Cal's Bybee experience

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#62
OK, they have spent a couples days on iTunes (lossless, uploaded commercial CD's) running at about 5 watts unfiltered on a dummy (sand cast 8 ohm resistors) load. I will continue this through the weekend to get to a couple hundred hours before I do more testing. The tone generator I downloaded told me my free trial expired. They only had about one days worth on it before I got the bad news.

Is this a fair way of running them in? In the 50 hours or so worth of music I have, sorry to say, only about 100 or so tunes are Jimmy Buffett. 🙂
 
#67
1. Can't spell Buffett
2. Unaware of the number of decent songs written by him.
3. Youtube is full of critics.

Quite simply if you don't get him, don't try. He's all about having fun, thinking, dreaming and story telling. Exactly what I look for in my music.

Dave: "You Had To Be There" 😀

Oops I guess we're way OT.
 
#68
Ok, it's Sunday morning and all is quiet in the Weldon residence. I sneak over to the computer to make sure the iTunes loop hasn't turned itself off overnight. While enjoying my morning coffee I can hear a faint bit of music outside and I was pleased to hear it was the Band - Life is a Carnival. Nice I thought because it was a great night of Family and festivities last night. The song fades and on comes The Band - The Weight. Wait a minute someone else has the same Best of The Band album I'm thinking. I check the iTunes and what do you know, that's the song that's on the loop right now. Coincidence? Enquiring minds want to know. OK something funny going on here. I put my ear down to the amp and bloody hell, it's the amp that is making this ever so faint sound. WTF? There are no speakers hooked up just the dummy load and the QP's. It's a little T-amp I believe. It comes under the name of Kama Bay but planet10 tells me it's a Yamaha chip in there. Regardless I've never heard an amp play music.

Call me a rookie but then then me what it is I am hearing. This has me very intrigued.
 
#69
Also, I notice the 10W, 10 ohm sand resistors are quite warm to the the touch. No maybe hot is a better word. I don't think I could hold them for more than a couple seconds. Am I running the amp a little high, it's still cool to the touch.

EDIT (15 minutes later): Turning the pot from 2 o'clock to 1 o'clock worked wonders. They are now much easier to handle.
 
#70
Get On With It...

Audible noise from amps driving dummy loads is perfectly common/normal in my experience....this radiated sound increases linearly with volume level and increases dramatically at clipping.
Most of this tizzy/nasty sound comes from the heatsinks...some manufacturers fitted rubber blocks between heatsink fins to damp vibration ala rubber blocks wedged into motor cycle engine cooling fins.

Eric.
 
#72
mrfeedback said:
Audible noise from amps driving dummy loads is perfectly common/normal in my experience....this radiated sound increases linearly with volume level and increases dramatically at clipping.
Most of this tizzy/nasty sound comes from the heatsinks...some manufacturers fitted rubber blocks between heatsink fins to damp vibration ala rubber blocks wedged into motor cycle engine cooling fins.

Eric.
Click to expand...

Yes that's normal. The shape/geometry of heatsinks often has more impact on an amps sound than the THD 😉
And in amps with transformers, unless the xformer has been very well build and impregnated, those xformers also sing along.

jan didden
 
#74
Cal Weldon said:
Ok, it's Sunday morning and all is quiet in the Weldon residence. I sneak over to the computer to make sure the iTunes loop hasn't turned itself off overnight. While enjoying my morning coffee I can hear a faint bit of music outside and I was pleased to hear it was the Band - Life is a Carnival. Nice I thought because it was a great night of Family and festivities last night. The song fades and on comes The Band - The Weight. Wait a minute someone else has the same Best of The Band album I'm thinking. I check the iTunes and what do you know, that's the song that's on the loop right now. Coincidence? Enquiring minds want to know. OK something funny going on here. I put my ear down to the amp and bloody hell, it's the amp that is making this ever so faint sound. WTF? There are no speakers hooked up just the dummy load and the QP's. It's a little T-amp I believe. It comes under the name of Kama Bay but planet10 tells me it's a Yamaha chip in there. Regardless I've never heard an amp play music.

Call me a rookie but then then me what it is I am hearing. This has me very intrigued.
Click to expand...

Happened to me with a nuforce icon at 2.8Vrms output level. It was the output inductors.

Add: As in play music, not vibration noise, like monotone coil-whine. Then again, the coils are whining but at a changing rate to produce music. Hmm.
 
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#75
Hi Cal,
Don't discount the capacitors for being the source of the noise. Zobel networks are the normal culprits. Ceramic disc caps are very bad for generating actual sound. Other caps may depending on their construction and place in the circuit.

If the heat sink is generating sound, I'm worried. Power transformers just hum along with the tune. 🙂

-Chris
 
#77
I agree Eric. I will take them off when I get home. The problem is I'm not sure when I can get to the testing. All my gear is here at the other house where my office is so it may be the weekend before I can spend any quality time with them. I will see what I can do about wrestling up a couple free hours. Work is really busy these days so it's hard to find time during the day.
 
#78
Hi Eric,
True, but some components are more vocal than others on average. I'd be freaked if I heard sound coming from the heat sink assy. I'm talking about a true heat sink, not the thin, engineered aluminum things we see these days.

I can't see any more changes from cooking those Bybees any longer either. But then, I strongly doubt they would change at all unless they were overheated. Maybe that's what they mean (Bybee pushers).

-Chris
 
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