Power output

[GRAHAMPERCY]

Hi, I'm running my old A&R A60 amp again with a Merantz CD player and Spendor prelude speakers. Great sound but volume control needs to be set a 1 or 2 otherwise it becomes far to loud. Full range of volume control not usable. I believe you can buy a product that deals with this by suppressing the output or imput. Can anybody offer advice?

Graham

[JaS]

If you do a Google search for 'In-Line Attenuators' you will find suitable products. Alternatively you could use something like a QED single input passive preamp between the CD player and amp to reduce the output (I presume the player hasn't got variable output?).

Regards,
JaS

[GRAHAMPERCY]

Many thanks JaS. I Knew I'd seen something on line before but couldn't recall the product name. Checked the CD and unfortunately i't dosn't have a variable output.

Regards

Graham.

[josephazannieri]

Yo GRAHAMPERCY:

There is a solution I use for this problem. I take a 250 K potentiometer, available at Radio Shack, and I put it in a little aluminum box, and I just plug it into the line between the high volume source and the amp input. It's easy to build, cheap, and totally passive, and does not add any distortion. You just turn the pot down until the volume is right. You will need to find out amp input impedance on that input, and the output impedance on the device you are trying to regulate, but generally I get good results from a 250K pot. You just get a cheap RCA male to RCA female extension and wire it into the box. Connect shield on one side to the box.

It's quick'n'dirty, and cheap. I will be happy to send you a diagram, but you will need to send a PM with your Email address. VE will not take images from my computer.

And good luck from that quick'n'dirty old guy,

Joe Z.

[aardvarkash10]

or parallel a 33k resistor to the volume pot (between earth and the output pins)...

Of course this will affect output levels for all inputs.

As an alternative and to only affect the CD volume, do a similar thing across the Aux input plug.

Schematic here

[josephazannieri]

Yo GRAHAMPERCY:

OK. advantage to A10's solution is that it is simpler, and it is adjustable in the sense that you can adjust the gain reduction by increasing the value of the resistor between the volume control wiper (Center tap) and ground, or across the input jack. It is also cheaper, because it only costs the value of the resistor, which will be about a half a buck each, at worst. But, once you have picked the resistor, you are stuck with the "adjusted" gain and if you put the resistor on the volume control, you adjust the gain downward for ALL inputs, including the phono section. Also, if you put the resistor on the input jack, you are adjusting the impedance of that input down, and it may affect the response of the source you are plugging into it.

My suggestion costs about $20.00 by the time you are through with it, and requires some considerable work to build it. BUT, it is infinitely adjustable from no attenuation to killing the input dead, and you can change it depending on the signal level coming out of the source. There is also the disadvantage that my alternative takes up more space.

So, it's whatever you want to do. I like my solution and I build these things all the time. It's what I would do when confronted by this problem. But thank you to A10 for suggesting his alternative, which I didn't see at all.

And good luck from that unseeing, but agreeable old purveyor of disagreement,

Joe Z.

[aardvarkash10]

Love it Joe!

I think we have come up with complimentary solutions - its perhaps typical of me to look for the cheapest approach, you the more flexible.

Salut!

[davidsrsb]

Two 1/4W resistors per channel fixed attenuator is the easiest and best solution. A 47k series resistor and 10k from the actual A60 Aux input to ground should be about right. The A60 dates back to the days when typical levels from tuners and cassette were around 150mV.