Hi all,
Can you guys help please. I have a pair of wave 8 amps and matching wave pre amp. The wave amps do hum, but with a passive pre it is exceptable. With the wave pre its too much and is really annoying. The passive pre is much a cleaner sound, but looses dynamics from the phono stage. I would like to try and remove the humming from the wave pre and get it back in the system.
The story so far;
I swapped the valves for better quality
swapped c2,4,7 & 8 for auricaps
Better diodes in the PSU
ALPS 100k vol pot
The sound quality did improve, but still spoilt by too much noise.
Hum was the same as before.
I have stripped the pre down and my plan is to rewire with better signal wire and follow advice for grounding. can you guys explain the correct grounding method and describe how to wire this pre for best results?
In the picture you can see the yellow earth is connected to the chassis but the signal ground is a different point (screw near PSU pcb) and this has ground cable back to this point from the rca ground and wrapped around signal wires. Is this correct, or is there a best practice with Pre amps?
The signal wires are single core with copper shielding, the shield is connected to the rca grounds only at the rca end and the vol pot grounds, which in turn connect to the chassis ground point.
Confused, i am!!!
I have taken some photos to help.
Does anyone have a circuit diagram for this pre, i cant find one?
Any advice you can offer
Thanks
ian
Can you guys help please. I have a pair of wave 8 amps and matching wave pre amp. The wave amps do hum, but with a passive pre it is exceptable. With the wave pre its too much and is really annoying. The passive pre is much a cleaner sound, but looses dynamics from the phono stage. I would like to try and remove the humming from the wave pre and get it back in the system.
The story so far;
I swapped the valves for better quality
swapped c2,4,7 & 8 for auricaps
Better diodes in the PSU
ALPS 100k vol pot
The sound quality did improve, but still spoilt by too much noise.
Hum was the same as before.
I have stripped the pre down and my plan is to rewire with better signal wire and follow advice for grounding. can you guys explain the correct grounding method and describe how to wire this pre for best results?
In the picture you can see the yellow earth is connected to the chassis but the signal ground is a different point (screw near PSU pcb) and this has ground cable back to this point from the rca ground and wrapped around signal wires. Is this correct, or is there a best practice with Pre amps?
The signal wires are single core with copper shielding, the shield is connected to the rca grounds only at the rca end and the vol pot grounds, which in turn connect to the chassis ground point.
Confused, i am!!!
I have taken some photos to help.
Does anyone have a circuit diagram for this pre, i cant find one?
Any advice you can offer
Thanks
ian
Attachments
Hi Ian,
I haven't modified this pre. Mine has a imbalance of the channels and a little hum as well. FWIW, John Broskie had a write up on how to fix up all wrongs of this preamp which was the motivation of his Aikido. Unfortunately, there is no search on his site, and it will need some efforts to dig it out. I have a print out of that, let see I can find it and and give you the article number.
Edit: here is the link to the article:
http://www.tubecad.com/april_may2001/page28.html
I haven't modified this pre. Mine has a imbalance of the channels and a little hum as well. FWIW, John Broskie had a write up on how to fix up all wrongs of this preamp which was the motivation of his Aikido. Unfortunately, there is no search on his site, and it will need some efforts to dig it out. I have a print out of that, let see I can find it and and give you the article number.
Edit: here is the link to the article:
http://www.tubecad.com/april_may2001/page28.html
Hi Fred, Thanks so much for the link. It has convinced me to just buy a new preamp, probably this kit;
http://wduk.worldomain.net/acatalog/info_WDPRE3.html
I will try a few things out in the meantime, but I can see cables aren't going to cure design problems.
Many thanks
Ian
http://wduk.worldomain.net/acatalog/info_WDPRE3.html
I will try a few things out in the meantime, but I can see cables aren't going to cure design problems.
Many thanks
Ian
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