OT Crossover Wiring

https://www.manualslib.com/manual/36...Schematic.html

Example, N501 8A. L.F. circuit.

Four resistive(power consuming components) in series configuration.

Amp to speaker wire(2x6 = 12 ft.), internal speaker cabinet and crossover wiring(2x3 = 6 ft.), 2 ohm DCR choke, driver Re = 6.3 ohm.


*18 AWG wire: 0.006385 ohm per ft. 18 ft. = 0.115 ohm

Current in circuit to give 3 Watt in Re is 0.69 amp. Amplifier power required to deliver 3 watt into Re is I(squared) x R( total in series),

0.69 x 0.69 x (0.115 + 2.0 + 6.3) = 4 watt


*8 AWG wire(0.0006 ohm per ft.): gives 0.69 x 0.69 x(0.108 + 2 + 6.3) = 3.96 watt from the amplifier.

A difference of 0.04 watt, giving a power change = 0.044dB at the amp, less at the driver.


Inaudible.


*If the wire had zero ohms resistance the amp power would only reduce to 3.95 watt for 3 watt at the driver.


*Using a 0.6 ohm choke and 18 AWG wiring requires 3.34 watt from the amplifier, a 0.66watt (0.78dB change).


I wouldn't get too fussed about the wiring.

That's the kind of post I like, based in real factual engineering science that proves what a lot of us have been saying all along.
Never the less, someone will be by shortly to tell us that we simply don't understand.
By the way, your calculations were not based on the ever so important Fulton length of 53.1589632789541 inches. At that specific length, all belief in physics, science and engineering is suspended and the resistance of the wire, if doubled drops to zero.
It's true, I heard it on the internet.

BillWojo

at some point, Todd will tire of all of this and pull the plug. then we will all have to find another forum.
moderation is the key

Tire of what, exactly, Phil? Factual posts?

Quote:

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Originally Posted by mah

I wouldn't get too fussed about the wiring.

---

Yeah, there's some losses involved that's not factored in, but still will be below human hearing threshold. After taxes [this mandatory IRA distribution really 'hit' me much harder than I'd assumed!], my next goal is to figure out how to get win10 to accept Office 2k, so I can use my various Excel calculators, which will allow me to do all the calcs using the math that the electrical world runs on, then onto MathCad 2k Pro as without them I'm not much smarter math wise than a box of rocks. I tried loading win XP Pro on an old Lenovo laptop, but no joy and according to the computer folks at Fry's, its architecture is the problem, so must find an even older LT or desktop that's not worn out [fat chance!], though guessing they just want to sell me the new 365 you have to pay an annual fee for, which ain't gonna happen just on general principle. Sure wish Open Office could run Excel micros.

GM

Quote:

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Originally Posted by Phil-G

at some point, Todd will tire of all of this and pull the plug. then we will all have to find another forum.
moderation is the key

---

FYI, he didn't ban Romy the Cat [I forget his Russian name] or anybody when I got ganged up on ~a decade? ago, so doubt this current state of affairs will ruffle any feathers.

If he does, I'll just do all my posting on DIYaudio or if I get too curmudgeonly in my dotage for them I'll go back to the HE forum where I started after the mail BBs became so violent.

GM

Has Romy met his match, here?

You've obviously never 'crossed swords' with him!

GM

Jeff, I also showed an example using 8 AWG wiring and an example using 'zero resistance' wiring - negligible difference. Little difference from the 18 awg example used for reference.

The contribution to power loss by the wiring is less than 1.4% for the 18 AWG example and less than 0.014% for the 8 AWG example. Insignificant.

You don't like It? Prove otherwise.

I agree with the first post. Its the correct way to calculate things. I too am trained like an EE, just not by the military.

I also believe in something we call "FM" in aviation. Its short for "F'ing magic". Sometimes things work when they shouldn't. I think audio is 90% facts and 10% FM.

FM is really an unpredicted event, explained in the aviation world by subsequent investigation, analysis, measurement and testing. This of course does not always happen with AM(Audio Magic).

