More extended highs for AA network

[3dzapper]

TTT

Rick

[ShapeShifter]

Last night I installed this mod on two of my AA Networks using two 1.00µF Crescendo Film-and-Foil Capacitors.

After two hours of play I could easily hear the tweeters begining to sound smoother, more laid back and less harsher at higher volume. I could also begin to hear more detail, even at lower volume. I expect even better results after 24 hrs of play time through the new caps. It is by far the biggest bang for less than $40 bucks I've ever received. One more pair to mod.

BTW - Installing these caps was a first time soldering experience for me.

Thanks to all who contributed to this thread.

Wes

[3dzapper]

BTW - Installing these caps was a first time soldering experience for me.

Good job Wes.

Rick

[Erik Mandaville]

I agree with Rick!

Great job, Wes! Learning to solder opens up so many possibilities, a sense of accomplishment and pride, and $avings!

[dubai2000]

Erik,

I warn you, if ever I set my foot into the US, you'll have yet another teachnig job to do .

Wolfram

[Deang]

"I often wondered why people were disconnecting those zener diodes, I assumed there was some real or imagined sonic improvement by taking them out of the circuit. I can imagine the sound levels must be at the annihilating point to actually have them start to conduct!! ..."

And that's exactly when they begin conduct -- when the speaker is near the top of its operating limits. The only other time would be from a spike during equipment turn on/off, or from someone swapping cables around with the equipment on. Other than that, they just sit there -- doing absolutely nothing. They're not even in series with the tweeter -- I can't believe anyone would hear something out of a part that's not doing anything. At any rate, anyone driving a speaker to this point SHOULD hear distortion --

I also have trouble with the idea about the zeners being able to fry an amp too. There must be thousands of AA's out there -- where's all the smoking amps? I understand what you're saying Al, but surely if it was true -- not only would it be common knowledge, but there would be a smoking gun, uh, I mean amp (a few hundred at least).

Everyone says to yank the screw, but I have it on good authority that removing the screw elevates an already problematic spike at 6Khz. Anyone ever consider the possibility that the effect of the screw was actually factored in?

I also have some mixed feelings about dropping caps in the A, AA, and B that have vanishing low ESRs (Hovlands). Since capacitors have "resistance", usually seen and interpreted as "loss" -- maybe we should additionally consider the possibility that the higher resistance inherent with the original capacitors also played an intregal part of the design and voicing. I mean, you wouldn't just arbitrarily raise or lower a resistor value in a circuit would you? Good capacitors have other positive attributes other than lowered ESR. I wonder if more benefit might be derived by simply dumping the motor runs, which are better suited for washing machines -- and using capacitors specifically designed for audio use, yet exhibiting and maintaining resistance or "loss" similiar to the original capacitors.

[djk]

"I also have trouble with the idea about the zeners being able to fry an amp too. There must be thousands of AA's out there -- where's all the smoking amps? I understand what you're saying Al, but surely if it was true -- not only would it be common knowledge, but there would be a smoking gun, uh, I mean amp (a few hundred at least)."

The diodes don't do anything until you exceed their breakdown voltage. Then they act like a variable resistor in parallel with the tweeter.

After '82 they were removed from the Klipschorns.

In '89 I went to a tradeshow and saw a new pair of HIP with the diodes, but a higher voltage.

"I also have some mixed feelings about dropping caps in the A, AA, and B that have vanishing low ESRs (Hovlands). Since capacitors have "resistance", usually seen and interpreted as "loss" -- maybe we should additionally consider the possibility that the higher resistance inherent with the original capacitors also played an intregal part of the design and voicing. I mean, you wouldn't just arbitrarily raise or lower a resistor value in a circuit would you? Good capacitors have other positive attributes other than lowered ESR. I wonder if more benefit might be derived by simply dumping the motor runs, which are better suited for washing machines -- and using capacitors specifically designed for audio use, yet exhibiting and maintaining resistance or "loss" similiar to the original capacitors."

I have a friend that bought some older Thiel three-ways, the current version goes for well over $3K a pair. Some of the bigger caps were electrolytics. He replaced them all with film types. The midrange was way too hot. He is really happy with the sound now, but it took a lot of effort to get the balance back.