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Canberra
09-14-2008, 10:27 PM
Hi,

I am trialling a Merdian CD player that has an output voltage of 4.6v. This must be significantly higher than my existing older Meridian since the volume is now significantly louder. The pre-amp volume can now only be set at less than 10% of maximum otherwise it is too loud.

Is there a way to reduce this voltage without degrading the sonic qualities of the CD player.

Any advice gratefully recieved.

Feanor
09-15-2008, 02:01 AM
Hi,

I am trialling a Merdian CD player that has an output voltage of 4.6v. This must be significantly higher than my existing older Meridian since the volume is now significantly louder. The pre-amp volume can now only be set at less than 10% of maximum otherwise it is too loud.

Is there a way to reduce this voltage without degrading the sonic qualities of the CD player.

Any advice gratefully recieved.

4.6 volts sounds away too high to me. 2 volts is considered fairly high, so I wonder if the component isn't actually defective?

Rich-n-Texas
09-15-2008, 04:56 AM
I don't think I've ever read a question like this being asked before.

E-Stat
09-15-2008, 05:59 AM
I am trialling a Merdian CD player that has an output voltage of 4.6v. This must be significantly higher than my existing older Meridian since the volume is now significantly louder. The pre-amp volume can now only be set at less than 10% of maximum otherwise it is too loud.
I ran into a similar situation years ago with a GamuT CD-1 having 4 volt output. While that is only double the nominal 2 volt output, it works out to a 6 db change. I experienced a similar challenge with an Audio Research preamp that even had a reduced gain (12 db) setting for the CD input.

You can buy in line attenuators, but I think that is less than ideal sonically. My solution? Don't fight it. I took full advantage of that characteristic and bypass the superfluous line stage altogether for the CD source. I use a DIY set of attenuators to drive the amps directly. I find the signal to have better resolution and improved soundstaging via increased separation.

rw

Canberra
09-15-2008, 06:20 PM
Many thanks for the coments and for E-Stat's suggestion that I will look into. I have been talking to a couple of other people who have suggested that I get the pre-amp modified to reduce the hgher voltage levels coming from the CD and also seeing if the CD has a software function to reduce its output.

I will let you know the outcome. It is a sweet sounding CD and I am keen to keep it but also want the amp and pre-amp to be working in their ideal range.

Gerard
09-16-2008, 03:50 AM
Hi Canberra,

Make it your first choice to check out if there is a software menu that allows for output control. If there is none, instead of having the pre-amp modded, you may consider to have the CD modded. Or you might want to follow E-Stat's way to go.

Either way, you need some DIY experience or know a friend who can handle this mod job. Let's look at the CD first. Usually uses OP AMPS or discreet devices as output stage. OP AMPS uses a gain resistor. Locate it and change to a suitable value. If it uses discreet stuff, usually transistors, see if one stage can be skipped. If very high gain devices are used, switch to a lower gain type.

Or you could go the way of E-Stat and acquire a passive pre-amp that feeds straight into your power amp. DIYers might want to consider building a resistor bank type of volume pot, or install the ALPS pot.

If you want your pre-amp modded, knowing the input impedence of a SELECTED input terminal, a voltage divider can be built and installed for that particular input terminal. Will certainly help to lower the incoming signal voltage. You can try KIWAME resistors here.

Regards,
Gerard

Canberra
09-16-2008, 06:59 PM
Hi Canberra,

Make it your first choice to check out if there is a software menu that allows for output control. If there is none, instead of having the pre-amp modded, you may consider to have the CD modded. Or you might want to follow E-Stat's way to go.

Either way, you need some DIY experience or know a friend who can handle this mod job. Let's look at the CD first. Usually uses OP AMPS or discreet devices as output stage. OP AMPS uses a gain resistor. Locate it and change to a suitable value. If it uses discreet stuff, usually transistors, see if one stage can be skipped. If very high gain devices are used, switch to a lower gain type.

Or you could go the way of E-Stat and acquire a passive pre-amp that feeds straight into your power amp. DIYers might want to consider building a resistor bank type of volume pot, or install the ALPS pot.

If you want your pre-amp modded, knowing the input impedence of a SELECTED input terminal, a voltage divider can be built and installed for that particular input terminal. Will certainly help to lower the incoming signal voltage. You can try KIWAME resistors here.

Regards,
Gerard

Hi Gerard,

Many thanks for the suggestions. Unfortunately, I am not somebody who would feel comfortable doing the DIY thing. As a consequende I have tracked down the designer of my per-amp and and I am discussing with him the possibility of modifying it to support the high voltage CD output. I think he feels that this is a reasonable solution.

I want to make sure that the amp is operating in its ideal range, not at about 5-10% which is not the 'sweet' spot. The Meridian sounds fantastic and I want to make sure I get the maximum benefit from it.

If this mod is possible and I can arrange it, then hopefully problem solved.

I wil post a note if this occurs and again, many thanks for the suggestions, they are appreciated.

Canberra
10-02-2008, 07:02 PM
Hi again,

I have now found out that the issue is not with the CD player, but with the volume control on my pre-amp. It appears that it has been faulty for quite a while and is providing more gain than it should. I am having the volume pot replaced and hopefully this will resolve the issue.

Thank you for those that commented.

Gerard
10-03-2008, 12:32 AM
Hi Canberra,

I hope the customer service centre that you sent your pre - amp in, is honest with you. It is rare that a faulty volume pot should give you higher gain than usual. Being a passive device, if the volume pot wears out, the normal symptoms are "crackling sound" from the speakers as you turn up or down the volume. Sometimes the speakers may even mute on reaching a certain spot. Or the left & right speakers have come unbalance, one side is louder than the other. Another symptom is that, when increasing the volume, the sound stays constant without respond, and then it suddenly goes very loud !

If you did not experience the above mentioned symptoms, I doubt that the volume pot is faulty. Then again there's Murphy's law, and I could be wrong. Be wary !

Regards,
Gerard