And I always thought it meant amplitude modulation:D

They're manufacturers, so naturally going to CYA themselves against a fairly long round trip between amp, speaker, but nothing's going to change the fact that basic wire size is a function of 'x' voltage drop over distance, consequently its dB equivalent, ergo once it's below the human hearing perception threshold, any lower serves no purpose and if you go too far below, then other distortions from increased inductance can actually make it audibly worse, though been known to be perceived as an improvement, which isn't the same as more accurately reproducing the signal.

GM

Quote:

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Originally Posted by Phil-G

at some point, Todd will tire of all of this and pull the plug. then we will all have to find another forum.
moderation is the key

---

I don't mind people sharing opposing views, but I don't allow personal attacks, and everyone knows it.

I am deleting or editing posts that have such characteristics. While some may call it censorship, it's my board and those are my rules (I don't have many), and, when I get a lot of complaints, it's time to take action, much as I hate to.

- Todd

- - - Updated - - -

Quote:

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Originally Posted by GM

You've obviously never 'crossed swords' with him!

GM

---

GM - I did ban Romy, but I don't recall not coming to your defense. If I did, I apologize. I've warned Jeff and am editing/deleting offensive posts of his.

Our forum is too helpful and people like you are too valuable to let one or two ruin it.

- Todd

Quote:

---

Originally Posted by Todd W. White

GM - I did ban Romy, but I don't recall not coming to your defense. If I did, I apologize.

Our forum is too helpful and people like you are too valuable to let one or two ruin it.

- Todd

---

My memory's bad enough I forget what all I posted WRT that, but WRT to him, no apology required, it was mostly on the HE forum and the horn one Mr. PiAlign had till he closed it down sometime after going 'toe to toe' with Danley. Frankly, don't remember hardly anything from him here, but I've had long absences from here, so could have just missed him.

Here, it was some folks who long ago took issue with the way I post that's not particularly friendly to an international audience, though FWIW I'd already polled some foreigners from various countries on other forums and they all either claimed knowing more than enough English and Southern slang to follow except for the occasional technical jargon. Some even asked I continue as they enjoyed knowing such arcane lingo/trivia.

My fave was one guy in Norway sent me a CD of a local 'Southern Rock' Band with them singing in English and again in Norwegian and honest to God they would fit right in at the 'redneck'/hillbilly/trucker bar just down the road and none would be the wiser! It's really depressing that many foreigners read, speak, write, English better than Americans born n' bred. Our 'leave no child behind' educational system needs to go the way of the Dodo bird.

GM

Todd so sorry for the delay as I said in my PM I have been working long hours and haven't had much time to go online... In that regard would like to Apologize to our members for not seeing this sooner.. I have BANNED LowOhms from our board ! We will not tolerate attacks on anyone ! Difference of opinion is fine ! Personal attacks are NOT !

I think that's sad. I found him entertaining.
And you certainly can't say he wasn't enthusiastic about his hobby and of course his A7's.

I've been on this forum longer than my join date would indicate (lost my login credentials and had to change my name) and have been on many car forums etc.
I learned long ago not to get into pissing matches whit someone you disagree with. It's just pointless.

BTW, I tried the 12ga silver plated wire he mentioned.
It was a pain in the ass to work with, but I like the results.

Ron

Quote:

---

BTW, I tried the 12ga silver plated wire he mentioned.
It was a pain in the ass to work with, but I like the results.

Ron

---

Most people do not have a willingness to think out of the box.

Just the way things are here on this planet.

For this moment anyway ...

As far as wire goes, most on this forum,

Understand , capacitance, inductance,

Resistance.

There is however more to , how wires 'sound',

Than those three things.

The magnetic field that is created, whenever a signal

Is applied, is also, and more important than the vast

Majority of humanity are able to understand.

So one person's 'facts', may very well

Be of limited value...


Jeff however is relentless in experimentation,

Altho his personality has a few rough edges,

That would be true for most people.

Some manage to keep their head on better than others.

This being a maturity issue...

Well, I talked with LowOhms at length, and he apologized for his behavior, and promised to behave from now on. However, I didn't have a chance to communicate that to my helper, AltecBest, and he banned LowOhms, because that's what I originally planned to do before he contacted me and apologized.

Therefore, I think it only right to reinstate LowOhms, on the proviso that he not smart off at people or speak condescendingly to others, and this will be done shortly.

I hope everyone understands my reasoning on this - everyone deserves a second chance, especially if they've apologized and promised not to do it again.

