Jump to content

Phono-Amp no longer working after moving


Recommended Posts

We moved into a new house. In our apt my setup worked fine. Rega RP1 and Cambridge Audio 640P amp. I've troubleshooted as much as I know how, I've plugged the TT directly into the receiver and it works, just very quietly as expected. I've switched out the cable between the preamp and receiver and still no sound. I feel like it must be the preamp. Does anyone have any idea why it would all of a sudden stop working?

Link to comment
Share on other sites

- Did you maybe unintentionally switch the phono and turntable power supplies? Not sure if they have different voltages, but if they do it might result in one piece working (though not without high risk) and not the other.

 

- Did you maybe flip the MM/MC switch on the back?

 

- Did you make sure that you used the right inputs and outputs on the phono ("output" for phono-receiver connection and "input" for table-phono connection)?

 

- Did you try using a different input on the receiver to hook up the 640p to?

 

- Did you throw it down the stairs and later forgot about it?

 

It's very rare that a phono stage would just stop working completely out of the blue. OR due to moving.

Link to comment
Share on other sites

My *blonde* wife (what have I gotten myself into), just told me there were 4 power cables that all looked the same and we only needed 3 so she threw one away. I tried the other 2. Is it possible for a preamp to be plugged in, lit up and looks like it's working while not being able to function? I do not have the 4th power cable so I cannot compare the specs to it.

Link to comment
Share on other sites

It's possible that you blew something in the unit when plugging in the wrong amperage ac adapter.  I would email Cambridge and see what they have to say about the ac adapter.  

 

Higher current won't hurt the equipment. The phono stage will only use as much as it needs. Higher voltage on the other hand would be a bad idea, if the unit doesn't have a proper voltage regulator.

Link to comment
Share on other sites

The Cambridge adaptor is AC to AC and I'll bet everything else is AC to DC, the Cambridge one is the one you need to get right

 

The Cambridge adaptor is just a transformer in a box with all the regulation and rectification going on inside the 640P but with the exception of a few of the Project turntables and components everything else will have an AC to DC adaptor with the rectification and if you're lucky the regulation going on inside the adaptor.

 

The output symbol on the Cambridge one will be ~ and the others will have a horizontal line with a dashed line above it.

Link to comment
Share on other sites

Link to comment
Share on other sites

I did. I decided that was the best way to go about it. I will post back if it works for other people who might unfortunately have this problem in the future.

I don't want to sound like an ass either, but to everyone that just chipped in with a unhelpful comment...that is not what this is about. Take it to a Brand New thread or something. I've been around here for a while...you can check my member date. Was just looking for some help.

Thank you to everyone that was helpful, extremely appreciate it!

Link to comment
Share on other sites

Because the Cambridge uses an AC to AC adaptor you don't need to worry about it's current or VA rating so much, as long as it's 12V and it's current rating is higher than the original one you will be fine. Obviously you don't need an enormous one and the original transformers VA rating will probably be 6VA  (0.5A X 12V) so as long as you are over that you are fine

 

If you're feeling technical you could just buy a 10 or 20VA toroidal transformer from ebay or someone like Digikey and put it in a box and that would be an upgrade over the original.

Link to comment
Share on other sites

Higher current won't hurt the equipment. The phono stage will only use as much as it needs. Higher voltage on the other hand would be a bad idea, if the unit doesn't have a proper voltage regulator.

 

If the power supply is regulated, it should be fine, however, if it's unregulated, the voltage may fluctuate due to the access amps.  The voltage could have also dipped, which might account for why the LED lights up, but the doesn't pass signal.  

 

This should be the take away from this: POWER ADAPTERS ARE NOT UNIVERSAL!  Other than just the amps and volts, there are differences in polarity, design, and connection type that could harm your electronics.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×

AdBlock Detected

spacer.png

We noticed that you're using an adBlocker

Yes, I'll whitelist