistors can also be dropped down to 2.2K if you want. The four resistor combination set some basic DC to keep the smoke in even without the opamp.The published schematic is just what I built and worked at the time.
> Probably borderline for the IRF parts and 2.2K
I would suggest 5.1k for FQPs and IRFs.
> The Toshiba parts are so consistent I wish they still made them.
I am sure PL has plenty in stock.
> It provides a lower impedance to drive the outputs and shorts potential noise from the optocouplers.
And also allow you to run closer to both rails without clipping (assuming not limited by opamp) ?
Cheers,
Patrick
I would suggest 5.1k for FQPs and IRFs.
> The Toshiba parts are so consistent I wish they still made them.
I am sure PL has plenty in stock.
> It provides a lower impedance to drive the outputs and shorts potential noise from the optocouplers.
And also allow you to run closer to both rails without clipping (assuming not limited by opamp) ?
Cheers,
Patrick
I occupied a bit with the HPA buffer and was a bit surprised.....good that Meldano asked.
Without caps Spice says the output is only half of the input, maybe understandable, because without caps you have a resistor divider 10k series and after that 10k to rail (means GRD)
And with caps the series resistor is bypassed.
So many things still open to understand.....
Without caps Spice says the output is only half of the input, maybe understandable, because without caps you have a resistor divider 10k series and after that 10k to rail (means GRD)
And with caps the series resistor is bypassed.
So many things still open to understand.....
Attachments
I finally got my board and I have been busy these last few evenings assembling everything.
I chose the OPA2134 op amp and I used a 50k alps pot and after testing, it's perfect, no gums, no hiss or buzz, everything is dead silent with no audio connected and also same with RCA cables connected and no audio playing.
I also added a line out for future use making use of the switched headphone jack and adding 100 ohm resistors to the cable run.
Music is crisp and to test further I listened to Evanescence Synthesis album and the sound stage is incredible. Will definitely be building another solid state amp that's for sure. Really pleased with this build.
I chose the OPA2134 op amp and I used a 50k alps pot and after testing, it's perfect, no gums, no hiss or buzz, everything is dead silent with no audio connected and also same with RCA cables connected and no audio playing.
I also added a line out for future use making use of the switched headphone jack and adding 100 ohm resistors to the cable run.
Music is crisp and to test further I listened to Evanescence Synthesis album and the sound stage is incredible. Will definitely be building another solid state amp that's for sure. Really pleased with this build.
Attachments
I finally got my board and I have been busy these last few evenings assembling everything.
I chose the OPA2134 op amp and I used a 50k alps pot and after testing, it's perfect, no gums, no hiss or buzz, everything is dead silent with no audio connected and also same with RCA cables connected and no audio playing.
I also added a line out for future use making use of the switched headphone jack and adding 100 ohm resistors to the cable run.
Music is crisp and to test further I listened to Evanescence Synthesis album and the sound stage is incredible. Will definitely be building another solid state amp that's for sure. Really pleased with this build.
Looks great.
Where did you add the 100 Ohm resistors for the line out?
Thanks