PREAMP BLUES

[Lazarus Short]

I was moving things around. The Luxman amp went with the KEF C25's for A/V duty. The Aiwa preamp went into the office to power the Proton 300/301's (with the 300 in powered speaker mode). There was a buzz which mostly went away using the tone controls, but I suspected it needed a recap. This morning I took it down to the shop, took the top cover off and examined the innards with a view to recap. Everything looked fine, and I turned away, not knowing the power cord was wrapped around an ankle. The thing fell about three feet onto the concrete floor, but cushioned by carpet and pad. I put the cover back on, took it upstairs and hooked it up - no buzz! Percussive maintenance at its best!!

Now it's back to NRK radio's jazz channel...

 

[Fishoz]

Fixed two scanners and a printer at work by dropping 'em. Going to cut time next time by starting with the drop instead of "trying to fix it".

 

[Lazarus Short]

Fixed two scanners and a printer at work by dropping 'em. Going to cut time next time by starting with the drop instead of "trying to fix it".

Just mind the height, and avoid bare concrete!

 

[Fishoz]

3 inches onto a desktop! I'm a hero!

 

[Netfly]

now turn it a liitle to the left and ...oops



I missed.

 

[Lazarus Short]

FedEx and "Oops" are joined at the hip in a percussive way. Big bada boom.

 

[VSAT88]

I was moving things around. The Luxman amp went with the KEF C25's for A/V duty. The Aiwa preamp went into the office to power the Proton 300/301's (with the 300 in powered speaker mode). There was a buzz which mostly went away using the tone controls, but I suspected it needed a recap. This morning I took it down to the shop, took the top cover off and examined the innards with a view to recap. Everything looked fine, and I turned away, not knowing the power cord was wrapped around an ankle. The thing fell about three feet onto the concrete floor, but cushioned by carpet and pad. I put the cover back on, took it upstairs and hooked it up - no buzz! Percussive maintenance at its best!!

Now it's back to NRK radio's jazz channel...

Back in my sat com days the hub would actually ask us if we did a drop test if an IDU was not working...; )

 

[Lazarus Short]

The hum would not go away, and I tried to reconfigure how I hooked the preamp to the Proton units. Still noisy. This evening, I took a three-prong power cord, cut it back so just the ground wire was exposed, plugged in it into the power strip and attached the ground wire to the the phono grounding screw on the back of the preamp. Hum is gone, gone, GONE.

 

[Northwinds]

Glad it worked out for you Laz!

 

[orange]

The hum would not go away, and I tried to reconfigure how I hooked the preamp to the Proton units. Still noisy. This evening, I took a three-prong power cord, cut it back so just the ground wire was exposed, plugged in it into the power strip and attached the ground wire to the the phono grounding screw on the back of the preamp. Hum is gone, gone, GONE.

That likely means the problem is in your power supply or the cable, Laz. Your GROUND.

 

[Lazarus Short]

That likely means the problem is in your power supply or the cable, Laz. Your GROUND.

Please explain, Stephen. Nothing was really grounded before, as neither the preamp nor the Proton units have grounded power plugs, just old-fashoned non-polarized two-prong plugs. Now there is a real connection to a real ground, and the sonic background is very quiet.

 

[Lazarus Short]

HUM AGAIN!


I had this weird hum after thinking I had it fixed - the system would hum intermittently, and to shush the hum I only had to swing a hand toward the Aiwa preamp without touching it - but the hum always came back. I put my Acoustat RP-2 in place of the Aiwa, and found that there was noise coming from the Proton 301. Well, rats. I dug out the Yamaha M-35 and a pair of Mission 70 speakers. The office system has never sounded better! No hum. No noise. All music. Listening to JS Bach.

 

[Northwinds]

Could be a cold solder joint somewhere Laz

 

[Lazarus Short]

Could be a cold solder joint somewhere Laz

Thanks, I will eventually have a look inside the Aiwa, but it's not much of a priority now, as the sound of the Acoustat is just glorious. I think it will get a recap in time, if just for gits & shiggles.

EDIT: Now I'm getting rumbling noises from the Yamaha M-35. They seem to be associated with the volume controls. I should not wonder, as it's been in storage for some months.