Some good DIY articles ...

[greg7]

Interesting articles for DIY ...

Found this a long time ago then managed to remember where to find it again yesterday. Some good construction tips.

http://www.soundstage.com/maxdb/maxdb091998.htm

http://www.soundstage.com/maxdb/maxdb101998.htm

http://www.soundstage.com/maxdb/maxdb111998.htm

 

[sam9]

Maybe I'm just grumpy tonite, but an article on DIY amps that spends a couple of pargraphs each on power cords and RCA jacks but nothing about Miller capacitance, dominant poles, Nyquist stability and other concepts I'm struggling just doesn't warm my heart.

Maybe I'll be more civil in the morning.

 

[Peter Daniel]

Maybe I'm just grumpy tonite, but an article on DIY amps that spends a couple of pargraphs each on power cords and RCA jacks but nothing about Miller capacitance, dominant poles, Nyquist stability and other concepts I'm struggling just doesn't warm my heart.

Maybe I'll be more civil in the morning.

I think you are forgetting that those articles are not about amplifier design. The title says: "The Amplifier: What’s Inside? What Makes a Difference? What’s Overlooked?" and it covers the subject very well. Had a good time reading them all and from my limited experience they bring quite important issues to amplifier construction and modification. Highly recommended. Here's some lines I liked in particular:


Doing a solid-state amp from scratch is not much different. Select the output devices carefully, combine with other good resistors and capacitors that are available today and you could get some pretty good sound from even older circuits.

However, building a high-end version of one of these amplifiers with performance pushing the limits of what is possible as we look at the change in millenniums is a lot more complicated. A lot more thought needs to go into the circuit, the parts, the specs, the subjective performance, the appearance, and the mechanical package. In spite of the attention to some details in high-end amplifiers, there are things that could be done to improve amplifier performance that are mostly or completely ignored by designers and manufacturers.

Careful component selection for a high-quality high-end product like an amplifier is very painstaking. The sheer number of choices is staggering, and the time it takes to break in every component one at a time stretches the process out to what seems like forever. Then a single change to some mechanical aspect of the amplifier can change the sound of the entire product, undoing all the component selection that had been done up to that point.

 

[greg7]

the third article's the best ...

The other two are more informational but the third has some great tips for reducing vibration and such. One thing I do like about YBA is that they seem to address the fine details like these mentioned in the article. It's definitely good reading, especially for gaincloning since it seems the implementation makes a big difference on the final sound quality ...

 

[Peter Daniel]

You are right, the third one is probably most interesting and I agree with what they write there, as I know about it from my own experience. Here's the example of my experimenting with amps feet http://www.diyaudio.com/forums/showthread.php?s=&postid=169248#post169248

 

[lawbadman]

I find this stuff hard to believe

Hey Guys

I have read Part 1 and I really dont see the logic in what he says about power cords. I dosnt seem to make sense that the mechanics of a power cord affect how current flows through the wire and therefore affect the sound. To me its BS.

Have any of you guys tried any experiments with power cords and have gotten good results?

 

[fdegrove]

GET THIS...

Hi,

Have any of you guys tried any experiments with power cords and have gotten good results?

Upfront, I haven't read any of the above articles...but what made a marked influence on my system and doesn't cost an arm and a legg is this:

Follow me: inside the wall you quite likely run solid core wiring, so
get rid of those multistrand powercords and use solid core instead.
Same gauge would be fine.

Not very practical to dress, I know, but you're going to love it...

Want more cheap tricks?

Use the same for your speakies...biwire? Even better...

Need more tips on the cheap? Just ring my bell.

Ciao,

P.S. Now I'll read those articles and if worthwhile I'll get back.

Cheers,

 

[Steve Eddy]

Re: I find this stuff hard to believe

I have read Part 1 and I really dont see the logic in what he says about power cords. I dosnt seem to make sense that the mechanics of a power cord affect how current flows through the wire and therefore affect the sound. To me its BS.

One way would be mechanical movement of the conductors relative to each other which would dynamically change the basic inductance and capacitance of the cable.

I did some off-the-cuff tests for this a couple years ago using a basic 18 gauge zip cord extension cord with the cord split down the middle and the split portion floating in a dish of water set on a concrete slab floor with the extension cord feeding both inductive loads and capacitive loads and I wasn't able to detect any movement, which would have been evident by rippling of the water.

se

 

[AKSA]

Greg,

I have a paper on audio amplifier design on my website, under Discussion|Papers|AKSA Design Philosophy.

This touches on most of the issues involved in good design, but contains no math. It does discuss stability issues, however, which are pivotal to amp design and have huge relevance for sonics.

