Greetings,
My Soundvalves VTP-101 preamp recently blew it's main's fuse. Inspection of the board's top side revealed all high voltage electrolytic caps had leaked. Inspection of the bottom side implied excessive heat around the SS Bridge Rectifier, which turned out to be failed shorted causing the blown fuse. All electrolytic caps were replaced using caps having the highest temp/ripple/lifetime available for that value, which were Nichinon brand. The original BR was rated 2amp/50volt, which I didn't have on hand, so I used 4amp/400volt. While I was in there I also changed the original 2.2uf 160v MKP output coupling caps to PIO Sprague Vit Q's 2.0uf 200v.
The preamp works again but is either noisier or more revealing than I remember. Maybe a little "nasal sounding". I realize the PIO's take some time to break in, but I'm not sure if that's what I'm hearing. The sound is very crisp and sometimes sounds like the stylus is dirty.
1. Are PIO's noisy before they break in? The system is improving gradually. This is my first experience with PIO's and I don't know if they start out noisy/blurry/undefined/crisp.
2. Could the Nichinon caps be contributing noise? Were the leaky original caps the cause of the blown BR? I have to believe they were.
3. Could the new BR be contributing noise? Should I have used the original 2A/50V value? I have a BR rated 4A /50V but I opted for the 4A /400 because I thought it would be more durable. I know valve rectifiers have their own sound, is that also true for SS BRs?
I don't have a schematic so I really can't describe the preamp any better. I'm wondering if anyone has any insight into what I'm hearing.
Thanks and Happy Thanksgiving! Rich
My Soundvalves VTP-101 preamp recently blew it's main's fuse. Inspection of the board's top side revealed all high voltage electrolytic caps had leaked. Inspection of the bottom side implied excessive heat around the SS Bridge Rectifier, which turned out to be failed shorted causing the blown fuse. All electrolytic caps were replaced using caps having the highest temp/ripple/lifetime available for that value, which were Nichinon brand. The original BR was rated 2amp/50volt, which I didn't have on hand, so I used 4amp/400volt. While I was in there I also changed the original 2.2uf 160v MKP output coupling caps to PIO Sprague Vit Q's 2.0uf 200v.
The preamp works again but is either noisier or more revealing than I remember. Maybe a little "nasal sounding". I realize the PIO's take some time to break in, but I'm not sure if that's what I'm hearing. The sound is very crisp and sometimes sounds like the stylus is dirty.
1. Are PIO's noisy before they break in? The system is improving gradually. This is my first experience with PIO's and I don't know if they start out noisy/blurry/undefined/crisp.
2. Could the Nichinon caps be contributing noise? Were the leaky original caps the cause of the blown BR? I have to believe they were.
3. Could the new BR be contributing noise? Should I have used the original 2A/50V value? I have a BR rated 4A /50V but I opted for the 4A /400 because I thought it would be more durable. I know valve rectifiers have their own sound, is that also true for SS BRs?
I don't have a schematic so I really can't describe the preamp any better. I'm wondering if anyone has any insight into what I'm hearing.
Thanks and Happy Thanksgiving! Rich