- Todd

AB you must be working very HARD good for you!!! I have read so many of your posts, I think you may have jumped the gun on this one a little. No big deal of course! I like Lowohms passion love the idea of trying any crazy idea to get more out of his and suggestions for our Altecs... LOWOHMS STICK AROUND!!!!

Juniper was not my call ! I received a p.m. from Todd stating that he wanted to ban LowOhms I just carried it out I was just following our owners wishes.. as Todd said he didn't communicate with me that he had changed his mind I only received a p.m. stating that he wanted to ban LowOhms like to apologize to Jeff for any inconvenience!

Todd give me a call this evening if you get a chance ?

Quote:

---

Originally Posted by tomt

Most people do not have a willingness to think out of the box.



The magnetic field that is created, whenever a signal

Is applied, is also, and more important than the vast

Majority of humanity are able to understand.

So one person's 'facts', may very well

Be of limited value...

---

The magnetic field statement is opinion on your part.:)

Many facts people claim are opinions. I do like posting with a disclaimer, such as YMMV.

Beyond that I have no issue with experimentation. I'm hoping we can just make things about sharing info and possibilities.

All that said, I've enjoyed your posts. Keep 'em up please.

Quote:

---

Originally Posted by Old Guy

The magnetic field statement is opinion on your part.:)

Many facts people claim are opinions. I do like posting with a disclaimer, such as YMMV.

Beyond that I have no issue with experimentation. I'm hoping we can just make things about sharing info and possibilities.

All that said, I've enjoyed your posts. Keep 'em up please.

---

I'm not Tom T, but since we are discussing wire, I read a post , done today, by my mentor, Dennis, on another Forum about wire, that I would like to bring to folk's attention. It was interesting to me, but YMMV :

RE: whats Better dynamically better quality but smaller or large awg?? - tube wrangler - SET Asylum

Have fun, I do !!


Low Ohms ... Jeff

Audio Asylum Thread PrinterLowOhms,


1. You have hijacked my thread.

2. Dennis' post reads like marketing copy for a 'woo' wire product.

3. How long will this whim last? i.e. thin will win over thick does the trick. See link above.

Quote:

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Originally Posted by RonSSS

I think that's sad. I found him entertaining.
And you certainly can't say he wasn't enthusiastic about his hobby and of course his A7's.

I've been on this forum longer than my join date would indicate (lost my login credentials and had to change my name) and have been on many car forums etc.
I learned long ago not to get into pissing matches whit someone you disagree with. It's just pointless.

BTW, I tried the 12ga silver plated wire he mentioned.
It was a pain in the ass to work with, but I like the results.

Ron

---

I found a 100ft roll of 12g Teflon silver/copper lurking in a back closet bought a decade back when surplus meant surplus, $0.25 per foot, using it now for XO wiring and speaker cable, like the results plenty, mid and highs clear without any smearing, bass has weight, punch, and clarity.

Quote:

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Originally Posted by mah

LowOhms,


1. You have hijacked my thread.

2. Dennis' post reads like marketing copy for a 'woo' wire product.

---

Dear Malcolm,

What you bring up in Post #24 above, MAY possibly be only your " opinion ". I suggest it MAY not be factual .

- - - - - - - - - - - - - - - -

No one has yet referred me to any ALTEC Forum rules, guidelines, concerning " hijacking ", for me to review.

- - - - - - - - - - - - - - - - - - - - - - - - - -

AS our President asked Congress, a week or so ago - let us proceed to a higher level here, for the sake of all folks concerned.

In the current Thread entitled " 511E Horns on eBay" , by Mr. Bill Wojo : Kindly refer to Post #18 by me, and review the next to the last paragraph, starting out with " Probably the best simplest solution is... ".

I don't think it is fair to ANYONE - for you and I to be butting heads against each other on this Forum.

I applaud your contribution, when you posted on AA (Audio Asylum ) and suggested a Model 14 and , I though you did an exceptionally intelligent job, really beautiful, in helping out the fellow re-doing Model 14s on THIS forum, very recently. I was impressed.

You obviously have a good brain, can be helpful, and you want to be helpful, heck, you have posted over 1,500 times here.

I too would like to be able to post here from time to time, but I have to " be myself ", true to myself, and our two ways of looking at things seem to clash.

