[TSHRED56]

Fet Valve CFR Preamplifier

When I press the up or down volume keys on the remote there's a slight buzzing coming through the speakers. It's not loud and in fact I can live with it but I'm just wondering if anybody else has experienced this and if it's normal?

I physically removed all inputs from the preamplifier and it still does it.

[WGH]

No buzzing with my CFR.

[TSHRED56]

No buzzing with my CFR.

That's interesting.
Did you listen up close to your speakers with nothing playing? It's fairly faint.

The only reason I know about it is because my wife has super good hearing and she could hear it when we were watching a show last night and I was changing the volume during your quiet passage.

[WGH]

Ear on speaker, remote in hand - dead silent at any volume. Amp is the AVA SET 400.

[TSHRED56]

Ear on speaker, remote in hand - dead silent at any volume. Amp is the AVA SET 400.

Thank you for checking.
I'm running an Odyssey Cyclops Extreme amplifier. I don't believe that should make any difference, but maybe.

[JackD]

Chances are it's the connection on the IC's on one end or the other.  Have your wife operate the remote while you check the four connections.  Have a pair of IC's with KLEI RCA ends that can cause this issue of not positioned just right.

[TSHRED56]

Hats off to Larry for replying to my email so quickly. I tested it and no loud hum. It's a relief to know this is a normal operation sound.

Here's his reply:

Hello,

The volume level is adjusted with a motor attached to the back of the volume control (potentiometer), and the buzzing you are hearing is the electrical field from the motor being coupled to the (very) close volume control contacts.  During the installation of the volume control we use a sharp tooth lock washer between the volume control and the chassis to electrically couple (ground) the volume control to the chassis to minimize the buzz.  One test you can try to see if the control is properly grounded is to touch the volume control with no music playing.  If you hear a loud buzz/hum that means the nut holding the volume control shaft has loosened to the point where the control is no longer grounded.  if you don't have a loud buzz/hum when touching the volume control knob then it's the buzz you are hearing when the volume control is moving is the normal electrical interference generated by the volume control drive motor when it's engaged.

Note that if you do have a loud hum/buzz when touching the volume control knob you can fix it by removing the knob (held on with one or possibly two set screws) then "firmly" tighten the nut holding the shaft with a 7/16 nut driver (or socket).  Be careful to not over tighten the nut as the volume control shaft is made of aluminum, and while unlikely, it's possible to strip the threads.

Best Regards,

Larry Jenkins
Audio by Van Alstine

[rcag_ils]

Another reason not to get the remote control, another potential point of failure. Getting up and turning the volume knob is not a problem for me. That's what we did back in the day.

[WGH]

Just in case anyone thinks the remote control in all the Van Alstine Fet Valve CFR preamps are noisy, they are not. I bought my CFR preamp in July, 2019 and it has performed flawlessly and quietly for the last 5 years making music for 16 hours a day, everyday. TSHRED56's post about a noisy volume control is the first I have seen since the preamp was released.

Tucson has an excellent independent radio station that has real DJ's that play almost anything they like 24 hours a day. That also means a little rap and hip hop sneak into the music mix. The remote is an invaluable accessory when that monotonous music comes out of my speakers.