Cheers,

Hugh

 

[Peter Daniel]

Here are some lines from a third article I found especially interesting:

"Binding posts and RCA jacks – When mounting the RCA jacks and binding posts, over-tight never sounds as good as snug. However, snug can be problematic, especially with binding posts. Any post that is too loose is liable to spin when tightened or loosened, and this is unacceptable. So you have to be careful if you loosen RCAs or binding posts.

The faulty four: rubber, plastic, nylon, steel

Several years ago, Michael Green told me "When you are trying to make a good-sounding audio component, the more rubber, plastic, nylon and steel you can get out of it, the better it will sound." I immediately went home and removed the rubber pads that were on both sides of the toroidal transformer in my amplifier. Unbelievable. The amp sounded unquestionably better without those pads. Leaving the transformer resting on the chassis is very dangerous, however. A later experiment raised the transformer on a sand-filled baggie, and the sound improved again. A little later I found a very small inner tube and used it as an air cushion under the transformer -- another improvement over the sand bag. In my moded CD player, I replaced the nylon circuit-board standoffs with brass screws -- a significant sonic upgrade. In fact, Michael Green recommended brass as the replacement material for the rubber, plastic, nylon and steel if possible. The resonance characteristics of brass are the most musical of any metal -- which is why musical instruments with metal in them usually employ brass. Aluminum is the second choice if using brass is not possible."

 

[Steve Eddy]

Here are some lines from a third article I found especially interesting:[/I]

And about as enlightening as this:

<i>Freezing your photographs costs you nothing but the loss of looking at the pictures, since they’ll have to stay in the freezer forever. It costs you nothing, and the results are stunning. I tried it because I was skeptical, and my photos have been in the freezer ever since.</i>



se

 

[Peter Daniel]

<i>Freezing your photographs costs you nothing but the loss of looking at the pictures, since they’ll have to stay in the freezer forever. It costs you nothing, and the results are stunning. I tried it because I was skeptical, and my photos have been in the freezer ever since.</i>



se

But what does it have to do with audio?

 

[Steve Eddy]

But what does it have to do with audio?

Because the stunning results mentioned is the improvement to the reviewer's audio system. In fact, it not only improved the sound of her system, her frozen photographs improved the sound of other systems she listened to. Including those at CES. This was from an article in AudioMusings.

se

 

[Peter Daniel]

Because the stunning results mentioned is the improvement to the reviewer's audio system. In fact, it not only improved the sound of her system, her frozen photographs improved the sound of other systems she listened to. Including those at CES. This was from an article in AudioMusings.

se

That sounds interesting. I have to try it. What would be the best photographs for that purpose? Did you try it already?

 

[Steve Eddy]

That sounds interesting. I have to try it. What would be the best photographs for that purpose? Did you try it already?

Two photographs of yourself, one as a child, the other as an adult. Put them in a ziplock bag and place them in your freezer.

I'd try it but I was an ugly child and my parents could never bring themselves to buying a camera and they kept me home from school on picture day so...

se

 

[Circlotron]

I'd try it but I was an ugly child and my parents could never bring themselves to buying a camera and they kept me home from school on picture day so...

You're lucky they didn't sell you to a factory that could use your face as a mold for making rubber gorilla masks.

 

[Circlotron]

And about as enlightening as this:

<i>Freezing your photographs costs you nothing but the loss of looking at the pictures, since they’ll have to stay in the freezer forever. It costs you nothing, and the results are stunning. I tried it because I was skeptical, and my photos have been in the freezer ever since.</i> se

With the quantum double talk they launched into, I'm surprised they didn't assert the photo effect wasn't the result of the person's and the photo's photons being entangled. Now *that* is a fascinating subject. Albert Einstein called this intermingling of photons process "spooky action at a distance" because the particles can immediately influence each other over huge distances, even halfway across the galaxy.

Another thing, given the "assymetric energy fields" blah blah blah they ought to have published details of where to stick acupuncture pins into your amplifier.

 

[haldor]

Here are some lines from a third article I found especially interesting:

The faulty four: rubber, plastic, nylon, steel

I immediately went home and removed the rubber pads that were on both sides of the toroidal transformer in my amplifier. Unbelievable. The amp sounded unquestionably better without those pads.
...
A later experiment raised the transformer on a sand-filled baggie, and the sound improved again. A little later I found a very small inner tube and used it as an air cushion under the transformer -- another improvement over the sand bag.[/I]

That's really funny, since inner tubes are made out of rubber. Looks like this person has gone full circle, ending up where they started and somehow got improvements at each step.

Phil

 

[P.Allan.]

Am i missing something here?
the final stage of this series of sonic improvements was to replace the sand bag with an inner tube presumably made of rubber the original material you eliminated in the first place!
Maybe i am just not in on the joke or the actual issues at play here are not the materials but the isolation from the chassis the mod provides.