Hence, my suggestion in Post #18 / 511Es..

What do you think we could work out. How about if we, as gentlemen, simply self - " BAN " ourselves, from ever interjecting posts in a thread we are participating in, that either you or I have started?? THAT would go a long way, to having Peace in the Valley. I am not sure what the downside to that would be. Maybe others could comment, come up with an even better suggestion. . But, if you, or I, violently disagree with what is being said, we both need to shut up, stay cool, or start a new thread.

What about posts OTHERS have started??

Lets work something out !! Self- Regulation. Unburden the Moderators. What would you propose? We will ALL be much happier. And I THINK, if we both will do this self-regulation, it perhaps MAY be positive, one never knows !!

This is important to resolve.

Can you, and will you think about this Malcolm, and can we work something out along the lines I have suggested.? I do this, last five years or so, with a fellow or two on the Audio Asylum, and its worked out very well.

Thanks, let us hear from you .

Sincerely,

Jeff Medwin

Quote:

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Originally Posted by SD-50

I found a 100ft roll of 12g Teflon silver/copper lurking in a back closet bought a decade back when surplus meant surplus, $0.25 per food, using it now for XO wiring and speaker cable, like the results plenty, mid and highs clear without any smearing, bass has weight, punch, and clarity.

---

Way Cool report !! How precisely did you implement the wire? I like to pay 50 cents a foot, on eBay, low-balling sellers, for 12 AWG.


With the step-down of the output transformer, ( assuming a tube amp ), you have current - drive, and one can and should ( IMHO ) safely use two to four paralleled runs of 12 AWG, between the amp, and the ALTEC passive crossover. The amount of paralleling, ( 2,3, or 4 runs in parallel, PER POLARITY) I gave everyone guidelines to, is dependent upon the number of Fulton ( 57 1/8th inch ) increments. Now, from the crossover, to the high frequency compression driver, ( as of the last week or so ), I have recently come to understand to NOT use even my existing 14 AWG of Mil Spec - to the 802DS. .More likely, it needs to be 16 AWG, or maybe, just maybe, even 18 AWG, ( so as not to lose the highs ). I need to A-B that when my DIY DC 2A3 JJ amps are done. YMMV.

Inside amps, IMHO, one must use a mixture of various gauge wires, 14 AWG Mil Spec is a decent compromise for many runs, certainly not just a use of 12 AWG. I have stockpiled as small as 18 AWG. I MAY even try 20 AWG on the amp's RCA input jack, to the control grid of the input triode. For that critical span, I shoot for only a two inch wire length, as the "positive" lead. For the direct-couple span, I might want to use 16 AWG, and keep it in the air, not touching anything, and under six inches.

I find it very important to never neatly bundle wire, with tie wraps. It always sounds better to me, when wires don't touch each other, and I like to cross wires at right angles to each other. All of this, I find, is layout, and it can make or break a SET amp, which ( I think ) the E.E.'s will tell us, has no common mode rejection. YMMV. Have fun, all of this is only IMHO.


SD-50, tell us about your precise implementation. Ron seems to like the wire too, wonder what he has done? I wanna to softly, kindly suggest to Ron, it may take more than just James Dickerson's suggestions, to get a A7 or 604 to go !! I think so, but Old Guy likes me to be a better poster, and add .... YMMV. Amen!!

Low Ohms.....Jeff Medwin

Quote:

---

Originally Posted by Altec Best

Juniper was not my call ! I received a p.m. from Todd stating that he wanted to ban LowOhms I just carried it out I was just following our owners wishes.. as Todd said he didn't communicate with me that he had changed his mind I only received a p.m. stating that he wanted to ban LowOhms like to apologize to Jeff for any inconvenience!

Todd give me a call this evening if you get a chance ?

---

My bad AB, you and Todd are the BEST!!!! Thanks again for all the help over the years!!!!

Quote:

---

Originally Posted by SD-50

I found a 100ft roll of 12g Teflon silver/copper lurking in a back closet bought a decade back when surplus meant surplus, $0.25 per food, using it now for XO wiring and speaker cable, like the results plenty, mid and highs clear without any smearing, bass has weight, punch, and clarity.

