Low Volume from Dual Turntable (via preamp) with Cambridge Audio Amp

[struth]

could be amp then... worth trying another if you can borrow one..

[Valentiaman]

Thanks again Grant, it's unlikely I can find one on my Island(!) but I've got my eye on a new Marantz PM5005, good deal on Amazon right now - €55 less than I could get it from a Dublin dealer, even with postage costs. Is that a good match for the Dual 505 (assuming it's OK).

[struth]

dont know much re the dual 505 tbh. more of a point will be the phono stage. decent one with a decent gain structure might be a need too, although the at95 is a bottom end cart it can sound pretty decent with a good phono stage. also what are your speakers

[Barry]

The hum could be caused by having the cartridge return leads (the blue and green coloured leads) swapped around. They may be correctly connected on the cartridge pins but could be incorrect within the headshell. It happened to me once.

[Valentiaman]

dont know much re the dual 505 tbh. more of a point will be the phono stage. decent one with a decent gain structure might be a need too, although the at95 is a bottom end cart it can sound pretty decent with a good phono stage. also what are your speakers

Speakers are Monitor Audio Bronze B2. Preamps are Behringer PP400 (47Kw) and NAD PP2 (47 kohms + 200 pf).

[Valentiaman]

The hum could be caused by having the cartridge return leads (the blue and green coloured leads) swapped around. They may be correctly connected on the cartridge pins but could be incorrect within the headshell. It happened to me once.

Thanks Barry. The hum is there even with the CD connected, or with nothing other than the speakers connected, and at about slightly more than halfway up on the volume dial.

[Barry]

Thanks Barry. The hum is there even with the CD connected, or with nothing other than the speakers connected, and at about slightly more than halfway up on the volume dial.

Then it sound like the problem is with the amplifier. If you only have a CD player connected but not playing, is the hum there with the volume set half way?

[Macca]

Perfectly normal to have to wind the volume up quite a bit more with vinyl. Phono stages don't tend to have as high an output voltage as a CD player. The hum sounds like it could be a ground loop. Alongside the phono cables running out of the TT you should have an earth lead. That needs to be connected to the phono stage. If it is already connected try disconnecting it.

[twotone]

Thanks Barry. The hum is there even with the CD connected, or with nothing other than the speakers connected, and at about slightly more than halfway up on the volume dial.

Sounds like an earth issue, try moving the phono stages away from the amp or TT or TV etc.

I had a similar problem with my current cartridge and previous amp, records were quiet at the same volume setting as the other line stages (tuner, CD etc) so I had to crank the amp's volume up to about almost full when listening to records but obviously had to remember to turn the volume down if I listened to another source I then changed the amp and bought an on-board MM module for the amp and now the same cartridge plays at the same volume level as all of the other line stages.

[Macca]

Thanks Barry. The hum is there even with the CD connected, or with nothing other than the speakers connected, and at about slightly more than halfway up on the volume dial.

That sounds like the amp. If the hum is always the same level regardless of the volume it is the transformer. If that's the case you'll need a new amplifier, repairing it won't be cost effective unless you can do it yourself.