---

IMHO Teflon and silver plate both offer improvements. Pricey stuff though. I've not found any evidence that solid silver works any better than plated. Didn't Mark Levinson use silver plated Teflon to wire preamps?

Quote:

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Originally Posted by Old Guy

IMHO Teflon and silver plate both offer improvements. Pricey stuff though. I've not found any evidence that solid silver works any better than plated. Didn't Mark Levinson use silver plated Teflon to wire preamps?

---

Hi Old Guy,

This Mil Spec wire ( stranded copper, silver plated, teflon coating, ) is m22759/11, and it can be found in various gauges, easily, reasonably, on eBay. I usually low-ball sellers, and pay 50 cents a foot for 12 AWG, and correspondingly less, for higher gauges. At those prices, I feel its a real bargain, a good value for the money spent. Its VERY nice wire to see, strip, solder, and work with IMHO.. Hey, its built to a military standard.

The silver plating must assist high frequencies over plain and pure copper , and one should select the proper gauges for the application, one size, I found out, does NOT fit every wheres. It been my favorite, last two years, YMMV. eBay searches " m22759/11 12, m22759/11 14, m22759/11 16 ", etc etc.

Low Ohms.....Jeff Medwin

[QUOTE=LowOhms;1970574]Way Cool report !! How precisely did you implement the wire? I like to pay 50 cents a foot, on eBay, low-balling sellers, for 12 AWG.
Hi Jeff
Nothing fancy to my setup, it's my bedroom system, 604-8Ks with the Markwart simplified XO, driven by a NAD C315 amp, music provided by Jolida CD-100 and a Perreaux tuner. Using 6ft lengths of the 12g twisted together, about 2 inches per twist, from amp to external XOs, twisted cables just sound better than straight runs. PIO caps linked with short runs of same 12g, at the output switched to 14g Teflon for both tweeter and woofer feeling that an all 12g setup might thicken the sound. An earlier post shows the XO just before the latest change.

For wiring fanatics:

Custom build for customer.

http://www.hostboard.com/forums/hbmc.../2017/03/7.jpg

Pass F5 Class A amp.

Quote:

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Originally Posted by westend9

For wiring fanatics:

Custom build for customer.

http://www.hostboard.com/forums/hbmc.../2017/03/7.jpg

Pass F5 Class A amp.

---

Whoahhh. I don't think that is well-thought out wiring at all. Its executed for eyes, not ears.

Here below, is how "I" , a DIYer, look at it, and others may look and interpret it totally differently, of course :

(1) look at the length of the lead ins, from the RCA jacks, to the input devices on the board, WAY WAY too long. ( In my DIY SETs, I try for 2 inches, or less to the control grid ).

(1a) Look at the close proximity, of the most delicate input wiring and RCA jacks, to the fields of the output wiring and connectors !!

(1b) Look at the close proximity, vertical panel right - rear side of the photo, of the 120 VAC LINE's INPUT receptacle, and 120 VAC wiring, and those fields, to both the RCA Input and Output wiring of that one close-by channel. Very poor and avoidable easy !!

The correct placement of the 120 VAC input's entry to this amp would have been the OTHER side of the amp, and there would be a short, non-polluting run to the power transformer. As done, the AC with its field, is running down the whole length of the amp, ( right side, bottom ) with its fields goofing up the audio channel. Totally avoidable with SOME thought. Some common sense needed to be applied !

(2) Do we really see a screw terminal plastic block, to connect the power transformer to the Supply leads ?? No soldering, no terminal block, just floating ( no. maybe secure, can't tell ) screw driver connections ?

(3) Look at all the wires, after the the screw driver connector, and how they are all touching each other, rather than floating across the chassis, and hopefully, not touching each other, at all !!!

(4) Worst of all is to use any sort of tie wraps, or wire bundling devices to make the wiring look " neat" as we all see, bottom rear, either side. That is always a mighty big NO NO in audio building.

(5) Why can someone like me, a lowly non-scientific Business Administration graduate, point these things out to others on a public Forum? I would think, the designer would have known how to lay out that amp better. Maybe he is real smart, builds to impress eyes, some ears, and SELLS a lot of stuff. Probably so.

These are just "my " opinions, expressed herein. Certainly, I could be wrong on all counts. I'm just a DIY hobbyist.


Low Ohms ........... Jeff Medwin

Being an aircraft electrician I appreciate neat wiring. Wiring is more than just point A-B, its also how it looks.
I think we can obey the proximity laws and make our wiring look neat. I know if I went inside one of my Ashly amps and cut all the zipties, and pulled the wiring out of the bundles, I would not be able to HEAR a difference. Nor do I think would the average audiophool

There are about as many ways to wire an amp as grains of sand on a beach, some better than others.

One criteria of the above example was the size of the case as dictated by the customer. It was pretty much a 10 lb sausage placed in a 5 Lb casing.

I've found no instances of any audiofoolery in having AC wires in close proximity. Typically, phases are opposite so that there is inherent cancellation of induction. The transformer was encased in it's copper and brass housing to eliminate inductive noise to the amp boards. The length of input and output leads to those boards, dictated by the placement of the high temperature devices on the heatsinks. This is a Class A amp so it operates at it's highest quiescent current when at idle. Believe me, temperature rules when biasing this amp.

I thought it might be of some interest to see the variety of different wire used inside the amp. Maybe not.

I don't see the obsession about not using a terminal block. They are made for exactly this purpose and others went before using similar process. I find it neater and more secure than soldering and laying wire in air space or laying them down within the case. Again, grains of sand.

About the only caveat I had in retrospect about "neatness" is that the input wiring could have become an antenna because of the layout. In use, that was proven to not be the case.

BTW, the input wiring from the switch to the boards (white) is teflon jacketed, teflon and copper shield, A Belden Product manufactured to use in very high frequency mil spec communication wiring. I've used it in a number of audio applications, including high-end SS preamps and it has shined in those applications.

Quote:

---

Originally Posted by Elitopus1

Being an aircraft electrician I appreciate neat wiring. Wiring is more than just point A-B, its also how it looks.
I think we can obey the proximity laws and make our wiring look neat. I know if I went inside one of my Ashly amps and cut all the zipties, and pulled the wiring out of the bundles, I would not be able to HEAR a difference. Nor do I think would the average audiophool

---

Hello,

Aircraft wiring you do, is not the same as audio amplifier wiring !! Never was, never will be.

I agree with you. " No detectable difference" may be the case in your Ashley amp, but it is not the case in a SET where there is no common mode rejection. I am talking apples, not oranges.

That which you state, "no detectable difference", also may be the case in an average guys' system.... or in a Push-Pull tube amp, which has common mode, .....not to detect a difference.

There are also many nuances that most amps won't detect, the vast majority of amps do not differentiate particularly well, which makes them average, and, it is often times to their detriment. What does that tell us? Yes, for sure, one's mileage may vary

Wire-dress certainly is a factor , audible, in the best layed-out and best designed gear.

Having wires touching, or in bundles, longer than necessary wire paths, wires not crossing at right angles, all degrades from the best possible sonic result.


We can choose, its a free country, we all have free will, as to do whatever pleases us, and use whatever equipment we want for our home's hi fi system, for source and powering. I am just explaining, pointing out to some who may have an interest, audio design factors - possibly things they were not ever aware of.


Jeff Medwin

Well, I know one thing, Jeff. your dogma about wiring is interfering with any type of design critique.

Tell me one thing--how do I get a 2" long wire to travel 6" to an amp board location? You can clearly see from the images that the output wires are set at the shortest possible length to reach the back plane of the amp chassis.

Edit: reread your post for clarity and I'm sensing a certain condescension. You can contact Nelson Pass and discuss with him the "averageness" or "differentiation" of his design. I know for a fact that certain builders of this amp design have pushed away their tube gear in favor of this Class A amp. I'm starting to get the feeling that someone is a "legend in their own mind".

Quote:

---

Originally Posted by LowOhms

Hello,

Aircraft wiring you do, is not the same as audio amplifier wiring !! Never was, never will be.

I agree with you. " No detectable difference" may be the case in your Ashley amp, but it is not the case in a SET where there is no common mode rejection. I am talking apples, not oranges.

That which you state, "no detectable difference", also may be the case in an average guys' system.... or in a Push-Pull tube amp, which has common mode, .....not to detect a difference.

There are also many nuances that most amps won't detect, the vast majority of amps do not differentiate particularly well, which makes them average, and, it is often times to their detriment. What does that tell us? Yes, for sure, one's mileage may vary

Wire-dress certainly is a factor , audible, in the best layed-out and best designed gear.

Having wires touching, or in bundles, longer than necessary wire paths, wires not crossing at right angles, all degrades from the best possible sonic result.


We can choose, its a free country, we all have free will, as to do whatever pleases us, and use whatever equipment we want for our home's hi fi system, for source and powering. I am just explaining, pointing out to some who may have an interest, audio design factors - possibly things they were not ever aware of.


Jeff Medwin

---

The amp in the pic a couple posts up is not a SET amp. That is the amp in question since you criticized how it was wired.

Quote:

---

Originally Posted by westend9

There are about as many ways to wire an amp as grains of sand on a beach, some better than others.

One criteria of the above example was the size of the case as dictated by the customer. It was pretty much a 10 lb sausage placed in a 5 Lb casing.

I've found no instances of any audiofoolery in having AC wires in close proximity. Typically, phases are opposite so that there is inherent cancellation of induction. The transformer was encased in it's copper and brass housing to eliminate inductive noise to the amp boards. The length of input and output leads to those boards, dictated by the placement of the high temperature devices on the heatsinks. This is a Class A amp so it operates at it's highest quiescent current when at idle. Believe me, temperature rules when biasing this amp.

I thought it might be of some interest to see the variety of different wire used inside the amp. Maybe not.

I don't see the obsession about not using a terminal block. They are made for exactly this purpose and others went before using similar process. I find it neater and more secure than soldering and laying wire in air space or laying them down within the case. Again, grains of sand.

About the only caveat I had in retrospect about "neatness" is that the input wiring could have become an antenna because of the layout. In use, that was proven to not be the case.

BTW, the input wiring from the switch to the boards (white) is teflon jacketed, teflon and copper shield, A Belden Product manufactured to use in very high frequency mil spec communication wiring. I've used it in a number of audio applications, including high-end SS preamps and it has shined in those applications.

---

He should have mounted the transistors two inches higher on the heart sink, raising the PC boards by that distance. He could add a $5.00 bracket, at the top of the amp, with a plexiglass plate bolted to it. The RCA input signal jack could be mounted on that plexiglass ( double insulation ) plate. The amplifier's top cover could be plasma cut during construction, to allow the end user access to the RCA jacks. Lead length would be direct, and maybe two inches, or less.

Its almost a FREE better-engineering solution, using an open mind, common sense, and its from me, a business major. The boards will also be further-distanced from the power transformer.

He needs to place the AC outlet, some wheres on the opposite side of the amp. And use a 20 A. IEC, not a crummy typical 15 A. one.


Low Ohms, .......Jeff Medwin

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Originally Posted by LowOhms

He should have mounted the transistors two inches higher on the heart sink, raising the PC boards by that distance. He could add a $5.00 bracket, at the top of the amp, with a plexiglass plate bolted to it. The RCA input signal jack could be mounted on that plexiglass ( double insulation ) plate. The amplifier's top cover could be plasma cut during construction, to allow the end user access to the RCA jacks. Lead length would be direct, and maybe two inches, or less.

Its almost a FREE better-engineering solution, using an open mind, common sense, and its from me, a business major. The boards will also be further-distanced from the power transformer.

He needs to place the AC outlet, some wheres on the opposite side of the amp. And use a 20 A. IEC, not a crummy typical 15 A. one.


Low Ohms, .......Jeff Medwin

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You truly are not looking at the layout of this amplifier and understanding some of the design criteria. You repeat that 2" thing like aliens brought it to the Egyptians. There is no possible placement of the amplifier boards that would accommodate the use of a 2" length of wire. The boards are approx 6" in length and there are positions of connections that prohibit the use of a such a small length. Further, a short length isn't necessary to carry the signal to/from the amp board. What's more important is that the junction temperature of the main devices be dissipated as efficiently as possible, i.e. no, they can't be raised to accommodate a 3" shorter wire. This is just foolishness, I'm now understanding. It is like teaching pigs to sing--it's difficult and the end result doesn't sound that good.

BTW, this will be my last post where Jeff Medwin has any type of discussion about or within.